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Diffstat (limited to 'vendor/memchr/src/arch')
29 files changed, 0 insertions, 10868 deletions
diff --git a/vendor/memchr/src/arch/aarch64/memchr.rs b/vendor/memchr/src/arch/aarch64/memchr.rs deleted file mode 100644 index e0053b2..0000000 --- a/vendor/memchr/src/arch/aarch64/memchr.rs +++ /dev/null @@ -1,137 +0,0 @@ -/*! -Wrapper routines for `memchr` and friends. - -These routines choose the best implementation at compile time. (This is -different from `x86_64` because it is expected that `neon` is almost always -available for `aarch64` targets.) -*/ - -macro_rules! defraw { - ($ty:ident, $find:ident, $start:ident, $end:ident, $($needles:ident),+) => {{ - #[cfg(target_feature = "neon")] - { - use crate::arch::aarch64::neon::memchr::$ty; - - debug!("chose neon for {}", stringify!($ty)); - debug_assert!($ty::is_available()); - // SAFETY: We know that wasm memchr is always available whenever - // code is compiled for `aarch64` with the `neon` target feature - // enabled. - $ty::new_unchecked($($needles),+).$find($start, $end) - } - #[cfg(not(target_feature = "neon"))] - { - use crate::arch::all::memchr::$ty; - - debug!( - "no neon feature available, using fallback for {}", - stringify!($ty), - ); - $ty::new($($needles),+).$find($start, $end) - } - }} -} - -/// memchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(One, find_raw, start, end, n1) -} - -/// memrchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(One, rfind_raw, start, end, n1) -} - -/// memchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Two, find_raw, start, end, n1, n2) -} - -/// memrchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Two, rfind_raw, start, end, n1, n2) -} - -/// memchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Three, find_raw, start, end, n1, n2, n3) -} - -/// memrchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Three, rfind_raw, start, end, n1, n2, n3) -} - -/// Count all matching bytes, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::count_raw`. -#[inline(always)] -pub(crate) unsafe fn count_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> usize { - defraw!(One, count_raw, start, end, n1) -} diff --git a/vendor/memchr/src/arch/aarch64/mod.rs b/vendor/memchr/src/arch/aarch64/mod.rs deleted file mode 100644 index 7b32912..0000000 --- a/vendor/memchr/src/arch/aarch64/mod.rs +++ /dev/null @@ -1,7 +0,0 @@ -/*! -Vector algorithms for the `aarch64` target. -*/ - -pub mod neon; - -pub(crate) mod memchr; diff --git a/vendor/memchr/src/arch/aarch64/neon/memchr.rs b/vendor/memchr/src/arch/aarch64/neon/memchr.rs deleted file mode 100644 index 5fcc762..0000000 --- a/vendor/memchr/src/arch/aarch64/neon/memchr.rs +++ /dev/null @@ -1,1031 +0,0 @@ -/*! -This module defines 128-bit vector implementations of `memchr` and friends. - -The main types in this module are [`One`], [`Two`] and [`Three`]. They are for -searching for one, two or three distinct bytes, respectively, in a haystack. -Each type also has corresponding double ended iterators. These searchers are -typically much faster than scalar routines accomplishing the same task. - -The `One` searcher also provides a [`One::count`] routine for efficiently -counting the number of times a single byte occurs in a haystack. This is -useful, for example, for counting the number of lines in a haystack. This -routine exists because it is usually faster, especially with a high match -count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its -`Iterator::count` implementation to use this routine.) - -Only one, two and three bytes are supported because three bytes is about -the point where one sees diminishing returns. Beyond this point and it's -probably (but not necessarily) better to just use a simple `[bool; 256]` array -or similar. However, it depends mightily on the specific work-load and the -expected match frequency. -*/ - -use core::arch::aarch64::uint8x16_t; - -use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector}; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub struct One(generic::One<uint8x16_t>); - -impl One { - /// Create a new searcher that finds occurrences of the needle byte given. - /// - /// This particular searcher is specialized to use neon vector instructions - /// that typically make it quite fast. - /// - /// If neon is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle: u8) -> Option<One> { - if One::is_available() { - // SAFETY: we check that neon is available above. - unsafe { Some(One::new_unchecked(needle)) } - } else { - None - } - } - - /// Create a new finder specific to neon vectors and routines without - /// checking that neon is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `neon` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to neon - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "neon")] - #[inline] - pub unsafe fn new_unchecked(needle: u8) -> One { - One(generic::One::new(needle)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`One::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `One::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "neon")] - { - true - } - #[cfg(not(target_feature = "neon"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Counts all occurrences of this byte in the given haystack. - #[inline] - pub fn count(&self, haystack: &[u8]) -> usize { - // SAFETY: All of our pointers are derived directly from a borrowed - // slice, which is guaranteed to be valid. - unsafe { - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - self.count_raw(start, end) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Like `count`, but accepts and returns raw pointers. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize { - if start >= end { - return 0; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::count_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.count_raw_impl(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Execute a count using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::count_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn count_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - self.0.count_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> { - OneIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of a single byte in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`One::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`One`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct OneIter<'a, 'h> { - searcher: &'a One, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for OneIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn count(self) -> usize { - self.it.count(|s, e| { - // SAFETY: We rely on our generic iterator to return valid start - // and end pointers. - unsafe { self.searcher.count_raw(s, e) } - }) - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Two(generic::Two<uint8x16_t>); - -impl Two { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use neon vector instructions - /// that typically make it quite fast. - /// - /// If neon is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8) -> Option<Two> { - if Two::is_available() { - // SAFETY: we check that neon is available above. - unsafe { Some(Two::new_unchecked(needle1, needle2)) } - } else { - None - } - } - - /// Create a new finder specific to neon vectors and routines without - /// checking that neon is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `neon` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to neon - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "neon")] - #[inline] - pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two { - Two(generic::Two::new(needle1, needle2)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Two::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Two::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "neon")] - { - true - } - #[cfg(not(target_feature = "neon"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle bytes in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> { - TwoIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of two possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Two::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Two`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct TwoIter<'a, 'h> { - searcher: &'a Two, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for TwoIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {} - -/// Finds all occurrences of three bytes in a haystack. -/// -/// That is, this reports matches of one of three possible bytes. For example, -/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets -/// `0`, `2`, `3`, `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Three(generic::Three<uint8x16_t>); - -impl Three { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use neon vector instructions - /// that typically make it quite fast. - /// - /// If neon is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> { - if Three::is_available() { - // SAFETY: we check that neon is available above. - unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) } - } else { - None - } - } - - /// Create a new finder specific to neon vectors and routines without - /// checking that neon is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `neon` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to neon - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "neon")] - #[inline] - pub unsafe fn new_unchecked( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Three { - Three(generic::Three::new(needle1, needle2, needle3)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Three::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Three::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "neon")] - { - true - } - #[cfg(not(target_feature = "neon"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < uint8x16_t::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'neon' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using neon vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a neon vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> { - ThreeIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of three possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Three::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Three`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct ThreeIter<'a, 'h> { - searcher: &'a Three, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for ThreeIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {} - -#[cfg(test)] -mod tests { - use super::*; - - define_memchr_quickcheck!(super); - - #[test] - fn forward_one() { - crate::tests::memchr::Runner::new(1).forward_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_one() { - crate::tests::memchr::Runner::new(1).reverse_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn count_one() { - crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).count()) - }) - } - - #[test] - fn forward_two() { - crate::tests::memchr::Runner::new(2).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_two() { - crate::tests::memchr::Runner::new(2).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn forward_three() { - crate::tests::memchr::Runner::new(3).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_three() { - crate::tests::memchr::Runner::new(3).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect()) - }, - ) - } -} diff --git a/vendor/memchr/src/arch/aarch64/neon/mod.rs b/vendor/memchr/src/arch/aarch64/neon/mod.rs deleted file mode 100644 index ccf9cf8..0000000 --- a/vendor/memchr/src/arch/aarch64/neon/mod.rs +++ /dev/null @@ -1,6 +0,0 @@ -/*! -Algorithms for the `aarch64` target using 128-bit vectors via NEON. -*/ - -pub mod memchr; -pub mod packedpair; diff --git a/vendor/memchr/src/arch/aarch64/neon/packedpair.rs b/vendor/memchr/src/arch/aarch64/neon/packedpair.rs deleted file mode 100644 index 6884882..0000000 --- a/vendor/memchr/src/arch/aarch64/neon/packedpair.rs +++ /dev/null @@ -1,236 +0,0 @@ -/*! -A 128-bit vector implementation of the "packed pair" SIMD algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use core::arch::aarch64::uint8x16_t; - -use crate::arch::{all::packedpair::Pair, generic::packedpair}; - -/// A "packed pair" finder that uses 128-bit vector operations. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -#[derive(Clone, Copy, Debug)] -pub struct Finder(packedpair::Finder<uint8x16_t>); - -/// A "packed pair" finder that uses 128-bit vector operations. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -impl Finder { - /// Create a new pair searcher. The searcher returned can either report - /// exact matches of `needle` or act as a prefilter and report candidate - /// positions of `needle`. - /// - /// If neon is unavailable in the current environment or if a [`Pair`] - /// could not be constructed from the needle given, then `None` is - /// returned. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - Finder::with_pair(needle, Pair::new(needle)?) - } - - /// Create a new "packed pair" finder using the pair of bytes given. - /// - /// This constructor permits callers to control precisely which pair of - /// bytes is used as a predicate. - /// - /// If neon is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> { - if Finder::is_available() { - // SAFETY: we check that sse2 is available above. We are also - // guaranteed to have needle.len() > 1 because we have a valid - // Pair. - unsafe { Some(Finder::with_pair_impl(needle, pair)) } - } else { - None - } - } - - /// Create a new `Finder` specific to neon vectors and routines. - /// - /// # Safety - /// - /// Same as the safety for `packedpair::Finder::new`, and callers must also - /// ensure that neon is available. - #[target_feature(enable = "neon")] - #[inline] - unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder { - let finder = packedpair::Finder::<uint8x16_t>::new(needle, pair); - Finder(finder) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Finder::with_pair`] will - /// return a `Some` value. Similarly, when it is false, it is guaranteed - /// that `Finder::with_pair` will return a `None` value. Notice that this - /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely, - /// even when `Finder::is_available` is true, it is not guaranteed that a - /// valid [`Pair`] can be found from the needle given. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "neon")] - { - true - } - #[cfg(not(target_feature = "neon"))] - { - false - } - } - - /// Execute a search using neon vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'neon' routines. - unsafe { self.find_impl(haystack, needle) } - } - - /// Execute a search using neon vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'neon' routines. - unsafe { self.find_prefilter_impl(haystack) } - } - - /// Execute a search using neon vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn find_impl( - &self, - haystack: &[u8], - needle: &[u8], - ) -> Option<usize> { - self.0.find(haystack, needle) - } - - /// Execute a prefilter search using neon vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `neon` routines.) - #[target_feature(enable = "neon")] - #[inline] - unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> { - self.0.find_prefilter(haystack) - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub fn pair(&self) -> &Pair { - self.0.pair() - } - - /// Returns the minimum haystack length that this `Finder` can search. - /// - /// Using a haystack with length smaller than this in a search will result - /// in a panic. The reason for this restriction is that this finder is - /// meant to be a low-level component that is part of a larger substring - /// strategy. In that sense, it avoids trying to handle all cases and - /// instead only handles the cases that it can handle very well. - #[inline] - pub fn min_haystack_len(&self) -> usize { - self.0.min_haystack_len() - } -} - -#[cfg(test)] -mod tests { - use super::*; - - fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> { - let f = Finder::new(needle)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - - define_substring_forward_quickcheck!(find); - - #[test] - fn forward_substring() { - crate::tests::substring::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair_prefilter() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find_prefilter(haystack)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } -} diff --git a/vendor/memchr/src/arch/all/memchr.rs b/vendor/memchr/src/arch/all/memchr.rs deleted file mode 100644 index 435b1be..0000000 --- a/vendor/memchr/src/arch/all/memchr.rs +++ /dev/null @@ -1,996 +0,0 @@ -/*! -Provides architecture independent implementations of `memchr` and friends. - -The main types in this module are [`One`], [`Two`] and [`Three`]. They are for -searching for one, two or three distinct bytes, respectively, in a haystack. -Each type also has corresponding double ended iterators. These searchers -are typically slower than hand-coded vector routines accomplishing the same -task, but are also typically faster than naive scalar code. These routines -effectively work by treating a `usize` as a vector of 8-bit lanes, and thus -achieves some level of data parallelism even without explicit vector support. - -The `One` searcher also provides a [`One::count`] routine for efficiently -counting the number of times a single byte occurs in a haystack. This is -useful, for example, for counting the number of lines in a haystack. This -routine exists because it is usually faster, especially with a high match -count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its -`Iterator::count` implementation to use this routine.) - -Only one, two and three bytes are supported because three bytes is about -the point where one sees diminishing returns. Beyond this point and it's -probably (but not necessarily) better to just use a simple `[bool; 256]` array -or similar. However, it depends mightily on the specific work-load and the -expected match frequency. -*/ - -use crate::{arch::generic::memchr as generic, ext::Pointer}; - -/// The number of bytes in a single `usize` value. -const USIZE_BYTES: usize = (usize::BITS / 8) as usize; -/// The bits that must be zero for a `*const usize` to be properly aligned. -const USIZE_ALIGN: usize = USIZE_BYTES - 1; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub struct One { - s1: u8, - v1: usize, -} - -impl One { - /// The number of bytes we examine per each iteration of our search loop. - const LOOP_BYTES: usize = 2 * USIZE_BYTES; - - /// Create a new searcher that finds occurrences of the byte given. - #[inline] - pub fn new(needle: u8) -> One { - One { s1: needle, v1: splat(needle) } - } - - /// A test-only routine so that we can bundle a bunch of quickcheck - /// properties into a single macro. Basically, this provides a constructor - /// that makes it identical to most other memchr implementations, which - /// have fallible constructors. - #[cfg(test)] - pub(crate) fn try_new(needle: u8) -> Option<One> { - Some(One::new(needle)) - } - - /// Return the first occurrence of the needle in the given haystack. If no - /// such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of the needle in the given haystack. If no - /// such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Counts all occurrences of this byte in the given haystack. - #[inline] - pub fn count(&self, haystack: &[u8]) -> usize { - // SAFETY: All of our pointers are derived directly from a borrowed - // slice, which is guaranteed to be valid. - unsafe { - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - self.count_raw(start, end) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // The start of the search may not be aligned to `*const usize`, - // so we do an unaligned load here. - let chunk = start.cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // And now we start our search at a guaranteed aligned position. - // The first iteration of the loop below will overlap with the the - // unaligned chunk above in cases where the search starts at an - // unaligned offset, but that's okay as we're only here if that - // above didn't find a match. - let mut cur = - start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN)); - debug_assert!(cur > start); - if len <= One::LOOP_BYTES { - return generic::fwd_byte_by_byte(cur, end, confirm); - } - debug_assert!(end.sub(One::LOOP_BYTES) >= start); - while cur <= end.sub(One::LOOP_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let a = cur.cast::<usize>().read(); - let b = cur.add(USIZE_BYTES).cast::<usize>().read(); - if self.has_needle(a) || self.has_needle(b) { - break; - } - cur = cur.add(One::LOOP_BYTES); - } - generic::fwd_byte_by_byte(cur, end, confirm) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let mut cur = end.sub(end.as_usize() & USIZE_ALIGN); - debug_assert!(start <= cur && cur <= end); - if len <= One::LOOP_BYTES { - return generic::rev_byte_by_byte(start, cur, confirm); - } - while cur >= start.add(One::LOOP_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let a = cur.sub(2 * USIZE_BYTES).cast::<usize>().read(); - let b = cur.sub(1 * USIZE_BYTES).cast::<usize>().read(); - if self.has_needle(a) || self.has_needle(b) { - break; - } - cur = cur.sub(One::LOOP_BYTES); - } - generic::rev_byte_by_byte(start, cur, confirm) - } - - /// Counts all occurrences of this byte in the given haystack represented - /// by raw pointers. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `0` will always be returned. - #[inline] - pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize { - if start >= end { - return 0; - } - // Sadly I couldn't get the SWAR approach to work here, so we just do - // one byte at a time for now. PRs to improve this are welcome. - let mut ptr = start; - let mut count = 0; - while ptr < end { - count += (ptr.read() == self.s1) as usize; - ptr = ptr.offset(1); - } - count - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> { - OneIter { searcher: self, it: generic::Iter::new(haystack) } - } - - #[inline(always)] - fn has_needle(&self, chunk: usize) -> bool { - has_zero_byte(self.v1 ^ chunk) - } - - #[inline(always)] - fn confirm(&self, haystack_byte: u8) -> bool { - self.s1 == haystack_byte - } -} - -/// An iterator over all occurrences of a single byte in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`One::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`One`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct OneIter<'a, 'h> { - /// The underlying memchr searcher. - searcher: &'a One, - /// Generic iterator implementation. - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for OneIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn count(self) -> usize { - self.it.count(|s, e| { - // SAFETY: We rely on our generic iterator to return valid start - // and end pointers. - unsafe { self.searcher.count_raw(s, e) } - }) - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Two { - s1: u8, - s2: u8, - v1: usize, - v2: usize, -} - -impl Two { - /// Create a new searcher that finds occurrences of the two needle bytes - /// given. - #[inline] - pub fn new(needle1: u8, needle2: u8) -> Two { - Two { - s1: needle1, - s2: needle2, - v1: splat(needle1), - v2: splat(needle2), - } - } - - /// A test-only routine so that we can bundle a bunch of quickcheck - /// properties into a single macro. Basically, this provides a constructor - /// that makes it identical to most other memchr implementations, which - /// have fallible constructors. - #[cfg(test)] - pub(crate) fn try_new(needle1: u8, needle2: u8) -> Option<Two> { - Some(Two::new(needle1, needle2)) - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // The start of the search may not be aligned to `*const usize`, - // so we do an unaligned load here. - let chunk = start.cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // And now we start our search at a guaranteed aligned position. - // The first iteration of the loop below will overlap with the the - // unaligned chunk above in cases where the search starts at an - // unaligned offset, but that's okay as we're only here if that - // above didn't find a match. - let mut cur = - start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN)); - debug_assert!(cur > start); - debug_assert!(end.sub(USIZE_BYTES) >= start); - while cur <= end.sub(USIZE_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let chunk = cur.cast::<usize>().read(); - if self.has_needle(chunk) { - break; - } - cur = cur.add(USIZE_BYTES); - } - generic::fwd_byte_by_byte(cur, end, confirm) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let mut cur = end.sub(end.as_usize() & USIZE_ALIGN); - debug_assert!(start <= cur && cur <= end); - while cur >= start.add(USIZE_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let chunk = cur.sub(USIZE_BYTES).cast::<usize>().read(); - if self.has_needle(chunk) { - break; - } - cur = cur.sub(USIZE_BYTES); - } - generic::rev_byte_by_byte(start, cur, confirm) - } - - /// Returns an iterator over all occurrences of one of the needle bytes in - /// the given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> { - TwoIter { searcher: self, it: generic::Iter::new(haystack) } - } - - #[inline(always)] - fn has_needle(&self, chunk: usize) -> bool { - has_zero_byte(self.v1 ^ chunk) || has_zero_byte(self.v2 ^ chunk) - } - - #[inline(always)] - fn confirm(&self, haystack_byte: u8) -> bool { - self.s1 == haystack_byte || self.s2 == haystack_byte - } -} - -/// An iterator over all occurrences of two possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Two::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Two`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct TwoIter<'a, 'h> { - /// The underlying memchr searcher. - searcher: &'a Two, - /// Generic iterator implementation. - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for TwoIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -/// Finds all occurrences of three bytes in a haystack. -/// -/// That is, this reports matches of one of three possible bytes. For example, -/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets -/// `0`, `2`, `3`, `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Three { - s1: u8, - s2: u8, - s3: u8, - v1: usize, - v2: usize, - v3: usize, -} - -impl Three { - /// Create a new searcher that finds occurrences of the three needle bytes - /// given. - #[inline] - pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Three { - Three { - s1: needle1, - s2: needle2, - s3: needle3, - v1: splat(needle1), - v2: splat(needle2), - v3: splat(needle3), - } - } - - /// A test-only routine so that we can bundle a bunch of quickcheck - /// properties into a single macro. Basically, this provides a constructor - /// that makes it identical to most other memchr implementations, which - /// have fallible constructors. - #[cfg(test)] - pub(crate) fn try_new( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Option<Three> { - Some(Three::new(needle1, needle2, needle3)) - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value for a non-empty haystack is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // The start of the search may not be aligned to `*const usize`, - // so we do an unaligned load here. - let chunk = start.cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::fwd_byte_by_byte(start, end, confirm); - } - - // And now we start our search at a guaranteed aligned position. - // The first iteration of the loop below will overlap with the the - // unaligned chunk above in cases where the search starts at an - // unaligned offset, but that's okay as we're only here if that - // above didn't find a match. - let mut cur = - start.add(USIZE_BYTES - (start.as_usize() & USIZE_ALIGN)); - debug_assert!(cur > start); - debug_assert!(end.sub(USIZE_BYTES) >= start); - while cur <= end.sub(USIZE_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let chunk = cur.cast::<usize>().read(); - if self.has_needle(chunk) { - break; - } - cur = cur.add(USIZE_BYTES); - } - generic::fwd_byte_by_byte(cur, end, confirm) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let confirm = |b| self.confirm(b); - let len = end.distance(start); - if len < USIZE_BYTES { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let chunk = end.sub(USIZE_BYTES).cast::<usize>().read_unaligned(); - if self.has_needle(chunk) { - return generic::rev_byte_by_byte(start, end, confirm); - } - - let mut cur = end.sub(end.as_usize() & USIZE_ALIGN); - debug_assert!(start <= cur && cur <= end); - while cur >= start.add(USIZE_BYTES) { - debug_assert_eq!(0, cur.as_usize() % USIZE_BYTES); - - let chunk = cur.sub(USIZE_BYTES).cast::<usize>().read(); - if self.has_needle(chunk) { - break; - } - cur = cur.sub(USIZE_BYTES); - } - generic::rev_byte_by_byte(start, cur, confirm) - } - - /// Returns an iterator over all occurrences of one of the needle bytes in - /// the given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> { - ThreeIter { searcher: self, it: generic::Iter::new(haystack) } - } - - #[inline(always)] - fn has_needle(&self, chunk: usize) -> bool { - has_zero_byte(self.v1 ^ chunk) - || has_zero_byte(self.v2 ^ chunk) - || has_zero_byte(self.v3 ^ chunk) - } - - #[inline(always)] - fn confirm(&self, haystack_byte: u8) -> bool { - self.s1 == haystack_byte - || self.s2 == haystack_byte - || self.s3 == haystack_byte - } -} - -/// An iterator over all occurrences of three possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Three::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Three`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct ThreeIter<'a, 'h> { - /// The underlying memchr searcher. - searcher: &'a Three, - /// Generic iterator implementation. - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for ThreeIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -/// Return `true` if `x` contains any zero byte. -/// -/// That is, this routine treats `x` as a register of 8-bit lanes and returns -/// true when any of those lanes is `0`. -/// -/// From "Matters Computational" by J. Arndt. -#[inline(always)] -fn has_zero_byte(x: usize) -> bool { - // "The idea is to subtract one from each of the bytes and then look for - // bytes where the borrow propagated all the way to the most significant - // bit." - const LO: usize = splat(0x01); - const HI: usize = splat(0x80); - - (x.wrapping_sub(LO) & !x & HI) != 0 -} - -/// Repeat the given byte into a word size number. That is, every 8 bits -/// is equivalent to the given byte. For example, if `b` is `\x4E` or -/// `01001110` in binary, then the returned value on a 32-bit system would be: -/// `01001110_01001110_01001110_01001110`. -#[inline(always)] -const fn splat(b: u8) -> usize { - // TODO: use `usize::from` once it can be used in const context. - (b as usize) * (usize::MAX / 255) -} - -#[cfg(test)] -mod tests { - use super::*; - - define_memchr_quickcheck!(super, try_new); - - #[test] - fn forward_one() { - crate::tests::memchr::Runner::new(1).forward_iter( - |haystack, needles| { - Some(One::new(needles[0]).iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_one() { - crate::tests::memchr::Runner::new(1).reverse_iter( - |haystack, needles| { - Some(One::new(needles[0]).iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn count_one() { - crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| { - Some(One::new(needles[0]).iter(haystack).count()) - }) - } - - #[test] - fn forward_two() { - crate::tests::memchr::Runner::new(2).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2).iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_two() { - crate::tests::memchr::Runner::new(2).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2).iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn forward_three() { - crate::tests::memchr::Runner::new(3).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3).iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_three() { - crate::tests::memchr::Runner::new(3).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3).iter(haystack).rev().collect()) - }, - ) - } - - // This was found by quickcheck in the course of refactoring this crate - // after memchr 2.5.0. - #[test] - fn regression_double_ended_iterator() { - let finder = One::new(b'a'); - let haystack = "a"; - let mut it = finder.iter(haystack.as_bytes()); - assert_eq!(Some(0), it.next()); - assert_eq!(None, it.next_back()); - } - - // This regression test was caught by ripgrep's test suite on i686 when - // upgrading to memchr 2.6. Namely, something about the \x0B bytes here - // screws with the SWAR counting approach I was using. This regression test - // prompted me to remove the SWAR counting approach and just replace it - // with a byte-at-a-time loop. - #[test] - fn regression_count_new_lines() { - let haystack = "01234567\x0b\n\x0b\n\x0b\n\x0b\nx"; - let count = One::new(b'\n').count(haystack.as_bytes()); - assert_eq!(4, count); - } -} diff --git a/vendor/memchr/src/arch/all/mod.rs b/vendor/memchr/src/arch/all/mod.rs deleted file mode 100644 index 559cb75..0000000 --- a/vendor/memchr/src/arch/all/mod.rs +++ /dev/null @@ -1,234 +0,0 @@ -/*! -Contains architecture independent routines. - -These routines are often used as a "fallback" implementation when the more -specialized architecture dependent routines are unavailable. -*/ - -pub mod memchr; -pub mod packedpair; -pub mod rabinkarp; -#[cfg(feature = "alloc")] -pub mod shiftor; -pub mod twoway; - -/// Returns true if and only if `needle` is a prefix of `haystack`. -/// -/// This uses a latency optimized variant of `memcmp` internally which *might* -/// make this faster for very short strings. -/// -/// # Inlining -/// -/// This routine is marked `inline(always)`. If you want to call this function -/// in a way that is not always inlined, you'll need to wrap a call to it in -/// another function that is marked as `inline(never)` or just `inline`. -#[inline(always)] -pub fn is_prefix(haystack: &[u8], needle: &[u8]) -> bool { - needle.len() <= haystack.len() - && is_equal(&haystack[..needle.len()], needle) -} - -/// Returns true if and only if `needle` is a suffix of `haystack`. -/// -/// This uses a latency optimized variant of `memcmp` internally which *might* -/// make this faster for very short strings. -/// -/// # Inlining -/// -/// This routine is marked `inline(always)`. If you want to call this function -/// in a way that is not always inlined, you'll need to wrap a call to it in -/// another function that is marked as `inline(never)` or just `inline`. -#[inline(always)] -pub fn is_suffix(haystack: &[u8], needle: &[u8]) -> bool { - needle.len() <= haystack.len() - && is_equal(&haystack[haystack.len() - needle.len()..], needle) -} - -/// Compare corresponding bytes in `x` and `y` for equality. -/// -/// That is, this returns true if and only if `x.len() == y.len()` and -/// `x[i] == y[i]` for all `0 <= i < x.len()`. -/// -/// # Inlining -/// -/// This routine is marked `inline(always)`. If you want to call this function -/// in a way that is not always inlined, you'll need to wrap a call to it in -/// another function that is marked as `inline(never)` or just `inline`. -/// -/// # Motivation -/// -/// Why not use slice equality instead? Well, slice equality usually results in -/// a call out to the current platform's `libc` which might not be inlineable -/// or have other overhead. This routine isn't guaranteed to be a win, but it -/// might be in some cases. -#[inline(always)] -pub fn is_equal(x: &[u8], y: &[u8]) -> bool { - if x.len() != y.len() { - return false; - } - // SAFETY: Our pointers are derived directly from borrowed slices which - // uphold all of our safety guarantees except for length. We account for - // length with the check above. - unsafe { is_equal_raw(x.as_ptr(), y.as_ptr(), x.len()) } -} - -/// Compare `n` bytes at the given pointers for equality. -/// -/// This returns true if and only if `*x.add(i) == *y.add(i)` for all -/// `0 <= i < n`. -/// -/// # Inlining -/// -/// This routine is marked `inline(always)`. If you want to call this function -/// in a way that is not always inlined, you'll need to wrap a call to it in -/// another function that is marked as `inline(never)` or just `inline`. -/// -/// # Motivation -/// -/// Why not use slice equality instead? Well, slice equality usually results in -/// a call out to the current platform's `libc` which might not be inlineable -/// or have other overhead. This routine isn't guaranteed to be a win, but it -/// might be in some cases. -/// -/// # Safety -/// -/// * Both `x` and `y` must be valid for reads of up to `n` bytes. -/// * Both `x` and `y` must point to an initialized value. -/// * Both `x` and `y` must each point to an allocated object and -/// must either be in bounds or at most one byte past the end of the -/// allocated object. `x` and `y` do not need to point to the same allocated -/// object, but they may. -/// * Both `x` and `y` must be _derived from_ a pointer to their respective -/// allocated objects. -/// * The distance between `x` and `x+n` must not overflow `isize`. Similarly -/// for `y` and `y+n`. -/// * The distance being in bounds must not rely on "wrapping around" the -/// address space. -#[inline(always)] -pub unsafe fn is_equal_raw( - mut x: *const u8, - mut y: *const u8, - mut n: usize, -) -> bool { - // When we have 4 or more bytes to compare, then proceed in chunks of 4 at - // a time using unaligned loads. - // - // Also, why do 4 byte loads instead of, say, 8 byte loads? The reason is - // that this particular version of memcmp is likely to be called with tiny - // needles. That means that if we do 8 byte loads, then a higher proportion - // of memcmp calls will use the slower variant above. With that said, this - // is a hypothesis and is only loosely supported by benchmarks. There's - // likely some improvement that could be made here. The main thing here - // though is to optimize for latency, not throughput. - - // SAFETY: The caller is responsible for ensuring the pointers we get are - // valid and readable for at least `n` bytes. We also do unaligned loads, - // so there's no need to ensure we're aligned. (This is justified by this - // routine being specifically for short strings.) - while n >= 4 { - let vx = x.cast::<u32>().read_unaligned(); - let vy = y.cast::<u32>().read_unaligned(); - if vx != vy { - return false; - } - x = x.add(4); - y = y.add(4); - n -= 4; - } - // If we don't have enough bytes to do 4-byte at a time loads, then - // do partial loads. Note that I used to have a byte-at-a-time - // loop here and that turned out to be quite a bit slower for the - // memmem/pathological/defeat-simple-vector-alphabet benchmark. - if n >= 2 { - let vx = x.cast::<u16>().read_unaligned(); - let vy = y.cast::<u16>().read_unaligned(); - if vx != vy { - return false; - } - x = x.add(2); - y = y.add(2); - n -= 2; - } - if n > 0 { - if x.read() != y.read() { - return false; - } - } - true -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn equals_different_lengths() { - assert!(!is_equal(b"", b"a")); - assert!(!is_equal(b"a", b"")); - assert!(!is_equal(b"ab", b"a")); - assert!(!is_equal(b"a", b"ab")); - } - - #[test] - fn equals_mismatch() { - let one_mismatch = [ - (&b"a"[..], &b"x"[..]), - (&b"ab"[..], &b"ax"[..]), - (&b"abc"[..], &b"abx"[..]), - (&b"abcd"[..], &b"abcx"[..]), - (&b"abcde"[..], &b"abcdx"[..]), - (&b"abcdef"[..], &b"abcdex"[..]), - (&b"abcdefg"[..], &b"abcdefx"[..]), - (&b"abcdefgh"[..], &b"abcdefgx"[..]), - (&b"abcdefghi"[..], &b"abcdefghx"[..]), - (&b"abcdefghij"[..], &b"abcdefghix"[..]), - (&b"abcdefghijk"[..], &b"abcdefghijx"[..]), - (&b"abcdefghijkl"[..], &b"abcdefghijkx"[..]), - (&b"abcdefghijklm"[..], &b"abcdefghijklx"[..]), - (&b"abcdefghijklmn"[..], &b"abcdefghijklmx"[..]), - ]; - for (x, y) in one_mismatch { - assert_eq!(x.len(), y.len(), "lengths should match"); - assert!(!is_equal(x, y)); - assert!(!is_equal(y, x)); - } - } - - #[test] - fn equals_yes() { - assert!(is_equal(b"", b"")); - assert!(is_equal(b"a", b"a")); - assert!(is_equal(b"ab", b"ab")); - assert!(is_equal(b"abc", b"abc")); - assert!(is_equal(b"abcd", b"abcd")); - assert!(is_equal(b"abcde", b"abcde")); - assert!(is_equal(b"abcdef", b"abcdef")); - assert!(is_equal(b"abcdefg", b"abcdefg")); - assert!(is_equal(b"abcdefgh", b"abcdefgh")); - assert!(is_equal(b"abcdefghi", b"abcdefghi")); - } - - #[test] - fn prefix() { - assert!(is_prefix(b"", b"")); - assert!(is_prefix(b"a", b"")); - assert!(is_prefix(b"ab", b"")); - assert!(is_prefix(b"foo", b"foo")); - assert!(is_prefix(b"foobar", b"foo")); - - assert!(!is_prefix(b"foo", b"fob")); - assert!(!is_prefix(b"foobar", b"fob")); - } - - #[test] - fn suffix() { - assert!(is_suffix(b"", b"")); - assert!(is_suffix(b"a", b"")); - assert!(is_suffix(b"ab", b"")); - assert!(is_suffix(b"foo", b"foo")); - assert!(is_suffix(b"foobar", b"bar")); - - assert!(!is_suffix(b"foo", b"goo")); - assert!(!is_suffix(b"foobar", b"gar")); - } -} diff --git a/vendor/memchr/src/arch/all/packedpair/default_rank.rs b/vendor/memchr/src/arch/all/packedpair/default_rank.rs deleted file mode 100644 index 6aa3895..0000000 --- a/vendor/memchr/src/arch/all/packedpair/default_rank.rs +++ /dev/null @@ -1,258 +0,0 @@ -pub(crate) const RANK: [u8; 256] = [ - 55, // '\x00' - 52, // '\x01' - 51, // '\x02' - 50, // '\x03' - 49, // '\x04' - 48, // '\x05' - 47, // '\x06' - 46, // '\x07' - 45, // '\x08' - 103, // '\t' - 242, // '\n' - 66, // '\x0b' - 67, // '\x0c' - 229, // '\r' - 44, // '\x0e' - 43, // '\x0f' - 42, // '\x10' - 41, // '\x11' - 40, // '\x12' - 39, // '\x13' - 38, // '\x14' - 37, // '\x15' - 36, // '\x16' - 35, // '\x17' - 34, // '\x18' - 33, // '\x19' - 56, // '\x1a' - 32, // '\x1b' - 31, // '\x1c' - 30, // '\x1d' - 29, // '\x1e' - 28, // '\x1f' - 255, // ' ' - 148, // '!' - 164, // '"' - 149, // '#' - 136, // '$' - 160, // '%' - 155, // '&' - 173, // "'" - 221, // '(' - 222, // ')' - 134, // '*' - 122, // '+' - 232, // ',' - 202, // '-' - 215, // '.' - 224, // '/' - 208, // '0' - 220, // '1' - 204, // '2' - 187, // '3' - 183, // '4' - 179, // '5' - 177, // '6' - 168, // '7' - 178, // '8' - 200, // '9' - 226, // ':' - 195, // ';' - 154, // '<' - 184, // '=' - 174, // '>' - 126, // '?' - 120, // '@' - 191, // 'A' - 157, // 'B' - 194, // 'C' - 170, // 'D' - 189, // 'E' - 162, // 'F' - 161, // 'G' - 150, // 'H' - 193, // 'I' - 142, // 'J' - 137, // 'K' - 171, // 'L' - 176, // 'M' - 185, // 'N' - 167, // 'O' - 186, // 'P' - 112, // 'Q' - 175, // 'R' - 192, // 'S' - 188, // 'T' - 156, // 'U' - 140, // 'V' - 143, // 'W' - 123, // 'X' - 133, // 'Y' - 128, // 'Z' - 147, // '[' - 138, // '\\' - 146, // ']' - 114, // '^' - 223, // '_' - 151, // '`' - 249, // 'a' - 216, // 'b' - 238, // 'c' - 236, // 'd' - 253, // 'e' - 227, // 'f' - 218, // 'g' - 230, // 'h' - 247, // 'i' - 135, // 'j' - 180, // 'k' - 241, // 'l' - 233, // 'm' - 246, // 'n' - 244, // 'o' - 231, // 'p' - 139, // 'q' - 245, // 'r' - 243, // 's' - 251, // 't' - 235, // 'u' - 201, // 'v' - 196, // 'w' - 240, // 'x' - 214, // 'y' - 152, // 'z' - 182, // '{' - 205, // '|' - 181, // '}' - 127, // '~' - 27, // '\x7f' - 212, // '\x80' - 211, // '\x81' - 210, // '\x82' - 213, // '\x83' - 228, // '\x84' - 197, // '\x85' - 169, // '\x86' - 159, // '\x87' - 131, // '\x88' - 172, // '\x89' - 105, // '\x8a' - 80, // '\x8b' - 98, // '\x8c' - 96, // '\x8d' - 97, // '\x8e' - 81, // '\x8f' - 207, // '\x90' - 145, // '\x91' - 116, // '\x92' - 115, // '\x93' - 144, // '\x94' - 130, // '\x95' - 153, // '\x96' - 121, // '\x97' - 107, // '\x98' - 132, // '\x99' - 109, // '\x9a' - 110, // '\x9b' - 124, // '\x9c' - 111, // '\x9d' - 82, // '\x9e' - 108, // '\x9f' - 118, // '\xa0' - 141, // '¡' - 113, // '¢' - 129, // '£' - 119, // '¤' - 125, // '¥' - 165, // '¦' - 117, // '§' - 92, // '¨' - 106, // '©' - 83, // 'ª' - 72, // '«' - 99, // '¬' - 93, // '\xad' - 65, // '®' - 79, // '¯' - 166, // '°' - 237, // '±' - 163, // '²' - 199, // '³' - 190, // '´' - 225, // 'µ' - 209, // '¶' - 203, // '·' - 198, // '¸' - 217, // '¹' - 219, // 'º' - 206, // '»' - 234, // '¼' - 248, // '½' - 158, // '¾' - 239, // '¿' - 255, // 'À' - 255, // 'Á' - 255, // 'Â' - 255, // 'Ã' - 255, // 'Ä' - 255, // 'Å' - 255, // 'Æ' - 255, // 'Ç' - 255, // 'È' - 255, // 'É' - 255, // 'Ê' - 255, // 'Ë' - 255, // 'Ì' - 255, // 'Í' - 255, // 'Î' - 255, // 'Ï' - 255, // 'Ð' - 255, // 'Ñ' - 255, // 'Ò' - 255, // 'Ó' - 255, // 'Ô' - 255, // 'Õ' - 255, // 'Ö' - 255, // '×' - 255, // 'Ø' - 255, // 'Ù' - 255, // 'Ú' - 255, // 'Û' - 255, // 'Ü' - 255, // 'Ý' - 255, // 'Þ' - 255, // 'ß' - 255, // 'à' - 255, // 'á' - 255, // 'â' - 255, // 'ã' - 255, // 'ä' - 255, // 'å' - 255, // 'æ' - 255, // 'ç' - 255, // 'è' - 255, // 'é' - 255, // 'ê' - 255, // 'ë' - 255, // 'ì' - 255, // 'í' - 255, // 'î' - 255, // 'ï' - 255, // 'ð' - 255, // 'ñ' - 255, // 'ò' - 255, // 'ó' - 255, // 'ô' - 255, // 'õ' - 255, // 'ö' - 255, // '÷' - 255, // 'ø' - 255, // 'ù' - 255, // 'ú' - 255, // 'û' - 255, // 'ü' - 255, // 'ý' - 255, // 'þ' - 255, // 'ÿ' -]; diff --git a/vendor/memchr/src/arch/all/packedpair/mod.rs b/vendor/memchr/src/arch/all/packedpair/mod.rs deleted file mode 100644 index 148a985..0000000 --- a/vendor/memchr/src/arch/all/packedpair/mod.rs +++ /dev/null @@ -1,359 +0,0 @@ -/*! -Provides an architecture independent implementation of the "packed pair" -algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. Note that -this module provides an architecture independent version that doesn't do as -good of a job keeping the search for candidates inside a SIMD hot path. It -however can be good enough in many circumstances. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use crate::memchr; - -mod default_rank; - -/// An architecture independent "packed pair" finder. -/// -/// This finder picks two bytes that it believes have high predictive power for -/// indicating an overall match of a needle. At search time, it reports offsets -/// where the needle could match based on whether the pair of bytes it chose -/// match. -/// -/// This is architecture independent because it utilizes `memchr` to find the -/// occurrence of one of the bytes in the pair, and then checks whether the -/// second byte matches. If it does, in the case of [`Finder::find_prefilter`], -/// the location at which the needle could match is returned. -/// -/// It is generally preferred to use architecture specific routines for a -/// "packed pair" prefilter, but this can be a useful fallback when the -/// architecture independent routines are unavailable. -#[derive(Clone, Copy, Debug)] -pub struct Finder { - pair: Pair, - byte1: u8, - byte2: u8, -} - -impl Finder { - /// Create a new prefilter that reports possible locations where the given - /// needle matches. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - Finder::with_pair(needle, Pair::new(needle)?) - } - - /// Create a new prefilter using the pair given. - /// - /// If the prefilter could not be constructed, then `None` is returned. - /// - /// This constructor permits callers to control precisely which pair of - /// bytes is used as a predicate. - #[inline] - pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> { - let byte1 = needle[usize::from(pair.index1())]; - let byte2 = needle[usize::from(pair.index2())]; - // Currently this can never fail so we could just return a Finder, - // but it's conceivable this could change. - Some(Finder { pair, byte1, byte2 }) - } - - /// Run this finder on the given haystack as a prefilter. - /// - /// If a candidate match is found, then an offset where the needle *could* - /// begin in the haystack is returned. - #[inline] - pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> { - let mut i = 0; - let index1 = usize::from(self.pair.index1()); - let index2 = usize::from(self.pair.index2()); - loop { - // Use a fast vectorized implementation to skip to the next - // occurrence of the rarest byte (heuristically chosen) in the - // needle. - i += memchr(self.byte1, &haystack[i..])?; - let found = i; - i += 1; - - // If we can't align our first byte match with the haystack, then a - // match is impossible. - let aligned1 = match found.checked_sub(index1) { - None => continue, - Some(aligned1) => aligned1, - }; - - // Now align the second byte match with the haystack. A mismatch - // means that a match is impossible. - let aligned2 = match aligned1.checked_add(index2) { - None => continue, - Some(aligned_index2) => aligned_index2, - }; - if haystack.get(aligned2).map_or(true, |&b| b != self.byte2) { - continue; - } - - // We've done what we can. There might be a match here. - return Some(aligned1); - } - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub fn pair(&self) -> &Pair { - &self.pair - } -} - -/// A pair of byte offsets into a needle to use as a predicate. -/// -/// This pair is used as a predicate to quickly filter out positions in a -/// haystack in which a needle cannot match. In some cases, this pair can even -/// be used in vector algorithms such that the vector algorithm only switches -/// over to scalar code once this pair has been found. -/// -/// A pair of offsets can be used in both substring search implementations and -/// in prefilters. The former will report matches of a needle in a haystack -/// where as the latter will only report possible matches of a needle. -/// -/// The offsets are limited each to a maximum of 255 to keep memory usage low. -/// Moreover, it's rarely advantageous to create a predicate using offsets -/// greater than 255 anyway. -/// -/// The only guarantee enforced on the pair of offsets is that they are not -/// equivalent. It is not necessarily the case that `index1 < index2` for -/// example. By convention, `index1` corresponds to the byte in the needle -/// that is believed to be most the predictive. Note also that because of the -/// requirement that the indices be both valid for the needle used to build -/// the pair and not equal, it follows that a pair can only be constructed for -/// needles with length at least 2. -#[derive(Clone, Copy, Debug)] -pub struct Pair { - index1: u8, - index2: u8, -} - -impl Pair { - /// Create a new pair of offsets from the given needle. - /// - /// If a pair could not be created (for example, if the needle is too - /// short), then `None` is returned. - /// - /// This chooses the pair in the needle that is believed to be as - /// predictive of an overall match of the needle as possible. - #[inline] - pub fn new(needle: &[u8]) -> Option<Pair> { - Pair::with_ranker(needle, DefaultFrequencyRank) - } - - /// Create a new pair of offsets from the given needle and ranker. - /// - /// This permits the caller to choose a background frequency distribution - /// with which bytes are selected. The idea is to select a pair of bytes - /// that is believed to strongly predict a match in the haystack. This - /// usually means selecting bytes that occur rarely in a haystack. - /// - /// If a pair could not be created (for example, if the needle is too - /// short), then `None` is returned. - #[inline] - pub fn with_ranker<R: HeuristicFrequencyRank>( - needle: &[u8], - ranker: R, - ) -> Option<Pair> { - if needle.len() <= 1 { - return None; - } - // Find the rarest two bytes. We make them distinct indices by - // construction. (The actual byte value may be the same in degenerate - // cases, but that's OK.) - let (mut rare1, mut index1) = (needle[0], 0); - let (mut rare2, mut index2) = (needle[1], 1); - if ranker.rank(rare2) < ranker.rank(rare1) { - core::mem::swap(&mut rare1, &mut rare2); - core::mem::swap(&mut index1, &mut index2); - } - let max = usize::from(core::u8::MAX); - for (i, &b) in needle.iter().enumerate().take(max).skip(2) { - if ranker.rank(b) < ranker.rank(rare1) { - rare2 = rare1; - index2 = index1; - rare1 = b; - index1 = u8::try_from(i).unwrap(); - } else if b != rare1 && ranker.rank(b) < ranker.rank(rare2) { - rare2 = b; - index2 = u8::try_from(i).unwrap(); - } - } - // While not strictly required for how a Pair is normally used, we - // really don't want these to be equivalent. If they were, it would - // reduce the effectiveness of candidate searching using these rare - // bytes by increasing the rate of false positives. - assert_ne!(index1, index2); - Some(Pair { index1, index2 }) - } - - /// Create a new pair using the offsets given for the needle given. - /// - /// This bypasses any sort of heuristic process for choosing the offsets - /// and permits the caller to choose the offsets themselves. - /// - /// Indices are limited to valid `u8` values so that a `Pair` uses less - /// memory. It is not possible to create a `Pair` with offsets bigger than - /// `u8::MAX`. It's likely that such a thing is not needed, but if it is, - /// it's suggested to build your own bespoke algorithm because you're - /// likely working on a very niche case. (File an issue if this suggestion - /// does not make sense to you.) - /// - /// If a pair could not be created (for example, if the needle is too - /// short), then `None` is returned. - #[inline] - pub fn with_indices( - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Pair> { - // While not strictly required for how a Pair is normally used, we - // really don't want these to be equivalent. If they were, it would - // reduce the effectiveness of candidate searching using these rare - // bytes by increasing the rate of false positives. - if index1 == index2 { - return None; - } - // Similarly, invalid indices means the Pair is invalid too. - if usize::from(index1) >= needle.len() { - return None; - } - if usize::from(index2) >= needle.len() { - return None; - } - Some(Pair { index1, index2 }) - } - - /// Returns the first offset of the pair. - #[inline] - pub fn index1(&self) -> u8 { - self.index1 - } - - /// Returns the second offset of the pair. - #[inline] - pub fn index2(&self) -> u8 { - self.index2 - } -} - -/// This trait allows the user to customize the heuristic used to determine the -/// relative frequency of a given byte in the dataset being searched. -/// -/// The use of this trait can have a dramatic impact on performance depending -/// on the type of data being searched. The details of why are explained in the -/// docs of [`crate::memmem::Prefilter`]. To summarize, the core algorithm uses -/// a prefilter to quickly identify candidate matches that are later verified -/// more slowly. This prefilter is implemented in terms of trying to find -/// `rare` bytes at specific offsets that will occur less frequently in the -/// dataset. While the concept of a `rare` byte is similar for most datasets, -/// there are some specific datasets (like binary executables) that have -/// dramatically different byte distributions. For these datasets customizing -/// the byte frequency heuristic can have a massive impact on performance, and -/// might even need to be done at runtime. -/// -/// The default implementation of `HeuristicFrequencyRank` reads from the -/// static frequency table defined in `src/memmem/byte_frequencies.rs`. This -/// is optimal for most inputs, so if you are unsure of the impact of using a -/// custom `HeuristicFrequencyRank` you should probably just use the default. -/// -/// # Example -/// -/// ``` -/// use memchr::{ -/// arch::all::packedpair::HeuristicFrequencyRank, -/// memmem::FinderBuilder, -/// }; -/// -/// /// A byte-frequency table that is good for scanning binary executables. -/// struct Binary; -/// -/// impl HeuristicFrequencyRank for Binary { -/// fn rank(&self, byte: u8) -> u8 { -/// const TABLE: [u8; 256] = [ -/// 255, 128, 61, 43, 50, 41, 27, 28, 57, 15, 21, 13, 24, 17, 17, -/// 89, 58, 16, 11, 7, 14, 23, 7, 6, 24, 9, 6, 5, 9, 4, 7, 16, -/// 68, 11, 9, 6, 88, 7, 4, 4, 23, 9, 4, 8, 8, 5, 10, 4, 30, 11, -/// 9, 24, 11, 5, 5, 5, 19, 11, 6, 17, 9, 9, 6, 8, -/// 48, 58, 11, 14, 53, 40, 9, 9, 254, 35, 3, 6, 52, 23, 6, 6, 27, -/// 4, 7, 11, 14, 13, 10, 11, 11, 5, 2, 10, 16, 12, 6, 19, -/// 19, 20, 5, 14, 16, 31, 19, 7, 14, 20, 4, 4, 19, 8, 18, 20, 24, -/// 1, 25, 19, 58, 29, 10, 5, 15, 20, 2, 2, 9, 4, 3, 5, -/// 51, 11, 4, 53, 23, 39, 6, 4, 13, 81, 4, 186, 5, 67, 3, 2, 15, -/// 0, 0, 1, 3, 2, 0, 0, 5, 0, 0, 0, 2, 0, 0, 0, -/// 12, 2, 1, 1, 3, 1, 1, 1, 6, 1, 2, 1, 3, 1, 1, 2, 9, 1, 1, 0, -/// 2, 2, 4, 4, 11, 6, 7, 3, 6, 9, 4, 5, -/// 46, 18, 8, 18, 17, 3, 8, 20, 16, 10, 3, 7, 175, 4, 6, 7, 13, -/// 3, 7, 3, 3, 1, 3, 3, 10, 3, 1, 5, 2, 0, 1, 2, -/// 16, 3, 5, 1, 6, 1, 1, 2, 58, 20, 3, 14, 12, 2, 1, 3, 16, 3, 5, -/// 8, 3, 1, 8, 6, 17, 6, 5, 3, 8, 6, 13, 175, -/// ]; -/// TABLE[byte as usize] -/// } -/// } -/// // Create a new finder with the custom heuristic. -/// let finder = FinderBuilder::new() -/// .build_forward_with_ranker(Binary, b"\x00\x00\xdd\xdd"); -/// // Find needle with custom heuristic. -/// assert!(finder.find(b"\x00\x00\x00\xdd\xdd").is_some()); -/// ``` -pub trait HeuristicFrequencyRank { - /// Return the heuristic frequency rank of the given byte. A lower rank - /// means the byte is believed to occur less frequently in the haystack. - /// - /// Some uses of this heuristic may treat arbitrary absolute rank values as - /// significant. For example, an implementation detail in this crate may - /// determine that heuristic prefilters are inappropriate if every byte in - /// the needle has a "high" rank. - fn rank(&self, byte: u8) -> u8; -} - -/// The default byte frequency heuristic that is good for most haystacks. -pub(crate) struct DefaultFrequencyRank; - -impl HeuristicFrequencyRank for DefaultFrequencyRank { - fn rank(&self, byte: u8) -> u8 { - self::default_rank::RANK[usize::from(byte)] - } -} - -/// This permits passing any implementation of `HeuristicFrequencyRank` as a -/// borrowed version of itself. -impl<'a, R> HeuristicFrequencyRank for &'a R -where - R: HeuristicFrequencyRank, -{ - fn rank(&self, byte: u8) -> u8 { - (**self).rank(byte) - } -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn forward_packedpair() { - fn find( - haystack: &[u8], - needle: &[u8], - _index1: u8, - _index2: u8, - ) -> Option<Option<usize>> { - // We ignore the index positions requested since it winds up making - // this test too slow overall. - let f = Finder::new(needle)?; - Some(f.find_prefilter(haystack)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } -} diff --git a/vendor/memchr/src/arch/all/rabinkarp.rs b/vendor/memchr/src/arch/all/rabinkarp.rs deleted file mode 100644 index e0bafba..0000000 --- a/vendor/memchr/src/arch/all/rabinkarp.rs +++ /dev/null @@ -1,390 +0,0 @@ -/*! -An implementation of the [Rabin-Karp substring search algorithm][rabinkarp]. - -Rabin-Karp works by creating a hash of the needle provided and then computing -a rolling hash for each needle sized window in the haystack. When the rolling -hash matches the hash of the needle, a byte-wise comparison is done to check -if a match exists. The worst case time complexity of Rabin-Karp is `O(m * -n)` where `m ~ len(needle)` and `n ~ len(haystack)`. Its worst case space -complexity is constant. - -The main utility of Rabin-Karp is that the searcher can be constructed very -quickly with very little memory. This makes it especially useful when searching -for small needles in small haystacks, as it might finish its search before a -beefier algorithm (like Two-Way) even starts. - -[rabinkarp]: https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm -*/ - -/* -(This was the comment I wrote for this module originally when it was not -exposed. The comment still looks useful, but it's a bit in the weeds, so it's -not public itself.) - -This module implements the classical Rabin-Karp substring search algorithm, -with no extra frills. While its use would seem to break our time complexity -guarantee of O(m+n) (RK's time complexity is O(mn)), we are careful to only -ever use RK on a constant subset of haystacks. The main point here is that -RK has good latency properties for small needles/haystacks. It's very quick -to compute a needle hash and zip through the haystack when compared to -initializing Two-Way, for example. And this is especially useful for cases -where the haystack is just too short for vector instructions to do much good. - -The hashing function used here is the same one recommended by ESMAJ. - -Another choice instead of Rabin-Karp would be Shift-Or. But its latency -isn't quite as good since its preprocessing time is a bit more expensive -(both in practice and in theory). However, perhaps Shift-Or has a place -somewhere else for short patterns. I think the main problem is that it -requires space proportional to the alphabet and the needle. If we, for -example, supported needles up to length 16, then the total table size would be -len(alphabet)*size_of::<u16>()==512 bytes. Which isn't exactly small, and it's -probably bad to put that on the stack. So ideally, we'd throw it on the heap, -but we'd really like to write as much code without using alloc/std as possible. -But maybe it's worth the special casing. It's a TODO to benchmark. - -Wikipedia has a decent explanation, if a bit heavy on the theory: -https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm - -But ESMAJ provides something a bit more concrete: -http://www-igm.univ-mlv.fr/~lecroq/string/node5.html - -Finally, aho-corasick uses Rabin-Karp for multiple pattern match in some cases: -https://github.com/BurntSushi/aho-corasick/blob/3852632f10587db0ff72ef29e88d58bf305a0946/src/packed/rabinkarp.rs -*/ - -use crate::ext::Pointer; - -/// A forward substring searcher using the Rabin-Karp algorithm. -/// -/// Note that, as a lower level API, a `Finder` does not have access to the -/// needle it was constructed with. For this reason, executing a search -/// with a `Finder` requires passing both the needle and the haystack, -/// where the needle is exactly equivalent to the one given to the `Finder` -/// at construction time. This design was chosen so that callers can have -/// more precise control over where and how many times a needle is stored. -/// For example, in cases where Rabin-Karp is just one of several possible -/// substring search algorithms. -#[derive(Clone, Debug)] -pub struct Finder { - /// The actual hash. - hash: Hash, - /// The factor needed to multiply a byte by in order to subtract it from - /// the hash. It is defined to be 2^(n-1) (using wrapping exponentiation), - /// where n is the length of the needle. This is how we "remove" a byte - /// from the hash once the hash window rolls past it. - hash_2pow: u32, -} - -impl Finder { - /// Create a new Rabin-Karp forward searcher for the given `needle`. - /// - /// The needle may be empty. The empty needle matches at every byte offset. - /// - /// Note that callers must pass the same needle to all search calls using - /// this `Finder`. - #[inline] - pub fn new(needle: &[u8]) -> Finder { - let mut s = Finder { hash: Hash::new(), hash_2pow: 1 }; - let first_byte = match needle.get(0) { - None => return s, - Some(&first_byte) => first_byte, - }; - s.hash.add(first_byte); - for b in needle.iter().copied().skip(1) { - s.hash.add(b); - s.hash_2pow = s.hash_2pow.wrapping_shl(1); - } - s - } - - /// Return the first occurrence of the `needle` in the `haystack` - /// given. If no such occurrence exists, then `None` is returned. - /// - /// The `needle` provided must match the needle given to this finder at - /// construction time. - /// - /// The maximum value this can return is `haystack.len()`, which can only - /// occur when the needle and haystack both have length zero. Otherwise, - /// for non-empty haystacks, the maximum value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - unsafe { - let hstart = haystack.as_ptr(); - let hend = hstart.add(haystack.len()); - let nstart = needle.as_ptr(); - let nend = nstart.add(needle.len()); - let found = self.find_raw(hstart, hend, nstart, nend)?; - Some(found.distance(hstart)) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `<= end`. The pointer returned is only ever equivalent - /// to `end` when both the needle and haystack are empty. (That is, the - /// empty string matches the empty string.) - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// Note that `start` and `end` below refer to both pairs of pointers given - /// to this routine. That is, the conditions apply to both `hstart`/`hend` - /// and `nstart`/`nend`. - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// * It must be the case that `start <= end`. - #[inline] - pub unsafe fn find_raw( - &self, - hstart: *const u8, - hend: *const u8, - nstart: *const u8, - nend: *const u8, - ) -> Option<*const u8> { - let hlen = hend.distance(hstart); - let nlen = nend.distance(nstart); - if nlen > hlen { - return None; - } - let mut cur = hstart; - let end = hend.sub(nlen); - let mut hash = Hash::forward(cur, cur.add(nlen)); - loop { - if self.hash == hash && is_equal_raw(cur, nstart, nlen) { - return Some(cur); - } - if cur >= end { - return None; - } - hash.roll(self, cur.read(), cur.add(nlen).read()); - cur = cur.add(1); - } - } -} - -/// A reverse substring searcher using the Rabin-Karp algorithm. -#[derive(Clone, Debug)] -pub struct FinderRev(Finder); - -impl FinderRev { - /// Create a new Rabin-Karp reverse searcher for the given `needle`. - #[inline] - pub fn new(needle: &[u8]) -> FinderRev { - let mut s = FinderRev(Finder { hash: Hash::new(), hash_2pow: 1 }); - let last_byte = match needle.last() { - None => return s, - Some(&last_byte) => last_byte, - }; - s.0.hash.add(last_byte); - for b in needle.iter().rev().copied().skip(1) { - s.0.hash.add(b); - s.0.hash_2pow = s.0.hash_2pow.wrapping_shl(1); - } - s - } - - /// Return the last occurrence of the `needle` in the `haystack` - /// given. If no such occurrence exists, then `None` is returned. - /// - /// The `needle` provided must match the needle given to this finder at - /// construction time. - /// - /// The maximum value this can return is `haystack.len()`, which can only - /// occur when the needle and haystack both have length zero. Otherwise, - /// for non-empty haystacks, the maximum value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - unsafe { - let hstart = haystack.as_ptr(); - let hend = hstart.add(haystack.len()); - let nstart = needle.as_ptr(); - let nend = nstart.add(needle.len()); - let found = self.rfind_raw(hstart, hend, nstart, nend)?; - Some(found.distance(hstart)) - } - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `<= end`. The pointer returned is only ever equivalent - /// to `end` when both the needle and haystack are empty. (That is, the - /// empty string matches the empty string.) - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// Note that `start` and `end` below refer to both pairs of pointers given - /// to this routine. That is, the conditions apply to both `hstart`/`hend` - /// and `nstart`/`nend`. - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// * It must be the case that `start <= end`. - #[inline] - pub unsafe fn rfind_raw( - &self, - hstart: *const u8, - hend: *const u8, - nstart: *const u8, - nend: *const u8, - ) -> Option<*const u8> { - let hlen = hend.distance(hstart); - let nlen = nend.distance(nstart); - if nlen > hlen { - return None; - } - let mut cur = hend.sub(nlen); - let start = hstart; - let mut hash = Hash::reverse(cur, cur.add(nlen)); - loop { - if self.0.hash == hash && is_equal_raw(cur, nstart, nlen) { - return Some(cur); - } - if cur <= start { - return None; - } - cur = cur.sub(1); - hash.roll(&self.0, cur.add(nlen).read(), cur.read()); - } - } -} - -/// Whether RK is believed to be very fast for the given needle/haystack. -#[inline] -pub(crate) fn is_fast(haystack: &[u8], _needle: &[u8]) -> bool { - haystack.len() < 16 -} - -/// A Rabin-Karp hash. This might represent the hash of a needle, or the hash -/// of a rolling window in the haystack. -#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)] -struct Hash(u32); - -impl Hash { - /// Create a new hash that represents the empty string. - #[inline(always)] - fn new() -> Hash { - Hash(0) - } - - /// Create a new hash from the bytes given for use in forward searches. - /// - /// # Safety - /// - /// The given pointers must be valid to read from within their range. - #[inline(always)] - unsafe fn forward(mut start: *const u8, end: *const u8) -> Hash { - let mut hash = Hash::new(); - while start < end { - hash.add(start.read()); - start = start.add(1); - } - hash - } - - /// Create a new hash from the bytes given for use in reverse searches. - /// - /// # Safety - /// - /// The given pointers must be valid to read from within their range. - #[inline(always)] - unsafe fn reverse(start: *const u8, mut end: *const u8) -> Hash { - let mut hash = Hash::new(); - while start < end { - end = end.sub(1); - hash.add(end.read()); - } - hash - } - - /// Add 'new' and remove 'old' from this hash. The given needle hash should - /// correspond to the hash computed for the needle being searched for. - /// - /// This is meant to be used when the rolling window of the haystack is - /// advanced. - #[inline(always)] - fn roll(&mut self, finder: &Finder, old: u8, new: u8) { - self.del(finder, old); - self.add(new); - } - - /// Add a byte to this hash. - #[inline(always)] - fn add(&mut self, byte: u8) { - self.0 = self.0.wrapping_shl(1).wrapping_add(u32::from(byte)); - } - - /// Remove a byte from this hash. The given needle hash should correspond - /// to the hash computed for the needle being searched for. - #[inline(always)] - fn del(&mut self, finder: &Finder, byte: u8) { - let factor = finder.hash_2pow; - self.0 = self.0.wrapping_sub(u32::from(byte).wrapping_mul(factor)); - } -} - -/// Returns true when `x[i] == y[i]` for all `0 <= i < n`. -/// -/// We forcefully don't inline this to hint at the compiler that it is unlikely -/// to be called. This causes the inner rabinkarp loop above to be a bit -/// tighter and leads to some performance improvement. See the -/// memmem/krate/prebuilt/sliceslice-words/words benchmark. -/// -/// # Safety -/// -/// Same as `crate::arch::all::is_equal_raw`. -#[cold] -#[inline(never)] -unsafe fn is_equal_raw(x: *const u8, y: *const u8, n: usize) -> bool { - crate::arch::all::is_equal_raw(x, y, n) -} - -#[cfg(test)] -mod tests { - use super::*; - - define_substring_forward_quickcheck!(|h, n| Some( - Finder::new(n).find(h, n) - )); - define_substring_reverse_quickcheck!(|h, n| Some( - FinderRev::new(n).rfind(h, n) - )); - - #[test] - fn forward() { - crate::tests::substring::Runner::new() - .fwd(|h, n| Some(Finder::new(n).find(h, n))) - .run(); - } - - #[test] - fn reverse() { - crate::tests::substring::Runner::new() - .rev(|h, n| Some(FinderRev::new(n).rfind(h, n))) - .run(); - } -} diff --git a/vendor/memchr/src/arch/all/shiftor.rs b/vendor/memchr/src/arch/all/shiftor.rs deleted file mode 100644 index b690564..0000000 --- a/vendor/memchr/src/arch/all/shiftor.rs +++ /dev/null @@ -1,89 +0,0 @@ -/*! -An implementation of the [Shift-Or substring search algorithm][shiftor]. - -[shiftor]: https://en.wikipedia.org/wiki/Bitap_algorithm -*/ - -use alloc::boxed::Box; - -/// The type of our mask. -/// -/// While we don't expose anyway to configure this in the public API, if one -/// really needs less memory usage or support for longer needles, then it is -/// suggested to copy the code from this module and modify it to fit your -/// needs. The code below is written to be correct regardless of whether Mask -/// is a u8, u16, u32, u64 or u128. -type Mask = u16; - -/// A forward substring searcher using the Shift-Or algorithm. -#[derive(Debug)] -pub struct Finder { - masks: Box<[Mask; 256]>, - needle_len: usize, -} - -impl Finder { - const MAX_NEEDLE_LEN: usize = (Mask::BITS - 1) as usize; - - /// Create a new Shift-Or forward searcher for the given `needle`. - /// - /// The needle may be empty. The empty needle matches at every byte offset. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - let needle_len = needle.len(); - if needle_len > Finder::MAX_NEEDLE_LEN { - // A match is found when bit 7 is set in 'result' in the search - // routine below. So our needle can't be bigger than 7. We could - // permit bigger needles by using u16, u32 or u64 for our mask - // entries. But this is all we need for this example. - return None; - } - let mut searcher = Finder { masks: Box::from([!0; 256]), needle_len }; - for (i, &byte) in needle.iter().enumerate() { - searcher.masks[usize::from(byte)] &= !(1 << i); - } - Some(searcher) - } - - /// Return the first occurrence of the needle given to `Finder::new` in - /// the `haystack` given. If no such occurrence exists, then `None` is - /// returned. - /// - /// Unlike most other substring search implementations in this crate, this - /// finder does not require passing the needle at search time. A match can - /// be determined without the needle at all since the required information - /// is already encoded into this finder at construction time. - /// - /// The maximum value this can return is `haystack.len()`, which can only - /// occur when the needle and haystack both have length zero. Otherwise, - /// for non-empty haystacks, the maximum value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - if self.needle_len == 0 { - return Some(0); - } - let mut result = !1; - for (i, &byte) in haystack.iter().enumerate() { - result |= self.masks[usize::from(byte)]; - result <<= 1; - if result & (1 << self.needle_len) == 0 { - return Some(i + 1 - self.needle_len); - } - } - None - } -} - -#[cfg(test)] -mod tests { - use super::*; - - define_substring_forward_quickcheck!(|h, n| Some(Finder::new(n)?.find(h))); - - #[test] - fn forward() { - crate::tests::substring::Runner::new() - .fwd(|h, n| Some(Finder::new(n)?.find(h))) - .run(); - } -} diff --git a/vendor/memchr/src/arch/all/twoway.rs b/vendor/memchr/src/arch/all/twoway.rs deleted file mode 100644 index 0df3b4a..0000000 --- a/vendor/memchr/src/arch/all/twoway.rs +++ /dev/null @@ -1,877 +0,0 @@ -/*! -An implementation of the [Two-Way substring search algorithm][two-way]. - -[`Finder`] can be built for forward searches, while [`FinderRev`] can be built -for reverse searches. - -Two-Way makes for a nice general purpose substring search algorithm because of -its time and space complexity properties. It also performs well in practice. -Namely, with `m = len(needle)` and `n = len(haystack)`, Two-Way takes `O(m)` -time to create a finder, `O(1)` space and `O(n)` search time. In other words, -the preprocessing step is quick, doesn't require any heap memory and the worst -case search time is guaranteed to be linear in the haystack regardless of the -size of the needle. - -While vector algorithms will usually beat Two-Way handedly, vector algorithms -also usually have pathological or edge cases that are better handled by Two-Way. -Moreover, not all targets support vector algorithms or implementations for them -simply may not exist yet. - -Two-Way can be found in the `memmem` implementations in at least [GNU libc] and -[musl]. - -[two-way]: https://en.wikipedia.org/wiki/Two-way_string-matching_algorithm -[GNU libc]: https://www.gnu.org/software/libc/ -[musl]: https://www.musl-libc.org/ -*/ - -use core::cmp; - -use crate::{ - arch::all::{is_prefix, is_suffix}, - memmem::Pre, -}; - -/// A forward substring searcher that uses the Two-Way algorithm. -#[derive(Clone, Copy, Debug)] -pub struct Finder(TwoWay); - -/// A reverse substring searcher that uses the Two-Way algorithm. -#[derive(Clone, Copy, Debug)] -pub struct FinderRev(TwoWay); - -/// An implementation of the TwoWay substring search algorithm. -/// -/// This searcher supports forward and reverse search, although not -/// simultaneously. It runs in `O(n + m)` time and `O(1)` space, where -/// `n ~ len(needle)` and `m ~ len(haystack)`. -/// -/// The implementation here roughly matches that which was developed by -/// Crochemore and Perrin in their 1991 paper "Two-way string-matching." The -/// changes in this implementation are 1) the use of zero-based indices, 2) a -/// heuristic skip table based on the last byte (borrowed from Rust's standard -/// library) and 3) the addition of heuristics for a fast skip loop. For (3), -/// callers can pass any kind of prefilter they want, but usually it's one -/// based on a heuristic that uses an approximate background frequency of bytes -/// to choose rare bytes to quickly look for candidate match positions. Note -/// though that currently, this prefilter functionality is not exposed directly -/// in the public API. (File an issue if you want it and provide a use case -/// please.) -/// -/// The heuristic for fast skipping is automatically shut off if it's -/// detected to be ineffective at search time. Generally, this only occurs in -/// pathological cases. But this is generally necessary in order to preserve -/// a `O(n + m)` time bound. -/// -/// The code below is fairly complex and not obviously correct at all. It's -/// likely necessary to read the Two-Way paper cited above in order to fully -/// grok this code. The essence of it is: -/// -/// 1. Do something to detect a "critical" position in the needle. -/// 2. For the current position in the haystack, look if `needle[critical..]` -/// matches at that position. -/// 3. If so, look if `needle[..critical]` matches. -/// 4. If a mismatch occurs, shift the search by some amount based on the -/// critical position and a pre-computed shift. -/// -/// This type is wrapped in the forward and reverse finders that expose -/// consistent forward or reverse APIs. -#[derive(Clone, Copy, Debug)] -struct TwoWay { - /// A small bitset used as a quick prefilter (in addition to any prefilter - /// given by the caller). Namely, a bit `i` is set if and only if `b%64==i` - /// for any `b == needle[i]`. - /// - /// When used as a prefilter, if the last byte at the current candidate - /// position is NOT in this set, then we can skip that entire candidate - /// position (the length of the needle). This is essentially the shift - /// trick found in Boyer-Moore, but only applied to bytes that don't appear - /// in the needle. - /// - /// N.B. This trick was inspired by something similar in std's - /// implementation of Two-Way. - byteset: ApproximateByteSet, - /// A critical position in needle. Specifically, this position corresponds - /// to beginning of either the minimal or maximal suffix in needle. (N.B. - /// See SuffixType below for why "minimal" isn't quite the correct word - /// here.) - /// - /// This is the position at which every search begins. Namely, search - /// starts by scanning text to the right of this position, and only if - /// there's a match does the text to the left of this position get scanned. - critical_pos: usize, - /// The amount we shift by in the Two-Way search algorithm. This - /// corresponds to the "small period" and "large period" cases. - shift: Shift, -} - -impl Finder { - /// Create a searcher that finds occurrences of the given `needle`. - /// - /// An empty `needle` results in a match at every position in a haystack, - /// including at `haystack.len()`. - #[inline] - pub fn new(needle: &[u8]) -> Finder { - let byteset = ApproximateByteSet::new(needle); - let min_suffix = Suffix::forward(needle, SuffixKind::Minimal); - let max_suffix = Suffix::forward(needle, SuffixKind::Maximal); - let (period_lower_bound, critical_pos) = - if min_suffix.pos > max_suffix.pos { - (min_suffix.period, min_suffix.pos) - } else { - (max_suffix.period, max_suffix.pos) - }; - let shift = Shift::forward(needle, period_lower_bound, critical_pos); - Finder(TwoWay { byteset, critical_pos, shift }) - } - - /// Returns the first occurrence of `needle` in the given `haystack`, or - /// `None` if no such occurrence could be found. - /// - /// The `needle` given must be the same as the `needle` provided to - /// [`Finder::new`]. - /// - /// An empty `needle` results in a match at every position in a haystack, - /// including at `haystack.len()`. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - self.find_with_prefilter(None, haystack, needle) - } - - /// This is like [`Finder::find`], but it accepts a prefilter for - /// accelerating searches. - /// - /// Currently this is not exposed in the public API because, at the time - /// of writing, I didn't want to spend time thinking about how to expose - /// the prefilter infrastructure (if at all). If you have a compelling use - /// case for exposing this routine, please create an issue. Do *not* open - /// a PR that just exposes `Pre` and friends. Exporting this routine will - /// require API design. - #[inline(always)] - pub(crate) fn find_with_prefilter( - &self, - pre: Option<Pre<'_>>, - haystack: &[u8], - needle: &[u8], - ) -> Option<usize> { - match self.0.shift { - Shift::Small { period } => { - self.find_small_imp(pre, haystack, needle, period) - } - Shift::Large { shift } => { - self.find_large_imp(pre, haystack, needle, shift) - } - } - } - - // Each of the two search implementations below can be accelerated by a - // prefilter, but it is not always enabled. To avoid its overhead when - // its disabled, we explicitly inline each search implementation based on - // whether a prefilter will be used or not. The decision on which to use - // is made in the parent meta searcher. - - #[inline(always)] - fn find_small_imp( - &self, - mut pre: Option<Pre<'_>>, - haystack: &[u8], - needle: &[u8], - period: usize, - ) -> Option<usize> { - let mut pos = 0; - let mut shift = 0; - let last_byte_pos = match needle.len().checked_sub(1) { - None => return Some(pos), - Some(last_byte) => last_byte, - }; - while pos + needle.len() <= haystack.len() { - let mut i = cmp::max(self.0.critical_pos, shift); - if let Some(pre) = pre.as_mut() { - if pre.is_effective() { - pos += pre.find(&haystack[pos..])?; - shift = 0; - i = self.0.critical_pos; - if pos + needle.len() > haystack.len() { - return None; - } - } - } - if !self.0.byteset.contains(haystack[pos + last_byte_pos]) { - pos += needle.len(); - shift = 0; - continue; - } - while i < needle.len() && needle[i] == haystack[pos + i] { - i += 1; - } - if i < needle.len() { - pos += i - self.0.critical_pos + 1; - shift = 0; - } else { - let mut j = self.0.critical_pos; - while j > shift && needle[j] == haystack[pos + j] { - j -= 1; - } - if j <= shift && needle[shift] == haystack[pos + shift] { - return Some(pos); - } - pos += period; - shift = needle.len() - period; - } - } - None - } - - #[inline(always)] - fn find_large_imp( - &self, - mut pre: Option<Pre<'_>>, - haystack: &[u8], - needle: &[u8], - shift: usize, - ) -> Option<usize> { - let mut pos = 0; - let last_byte_pos = match needle.len().checked_sub(1) { - None => return Some(pos), - Some(last_byte) => last_byte, - }; - 'outer: while pos + needle.len() <= haystack.len() { - if let Some(pre) = pre.as_mut() { - if pre.is_effective() { - pos += pre.find(&haystack[pos..])?; - if pos + needle.len() > haystack.len() { - return None; - } - } - } - - if !self.0.byteset.contains(haystack[pos + last_byte_pos]) { - pos += needle.len(); - continue; - } - let mut i = self.0.critical_pos; - while i < needle.len() && needle[i] == haystack[pos + i] { - i += 1; - } - if i < needle.len() { - pos += i - self.0.critical_pos + 1; - } else { - for j in (0..self.0.critical_pos).rev() { - if needle[j] != haystack[pos + j] { - pos += shift; - continue 'outer; - } - } - return Some(pos); - } - } - None - } -} - -impl FinderRev { - /// Create a searcher that finds occurrences of the given `needle`. - /// - /// An empty `needle` results in a match at every position in a haystack, - /// including at `haystack.len()`. - #[inline] - pub fn new(needle: &[u8]) -> FinderRev { - let byteset = ApproximateByteSet::new(needle); - let min_suffix = Suffix::reverse(needle, SuffixKind::Minimal); - let max_suffix = Suffix::reverse(needle, SuffixKind::Maximal); - let (period_lower_bound, critical_pos) = - if min_suffix.pos < max_suffix.pos { - (min_suffix.period, min_suffix.pos) - } else { - (max_suffix.period, max_suffix.pos) - }; - let shift = Shift::reverse(needle, period_lower_bound, critical_pos); - FinderRev(TwoWay { byteset, critical_pos, shift }) - } - - /// Returns the last occurrence of `needle` in the given `haystack`, or - /// `None` if no such occurrence could be found. - /// - /// The `needle` given must be the same as the `needle` provided to - /// [`FinderRev::new`]. - /// - /// An empty `needle` results in a match at every position in a haystack, - /// including at `haystack.len()`. - #[inline] - pub fn rfind(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - // For the reverse case, we don't use a prefilter. It's plausible that - // perhaps we should, but it's a lot of additional code to do it, and - // it's not clear that it's actually worth it. If you have a really - // compelling use case for this, please file an issue. - match self.0.shift { - Shift::Small { period } => { - self.rfind_small_imp(haystack, needle, period) - } - Shift::Large { shift } => { - self.rfind_large_imp(haystack, needle, shift) - } - } - } - - #[inline(always)] - fn rfind_small_imp( - &self, - haystack: &[u8], - needle: &[u8], - period: usize, - ) -> Option<usize> { - let nlen = needle.len(); - let mut pos = haystack.len(); - let mut shift = nlen; - let first_byte = match needle.get(0) { - None => return Some(pos), - Some(&first_byte) => first_byte, - }; - while pos >= nlen { - if !self.0.byteset.contains(haystack[pos - nlen]) { - pos -= nlen; - shift = nlen; - continue; - } - let mut i = cmp::min(self.0.critical_pos, shift); - while i > 0 && needle[i - 1] == haystack[pos - nlen + i - 1] { - i -= 1; - } - if i > 0 || first_byte != haystack[pos - nlen] { - pos -= self.0.critical_pos - i + 1; - shift = nlen; - } else { - let mut j = self.0.critical_pos; - while j < shift && needle[j] == haystack[pos - nlen + j] { - j += 1; - } - if j >= shift { - return Some(pos - nlen); - } - pos -= period; - shift = period; - } - } - None - } - - #[inline(always)] - fn rfind_large_imp( - &self, - haystack: &[u8], - needle: &[u8], - shift: usize, - ) -> Option<usize> { - let nlen = needle.len(); - let mut pos = haystack.len(); - let first_byte = match needle.get(0) { - None => return Some(pos), - Some(&first_byte) => first_byte, - }; - while pos >= nlen { - if !self.0.byteset.contains(haystack[pos - nlen]) { - pos -= nlen; - continue; - } - let mut i = self.0.critical_pos; - while i > 0 && needle[i - 1] == haystack[pos - nlen + i - 1] { - i -= 1; - } - if i > 0 || first_byte != haystack[pos - nlen] { - pos -= self.0.critical_pos - i + 1; - } else { - let mut j = self.0.critical_pos; - while j < nlen && needle[j] == haystack[pos - nlen + j] { - j += 1; - } - if j == nlen { - return Some(pos - nlen); - } - pos -= shift; - } - } - None - } -} - -/// A representation of the amount we're allowed to shift by during Two-Way -/// search. -/// -/// When computing a critical factorization of the needle, we find the position -/// of the critical factorization by finding the needle's maximal (or minimal) -/// suffix, along with the period of that suffix. It turns out that the period -/// of that suffix is a lower bound on the period of the needle itself. -/// -/// This lower bound is equivalent to the actual period of the needle in -/// some cases. To describe that case, we denote the needle as `x` where -/// `x = uv` and `v` is the lexicographic maximal suffix of `v`. The lower -/// bound given here is always the period of `v`, which is `<= period(x)`. The -/// case where `period(v) == period(x)` occurs when `len(u) < (len(x) / 2)` and -/// where `u` is a suffix of `v[0..period(v)]`. -/// -/// This case is important because the search algorithm for when the -/// periods are equivalent is slightly different than the search algorithm -/// for when the periods are not equivalent. In particular, when they aren't -/// equivalent, we know that the period of the needle is no less than half its -/// length. In this case, we shift by an amount less than or equal to the -/// period of the needle (determined by the maximum length of the components -/// of the critical factorization of `x`, i.e., `max(len(u), len(v))`).. -/// -/// The above two cases are represented by the variants below. Each entails -/// a different instantiation of the Two-Way search algorithm. -/// -/// N.B. If we could find a way to compute the exact period in all cases, -/// then we could collapse this case analysis and simplify the algorithm. The -/// Two-Way paper suggests this is possible, but more reading is required to -/// grok why the authors didn't pursue that path. -#[derive(Clone, Copy, Debug)] -enum Shift { - Small { period: usize }, - Large { shift: usize }, -} - -impl Shift { - /// Compute the shift for a given needle in the forward direction. - /// - /// This requires a lower bound on the period and a critical position. - /// These can be computed by extracting both the minimal and maximal - /// lexicographic suffixes, and choosing the right-most starting position. - /// The lower bound on the period is then the period of the chosen suffix. - fn forward( - needle: &[u8], - period_lower_bound: usize, - critical_pos: usize, - ) -> Shift { - let large = cmp::max(critical_pos, needle.len() - critical_pos); - if critical_pos * 2 >= needle.len() { - return Shift::Large { shift: large }; - } - - let (u, v) = needle.split_at(critical_pos); - if !is_suffix(&v[..period_lower_bound], u) { - return Shift::Large { shift: large }; - } - Shift::Small { period: period_lower_bound } - } - - /// Compute the shift for a given needle in the reverse direction. - /// - /// This requires a lower bound on the period and a critical position. - /// These can be computed by extracting both the minimal and maximal - /// lexicographic suffixes, and choosing the left-most starting position. - /// The lower bound on the period is then the period of the chosen suffix. - fn reverse( - needle: &[u8], - period_lower_bound: usize, - critical_pos: usize, - ) -> Shift { - let large = cmp::max(critical_pos, needle.len() - critical_pos); - if (needle.len() - critical_pos) * 2 >= needle.len() { - return Shift::Large { shift: large }; - } - - let (v, u) = needle.split_at(critical_pos); - if !is_prefix(&v[v.len() - period_lower_bound..], u) { - return Shift::Large { shift: large }; - } - Shift::Small { period: period_lower_bound } - } -} - -/// A suffix extracted from a needle along with its period. -#[derive(Debug)] -struct Suffix { - /// The starting position of this suffix. - /// - /// If this is a forward suffix, then `&bytes[pos..]` can be used. If this - /// is a reverse suffix, then `&bytes[..pos]` can be used. That is, for - /// forward suffixes, this is an inclusive starting position, where as for - /// reverse suffixes, this is an exclusive ending position. - pos: usize, - /// The period of this suffix. - /// - /// Note that this is NOT necessarily the period of the string from which - /// this suffix comes from. (It is always less than or equal to the period - /// of the original string.) - period: usize, -} - -impl Suffix { - fn forward(needle: &[u8], kind: SuffixKind) -> Suffix { - // suffix represents our maximal (or minimal) suffix, along with - // its period. - let mut suffix = Suffix { pos: 0, period: 1 }; - // The start of a suffix in `needle` that we are considering as a - // more maximal (or minimal) suffix than what's in `suffix`. - let mut candidate_start = 1; - // The current offset of our suffixes that we're comparing. - // - // When the characters at this offset are the same, then we mush on - // to the next position since no decision is possible. When the - // candidate's character is greater (or lesser) than the corresponding - // character than our current maximal (or minimal) suffix, then the - // current suffix is changed over to the candidate and we restart our - // search. Otherwise, the candidate suffix is no good and we restart - // our search on the next candidate. - // - // The three cases above correspond to the three cases in the loop - // below. - let mut offset = 0; - - while candidate_start + offset < needle.len() { - let current = needle[suffix.pos + offset]; - let candidate = needle[candidate_start + offset]; - match kind.cmp(current, candidate) { - SuffixOrdering::Accept => { - suffix = Suffix { pos: candidate_start, period: 1 }; - candidate_start += 1; - offset = 0; - } - SuffixOrdering::Skip => { - candidate_start += offset + 1; - offset = 0; - suffix.period = candidate_start - suffix.pos; - } - SuffixOrdering::Push => { - if offset + 1 == suffix.period { - candidate_start += suffix.period; - offset = 0; - } else { - offset += 1; - } - } - } - } - suffix - } - - fn reverse(needle: &[u8], kind: SuffixKind) -> Suffix { - // See the comments in `forward` for how this works. - let mut suffix = Suffix { pos: needle.len(), period: 1 }; - if needle.len() == 1 { - return suffix; - } - let mut candidate_start = match needle.len().checked_sub(1) { - None => return suffix, - Some(candidate_start) => candidate_start, - }; - let mut offset = 0; - - while offset < candidate_start { - let current = needle[suffix.pos - offset - 1]; - let candidate = needle[candidate_start - offset - 1]; - match kind.cmp(current, candidate) { - SuffixOrdering::Accept => { - suffix = Suffix { pos: candidate_start, period: 1 }; - candidate_start -= 1; - offset = 0; - } - SuffixOrdering::Skip => { - candidate_start -= offset + 1; - offset = 0; - suffix.period = suffix.pos - candidate_start; - } - SuffixOrdering::Push => { - if offset + 1 == suffix.period { - candidate_start -= suffix.period; - offset = 0; - } else { - offset += 1; - } - } - } - } - suffix - } -} - -/// The kind of suffix to extract. -#[derive(Clone, Copy, Debug)] -enum SuffixKind { - /// Extract the smallest lexicographic suffix from a string. - /// - /// Technically, this doesn't actually pick the smallest lexicographic - /// suffix. e.g., Given the choice between `a` and `aa`, this will choose - /// the latter over the former, even though `a < aa`. The reasoning for - /// this isn't clear from the paper, but it still smells like a minimal - /// suffix. - Minimal, - /// Extract the largest lexicographic suffix from a string. - /// - /// Unlike `Minimal`, this really does pick the maximum suffix. e.g., Given - /// the choice between `z` and `zz`, this will choose the latter over the - /// former. - Maximal, -} - -/// The result of comparing corresponding bytes between two suffixes. -#[derive(Clone, Copy, Debug)] -enum SuffixOrdering { - /// This occurs when the given candidate byte indicates that the candidate - /// suffix is better than the current maximal (or minimal) suffix. That is, - /// the current candidate suffix should supplant the current maximal (or - /// minimal) suffix. - Accept, - /// This occurs when the given candidate byte excludes the candidate suffix - /// from being better than the current maximal (or minimal) suffix. That - /// is, the current candidate suffix should be dropped and the next one - /// should be considered. - Skip, - /// This occurs when no decision to accept or skip the candidate suffix - /// can be made, e.g., when corresponding bytes are equivalent. In this - /// case, the next corresponding bytes should be compared. - Push, -} - -impl SuffixKind { - /// Returns true if and only if the given candidate byte indicates that - /// it should replace the current suffix as the maximal (or minimal) - /// suffix. - fn cmp(self, current: u8, candidate: u8) -> SuffixOrdering { - use self::SuffixOrdering::*; - - match self { - SuffixKind::Minimal if candidate < current => Accept, - SuffixKind::Minimal if candidate > current => Skip, - SuffixKind::Minimal => Push, - SuffixKind::Maximal if candidate > current => Accept, - SuffixKind::Maximal if candidate < current => Skip, - SuffixKind::Maximal => Push, - } - } -} - -/// A bitset used to track whether a particular byte exists in a needle or not. -/// -/// Namely, bit 'i' is set if and only if byte%64==i for any byte in the -/// needle. If a particular byte in the haystack is NOT in this set, then one -/// can conclude that it is also not in the needle, and thus, one can advance -/// in the haystack by needle.len() bytes. -#[derive(Clone, Copy, Debug)] -struct ApproximateByteSet(u64); - -impl ApproximateByteSet { - /// Create a new set from the given needle. - fn new(needle: &[u8]) -> ApproximateByteSet { - let mut bits = 0; - for &b in needle { - bits |= 1 << (b % 64); - } - ApproximateByteSet(bits) - } - - /// Return true if and only if the given byte might be in this set. This - /// may return a false positive, but will never return a false negative. - #[inline(always)] - fn contains(&self, byte: u8) -> bool { - self.0 & (1 << (byte % 64)) != 0 - } -} - -#[cfg(test)] -mod tests { - use alloc::vec::Vec; - - use super::*; - - /// Convenience wrapper for computing the suffix as a byte string. - fn get_suffix_forward(needle: &[u8], kind: SuffixKind) -> (&[u8], usize) { - let s = Suffix::forward(needle, kind); - (&needle[s.pos..], s.period) - } - - /// Convenience wrapper for computing the reverse suffix as a byte string. - fn get_suffix_reverse(needle: &[u8], kind: SuffixKind) -> (&[u8], usize) { - let s = Suffix::reverse(needle, kind); - (&needle[..s.pos], s.period) - } - - /// Return all of the non-empty suffixes in the given byte string. - fn suffixes(bytes: &[u8]) -> Vec<&[u8]> { - (0..bytes.len()).map(|i| &bytes[i..]).collect() - } - - /// Return the lexicographically maximal suffix of the given byte string. - fn naive_maximal_suffix_forward(needle: &[u8]) -> &[u8] { - let mut sufs = suffixes(needle); - sufs.sort(); - sufs.pop().unwrap() - } - - /// Return the lexicographically maximal suffix of the reverse of the given - /// byte string. - fn naive_maximal_suffix_reverse(needle: &[u8]) -> Vec<u8> { - let mut reversed = needle.to_vec(); - reversed.reverse(); - let mut got = naive_maximal_suffix_forward(&reversed).to_vec(); - got.reverse(); - got - } - - define_substring_forward_quickcheck!(|h, n| Some( - Finder::new(n).find(h, n) - )); - define_substring_reverse_quickcheck!(|h, n| Some( - FinderRev::new(n).rfind(h, n) - )); - - #[test] - fn forward() { - crate::tests::substring::Runner::new() - .fwd(|h, n| Some(Finder::new(n).find(h, n))) - .run(); - } - - #[test] - fn reverse() { - crate::tests::substring::Runner::new() - .rev(|h, n| Some(FinderRev::new(n).rfind(h, n))) - .run(); - } - - #[test] - fn suffix_forward() { - macro_rules! assert_suffix_min { - ($given:expr, $expected:expr, $period:expr) => { - let (got_suffix, got_period) = - get_suffix_forward($given.as_bytes(), SuffixKind::Minimal); - let got_suffix = core::str::from_utf8(got_suffix).unwrap(); - assert_eq!(($expected, $period), (got_suffix, got_period)); - }; - } - - macro_rules! assert_suffix_max { - ($given:expr, $expected:expr, $period:expr) => { - let (got_suffix, got_period) = - get_suffix_forward($given.as_bytes(), SuffixKind::Maximal); - let got_suffix = core::str::from_utf8(got_suffix).unwrap(); - assert_eq!(($expected, $period), (got_suffix, got_period)); - }; - } - - assert_suffix_min!("a", "a", 1); - assert_suffix_max!("a", "a", 1); - - assert_suffix_min!("ab", "ab", 2); - assert_suffix_max!("ab", "b", 1); - - assert_suffix_min!("ba", "a", 1); - assert_suffix_max!("ba", "ba", 2); - - assert_suffix_min!("abc", "abc", 3); - assert_suffix_max!("abc", "c", 1); - - assert_suffix_min!("acb", "acb", 3); - assert_suffix_max!("acb", "cb", 2); - - assert_suffix_min!("cba", "a", 1); - assert_suffix_max!("cba", "cba", 3); - - assert_suffix_min!("abcabc", "abcabc", 3); - assert_suffix_max!("abcabc", "cabc", 3); - - assert_suffix_min!("abcabcabc", "abcabcabc", 3); - assert_suffix_max!("abcabcabc", "cabcabc", 3); - - assert_suffix_min!("abczz", "abczz", 5); - assert_suffix_max!("abczz", "zz", 1); - - assert_suffix_min!("zzabc", "abc", 3); - assert_suffix_max!("zzabc", "zzabc", 5); - - assert_suffix_min!("aaa", "aaa", 1); - assert_suffix_max!("aaa", "aaa", 1); - - assert_suffix_min!("foobar", "ar", 2); - assert_suffix_max!("foobar", "r", 1); - } - - #[test] - fn suffix_reverse() { - macro_rules! assert_suffix_min { - ($given:expr, $expected:expr, $period:expr) => { - let (got_suffix, got_period) = - get_suffix_reverse($given.as_bytes(), SuffixKind::Minimal); - let got_suffix = core::str::from_utf8(got_suffix).unwrap(); - assert_eq!(($expected, $period), (got_suffix, got_period)); - }; - } - - macro_rules! assert_suffix_max { - ($given:expr, $expected:expr, $period:expr) => { - let (got_suffix, got_period) = - get_suffix_reverse($given.as_bytes(), SuffixKind::Maximal); - let got_suffix = core::str::from_utf8(got_suffix).unwrap(); - assert_eq!(($expected, $period), (got_suffix, got_period)); - }; - } - - assert_suffix_min!("a", "a", 1); - assert_suffix_max!("a", "a", 1); - - assert_suffix_min!("ab", "a", 1); - assert_suffix_max!("ab", "ab", 2); - - assert_suffix_min!("ba", "ba", 2); - assert_suffix_max!("ba", "b", 1); - - assert_suffix_min!("abc", "a", 1); - assert_suffix_max!("abc", "abc", 3); - - assert_suffix_min!("acb", "a", 1); - assert_suffix_max!("acb", "ac", 2); - - assert_suffix_min!("cba", "cba", 3); - assert_suffix_max!("cba", "c", 1); - - assert_suffix_min!("abcabc", "abca", 3); - assert_suffix_max!("abcabc", "abcabc", 3); - - assert_suffix_min!("abcabcabc", "abcabca", 3); - assert_suffix_max!("abcabcabc", "abcabcabc", 3); - - assert_suffix_min!("abczz", "a", 1); - assert_suffix_max!("abczz", "abczz", 5); - - assert_suffix_min!("zzabc", "zza", 3); - assert_suffix_max!("zzabc", "zz", 1); - - assert_suffix_min!("aaa", "aaa", 1); - assert_suffix_max!("aaa", "aaa", 1); - } - - #[cfg(not(miri))] - quickcheck::quickcheck! { - fn qc_suffix_forward_maximal(bytes: Vec<u8>) -> bool { - if bytes.is_empty() { - return true; - } - - let (got, _) = get_suffix_forward(&bytes, SuffixKind::Maximal); - let expected = naive_maximal_suffix_forward(&bytes); - got == expected - } - - fn qc_suffix_reverse_maximal(bytes: Vec<u8>) -> bool { - if bytes.is_empty() { - return true; - } - - let (got, _) = get_suffix_reverse(&bytes, SuffixKind::Maximal); - let expected = naive_maximal_suffix_reverse(&bytes); - expected == got - } - } - - // This is a regression test caught by quickcheck that exercised a bug in - // the reverse small period handling. The bug was that we were using 'if j - // == shift' to determine if a match occurred, but the correct guard is 'if - // j >= shift', which matches the corresponding guard in the forward impl. - #[test] - fn regression_rev_small_period() { - let rfind = |h, n| FinderRev::new(n).rfind(h, n); - let haystack = "ababaz"; - let needle = "abab"; - assert_eq!(Some(0), rfind(haystack.as_bytes(), needle.as_bytes())); - } -} diff --git a/vendor/memchr/src/arch/generic/memchr.rs b/vendor/memchr/src/arch/generic/memchr.rs deleted file mode 100644 index 580b3cc..0000000 --- a/vendor/memchr/src/arch/generic/memchr.rs +++ /dev/null @@ -1,1214 +0,0 @@ -/*! -Generic crate-internal routines for the `memchr` family of functions. -*/ - -// What follows is a vector algorithm generic over the specific vector -// type to detect the position of one, two or three needles in a haystack. -// From what I know, this is a "classic" algorithm, although I don't -// believe it has been published in any peer reviewed journal. I believe -// it can be found in places like glibc and Go's standard library. It -// appears to be well known and is elaborated on in more detail here: -// https://gms.tf/stdfind-and-memchr-optimizations.html -// -// While the routine below is fairly long and perhaps intimidating, the basic -// idea is actually very simple and can be expressed straight-forwardly in -// pseudo code. The psuedo code below is written for 128 bit vectors, but the -// actual code below works for anything that implements the Vector trait. -// -// needle = (n1 << 15) | (n1 << 14) | ... | (n1 << 1) | n1 -// // Note: shift amount is in bytes -// -// while i <= haystack.len() - 16: -// // A 16 byte vector. Each byte in chunk corresponds to a byte in -// // the haystack. -// chunk = haystack[i:i+16] -// // Compare bytes in needle with bytes in chunk. The result is a 16 -// // byte chunk where each byte is 0xFF if the corresponding bytes -// // in needle and chunk were equal, or 0x00 otherwise. -// eqs = cmpeq(needle, chunk) -// // Return a 32 bit integer where the most significant 16 bits -// // are always 0 and the lower 16 bits correspond to whether the -// // most significant bit in the correspond byte in `eqs` is set. -// // In other words, `mask as u16` has bit i set if and only if -// // needle[i] == chunk[i]. -// mask = movemask(eqs) -// -// // Mask is 0 if there is no match, and non-zero otherwise. -// if mask != 0: -// // trailing_zeros tells us the position of the least significant -// // bit that is set. -// return i + trailing_zeros(mask) -// -// // haystack length may not be a multiple of 16, so search the rest. -// while i < haystack.len(): -// if haystack[i] == n1: -// return i -// -// // No match found. -// return NULL -// -// In fact, we could loosely translate the above code to Rust line-for-line -// and it would be a pretty fast algorithm. But, we pull out all the stops -// to go as fast as possible: -// -// 1. We use aligned loads. That is, we do some finagling to make sure our -// primary loop not only proceeds in increments of 16 bytes, but that -// the address of haystack's pointer that we dereference is aligned to -// 16 bytes. 16 is a magic number here because it is the size of SSE2 -// 128-bit vector. (For the AVX2 algorithm, 32 is the magic number.) -// Therefore, to get aligned loads, our pointer's address must be evenly -// divisible by 16. -// 2. Our primary loop proceeds 64 bytes at a time instead of 16. It's -// kind of like loop unrolling, but we combine the equality comparisons -// using a vector OR such that we only need to extract a single mask to -// determine whether a match exists or not. If so, then we do some -// book-keeping to determine the precise location but otherwise mush on. -// 3. We use our "chunk" comparison routine in as many places as possible, -// even if it means using unaligned loads. In particular, if haystack -// starts with an unaligned address, then we do an unaligned load to -// search the first 16 bytes. We then start our primary loop at the -// smallest subsequent aligned address, which will actually overlap with -// previously searched bytes. But we're OK with that. We do a similar -// dance at the end of our primary loop. Finally, to avoid a -// byte-at-a-time loop at the end, we do a final 16 byte unaligned load -// that may overlap with a previous load. This is OK because it converts -// a loop into a small number of very fast vector instructions. The overlap -// is OK because we know the place where the overlap occurs does not -// contain a match. -// -// And that's pretty all there is to it. Note that since the below is -// generic and since it's meant to be inlined into routines with a -// `#[target_feature(enable = "...")]` annotation, we must mark all routines as -// both unsafe and `#[inline(always)]`. -// -// The fact that the code below is generic does somewhat inhibit us. For -// example, I've noticed that introducing an unlineable `#[cold]` function to -// handle the match case in the loop generates tighter assembly, but there is -// no way to do this in the generic code below because the generic code doesn't -// know what `target_feature` annotation to apply to the unlineable function. -// We could make such functions part of the `Vector` trait, but we instead live -// with the slightly sub-optimal codegen for now since it doesn't seem to have -// a noticeable perf difference. - -use crate::{ - ext::Pointer, - vector::{MoveMask, Vector}, -}; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub(crate) struct One<V> { - s1: u8, - v1: V, -} - -impl<V: Vector> One<V> { - /// The number of bytes we examine per each iteration of our search loop. - const LOOP_SIZE: usize = 4 * V::BYTES; - - /// Create a new searcher that finds occurrences of the byte given. - #[inline(always)] - pub(crate) unsafe fn new(needle: u8) -> One<V> { - One { s1: needle, v1: V::splat(needle) } - } - - /// Returns the needle given to `One::new`. - #[inline(always)] - pub(crate) fn needle1(&self) -> u8 { - self.s1 - } - - /// Return a pointer to the first occurrence of the needle in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::first_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - // Search a possibly unaligned chunk at `start`. This covers any part - // of the haystack prior to where aligned loads can start. - if let Some(cur) = self.search_chunk(start, topos) { - return Some(cur); - } - // Set `cur` to the first V-aligned pointer greater than `start`. - let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN)); - debug_assert!(cur > start && end.sub(V::BYTES) >= start); - if len >= Self::LOOP_SIZE { - while cur <= end.sub(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(1 * V::BYTES)); - let c = V::load_aligned(cur.add(2 * V::BYTES)); - let d = V::load_aligned(cur.add(3 * V::BYTES)); - let eqa = self.v1.cmpeq(a); - let eqb = self.v1.cmpeq(b); - let eqc = self.v1.cmpeq(c); - let eqd = self.v1.cmpeq(d); - let or1 = eqa.or(eqb); - let or2 = eqc.or(eqd); - let or3 = or1.or(or2); - if or3.movemask_will_have_non_zero() { - let mask = eqa.movemask(); - if mask.has_non_zero() { - return Some(cur.add(topos(mask))); - } - - let mask = eqb.movemask(); - if mask.has_non_zero() { - return Some(cur.add(1 * V::BYTES).add(topos(mask))); - } - - let mask = eqc.movemask(); - if mask.has_non_zero() { - return Some(cur.add(2 * V::BYTES).add(topos(mask))); - } - - let mask = eqd.movemask(); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(3 * V::BYTES).add(topos(mask))); - } - cur = cur.add(Self::LOOP_SIZE); - } - } - // Handle any leftovers after the aligned loop above. We use unaligned - // loads here, but I believe we are guaranteed that they are aligned - // since `cur` is aligned. - while cur <= end.sub(V::BYTES) { - debug_assert!(end.distance(cur) >= V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - cur = cur.add(V::BYTES); - } - // Finally handle any remaining bytes less than the size of V. In this - // case, our pointer may indeed be unaligned and the load may overlap - // with the previous one. But that's okay since we know the previous - // load didn't lead to a match (otherwise we wouldn't be here). - if cur < end { - debug_assert!(end.distance(cur) < V::BYTES); - cur = cur.sub(V::BYTES - end.distance(cur)); - debug_assert_eq!(end.distance(cur), V::BYTES); - return self.search_chunk(cur, topos); - } - None - } - - /// Return a pointer to the last occurrence of the needle in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::last_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) { - return Some(cur); - } - let mut cur = end.sub(end.as_usize() & V::ALIGN); - debug_assert!(start <= cur && cur <= end); - if len >= Self::LOOP_SIZE { - while cur >= start.add(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - cur = cur.sub(Self::LOOP_SIZE); - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(1 * V::BYTES)); - let c = V::load_aligned(cur.add(2 * V::BYTES)); - let d = V::load_aligned(cur.add(3 * V::BYTES)); - let eqa = self.v1.cmpeq(a); - let eqb = self.v1.cmpeq(b); - let eqc = self.v1.cmpeq(c); - let eqd = self.v1.cmpeq(d); - let or1 = eqa.or(eqb); - let or2 = eqc.or(eqd); - let or3 = or1.or(or2); - if or3.movemask_will_have_non_zero() { - let mask = eqd.movemask(); - if mask.has_non_zero() { - return Some(cur.add(3 * V::BYTES).add(topos(mask))); - } - - let mask = eqc.movemask(); - if mask.has_non_zero() { - return Some(cur.add(2 * V::BYTES).add(topos(mask))); - } - - let mask = eqb.movemask(); - if mask.has_non_zero() { - return Some(cur.add(1 * V::BYTES).add(topos(mask))); - } - - let mask = eqa.movemask(); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(topos(mask))); - } - } - } - while cur >= start.add(V::BYTES) { - debug_assert!(cur.distance(start) >= V::BYTES); - cur = cur.sub(V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - } - if cur > start { - debug_assert!(cur.distance(start) < V::BYTES); - return self.search_chunk(start, topos); - } - None - } - - /// Return a count of all matching bytes in the given haystack. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn count_raw( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let confirm = |b| b == self.needle1(); - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - // Set `cur` to the first V-aligned pointer greater than `start`. - let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN)); - // Count any matching bytes before we start our aligned loop. - let mut count = count_byte_by_byte(start, cur, confirm); - debug_assert!(cur > start && end.sub(V::BYTES) >= start); - if len >= Self::LOOP_SIZE { - while cur <= end.sub(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(1 * V::BYTES)); - let c = V::load_aligned(cur.add(2 * V::BYTES)); - let d = V::load_aligned(cur.add(3 * V::BYTES)); - let eqa = self.v1.cmpeq(a); - let eqb = self.v1.cmpeq(b); - let eqc = self.v1.cmpeq(c); - let eqd = self.v1.cmpeq(d); - count += eqa.movemask().count_ones(); - count += eqb.movemask().count_ones(); - count += eqc.movemask().count_ones(); - count += eqd.movemask().count_ones(); - cur = cur.add(Self::LOOP_SIZE); - } - } - // Handle any leftovers after the aligned loop above. We use unaligned - // loads here, but I believe we are guaranteed that they are aligned - // since `cur` is aligned. - while cur <= end.sub(V::BYTES) { - debug_assert!(end.distance(cur) >= V::BYTES); - let chunk = V::load_unaligned(cur); - count += self.v1.cmpeq(chunk).movemask().count_ones(); - cur = cur.add(V::BYTES); - } - // And finally count any leftovers that weren't caught above. - count += count_byte_by_byte(cur, end, confirm); - count - } - - /// Search `V::BYTES` starting at `cur` via an unaligned load. - /// - /// `mask_to_offset` should be a function that converts a `movemask` to - /// an offset such that `cur.add(offset)` corresponds to a pointer to the - /// match location if one is found. Generally it is expected to use either - /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether - /// one is implementing a forward or reverse search, respectively. - /// - /// # Safety - /// - /// `cur` must be a valid pointer and it must be valid to do an unaligned - /// load of size `V::BYTES` at `cur`. - #[inline(always)] - unsafe fn search_chunk( - &self, - cur: *const u8, - mask_to_offset: impl Fn(V::Mask) -> usize, - ) -> Option<*const u8> { - let chunk = V::load_unaligned(cur); - let mask = self.v1.cmpeq(chunk).movemask(); - if mask.has_non_zero() { - Some(cur.add(mask_to_offset(mask))) - } else { - None - } - } -} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub(crate) struct Two<V> { - s1: u8, - s2: u8, - v1: V, - v2: V, -} - -impl<V: Vector> Two<V> { - /// The number of bytes we examine per each iteration of our search loop. - const LOOP_SIZE: usize = 2 * V::BYTES; - - /// Create a new searcher that finds occurrences of the byte given. - #[inline(always)] - pub(crate) unsafe fn new(needle1: u8, needle2: u8) -> Two<V> { - Two { - s1: needle1, - s2: needle2, - v1: V::splat(needle1), - v2: V::splat(needle2), - } - } - - /// Returns the first needle given to `Two::new`. - #[inline(always)] - pub(crate) fn needle1(&self) -> u8 { - self.s1 - } - - /// Returns the second needle given to `Two::new`. - #[inline(always)] - pub(crate) fn needle2(&self) -> u8 { - self.s2 - } - - /// Return a pointer to the first occurrence of one of the needles in the - /// given haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::first_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - // Search a possibly unaligned chunk at `start`. This covers any part - // of the haystack prior to where aligned loads can start. - if let Some(cur) = self.search_chunk(start, topos) { - return Some(cur); - } - // Set `cur` to the first V-aligned pointer greater than `start`. - let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN)); - debug_assert!(cur > start && end.sub(V::BYTES) >= start); - if len >= Self::LOOP_SIZE { - while cur <= end.sub(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(V::BYTES)); - let eqa1 = self.v1.cmpeq(a); - let eqb1 = self.v1.cmpeq(b); - let eqa2 = self.v2.cmpeq(a); - let eqb2 = self.v2.cmpeq(b); - let or1 = eqa1.or(eqb1); - let or2 = eqa2.or(eqb2); - let or3 = or1.or(or2); - if or3.movemask_will_have_non_zero() { - let mask = eqa1.movemask().or(eqa2.movemask()); - if mask.has_non_zero() { - return Some(cur.add(topos(mask))); - } - - let mask = eqb1.movemask().or(eqb2.movemask()); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(V::BYTES).add(topos(mask))); - } - cur = cur.add(Self::LOOP_SIZE); - } - } - // Handle any leftovers after the aligned loop above. We use unaligned - // loads here, but I believe we are guaranteed that they are aligned - // since `cur` is aligned. - while cur <= end.sub(V::BYTES) { - debug_assert!(end.distance(cur) >= V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - cur = cur.add(V::BYTES); - } - // Finally handle any remaining bytes less than the size of V. In this - // case, our pointer may indeed be unaligned and the load may overlap - // with the previous one. But that's okay since we know the previous - // load didn't lead to a match (otherwise we wouldn't be here). - if cur < end { - debug_assert!(end.distance(cur) < V::BYTES); - cur = cur.sub(V::BYTES - end.distance(cur)); - debug_assert_eq!(end.distance(cur), V::BYTES); - return self.search_chunk(cur, topos); - } - None - } - - /// Return a pointer to the last occurrence of the needle in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::last_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) { - return Some(cur); - } - let mut cur = end.sub(end.as_usize() & V::ALIGN); - debug_assert!(start <= cur && cur <= end); - if len >= Self::LOOP_SIZE { - while cur >= start.add(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - cur = cur.sub(Self::LOOP_SIZE); - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(V::BYTES)); - let eqa1 = self.v1.cmpeq(a); - let eqb1 = self.v1.cmpeq(b); - let eqa2 = self.v2.cmpeq(a); - let eqb2 = self.v2.cmpeq(b); - let or1 = eqa1.or(eqb1); - let or2 = eqa2.or(eqb2); - let or3 = or1.or(or2); - if or3.movemask_will_have_non_zero() { - let mask = eqb1.movemask().or(eqb2.movemask()); - if mask.has_non_zero() { - return Some(cur.add(V::BYTES).add(topos(mask))); - } - - let mask = eqa1.movemask().or(eqa2.movemask()); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(topos(mask))); - } - } - } - while cur >= start.add(V::BYTES) { - debug_assert!(cur.distance(start) >= V::BYTES); - cur = cur.sub(V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - } - if cur > start { - debug_assert!(cur.distance(start) < V::BYTES); - return self.search_chunk(start, topos); - } - None - } - - /// Search `V::BYTES` starting at `cur` via an unaligned load. - /// - /// `mask_to_offset` should be a function that converts a `movemask` to - /// an offset such that `cur.add(offset)` corresponds to a pointer to the - /// match location if one is found. Generally it is expected to use either - /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether - /// one is implementing a forward or reverse search, respectively. - /// - /// # Safety - /// - /// `cur` must be a valid pointer and it must be valid to do an unaligned - /// load of size `V::BYTES` at `cur`. - #[inline(always)] - unsafe fn search_chunk( - &self, - cur: *const u8, - mask_to_offset: impl Fn(V::Mask) -> usize, - ) -> Option<*const u8> { - let chunk = V::load_unaligned(cur); - let eq1 = self.v1.cmpeq(chunk); - let eq2 = self.v2.cmpeq(chunk); - let mask = eq1.or(eq2).movemask(); - if mask.has_non_zero() { - let mask1 = eq1.movemask(); - let mask2 = eq2.movemask(); - Some(cur.add(mask_to_offset(mask1.or(mask2)))) - } else { - None - } - } -} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub(crate) struct Three<V> { - s1: u8, - s2: u8, - s3: u8, - v1: V, - v2: V, - v3: V, -} - -impl<V: Vector> Three<V> { - /// The number of bytes we examine per each iteration of our search loop. - const LOOP_SIZE: usize = 2 * V::BYTES; - - /// Create a new searcher that finds occurrences of the byte given. - #[inline(always)] - pub(crate) unsafe fn new( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Three<V> { - Three { - s1: needle1, - s2: needle2, - s3: needle3, - v1: V::splat(needle1), - v2: V::splat(needle2), - v3: V::splat(needle3), - } - } - - /// Returns the first needle given to `Three::new`. - #[inline(always)] - pub(crate) fn needle1(&self) -> u8 { - self.s1 - } - - /// Returns the second needle given to `Three::new`. - #[inline(always)] - pub(crate) fn needle2(&self) -> u8 { - self.s2 - } - - /// Returns the third needle given to `Three::new`. - #[inline(always)] - pub(crate) fn needle3(&self) -> u8 { - self.s3 - } - - /// Return a pointer to the first occurrence of one of the needles in the - /// given haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::first_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - // Search a possibly unaligned chunk at `start`. This covers any part - // of the haystack prior to where aligned loads can start. - if let Some(cur) = self.search_chunk(start, topos) { - return Some(cur); - } - // Set `cur` to the first V-aligned pointer greater than `start`. - let mut cur = start.add(V::BYTES - (start.as_usize() & V::ALIGN)); - debug_assert!(cur > start && end.sub(V::BYTES) >= start); - if len >= Self::LOOP_SIZE { - while cur <= end.sub(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(V::BYTES)); - let eqa1 = self.v1.cmpeq(a); - let eqb1 = self.v1.cmpeq(b); - let eqa2 = self.v2.cmpeq(a); - let eqb2 = self.v2.cmpeq(b); - let eqa3 = self.v3.cmpeq(a); - let eqb3 = self.v3.cmpeq(b); - let or1 = eqa1.or(eqb1); - let or2 = eqa2.or(eqb2); - let or3 = eqa3.or(eqb3); - let or4 = or1.or(or2); - let or5 = or3.or(or4); - if or5.movemask_will_have_non_zero() { - let mask = eqa1 - .movemask() - .or(eqa2.movemask()) - .or(eqa3.movemask()); - if mask.has_non_zero() { - return Some(cur.add(topos(mask))); - } - - let mask = eqb1 - .movemask() - .or(eqb2.movemask()) - .or(eqb3.movemask()); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(V::BYTES).add(topos(mask))); - } - cur = cur.add(Self::LOOP_SIZE); - } - } - // Handle any leftovers after the aligned loop above. We use unaligned - // loads here, but I believe we are guaranteed that they are aligned - // since `cur` is aligned. - while cur <= end.sub(V::BYTES) { - debug_assert!(end.distance(cur) >= V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - cur = cur.add(V::BYTES); - } - // Finally handle any remaining bytes less than the size of V. In this - // case, our pointer may indeed be unaligned and the load may overlap - // with the previous one. But that's okay since we know the previous - // load didn't lead to a match (otherwise we wouldn't be here). - if cur < end { - debug_assert!(end.distance(cur) < V::BYTES); - cur = cur.sub(V::BYTES - end.distance(cur)); - debug_assert_eq!(end.distance(cur), V::BYTES); - return self.search_chunk(cur, topos); - } - None - } - - /// Return a pointer to the last occurrence of the needle in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// # Safety - /// - /// * It must be the case that `start < end` and that the distance between - /// them is at least equal to `V::BYTES`. That is, it must always be valid - /// to do at least an unaligned load of `V` at `start`. - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - #[inline(always)] - pub(crate) unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - // If we want to support vectors bigger than 256 bits, we probably - // need to move up to using a u64 for the masks used below. Currently - // they are 32 bits, which means we're SOL for vectors that need masks - // bigger than 32 bits. Overall unclear until there's a use case. - debug_assert!(V::BYTES <= 32, "vector cannot be bigger than 32 bytes"); - - let topos = V::Mask::last_offset; - let len = end.distance(start); - debug_assert!( - len >= V::BYTES, - "haystack has length {}, but must be at least {}", - len, - V::BYTES - ); - - if let Some(cur) = self.search_chunk(end.sub(V::BYTES), topos) { - return Some(cur); - } - let mut cur = end.sub(end.as_usize() & V::ALIGN); - debug_assert!(start <= cur && cur <= end); - if len >= Self::LOOP_SIZE { - while cur >= start.add(Self::LOOP_SIZE) { - debug_assert_eq!(0, cur.as_usize() % V::BYTES); - - cur = cur.sub(Self::LOOP_SIZE); - let a = V::load_aligned(cur); - let b = V::load_aligned(cur.add(V::BYTES)); - let eqa1 = self.v1.cmpeq(a); - let eqb1 = self.v1.cmpeq(b); - let eqa2 = self.v2.cmpeq(a); - let eqb2 = self.v2.cmpeq(b); - let eqa3 = self.v3.cmpeq(a); - let eqb3 = self.v3.cmpeq(b); - let or1 = eqa1.or(eqb1); - let or2 = eqa2.or(eqb2); - let or3 = eqa3.or(eqb3); - let or4 = or1.or(or2); - let or5 = or3.or(or4); - if or5.movemask_will_have_non_zero() { - let mask = eqb1 - .movemask() - .or(eqb2.movemask()) - .or(eqb3.movemask()); - if mask.has_non_zero() { - return Some(cur.add(V::BYTES).add(topos(mask))); - } - - let mask = eqa1 - .movemask() - .or(eqa2.movemask()) - .or(eqa3.movemask()); - debug_assert!(mask.has_non_zero()); - return Some(cur.add(topos(mask))); - } - } - } - while cur >= start.add(V::BYTES) { - debug_assert!(cur.distance(start) >= V::BYTES); - cur = cur.sub(V::BYTES); - if let Some(cur) = self.search_chunk(cur, topos) { - return Some(cur); - } - } - if cur > start { - debug_assert!(cur.distance(start) < V::BYTES); - return self.search_chunk(start, topos); - } - None - } - - /// Search `V::BYTES` starting at `cur` via an unaligned load. - /// - /// `mask_to_offset` should be a function that converts a `movemask` to - /// an offset such that `cur.add(offset)` corresponds to a pointer to the - /// match location if one is found. Generally it is expected to use either - /// `mask_to_first_offset` or `mask_to_last_offset`, depending on whether - /// one is implementing a forward or reverse search, respectively. - /// - /// # Safety - /// - /// `cur` must be a valid pointer and it must be valid to do an unaligned - /// load of size `V::BYTES` at `cur`. - #[inline(always)] - unsafe fn search_chunk( - &self, - cur: *const u8, - mask_to_offset: impl Fn(V::Mask) -> usize, - ) -> Option<*const u8> { - let chunk = V::load_unaligned(cur); - let eq1 = self.v1.cmpeq(chunk); - let eq2 = self.v2.cmpeq(chunk); - let eq3 = self.v3.cmpeq(chunk); - let mask = eq1.or(eq2).or(eq3).movemask(); - if mask.has_non_zero() { - let mask1 = eq1.movemask(); - let mask2 = eq2.movemask(); - let mask3 = eq3.movemask(); - Some(cur.add(mask_to_offset(mask1.or(mask2).or(mask3)))) - } else { - None - } - } -} - -/// An iterator over all occurrences of a set of bytes in a haystack. -/// -/// This iterator implements the routines necessary to provide a -/// `DoubleEndedIterator` impl, which means it can also be used to find -/// occurrences in reverse order. -/// -/// The lifetime parameters are as follows: -/// -/// * `'h` refers to the lifetime of the haystack being searched. -/// -/// This type is intended to be used to implement all iterators for the -/// `memchr` family of functions. It handles a tiny bit of marginally tricky -/// raw pointer math, but otherwise expects the caller to provide `find_raw` -/// and `rfind_raw` routines for each call of `next` and `next_back`, -/// respectively. -#[derive(Clone, Debug)] -pub(crate) struct Iter<'h> { - /// The original starting point into the haystack. We use this to convert - /// pointers to offsets. - original_start: *const u8, - /// The current starting point into the haystack. That is, where the next - /// search will begin. - start: *const u8, - /// The current ending point into the haystack. That is, where the next - /// reverse search will begin. - end: *const u8, - /// A marker for tracking the lifetime of the start/cur_start/cur_end - /// pointers above, which all point into the haystack. - haystack: core::marker::PhantomData<&'h [u8]>, -} - -// SAFETY: Iter contains no shared references to anything that performs any -// interior mutations. Also, the lifetime guarantees that Iter will not outlive -// the haystack. -unsafe impl<'h> Send for Iter<'h> {} - -// SAFETY: Iter perform no interior mutations, therefore no explicit -// synchronization is necessary. Also, the lifetime guarantees that Iter will -// not outlive the haystack. -unsafe impl<'h> Sync for Iter<'h> {} - -impl<'h> Iter<'h> { - /// Create a new generic memchr iterator. - #[inline(always)] - pub(crate) fn new(haystack: &'h [u8]) -> Iter<'h> { - Iter { - original_start: haystack.as_ptr(), - start: haystack.as_ptr(), - end: haystack.as_ptr().wrapping_add(haystack.len()), - haystack: core::marker::PhantomData, - } - } - - /// Returns the next occurrence in the forward direction. - /// - /// # Safety - /// - /// Callers must ensure that if a pointer is returned from the closure - /// provided, then it must be greater than or equal to the start pointer - /// and less than the end pointer. - #[inline(always)] - pub(crate) unsafe fn next( - &mut self, - mut find_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>, - ) -> Option<usize> { - // SAFETY: Pointers are derived directly from the same &[u8] haystack. - // We only ever modify start/end corresponding to a matching offset - // found between start and end. Thus all changes to start/end maintain - // our safety requirements. - // - // The only other assumption we rely on is that the pointer returned - // by `find_raw` satisfies `self.start <= found < self.end`, and that - // safety contract is forwarded to the caller. - let found = find_raw(self.start, self.end)?; - let result = found.distance(self.original_start); - self.start = found.add(1); - Some(result) - } - - /// Returns the number of remaining elements in this iterator. - #[inline(always)] - pub(crate) fn count( - self, - mut count_raw: impl FnMut(*const u8, *const u8) -> usize, - ) -> usize { - // SAFETY: Pointers are derived directly from the same &[u8] haystack. - // We only ever modify start/end corresponding to a matching offset - // found between start and end. Thus all changes to start/end maintain - // our safety requirements. - count_raw(self.start, self.end) - } - - /// Returns the next occurrence in reverse. - /// - /// # Safety - /// - /// Callers must ensure that if a pointer is returned from the closure - /// provided, then it must be greater than or equal to the start pointer - /// and less than the end pointer. - #[inline(always)] - pub(crate) unsafe fn next_back( - &mut self, - mut rfind_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>, - ) -> Option<usize> { - // SAFETY: Pointers are derived directly from the same &[u8] haystack. - // We only ever modify start/end corresponding to a matching offset - // found between start and end. Thus all changes to start/end maintain - // our safety requirements. - // - // The only other assumption we rely on is that the pointer returned - // by `rfind_raw` satisfies `self.start <= found < self.end`, and that - // safety contract is forwarded to the caller. - let found = rfind_raw(self.start, self.end)?; - let result = found.distance(self.original_start); - self.end = found; - Some(result) - } - - /// Provides an implementation of `Iterator::size_hint`. - #[inline(always)] - pub(crate) fn size_hint(&self) -> (usize, Option<usize>) { - (0, Some(self.end.as_usize().saturating_sub(self.start.as_usize()))) - } -} - -/// Search a slice using a function that operates on raw pointers. -/// -/// Given a function to search a contiguous sequence of memory for the location -/// of a non-empty set of bytes, this will execute that search on a slice of -/// bytes. The pointer returned by the given function will be converted to an -/// offset relative to the starting point of the given slice. That is, if a -/// match is found, the offset returned by this routine is guaranteed to be a -/// valid index into `haystack`. -/// -/// Callers may use this for a forward or reverse search. -/// -/// # Safety -/// -/// Callers must ensure that if a pointer is returned by `find_raw`, then the -/// pointer must be greater than or equal to the starting pointer and less than -/// the end pointer. -#[inline(always)] -pub(crate) unsafe fn search_slice_with_raw( - haystack: &[u8], - mut find_raw: impl FnMut(*const u8, *const u8) -> Option<*const u8>, -) -> Option<usize> { - // SAFETY: We rely on `find_raw` to return a correct and valid pointer, but - // otherwise, `start` and `end` are valid due to the guarantees provided by - // a &[u8]. - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - let found = find_raw(start, end)?; - Some(found.distance(start)) -} - -/// Performs a forward byte-at-a-time loop until either `ptr >= end_ptr` or -/// until `confirm(*ptr)` returns `true`. If the former occurs, then `None` is -/// returned. If the latter occurs, then the pointer at which `confirm` returns -/// `true` is returned. -/// -/// # Safety -/// -/// Callers must provide valid pointers and they must satisfy `start_ptr <= -/// ptr` and `ptr <= end_ptr`. -#[inline(always)] -pub(crate) unsafe fn fwd_byte_by_byte<F: Fn(u8) -> bool>( - start: *const u8, - end: *const u8, - confirm: F, -) -> Option<*const u8> { - debug_assert!(start <= end); - let mut ptr = start; - while ptr < end { - if confirm(*ptr) { - return Some(ptr); - } - ptr = ptr.offset(1); - } - None -} - -/// Performs a reverse byte-at-a-time loop until either `ptr < start_ptr` or -/// until `confirm(*ptr)` returns `true`. If the former occurs, then `None` is -/// returned. If the latter occurs, then the pointer at which `confirm` returns -/// `true` is returned. -/// -/// # Safety -/// -/// Callers must provide valid pointers and they must satisfy `start_ptr <= -/// ptr` and `ptr <= end_ptr`. -#[inline(always)] -pub(crate) unsafe fn rev_byte_by_byte<F: Fn(u8) -> bool>( - start: *const u8, - end: *const u8, - confirm: F, -) -> Option<*const u8> { - debug_assert!(start <= end); - - let mut ptr = end; - while ptr > start { - ptr = ptr.offset(-1); - if confirm(*ptr) { - return Some(ptr); - } - } - None -} - -/// Performs a forward byte-at-a-time loop until `ptr >= end_ptr` and returns -/// the number of times `confirm(*ptr)` returns `true`. -/// -/// # Safety -/// -/// Callers must provide valid pointers and they must satisfy `start_ptr <= -/// ptr` and `ptr <= end_ptr`. -#[inline(always)] -pub(crate) unsafe fn count_byte_by_byte<F: Fn(u8) -> bool>( - start: *const u8, - end: *const u8, - confirm: F, -) -> usize { - debug_assert!(start <= end); - let mut ptr = start; - let mut count = 0; - while ptr < end { - if confirm(*ptr) { - count += 1; - } - ptr = ptr.offset(1); - } - count -} diff --git a/vendor/memchr/src/arch/generic/mod.rs b/vendor/memchr/src/arch/generic/mod.rs deleted file mode 100644 index 63ee3f0..0000000 --- a/vendor/memchr/src/arch/generic/mod.rs +++ /dev/null @@ -1,14 +0,0 @@ -/*! -This module defines "generic" routines that can be specialized to specific -architectures. - -We don't expose this module primarily because it would require exposing all -of the internal infrastructure required to write these generic routines. -That infrastructure should be treated as an implementation detail so that -it is allowed to evolve. Instead, what we expose are architecture specific -instantiations of these generic implementations. The generic code just lets us -write the code once (usually). -*/ - -pub(crate) mod memchr; -pub(crate) mod packedpair; diff --git a/vendor/memchr/src/arch/generic/packedpair.rs b/vendor/memchr/src/arch/generic/packedpair.rs deleted file mode 100644 index 8d97cf2..0000000 --- a/vendor/memchr/src/arch/generic/packedpair.rs +++ /dev/null @@ -1,317 +0,0 @@ -/*! -Generic crate-internal routines for the "packed pair" SIMD algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use crate::{ - arch::all::{is_equal_raw, packedpair::Pair}, - ext::Pointer, - vector::{MoveMask, Vector}, -}; - -/// A generic architecture dependent "packed pair" finder. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -/// -/// This is architecture dependent because it uses specific vector operations -/// to look for occurrences of the pair of bytes. -/// -/// This type is not meant to be exported and is instead meant to be used as -/// the implementation for architecture specific facades. Why? Because it's a -/// bit of a quirky API that requires `inline(always)` annotations. And pretty -/// much everything has safety obligations due (at least) to the caller needing -/// to inline calls into routines marked with -/// `#[target_feature(enable = "...")]`. -#[derive(Clone, Copy, Debug)] -pub(crate) struct Finder<V> { - pair: Pair, - v1: V, - v2: V, - min_haystack_len: usize, -} - -impl<V: Vector> Finder<V> { - /// Create a new pair searcher. The searcher returned can either report - /// exact matches of `needle` or act as a prefilter and report candidate - /// positions of `needle`. - /// - /// # Safety - /// - /// Callers must ensure that whatever vector type this routine is called - /// with is supported by the current environment. - /// - /// Callers must also ensure that `needle.len() >= 2`. - #[inline(always)] - pub(crate) unsafe fn new(needle: &[u8], pair: Pair) -> Finder<V> { - let max_index = pair.index1().max(pair.index2()); - let min_haystack_len = - core::cmp::max(needle.len(), usize::from(max_index) + V::BYTES); - let v1 = V::splat(needle[usize::from(pair.index1())]); - let v2 = V::splat(needle[usize::from(pair.index2())]); - Finder { pair, v1, v2, min_haystack_len } - } - - /// Searches the given haystack for the given needle. The needle given - /// should be the same as the needle that this finder was initialized - /// with. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// Since this is meant to be used with vector functions, callers need to - /// specialize this inside of a function with a `target_feature` attribute. - /// Therefore, callers must ensure that whatever target feature is being - /// used supports the vector functions that this function is specialized - /// for. (For the specific vector functions used, see the Vector trait - /// implementations.) - #[inline(always)] - pub(crate) unsafe fn find( - &self, - haystack: &[u8], - needle: &[u8], - ) -> Option<usize> { - assert!( - haystack.len() >= self.min_haystack_len, - "haystack too small, should be at least {} but got {}", - self.min_haystack_len, - haystack.len(), - ); - - let all = V::Mask::all_zeros_except_least_significant(0); - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - let max = end.sub(self.min_haystack_len); - let mut cur = start; - - // N.B. I did experiment with unrolling the loop to deal with size(V) - // bytes at a time and 2*size(V) bytes at a time. The double unroll - // was marginally faster while the quadruple unroll was unambiguously - // slower. In the end, I decided the complexity from unrolling wasn't - // worth it. I used the memmem/krate/prebuilt/huge-en/ benchmarks to - // compare. - while cur <= max { - if let Some(chunki) = self.find_in_chunk(needle, cur, end, all) { - return Some(matched(start, cur, chunki)); - } - cur = cur.add(V::BYTES); - } - if cur < end { - let remaining = end.distance(cur); - debug_assert!( - remaining < self.min_haystack_len, - "remaining bytes should be smaller than the minimum haystack \ - length of {}, but there are {} bytes remaining", - self.min_haystack_len, - remaining, - ); - if remaining < needle.len() { - return None; - } - debug_assert!( - max < cur, - "after main loop, cur should have exceeded max", - ); - let overlap = cur.distance(max); - debug_assert!( - overlap > 0, - "overlap ({}) must always be non-zero", - overlap, - ); - debug_assert!( - overlap < V::BYTES, - "overlap ({}) cannot possibly be >= than a vector ({})", - overlap, - V::BYTES, - ); - // The mask has all of its bits set except for the first N least - // significant bits, where N=overlap. This way, any matches that - // occur in find_in_chunk within the overlap are automatically - // ignored. - let mask = V::Mask::all_zeros_except_least_significant(overlap); - cur = max; - let m = self.find_in_chunk(needle, cur, end, mask); - if let Some(chunki) = m { - return Some(matched(start, cur, chunki)); - } - } - None - } - - /// Searches the given haystack for offsets that represent candidate - /// matches of the `needle` given to this finder's constructor. The offsets - /// returned, if they are a match, correspond to the starting offset of - /// `needle` in the given `haystack`. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// Since this is meant to be used with vector functions, callers need to - /// specialize this inside of a function with a `target_feature` attribute. - /// Therefore, callers must ensure that whatever target feature is being - /// used supports the vector functions that this function is specialized - /// for. (For the specific vector functions used, see the Vector trait - /// implementations.) - #[inline(always)] - pub(crate) unsafe fn find_prefilter( - &self, - haystack: &[u8], - ) -> Option<usize> { - assert!( - haystack.len() >= self.min_haystack_len, - "haystack too small, should be at least {} but got {}", - self.min_haystack_len, - haystack.len(), - ); - - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - let max = end.sub(self.min_haystack_len); - let mut cur = start; - - // N.B. I did experiment with unrolling the loop to deal with size(V) - // bytes at a time and 2*size(V) bytes at a time. The double unroll - // was marginally faster while the quadruple unroll was unambiguously - // slower. In the end, I decided the complexity from unrolling wasn't - // worth it. I used the memmem/krate/prebuilt/huge-en/ benchmarks to - // compare. - while cur <= max { - if let Some(chunki) = self.find_prefilter_in_chunk(cur) { - return Some(matched(start, cur, chunki)); - } - cur = cur.add(V::BYTES); - } - if cur < end { - // This routine immediately quits if a candidate match is found. - // That means that if we're here, no candidate matches have been - // found at or before 'ptr'. Thus, we don't need to mask anything - // out even though we might technically search part of the haystack - // that we've already searched (because we know it can't match). - cur = max; - if let Some(chunki) = self.find_prefilter_in_chunk(cur) { - return Some(matched(start, cur, chunki)); - } - } - None - } - - /// Search for an occurrence of our byte pair from the needle in the chunk - /// pointed to by cur, with the end of the haystack pointed to by end. - /// When an occurrence is found, memcmp is run to check if a match occurs - /// at the corresponding position. - /// - /// `mask` should have bits set corresponding the positions in the chunk - /// in which matches are considered. This is only used for the last vector - /// load where the beginning of the vector might have overlapped with the - /// last load in the main loop. The mask lets us avoid visiting positions - /// that have already been discarded as matches. - /// - /// # Safety - /// - /// It must be safe to do an unaligned read of size(V) bytes starting at - /// both (cur + self.index1) and (cur + self.index2). It must also be safe - /// to do unaligned loads on cur up to (end - needle.len()). - #[inline(always)] - unsafe fn find_in_chunk( - &self, - needle: &[u8], - cur: *const u8, - end: *const u8, - mask: V::Mask, - ) -> Option<usize> { - let index1 = usize::from(self.pair.index1()); - let index2 = usize::from(self.pair.index2()); - let chunk1 = V::load_unaligned(cur.add(index1)); - let chunk2 = V::load_unaligned(cur.add(index2)); - let eq1 = chunk1.cmpeq(self.v1); - let eq2 = chunk2.cmpeq(self.v2); - - let mut offsets = eq1.and(eq2).movemask().and(mask); - while offsets.has_non_zero() { - let offset = offsets.first_offset(); - let cur = cur.add(offset); - if end.sub(needle.len()) < cur { - return None; - } - if is_equal_raw(needle.as_ptr(), cur, needle.len()) { - return Some(offset); - } - offsets = offsets.clear_least_significant_bit(); - } - None - } - - /// Search for an occurrence of our byte pair from the needle in the chunk - /// pointed to by cur, with the end of the haystack pointed to by end. - /// When an occurrence is found, memcmp is run to check if a match occurs - /// at the corresponding position. - /// - /// # Safety - /// - /// It must be safe to do an unaligned read of size(V) bytes starting at - /// both (cur + self.index1) and (cur + self.index2). It must also be safe - /// to do unaligned reads on cur up to (end - needle.len()). - #[inline(always)] - unsafe fn find_prefilter_in_chunk(&self, cur: *const u8) -> Option<usize> { - let index1 = usize::from(self.pair.index1()); - let index2 = usize::from(self.pair.index2()); - let chunk1 = V::load_unaligned(cur.add(index1)); - let chunk2 = V::load_unaligned(cur.add(index2)); - let eq1 = chunk1.cmpeq(self.v1); - let eq2 = chunk2.cmpeq(self.v2); - - let offsets = eq1.and(eq2).movemask(); - if !offsets.has_non_zero() { - return None; - } - Some(offsets.first_offset()) - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub(crate) fn pair(&self) -> &Pair { - &self.pair - } - - /// Returns the minimum haystack length that this `Finder` can search. - /// - /// Providing a haystack to this `Finder` shorter than this length is - /// guaranteed to result in a panic. - #[inline(always)] - pub(crate) fn min_haystack_len(&self) -> usize { - self.min_haystack_len - } -} - -/// Accepts a chunk-relative offset and returns a haystack relative offset. -/// -/// This used to be marked `#[cold]` and `#[inline(never)]`, but I couldn't -/// observe a consistent measureable difference between that and just inlining -/// it. So we go with inlining it. -/// -/// # Safety -/// -/// Same at `ptr::offset_from` in addition to `cur >= start`. -#[inline(always)] -unsafe fn matched(start: *const u8, cur: *const u8, chunki: usize) -> usize { - cur.distance(start) + chunki -} - -// If you're looking for tests, those are run for each instantiation of the -// above code. So for example, see arch::x86_64::sse2::packedpair. diff --git a/vendor/memchr/src/arch/mod.rs b/vendor/memchr/src/arch/mod.rs deleted file mode 100644 index 2f63a1a..0000000 --- a/vendor/memchr/src/arch/mod.rs +++ /dev/null @@ -1,16 +0,0 @@ -/*! -A module with low-level architecture dependent routines. - -These routines are useful as primitives for tasks not covered by the higher -level crate API. -*/ - -pub mod all; -pub(crate) mod generic; - -#[cfg(target_arch = "aarch64")] -pub mod aarch64; -#[cfg(target_arch = "wasm32")] -pub mod wasm32; -#[cfg(target_arch = "x86_64")] -pub mod x86_64; diff --git a/vendor/memchr/src/arch/wasm32/memchr.rs b/vendor/memchr/src/arch/wasm32/memchr.rs deleted file mode 100644 index b0bbd1c..0000000 --- a/vendor/memchr/src/arch/wasm32/memchr.rs +++ /dev/null @@ -1,137 +0,0 @@ -/*! -Wrapper routines for `memchr` and friends. - -These routines choose the best implementation at compile time. (This is -different from `x86_64` because it is expected that `simd128` is almost always -available for `wasm32` targets.) -*/ - -macro_rules! defraw { - ($ty:ident, $find:ident, $start:ident, $end:ident, $($needles:ident),+) => {{ - #[cfg(target_feature = "simd128")] - { - use crate::arch::wasm32::simd128::memchr::$ty; - - debug!("chose simd128 for {}", stringify!($ty)); - debug_assert!($ty::is_available()); - // SAFETY: We know that wasm memchr is always available whenever - // code is compiled for `wasm32` with the `simd128` target feature - // enabled. - $ty::new_unchecked($($needles),+).$find($start, $end) - } - #[cfg(not(target_feature = "simd128"))] - { - use crate::arch::all::memchr::$ty; - - debug!( - "no simd128 feature available, using fallback for {}", - stringify!($ty), - ); - $ty::new($($needles),+).$find($start, $end) - } - }} -} - -/// memchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(One, find_raw, start, end, n1) -} - -/// memrchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(One, rfind_raw, start, end, n1) -} - -/// memchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Two, find_raw, start, end, n1, n2) -} - -/// memrchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Two, rfind_raw, start, end, n1, n2) -} - -/// memchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::find_raw`. -#[inline(always)] -pub(crate) unsafe fn memchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Three, find_raw, start, end, n1, n2, n3) -} - -/// memrchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::rfind_raw`. -#[inline(always)] -pub(crate) unsafe fn memrchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - defraw!(Three, rfind_raw, start, end, n1, n2, n3) -} - -/// Count all matching bytes, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::count_raw`. -#[inline(always)] -pub(crate) unsafe fn count_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> usize { - defraw!(One, count_raw, start, end, n1) -} diff --git a/vendor/memchr/src/arch/wasm32/mod.rs b/vendor/memchr/src/arch/wasm32/mod.rs deleted file mode 100644 index 209f876..0000000 --- a/vendor/memchr/src/arch/wasm32/mod.rs +++ /dev/null @@ -1,7 +0,0 @@ -/*! -Vector algorithms for the `wasm32` target. -*/ - -pub mod simd128; - -pub(crate) mod memchr; diff --git a/vendor/memchr/src/arch/wasm32/simd128/memchr.rs b/vendor/memchr/src/arch/wasm32/simd128/memchr.rs deleted file mode 100644 index fa314c9..0000000 --- a/vendor/memchr/src/arch/wasm32/simd128/memchr.rs +++ /dev/null @@ -1,1020 +0,0 @@ -/*! -This module defines 128-bit vector implementations of `memchr` and friends. - -The main types in this module are [`One`], [`Two`] and [`Three`]. They are for -searching for one, two or three distinct bytes, respectively, in a haystack. -Each type also has corresponding double ended iterators. These searchers are -typically much faster than scalar routines accomplishing the same task. - -The `One` searcher also provides a [`One::count`] routine for efficiently -counting the number of times a single byte occurs in a haystack. This is -useful, for example, for counting the number of lines in a haystack. This -routine exists because it is usually faster, especially with a high match -count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its -`Iterator::count` implementation to use this routine.) - -Only one, two and three bytes are supported because three bytes is about -the point where one sees diminishing returns. Beyond this point and it's -probably (but not necessarily) better to just use a simple `[bool; 256]` array -or similar. However, it depends mightily on the specific work-load and the -expected match frequency. -*/ - -use core::arch::wasm32::v128; - -use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector}; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub struct One(generic::One<v128>); - -impl One { - /// Create a new searcher that finds occurrences of the needle byte given. - /// - /// This particular searcher is specialized to use simd128 vector - /// instructions that typically make it quite fast. - /// - /// If simd128 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle: u8) -> Option<One> { - if One::is_available() { - // SAFETY: we check that simd128 is available above. - unsafe { Some(One::new_unchecked(needle)) } - } else { - None - } - } - - /// Create a new finder specific to simd128 vectors and routines without - /// checking that simd128 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `simd128` - /// instructions in the current environment. - #[target_feature(enable = "simd128")] - #[inline] - pub unsafe fn new_unchecked(needle: u8) -> One { - One(generic::One::new(needle)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`One::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `One::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "simd128")] - { - true - } - #[cfg(not(target_feature = "simd128"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Counts all occurrences of this byte in the given haystack. - #[inline] - pub fn count(&self, haystack: &[u8]) -> usize { - // SAFETY: All of our pointers are derived directly from a borrowed - // slice, which is guaranteed to be valid. - unsafe { - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - self.count_raw(start, end) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'simd128' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'simd128' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Counts all occurrences of this byte in the given haystack represented - /// by raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize { - if start >= end { - return 0; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::count_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'simd128' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.count_raw_impl(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Execute a count using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::count_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn count_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - self.0.count_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> { - OneIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of a single byte in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`One::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`One`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct OneIter<'a, 'h> { - searcher: &'a One, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for OneIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn count(self) -> usize { - self.it.count(|s, e| { - // SAFETY: We rely on our generic iterator to return valid start - // and end pointers. - unsafe { self.searcher.count_raw(s, e) } - }) - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Two(generic::Two<v128>); - -impl Two { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use simd128 vector - /// instructions that typically make it quite fast. - /// - /// If simd128 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8) -> Option<Two> { - if Two::is_available() { - // SAFETY: we check that simd128 is available above. - unsafe { Some(Two::new_unchecked(needle1, needle2)) } - } else { - None - } - } - - /// Create a new finder specific to simd128 vectors and routines without - /// checking that simd128 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `simd128` - /// instructions in the current environment. - #[target_feature(enable = "simd128")] - #[inline] - pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two { - Two(generic::Two::new(needle1, needle2)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Two::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Two::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "simd128")] - { - true - } - #[cfg(not(target_feature = "simd128"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'simd128' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'simd128' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle bytes in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> { - TwoIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of two possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Two::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Two`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct TwoIter<'a, 'h> { - searcher: &'a Two, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for TwoIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {} - -/// Finds all occurrences of three bytes in a haystack. -/// -/// That is, this reports matches of one of three possible bytes. For example, -/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets -/// `0`, `2`, `3`, `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Three(generic::Three<v128>); - -impl Three { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use simd128 vector - /// instructions that typically make it quite fast. - /// - /// If simd128 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> { - if Three::is_available() { - // SAFETY: we check that simd128 is available above. - unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) } - } else { - None - } - } - - /// Create a new finder specific to simd128 vectors and routines without - /// checking that simd128 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `simd128` - /// instructions in the current environment. - #[target_feature(enable = "simd128")] - #[inline] - pub unsafe fn new_unchecked( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Three { - Three(generic::Three::new(needle1, needle2, needle3)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Three::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Three::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "simd128")] - { - true - } - #[cfg(not(target_feature = "simd128"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'simd128' - // routines. Also, we've checked that our haystack is big enough to run - // on the vector routine. Pointer validity is caller's responsibility. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < v128::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'simd128' - // routines. Also, we've checked that our haystack is big enough to run - // on the vector routine. Pointer validity is caller's responsibility. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::find_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of a simd128 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> { - ThreeIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of three possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Three::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Three`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct ThreeIter<'a, 'h> { - searcher: &'a Three, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for ThreeIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {} - -#[cfg(test)] -mod tests { - use super::*; - - define_memchr_quickcheck!(super); - - #[test] - fn forward_one() { - crate::tests::memchr::Runner::new(1).forward_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_one() { - crate::tests::memchr::Runner::new(1).reverse_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn count_one() { - crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).count()) - }) - } - - #[test] - fn forward_two() { - crate::tests::memchr::Runner::new(2).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_two() { - crate::tests::memchr::Runner::new(2).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn forward_three() { - crate::tests::memchr::Runner::new(3).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_three() { - crate::tests::memchr::Runner::new(3).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect()) - }, - ) - } -} diff --git a/vendor/memchr/src/arch/wasm32/simd128/mod.rs b/vendor/memchr/src/arch/wasm32/simd128/mod.rs deleted file mode 100644 index b55d1f0..0000000 --- a/vendor/memchr/src/arch/wasm32/simd128/mod.rs +++ /dev/null @@ -1,6 +0,0 @@ -/*! -Algorithms for the `wasm32` target using 128-bit vectors via simd128. -*/ - -pub mod memchr; -pub mod packedpair; diff --git a/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs b/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs deleted file mode 100644 index b629377..0000000 --- a/vendor/memchr/src/arch/wasm32/simd128/packedpair.rs +++ /dev/null @@ -1,229 +0,0 @@ -/*! -A 128-bit vector implementation of the "packed pair" SIMD algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use core::arch::wasm32::v128; - -use crate::arch::{all::packedpair::Pair, generic::packedpair}; - -/// A "packed pair" finder that uses 128-bit vector operations. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -#[derive(Clone, Copy, Debug)] -pub struct Finder(packedpair::Finder<v128>); - -impl Finder { - /// Create a new pair searcher. The searcher returned can either report - /// exact matches of `needle` or act as a prefilter and report candidate - /// positions of `needle`. - /// - /// If simd128 is unavailable in the current environment or if a [`Pair`] - /// could not be constructed from the needle given, then `None` is - /// returned. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - Finder::with_pair(needle, Pair::new(needle)?) - } - - /// Create a new "packed pair" finder using the pair of bytes given. - /// - /// This constructor permits callers to control precisely which pair of - /// bytes is used as a predicate. - /// - /// If simd128 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> { - if Finder::is_available() { - // SAFETY: we check that simd128 is available above. We are also - // guaranteed to have needle.len() > 1 because we have a valid - // Pair. - unsafe { Some(Finder::with_pair_impl(needle, pair)) } - } else { - None - } - } - - /// Create a new `Finder` specific to simd128 vectors and routines. - /// - /// # Safety - /// - /// Same as the safety for `packedpair::Finder::new`, and callers must also - /// ensure that simd128 is available. - #[target_feature(enable = "simd128")] - #[inline] - unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder { - let finder = packedpair::Finder::<v128>::new(needle, pair); - Finder(finder) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Finder::with_pair`] will - /// return a `Some` value. Similarly, when it is false, it is guaranteed - /// that `Finder::with_pair` will return a `None` value. Notice that this - /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely, - /// even when `Finder::is_available` is true, it is not guaranteed that a - /// valid [`Pair`] can be found from the needle given. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "simd128")] - { - true - } - #[cfg(not(target_feature = "simd128"))] - { - false - } - } - - /// Execute a search using wasm32 v128 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - self.find_impl(haystack, needle) - } - - /// Execute a search using wasm32 v128 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> { - self.find_prefilter_impl(haystack) - } - - /// Execute a search using wasm32 v128 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - fn find_impl(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - // SAFETY: The target feature safety obligation is automatically - // fulfilled by virtue of being a method on `Finder`, which can only be - // constructed when it is safe to call `simd128` routines. - unsafe { self.0.find(haystack, needle) } - } - - /// Execute a prefilter search using wasm32 v128 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `simd128` routines.) - #[target_feature(enable = "simd128")] - #[inline] - fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: The target feature safety obligation is automatically - // fulfilled by virtue of being a method on `Finder`, which can only be - // constructed when it is safe to call `simd128` routines. - unsafe { self.0.find_prefilter(haystack) } - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub fn pair(&self) -> &Pair { - self.0.pair() - } - - /// Returns the minimum haystack length that this `Finder` can search. - /// - /// Using a haystack with length smaller than this in a search will result - /// in a panic. The reason for this restriction is that this finder is - /// meant to be a low-level component that is part of a larger substring - /// strategy. In that sense, it avoids trying to handle all cases and - /// instead only handles the cases that it can handle very well. - #[inline] - pub fn min_haystack_len(&self) -> usize { - self.0.min_haystack_len() - } -} - -#[cfg(test)] -mod tests { - use super::*; - - fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> { - let f = Finder::new(needle)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - - define_substring_forward_quickcheck!(find); - - #[test] - fn forward_substring() { - crate::tests::substring::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair_prefilter() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find_prefilter(haystack)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } -} diff --git a/vendor/memchr/src/arch/x86_64/avx2/memchr.rs b/vendor/memchr/src/arch/x86_64/avx2/memchr.rs deleted file mode 100644 index 59f8c7f..0000000 --- a/vendor/memchr/src/arch/x86_64/avx2/memchr.rs +++ /dev/null @@ -1,1352 +0,0 @@ -/*! -This module defines 256-bit vector implementations of `memchr` and friends. - -The main types in this module are [`One`], [`Two`] and [`Three`]. They are for -searching for one, two or three distinct bytes, respectively, in a haystack. -Each type also has corresponding double ended iterators. These searchers are -typically much faster than scalar routines accomplishing the same task. - -The `One` searcher also provides a [`One::count`] routine for efficiently -counting the number of times a single byte occurs in a haystack. This is -useful, for example, for counting the number of lines in a haystack. This -routine exists because it is usually faster, especially with a high match -count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its -`Iterator::count` implementation to use this routine.) - -Only one, two and three bytes are supported because three bytes is about -the point where one sees diminishing returns. Beyond this point and it's -probably (but not necessarily) better to just use a simple `[bool; 256]` array -or similar. However, it depends mightily on the specific work-load and the -expected match frequency. -*/ - -use core::arch::x86_64::{__m128i, __m256i}; - -use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector}; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub struct One { - /// Used for haystacks less than 32 bytes. - sse2: generic::One<__m128i>, - /// Used for haystacks bigger than 32 bytes. - avx2: generic::One<__m256i>, -} - -impl One { - /// Create a new searcher that finds occurrences of the needle byte given. - /// - /// This particular searcher is specialized to use AVX2 vector instructions - /// that typically make it quite fast. (SSE2 is used for haystacks that - /// are too short to accommodate an AVX2 vector.) - /// - /// If either SSE2 or AVX2 is unavailable in the current environment, then - /// `None` is returned. - #[inline] - pub fn new(needle: u8) -> Option<One> { - if One::is_available() { - // SAFETY: we check that sse2 and avx2 are available above. - unsafe { Some(One::new_unchecked(needle)) } - } else { - None - } - } - - /// Create a new finder specific to AVX2 vectors and routines without - /// checking that either SSE2 or AVX2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute both `sse2` and - /// `avx2` instructions in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - pub unsafe fn new_unchecked(needle: u8) -> One { - One { - sse2: generic::One::new(needle), - avx2: generic::One::new(needle), - } - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`One::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `One::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(not(target_feature = "sse2"))] - { - false - } - #[cfg(target_feature = "sse2")] - { - #[cfg(target_feature = "avx2")] - { - true - } - #[cfg(not(target_feature = "avx2"))] - { - #[cfg(feature = "std")] - { - std::is_x86_feature_detected!("avx2") - } - #[cfg(not(feature = "std"))] - { - false - } - } - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Counts all occurrences of this byte in the given haystack. - #[inline] - pub fn count(&self, haystack: &[u8]) -> usize { - // SAFETY: All of our pointers are derived directly from a borrowed - // slice, which is guaranteed to be valid. - unsafe { - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - self.count_raw(start, end) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::fwd_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.find_raw_sse2(start, end) - }; - } - // SAFETY: Building a `One` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // Note that we could call `self.avx2.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `One`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless - // the caller code has the same target feature annotations. Namely, - // the common case (at time of writing) is for calling code to not - // have the `avx2` target feature enabled *at compile time*. Without - // `target_feature` on this routine, it can be inlined which will - // handle some of the short-haystack cases above without touching the - // architecture specific code. - self.find_raw_avx2(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::rev_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.rfind_raw_sse2(start, end) - }; - } - // SAFETY: Building a `One` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // See note in forward routine above for why we don't just call - // `self.avx2.rfind_raw` directly here. - self.rfind_raw_avx2(start, end) - } - - /// Counts all occurrences of this byte in the given haystack represented - /// by raw pointers. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `0` will always be returned. - #[inline] - pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize { - if start >= end { - return 0; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::count_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.count_raw_sse2(start, end) - }; - } - // SAFETY: Building a `One` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - self.count_raw_avx2(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.rfind_raw(start, end) - } - - /// Execute a count using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::count_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn count_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - self.sse2.count_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn find_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.find_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn rfind_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.rfind_raw(start, end) - } - - /// Execute a count using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::count_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn count_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - self.avx2.count_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> { - OneIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of a single byte in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`One::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`One`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct OneIter<'a, 'h> { - searcher: &'a One, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for OneIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn count(self) -> usize { - self.it.count(|s, e| { - // SAFETY: We rely on our generic iterator to return valid start - // and end pointers. - unsafe { self.searcher.count_raw(s, e) } - }) - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Two { - /// Used for haystacks less than 32 bytes. - sse2: generic::Two<__m128i>, - /// Used for haystacks bigger than 32 bytes. - avx2: generic::Two<__m256i>, -} - -impl Two { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use AVX2 vector instructions - /// that typically make it quite fast. (SSE2 is used for haystacks that - /// are too short to accommodate an AVX2 vector.) - /// - /// If either SSE2 or AVX2 is unavailable in the current environment, then - /// `None` is returned. - #[inline] - pub fn new(needle1: u8, needle2: u8) -> Option<Two> { - if Two::is_available() { - // SAFETY: we check that sse2 and avx2 are available above. - unsafe { Some(Two::new_unchecked(needle1, needle2)) } - } else { - None - } - } - - /// Create a new finder specific to AVX2 vectors and routines without - /// checking that either SSE2 or AVX2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute both `sse2` and - /// `avx2` instructions in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two { - Two { - sse2: generic::Two::new(needle1, needle2), - avx2: generic::Two::new(needle1, needle2), - } - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Two::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Two::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(not(target_feature = "sse2"))] - { - false - } - #[cfg(target_feature = "sse2")] - { - #[cfg(target_feature = "avx2")] - { - true - } - #[cfg(not(target_feature = "avx2"))] - { - #[cfg(feature = "std")] - { - std::is_x86_feature_detected!("avx2") - } - #[cfg(not(feature = "std"))] - { - false - } - } - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::fwd_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() || b == self.sse2.needle2() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.find_raw_sse2(start, end) - }; - } - // SAFETY: Building a `Two` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // Note that we could call `self.avx2.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `Two`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless - // the caller code has the same target feature annotations. Namely, - // the common case (at time of writing) is for calling code to not - // have the `avx2` target feature enabled *at compile time*. Without - // `target_feature` on this routine, it can be inlined which will - // handle some of the short-haystack cases above without touching the - // architecture specific code. - self.find_raw_avx2(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::rev_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() || b == self.sse2.needle2() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.rfind_raw_sse2(start, end) - }; - } - // SAFETY: Building a `Two` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // See note in forward routine above for why we don't just call - // `self.avx2.rfind_raw` directly here. - self.rfind_raw_avx2(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.rfind_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn find_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.find_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn rfind_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle bytes in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> { - TwoIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of two possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Two::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Two`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct TwoIter<'a, 'h> { - searcher: &'a Two, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for TwoIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {} - -/// Finds all occurrences of three bytes in a haystack. -/// -/// That is, this reports matches of one of three possible bytes. For example, -/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets -/// `0`, `2`, `3`, `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Three { - /// Used for haystacks less than 32 bytes. - sse2: generic::Three<__m128i>, - /// Used for haystacks bigger than 32 bytes. - avx2: generic::Three<__m256i>, -} - -impl Three { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use AVX2 vector instructions - /// that typically make it quite fast. (SSE2 is used for haystacks that - /// are too short to accommodate an AVX2 vector.) - /// - /// If either SSE2 or AVX2 is unavailable in the current environment, then - /// `None` is returned. - #[inline] - pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> { - if Three::is_available() { - // SAFETY: we check that sse2 and avx2 are available above. - unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) } - } else { - None - } - } - - /// Create a new finder specific to AVX2 vectors and routines without - /// checking that either SSE2 or AVX2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute both `sse2` and - /// `avx2` instructions in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - pub unsafe fn new_unchecked( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Three { - Three { - sse2: generic::Three::new(needle1, needle2, needle3), - avx2: generic::Three::new(needle1, needle2, needle3), - } - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Three::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Three::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(not(target_feature = "sse2"))] - { - false - } - #[cfg(target_feature = "sse2")] - { - #[cfg(target_feature = "avx2")] - { - true - } - #[cfg(not(target_feature = "avx2"))] - { - #[cfg(feature = "std")] - { - std::is_x86_feature_detected!("avx2") - } - #[cfg(not(feature = "std"))] - { - false - } - } - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::fwd_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() - || b == self.sse2.needle2() - || b == self.sse2.needle3() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.find_raw_sse2(start, end) - }; - } - // SAFETY: Building a `Three` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // Note that we could call `self.avx2.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `Three`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless - // the caller code has the same target feature annotations. Namely, - // the common case (at time of writing) is for calling code to not - // have the `avx2` target feature enabled *at compile time*. Without - // `target_feature` on this routine, it can be inlined which will - // handle some of the short-haystack cases above without touching the - // architecture specific code. - self.find_raw_avx2(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - let len = end.distance(start); - if len < __m256i::BYTES { - return if len < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end - // pointers. - generic::rev_byte_by_byte(start, end, |b| { - b == self.sse2.needle1() - || b == self.sse2.needle2() - || b == self.sse2.needle3() - }) - } else { - // SAFETY: We require the caller to pass valid start/end - // pointers. - self.rfind_raw_sse2(start, end) - }; - } - // SAFETY: Building a `Three` means it's safe to call both 'sse2' and - // 'avx2' routines. Also, we've checked that our haystack is big - // enough to run on the vector routine. Pointer validity is caller's - // responsibility. - // - // See note in forward routine above for why we don't just call - // `self.avx2.rfind_raw` directly here. - self.rfind_raw_avx2(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_sse2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.sse2.rfind_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn find_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.find_raw(start, end) - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an AVX2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2`/`avx2` routines.) - #[target_feature(enable = "avx2")] - #[inline] - unsafe fn rfind_raw_avx2( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.avx2.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle bytes in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> { - ThreeIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of three possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Three::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Three`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct ThreeIter<'a, 'h> { - searcher: &'a Three, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for ThreeIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {} - -#[cfg(test)] -mod tests { - use super::*; - - define_memchr_quickcheck!(super); - - #[test] - fn forward_one() { - crate::tests::memchr::Runner::new(1).forward_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_one() { - crate::tests::memchr::Runner::new(1).reverse_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn count_one() { - crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).count()) - }) - } - - #[test] - fn forward_two() { - crate::tests::memchr::Runner::new(2).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_two() { - crate::tests::memchr::Runner::new(2).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn forward_three() { - crate::tests::memchr::Runner::new(3).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_three() { - crate::tests::memchr::Runner::new(3).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect()) - }, - ) - } -} diff --git a/vendor/memchr/src/arch/x86_64/avx2/mod.rs b/vendor/memchr/src/arch/x86_64/avx2/mod.rs deleted file mode 100644 index ee4097d..0000000 --- a/vendor/memchr/src/arch/x86_64/avx2/mod.rs +++ /dev/null @@ -1,6 +0,0 @@ -/*! -Algorithms for the `x86_64` target using 256-bit vectors via AVX2. -*/ - -pub mod memchr; -pub mod packedpair; diff --git a/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs b/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs deleted file mode 100644 index efae7b6..0000000 --- a/vendor/memchr/src/arch/x86_64/avx2/packedpair.rs +++ /dev/null @@ -1,272 +0,0 @@ -/*! -A 256-bit vector implementation of the "packed pair" SIMD algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use core::arch::x86_64::{__m128i, __m256i}; - -use crate::arch::{all::packedpair::Pair, generic::packedpair}; - -/// A "packed pair" finder that uses 256-bit vector operations. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -#[derive(Clone, Copy, Debug)] -pub struct Finder { - sse2: packedpair::Finder<__m128i>, - avx2: packedpair::Finder<__m256i>, -} - -impl Finder { - /// Create a new pair searcher. The searcher returned can either report - /// exact matches of `needle` or act as a prefilter and report candidate - /// positions of `needle`. - /// - /// If AVX2 is unavailable in the current environment or if a [`Pair`] - /// could not be constructed from the needle given, then `None` is - /// returned. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - Finder::with_pair(needle, Pair::new(needle)?) - } - - /// Create a new "packed pair" finder using the pair of bytes given. - /// - /// This constructor permits callers to control precisely which pair of - /// bytes is used as a predicate. - /// - /// If AVX2 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> { - if Finder::is_available() { - // SAFETY: we check that sse2/avx2 is available above. We are also - // guaranteed to have needle.len() > 1 because we have a valid - // Pair. - unsafe { Some(Finder::with_pair_impl(needle, pair)) } - } else { - None - } - } - - /// Create a new `Finder` specific to SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as the safety for `packedpair::Finder::new`, and callers must also - /// ensure that both SSE2 and AVX2 are available. - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder { - let sse2 = packedpair::Finder::<__m128i>::new(needle, pair); - let avx2 = packedpair::Finder::<__m256i>::new(needle, pair); - Finder { sse2, avx2 } - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Finder::with_pair`] will - /// return a `Some` value. Similarly, when it is false, it is guaranteed - /// that `Finder::with_pair` will return a `None` value. Notice that this - /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely, - /// even when `Finder::is_available` is true, it is not guaranteed that a - /// valid [`Pair`] can be found from the needle given. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(not(target_feature = "sse2"))] - { - false - } - #[cfg(target_feature = "sse2")] - { - #[cfg(target_feature = "avx2")] - { - true - } - #[cfg(not(target_feature = "avx2"))] - { - #[cfg(feature = "std")] - { - std::is_x86_feature_detected!("avx2") - } - #[cfg(not(feature = "std"))] - { - false - } - } - } - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines. - unsafe { self.find_impl(haystack, needle) } - } - - /// Run this finder on the given haystack as a prefilter. - /// - /// If a candidate match is found, then an offset where the needle *could* - /// begin in the haystack is returned. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines. - unsafe { self.find_prefilter_impl(haystack) } - } - - /// Execute a search using AVX2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `sse2` and `avx2` routines.) - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - unsafe fn find_impl( - &self, - haystack: &[u8], - needle: &[u8], - ) -> Option<usize> { - if haystack.len() < self.avx2.min_haystack_len() { - self.sse2.find(haystack, needle) - } else { - self.avx2.find(haystack, needle) - } - } - - /// Execute a prefilter search using AVX2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `sse2` and `avx2` routines.) - #[target_feature(enable = "sse2", enable = "avx2")] - #[inline] - unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> { - if haystack.len() < self.avx2.min_haystack_len() { - self.sse2.find_prefilter(haystack) - } else { - self.avx2.find_prefilter(haystack) - } - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub fn pair(&self) -> &Pair { - self.avx2.pair() - } - - /// Returns the minimum haystack length that this `Finder` can search. - /// - /// Using a haystack with length smaller than this in a search will result - /// in a panic. The reason for this restriction is that this finder is - /// meant to be a low-level component that is part of a larger substring - /// strategy. In that sense, it avoids trying to handle all cases and - /// instead only handles the cases that it can handle very well. - #[inline] - pub fn min_haystack_len(&self) -> usize { - // The caller doesn't need to care about AVX2's min_haystack_len - // since this implementation will automatically switch to the SSE2 - // implementation if the haystack is too short for AVX2. Therefore, the - // caller only needs to care about SSE2's min_haystack_len. - // - // This does assume that SSE2's min_haystack_len is less than or - // equal to AVX2's min_haystack_len. In practice, this is true and - // there is no way it could be false based on how this Finder is - // implemented. Namely, both SSE2 and AVX2 use the same `Pair`. If - // they used different pairs, then it's possible (although perhaps - // pathological) for SSE2's min_haystack_len to be bigger than AVX2's. - self.sse2.min_haystack_len() - } -} - -#[cfg(test)] -mod tests { - use super::*; - - fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> { - let f = Finder::new(needle)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - - define_substring_forward_quickcheck!(find); - - #[test] - fn forward_substring() { - crate::tests::substring::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair_prefilter() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - if !cfg!(target_feature = "sse2") { - return None; - } - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find_prefilter(haystack)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } -} diff --git a/vendor/memchr/src/arch/x86_64/memchr.rs b/vendor/memchr/src/arch/x86_64/memchr.rs deleted file mode 100644 index fcb1399..0000000 --- a/vendor/memchr/src/arch/x86_64/memchr.rs +++ /dev/null @@ -1,335 +0,0 @@ -/*! -Wrapper routines for `memchr` and friends. - -These routines efficiently dispatch to the best implementation based on what -the CPU supports. -*/ - -/// Provides a way to run a memchr-like function while amortizing the cost of -/// runtime CPU feature detection. -/// -/// This works by loading a function pointer from an atomic global. Initially, -/// this global is set to a function that does CPU feature detection. For -/// example, if AVX2 is enabled, then the AVX2 implementation is used. -/// Otherwise, at least on x86_64, the SSE2 implementation is used. (And -/// in some niche cases, if SSE2 isn't available, then the architecture -/// independent fallback implementation is used.) -/// -/// After the first call to this function, the atomic global is replaced with -/// the specific AVX2, SSE2 or fallback routine chosen. Subsequent calls then -/// will directly call the chosen routine instead of needing to go through the -/// CPU feature detection branching again. -/// -/// This particular macro is specifically written to provide the implementation -/// of functions with the following signature: -/// -/// ```ignore -/// fn memchr(needle1: u8, start: *const u8, end: *const u8) -> Option<usize>; -/// ``` -/// -/// Where you can also have `memchr2` and `memchr3`, but with `needle2` and -/// `needle3`, respectively. The `start` and `end` parameters correspond to the -/// start and end of the haystack, respectively. -/// -/// We use raw pointers here instead of the more obvious `haystack: &[u8]` so -/// that the function is compatible with our lower level iterator logic that -/// operates on raw pointers. We use this macro to implement "raw" memchr -/// routines with the signature above, and then define memchr routines using -/// regular slices on top of them. -/// -/// Note that we use `#[cfg(target_feature = "sse2")]` below even though -/// it shouldn't be strictly necessary because without it, it seems to -/// cause the compiler to blow up. I guess it can't handle a function -/// pointer being created with a sse target feature? Dunno. See the -/// `build-for-x86-64-but-non-sse-target` CI job if you want to experiment with -/// this. -/// -/// # Safety -/// -/// Primarily callers must that `$fnty` is a correct function pointer type and -/// not something else. -/// -/// Callers must also ensure that `$memchrty::$memchrfind` corresponds to a -/// routine that returns a valid function pointer when a match is found. That -/// is, a pointer that is `>= start` and `< end`. -/// -/// Callers must also ensure that the `$hay_start` and `$hay_end` identifiers -/// correspond to valid pointers. -macro_rules! unsafe_ifunc { - ( - $memchrty:ident, - $memchrfind:ident, - $fnty:ty, - $retty:ty, - $hay_start:ident, - $hay_end:ident, - $($needle:ident),+ - ) => {{ - #![allow(unused_unsafe)] - - use core::sync::atomic::{AtomicPtr, Ordering}; - - type Fn = *mut (); - type RealFn = $fnty; - static FN: AtomicPtr<()> = AtomicPtr::new(detect as Fn); - - #[cfg(target_feature = "sse2")] - #[target_feature(enable = "sse2", enable = "avx2")] - unsafe fn find_avx2( - $($needle: u8),+, - $hay_start: *const u8, - $hay_end: *const u8, - ) -> $retty { - use crate::arch::x86_64::avx2::memchr::$memchrty; - $memchrty::new_unchecked($($needle),+) - .$memchrfind($hay_start, $hay_end) - } - - #[cfg(target_feature = "sse2")] - #[target_feature(enable = "sse2")] - unsafe fn find_sse2( - $($needle: u8),+, - $hay_start: *const u8, - $hay_end: *const u8, - ) -> $retty { - use crate::arch::x86_64::sse2::memchr::$memchrty; - $memchrty::new_unchecked($($needle),+) - .$memchrfind($hay_start, $hay_end) - } - - unsafe fn find_fallback( - $($needle: u8),+, - $hay_start: *const u8, - $hay_end: *const u8, - ) -> $retty { - use crate::arch::all::memchr::$memchrty; - $memchrty::new($($needle),+).$memchrfind($hay_start, $hay_end) - } - - unsafe fn detect( - $($needle: u8),+, - $hay_start: *const u8, - $hay_end: *const u8, - ) -> $retty { - let fun = { - #[cfg(not(target_feature = "sse2"))] - { - debug!( - "no sse2 feature available, using fallback for {}", - stringify!($memchrty), - ); - find_fallback as RealFn - } - #[cfg(target_feature = "sse2")] - { - use crate::arch::x86_64::{sse2, avx2}; - if avx2::memchr::$memchrty::is_available() { - debug!("chose AVX2 for {}", stringify!($memchrty)); - find_avx2 as RealFn - } else if sse2::memchr::$memchrty::is_available() { - debug!("chose SSE2 for {}", stringify!($memchrty)); - find_sse2 as RealFn - } else { - debug!("chose fallback for {}", stringify!($memchrty)); - find_fallback as RealFn - } - } - }; - FN.store(fun as Fn, Ordering::Relaxed); - // SAFETY: The only thing we need to uphold here is the - // `#[target_feature]` requirements. Since we check is_available - // above before using the corresponding implementation, we are - // guaranteed to only call code that is supported on the current - // CPU. - fun($($needle),+, $hay_start, $hay_end) - } - - // SAFETY: By virtue of the caller contract, RealFn is a function - // pointer, which is always safe to transmute with a *mut (). Also, - // since we use $memchrty::is_available, it is guaranteed to be safe - // to call $memchrty::$memchrfind. - unsafe { - let fun = FN.load(Ordering::Relaxed); - core::mem::transmute::<Fn, RealFn>(fun)( - $($needle),+, - $hay_start, - $hay_end, - ) - } - }}; -} - -// The routines below dispatch to AVX2, SSE2 or a fallback routine based on -// what's available in the current environment. The secret sauce here is that -// we only check for which one to use approximately once, and then "cache" that -// choice into a global function pointer. Subsequent invocations then just call -// the appropriate function directly. - -/// memchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::find_raw`. -#[inline(always)] -pub(crate) fn memchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - One, - find_raw, - unsafe fn(u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1 - ) -} - -/// memrchr, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::rfind_raw`. -#[inline(always)] -pub(crate) fn memrchr_raw( - n1: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - One, - rfind_raw, - unsafe fn(u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1 - ) -} - -/// memchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::find_raw`. -#[inline(always)] -pub(crate) fn memchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - Two, - find_raw, - unsafe fn(u8, u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1, - n2 - ) -} - -/// memrchr2, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Two::rfind_raw`. -#[inline(always)] -pub(crate) fn memrchr2_raw( - n1: u8, - n2: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - Two, - rfind_raw, - unsafe fn(u8, u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1, - n2 - ) -} - -/// memchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::find_raw`. -#[inline(always)] -pub(crate) fn memchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - Three, - find_raw, - unsafe fn(u8, u8, u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1, - n2, - n3 - ) -} - -/// memrchr3, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `Three::rfind_raw`. -#[inline(always)] -pub(crate) fn memrchr3_raw( - n1: u8, - n2: u8, - n3: u8, - start: *const u8, - end: *const u8, -) -> Option<*const u8> { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - Three, - rfind_raw, - unsafe fn(u8, u8, u8, *const u8, *const u8) -> Option<*const u8>, - Option<*const u8>, - start, - end, - n1, - n2, - n3 - ) -} - -/// Count all matching bytes, but using raw pointers to represent the haystack. -/// -/// # Safety -/// -/// Pointers must be valid. See `One::count_raw`. -#[inline(always)] -pub(crate) fn count_raw(n1: u8, start: *const u8, end: *const u8) -> usize { - // SAFETY: We provide a valid function pointer type. - unsafe_ifunc!( - One, - count_raw, - unsafe fn(u8, *const u8, *const u8) -> usize, - usize, - start, - end, - n1 - ) -} diff --git a/vendor/memchr/src/arch/x86_64/mod.rs b/vendor/memchr/src/arch/x86_64/mod.rs deleted file mode 100644 index 5dad721..0000000 --- a/vendor/memchr/src/arch/x86_64/mod.rs +++ /dev/null @@ -1,8 +0,0 @@ -/*! -Vector algorithms for the `x86_64` target. -*/ - -pub mod avx2; -pub mod sse2; - -pub(crate) mod memchr; diff --git a/vendor/memchr/src/arch/x86_64/sse2/memchr.rs b/vendor/memchr/src/arch/x86_64/sse2/memchr.rs deleted file mode 100644 index c6f75df..0000000 --- a/vendor/memchr/src/arch/x86_64/sse2/memchr.rs +++ /dev/null @@ -1,1077 +0,0 @@ -/*! -This module defines 128-bit vector implementations of `memchr` and friends. - -The main types in this module are [`One`], [`Two`] and [`Three`]. They are for -searching for one, two or three distinct bytes, respectively, in a haystack. -Each type also has corresponding double ended iterators. These searchers are -typically much faster than scalar routines accomplishing the same task. - -The `One` searcher also provides a [`One::count`] routine for efficiently -counting the number of times a single byte occurs in a haystack. This is -useful, for example, for counting the number of lines in a haystack. This -routine exists because it is usually faster, especially with a high match -count, then using [`One::find`] repeatedly. ([`OneIter`] specializes its -`Iterator::count` implementation to use this routine.) - -Only one, two and three bytes are supported because three bytes is about -the point where one sees diminishing returns. Beyond this point and it's -probably (but not necessarily) better to just use a simple `[bool; 256]` array -or similar. However, it depends mightily on the specific work-load and the -expected match frequency. -*/ - -use core::arch::x86_64::__m128i; - -use crate::{arch::generic::memchr as generic, ext::Pointer, vector::Vector}; - -/// Finds all occurrences of a single byte in a haystack. -#[derive(Clone, Copy, Debug)] -pub struct One(generic::One<__m128i>); - -impl One { - /// Create a new searcher that finds occurrences of the needle byte given. - /// - /// This particular searcher is specialized to use SSE2 vector instructions - /// that typically make it quite fast. - /// - /// If SSE2 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle: u8) -> Option<One> { - if One::is_available() { - // SAFETY: we check that sse2 is available above. - unsafe { Some(One::new_unchecked(needle)) } - } else { - None - } - } - - /// Create a new finder specific to SSE2 vectors and routines without - /// checking that SSE2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `sse2` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2")] - #[inline] - pub unsafe fn new_unchecked(needle: u8) -> One { - One(generic::One::new(needle)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`One::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `One::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "sse2")] - { - true - } - #[cfg(not(target_feature = "sse2"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Counts all occurrences of this byte in the given haystack. - #[inline] - pub fn count(&self, haystack: &[u8]) -> usize { - // SAFETY: All of our pointers are derived directly from a borrowed - // slice, which is guaranteed to be valid. - unsafe { - let start = haystack.as_ptr(); - let end = start.add(haystack.len()); - self.count_raw(start, end) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // Note that we could call `self.0.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `One`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless the - // caller code has the same target feature annotations. Which is maybe - // okay for SSE2, but we do the same thing for AVX2 where caller code - // probably usually doesn't have AVX2 enabled. That means that this - // routine can be inlined which will handle some of the short-haystack - // cases above without touching the architecture specific code. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // See note in forward routine above for why we don't just call - // `self.0.rfind_raw` directly here. - self.rfind_raw_impl(start, end) - } - - /// Counts all occurrences of this byte in the given haystack represented - /// by raw pointers. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `0` will always be returned. - #[inline] - pub unsafe fn count_raw(&self, start: *const u8, end: *const u8) -> usize { - if start >= end { - return 0; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::count_byte_by_byte(start, end, |b| { - b == self.0.needle1() - }); - } - // SAFETY: Building a `One` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - self.count_raw_impl(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Execute a count using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`One::count_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `One`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn count_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> usize { - self.0.count_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> OneIter<'a, 'h> { - OneIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of a single byte in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`One::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`One`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct OneIter<'a, 'h> { - searcher: &'a One, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for OneIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn count(self) -> usize { - self.it.count(|s, e| { - // SAFETY: We rely on our generic iterator to return valid start - // and end pointers. - unsafe { self.searcher.count_raw(s, e) } - }) - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for OneIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for OneIter<'a, 'h> {} - -/// Finds all occurrences of two bytes in a haystack. -/// -/// That is, this reports matches of one of two possible bytes. For example, -/// searching for `a` or `b` in `afoobar` would report matches at offsets `0`, -/// `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Two(generic::Two<__m128i>); - -impl Two { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use SSE2 vector instructions - /// that typically make it quite fast. - /// - /// If SSE2 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8) -> Option<Two> { - if Two::is_available() { - // SAFETY: we check that sse2 is available above. - unsafe { Some(Two::new_unchecked(needle1, needle2)) } - } else { - None - } - } - - /// Create a new finder specific to SSE2 vectors and routines without - /// checking that SSE2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `sse2` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2")] - #[inline] - pub unsafe fn new_unchecked(needle1: u8, needle2: u8) -> Two { - Two(generic::Two::new(needle1, needle2)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Two::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Two::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "sse2")] - { - true - } - #[cfg(not(target_feature = "sse2"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // Note that we could call `self.0.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `Two`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless the - // caller code has the same target feature annotations. Which is maybe - // okay for SSE2, but we do the same thing for AVX2 where caller code - // probably usually doesn't have AVX2 enabled. That means that this - // routine can be inlined which will handle some of the short-haystack - // cases above without touching the architecture specific code. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() || b == self.0.needle2() - }); - } - // SAFETY: Building a `Two` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // See note in forward routine above for why we don't just call - // `self.0.rfind_raw` directly here. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Two::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Two`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle bytes in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> TwoIter<'a, 'h> { - TwoIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of two possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Two::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Two`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct TwoIter<'a, 'h> { - searcher: &'a Two, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for TwoIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for TwoIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for TwoIter<'a, 'h> {} - -/// Finds all occurrences of three bytes in a haystack. -/// -/// That is, this reports matches of one of three possible bytes. For example, -/// searching for `a`, `b` or `o` in `afoobar` would report matches at offsets -/// `0`, `2`, `3`, `4` and `5`. -#[derive(Clone, Copy, Debug)] -pub struct Three(generic::Three<__m128i>); - -impl Three { - /// Create a new searcher that finds occurrences of the needle bytes given. - /// - /// This particular searcher is specialized to use SSE2 vector instructions - /// that typically make it quite fast. - /// - /// If SSE2 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn new(needle1: u8, needle2: u8, needle3: u8) -> Option<Three> { - if Three::is_available() { - // SAFETY: we check that sse2 is available above. - unsafe { Some(Three::new_unchecked(needle1, needle2, needle3)) } - } else { - None - } - } - - /// Create a new finder specific to SSE2 vectors and routines without - /// checking that SSE2 is available. - /// - /// # Safety - /// - /// Callers must guarantee that it is safe to execute `sse2` instructions - /// in the current environment. - /// - /// Note that it is a common misconception that if one compiles for an - /// `x86_64` target, then they therefore automatically have access to SSE2 - /// instructions. While this is almost always the case, it isn't true in - /// 100% of cases. - #[target_feature(enable = "sse2")] - #[inline] - pub unsafe fn new_unchecked( - needle1: u8, - needle2: u8, - needle3: u8, - ) -> Three { - Three(generic::Three::new(needle1, needle2, needle3)) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Three::new`] will return - /// a `Some` value. Similarly, when it is false, it is guaranteed that - /// `Three::new` will return a `None` value. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(target_feature = "sse2")] - { - true - } - #[cfg(not(target_feature = "sse2"))] - { - false - } - } - - /// Return the first occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn find(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `find_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.find_raw(s, e) - }) - } - } - - /// Return the last occurrence of one of the needle bytes in the given - /// haystack. If no such occurrence exists, then `None` is returned. - /// - /// The occurrence is reported as an offset into `haystack`. Its maximum - /// value is `haystack.len() - 1`. - #[inline] - pub fn rfind(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: `rfind_raw` guarantees that if a pointer is returned, it - // falls within the bounds of the start and end pointers. - unsafe { - generic::search_slice_with_raw(haystack, |s, e| { - self.rfind_raw(s, e) - }) - } - } - - /// Like `find`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn find_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::fwd_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // Note that we could call `self.0.find_raw` directly here. But that - // means we'd have to annotate this routine with `target_feature`. - // Which is fine, because this routine is `unsafe` anyway and the - // `target_feature` obligation is met by virtue of building a `Three`. - // The real problem is that a routine with a `target_feature` - // annotation generally can't be inlined into caller code unless the - // caller code has the same target feature annotations. Which is maybe - // okay for SSE2, but we do the same thing for AVX2 where caller code - // probably usually doesn't have AVX2 enabled. That means that this - // routine can be inlined which will handle some of the short-haystack - // cases above without touching the architecture specific code. - self.find_raw_impl(start, end) - } - - /// Like `rfind`, but accepts and returns raw pointers. - /// - /// When a match is found, the pointer returned is guaranteed to be - /// `>= start` and `< end`. - /// - /// This routine is useful if you're already using raw pointers and would - /// like to avoid converting back to a slice before executing a search. - /// - /// # Safety - /// - /// * Both `start` and `end` must be valid for reads. - /// * Both `start` and `end` must point to an initialized value. - /// * Both `start` and `end` must point to the same allocated object and - /// must either be in bounds or at most one byte past the end of the - /// allocated object. - /// * Both `start` and `end` must be _derived from_ a pointer to the same - /// object. - /// * The distance between `start` and `end` must not overflow `isize`. - /// * The distance being in bounds must not rely on "wrapping around" the - /// address space. - /// - /// Note that callers may pass a pair of pointers such that `start >= end`. - /// In that case, `None` will always be returned. - #[inline] - pub unsafe fn rfind_raw( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - if start >= end { - return None; - } - if end.distance(start) < __m128i::BYTES { - // SAFETY: We require the caller to pass valid start/end pointers. - return generic::rev_byte_by_byte(start, end, |b| { - b == self.0.needle1() - || b == self.0.needle2() - || b == self.0.needle3() - }); - } - // SAFETY: Building a `Three` means it's safe to call 'sse2' routines. - // Also, we've checked that our haystack is big enough to run on the - // vector routine. Pointer validity is caller's responsibility. - // - // See note in forward routine above for why we don't just call - // `self.0.rfind_raw` directly here. - self.rfind_raw_impl(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::find_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.find_raw(start, end) - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as [`Three::rfind_raw`], except the distance between `start` and - /// `end` must be at least the size of an SSE2 vector (in bytes). - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Three`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn rfind_raw_impl( - &self, - start: *const u8, - end: *const u8, - ) -> Option<*const u8> { - self.0.rfind_raw(start, end) - } - - /// Returns an iterator over all occurrences of the needle byte in the - /// given haystack. - /// - /// The iterator returned implements `DoubleEndedIterator`. This means it - /// can also be used to find occurrences in reverse order. - #[inline] - pub fn iter<'a, 'h>(&'a self, haystack: &'h [u8]) -> ThreeIter<'a, 'h> { - ThreeIter { searcher: self, it: generic::Iter::new(haystack) } - } -} - -/// An iterator over all occurrences of three possible bytes in a haystack. -/// -/// This iterator implements `DoubleEndedIterator`, which means it can also be -/// used to find occurrences in reverse order. -/// -/// This iterator is created by the [`Three::iter`] method. -/// -/// The lifetime parameters are as follows: -/// -/// * `'a` refers to the lifetime of the underlying [`Three`] searcher. -/// * `'h` refers to the lifetime of the haystack being searched. -#[derive(Clone, Debug)] -pub struct ThreeIter<'a, 'h> { - searcher: &'a Three, - it: generic::Iter<'h>, -} - -impl<'a, 'h> Iterator for ThreeIter<'a, 'h> { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'find_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next(|s, e| self.searcher.find_raw(s, e)) } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - self.it.size_hint() - } -} - -impl<'a, 'h> DoubleEndedIterator for ThreeIter<'a, 'h> { - #[inline] - fn next_back(&mut self) -> Option<usize> { - // SAFETY: We rely on the generic iterator to provide valid start - // and end pointers, but we guarantee that any pointer returned by - // 'rfind_raw' falls within the bounds of the start and end pointer. - unsafe { self.it.next_back(|s, e| self.searcher.rfind_raw(s, e)) } - } -} - -impl<'a, 'h> core::iter::FusedIterator for ThreeIter<'a, 'h> {} - -#[cfg(test)] -mod tests { - use super::*; - - define_memchr_quickcheck!(super); - - #[test] - fn forward_one() { - crate::tests::memchr::Runner::new(1).forward_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_one() { - crate::tests::memchr::Runner::new(1).reverse_iter( - |haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn count_one() { - crate::tests::memchr::Runner::new(1).count_iter(|haystack, needles| { - Some(One::new(needles[0])?.iter(haystack).count()) - }) - } - - #[test] - fn forward_two() { - crate::tests::memchr::Runner::new(2).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_two() { - crate::tests::memchr::Runner::new(2).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - Some(Two::new(n1, n2)?.iter(haystack).rev().collect()) - }, - ) - } - - #[test] - fn forward_three() { - crate::tests::memchr::Runner::new(3).forward_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).collect()) - }, - ) - } - - #[test] - fn reverse_three() { - crate::tests::memchr::Runner::new(3).reverse_iter( - |haystack, needles| { - let n1 = needles.get(0).copied()?; - let n2 = needles.get(1).copied()?; - let n3 = needles.get(2).copied()?; - Some(Three::new(n1, n2, n3)?.iter(haystack).rev().collect()) - }, - ) - } -} diff --git a/vendor/memchr/src/arch/x86_64/sse2/mod.rs b/vendor/memchr/src/arch/x86_64/sse2/mod.rs deleted file mode 100644 index bcb8307..0000000 --- a/vendor/memchr/src/arch/x86_64/sse2/mod.rs +++ /dev/null @@ -1,6 +0,0 @@ -/*! -Algorithms for the `x86_64` target using 128-bit vectors via SSE2. -*/ - -pub mod memchr; -pub mod packedpair; diff --git a/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs b/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs deleted file mode 100644 index c8b5b99..0000000 --- a/vendor/memchr/src/arch/x86_64/sse2/packedpair.rs +++ /dev/null @@ -1,232 +0,0 @@ -/*! -A 128-bit vector implementation of the "packed pair" SIMD algorithm. - -The "packed pair" algorithm is based on the [generic SIMD] algorithm. The main -difference is that it (by default) uses a background distribution of byte -frequencies to heuristically select the pair of bytes to search for. - -[generic SIMD]: http://0x80.pl/articles/simd-strfind.html#first-and-last -*/ - -use core::arch::x86_64::__m128i; - -use crate::arch::{all::packedpair::Pair, generic::packedpair}; - -/// A "packed pair" finder that uses 128-bit vector operations. -/// -/// This finder picks two bytes that it believes have high predictive power -/// for indicating an overall match of a needle. Depending on whether -/// `Finder::find` or `Finder::find_prefilter` is used, it reports offsets -/// where the needle matches or could match. In the prefilter case, candidates -/// are reported whenever the [`Pair`] of bytes given matches. -#[derive(Clone, Copy, Debug)] -pub struct Finder(packedpair::Finder<__m128i>); - -impl Finder { - /// Create a new pair searcher. The searcher returned can either report - /// exact matches of `needle` or act as a prefilter and report candidate - /// positions of `needle`. - /// - /// If SSE2 is unavailable in the current environment or if a [`Pair`] - /// could not be constructed from the needle given, then `None` is - /// returned. - #[inline] - pub fn new(needle: &[u8]) -> Option<Finder> { - Finder::with_pair(needle, Pair::new(needle)?) - } - - /// Create a new "packed pair" finder using the pair of bytes given. - /// - /// This constructor permits callers to control precisely which pair of - /// bytes is used as a predicate. - /// - /// If SSE2 is unavailable in the current environment, then `None` is - /// returned. - #[inline] - pub fn with_pair(needle: &[u8], pair: Pair) -> Option<Finder> { - if Finder::is_available() { - // SAFETY: we check that sse2 is available above. We are also - // guaranteed to have needle.len() > 1 because we have a valid - // Pair. - unsafe { Some(Finder::with_pair_impl(needle, pair)) } - } else { - None - } - } - - /// Create a new `Finder` specific to SSE2 vectors and routines. - /// - /// # Safety - /// - /// Same as the safety for `packedpair::Finder::new`, and callers must also - /// ensure that SSE2 is available. - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn with_pair_impl(needle: &[u8], pair: Pair) -> Finder { - let finder = packedpair::Finder::<__m128i>::new(needle, pair); - Finder(finder) - } - - /// Returns true when this implementation is available in the current - /// environment. - /// - /// When this is true, it is guaranteed that [`Finder::with_pair`] will - /// return a `Some` value. Similarly, when it is false, it is guaranteed - /// that `Finder::with_pair` will return a `None` value. Notice that this - /// does not guarantee that [`Finder::new`] will return a `Finder`. Namely, - /// even when `Finder::is_available` is true, it is not guaranteed that a - /// valid [`Pair`] can be found from the needle given. - /// - /// Note also that for the lifetime of a single program, if this returns - /// true then it will always return true. - #[inline] - pub fn is_available() -> bool { - #[cfg(not(target_feature = "sse2"))] - { - false - } - #[cfg(target_feature = "sse2")] - { - true - } - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find(&self, haystack: &[u8], needle: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines. - unsafe { self.find_impl(haystack, needle) } - } - - /// Run this finder on the given haystack as a prefilter. - /// - /// If a candidate match is found, then an offset where the needle *could* - /// begin in the haystack is returned. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - #[inline] - pub fn find_prefilter(&self, haystack: &[u8]) -> Option<usize> { - // SAFETY: Building a `Finder` means it's safe to call 'sse2' routines. - unsafe { self.find_prefilter_impl(haystack) } - } - - /// Execute a search using SSE2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_impl( - &self, - haystack: &[u8], - needle: &[u8], - ) -> Option<usize> { - self.0.find(haystack, needle) - } - - /// Execute a prefilter search using SSE2 vectors and routines. - /// - /// # Panics - /// - /// When `haystack.len()` is less than [`Finder::min_haystack_len`]. - /// - /// # Safety - /// - /// (The target feature safety obligation is automatically fulfilled by - /// virtue of being a method on `Finder`, which can only be constructed - /// when it is safe to call `sse2` routines.) - #[target_feature(enable = "sse2")] - #[inline] - unsafe fn find_prefilter_impl(&self, haystack: &[u8]) -> Option<usize> { - self.0.find_prefilter(haystack) - } - - /// Returns the pair of offsets (into the needle) used to check as a - /// predicate before confirming whether a needle exists at a particular - /// position. - #[inline] - pub fn pair(&self) -> &Pair { - self.0.pair() - } - - /// Returns the minimum haystack length that this `Finder` can search. - /// - /// Using a haystack with length smaller than this in a search will result - /// in a panic. The reason for this restriction is that this finder is - /// meant to be a low-level component that is part of a larger substring - /// strategy. In that sense, it avoids trying to handle all cases and - /// instead only handles the cases that it can handle very well. - #[inline] - pub fn min_haystack_len(&self) -> usize { - self.0.min_haystack_len() - } -} - -#[cfg(test)] -mod tests { - use super::*; - - fn find(haystack: &[u8], needle: &[u8]) -> Option<Option<usize>> { - let f = Finder::new(needle)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - - define_substring_forward_quickcheck!(find); - - #[test] - fn forward_substring() { - crate::tests::substring::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find(haystack, needle)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } - - #[test] - fn forward_packedpair_prefilter() { - fn find( - haystack: &[u8], - needle: &[u8], - index1: u8, - index2: u8, - ) -> Option<Option<usize>> { - let pair = Pair::with_indices(needle, index1, index2)?; - let f = Finder::with_pair(needle, pair)?; - if haystack.len() < f.min_haystack_len() { - return None; - } - Some(f.find_prefilter(haystack)) - } - crate::tests::packedpair::Runner::new().fwd(find).run() - } -} |