diff options
Diffstat (limited to 'vendor/memchr/src/tests/substring')
| -rw-r--r-- | vendor/memchr/src/tests/substring/mod.rs | 232 | ||||
| -rw-r--r-- | vendor/memchr/src/tests/substring/naive.rs | 45 | ||||
| -rw-r--r-- | vendor/memchr/src/tests/substring/prop.rs | 126 |
3 files changed, 403 insertions, 0 deletions
diff --git a/vendor/memchr/src/tests/substring/mod.rs b/vendor/memchr/src/tests/substring/mod.rs new file mode 100644 index 0000000..dd10cbd --- /dev/null +++ b/vendor/memchr/src/tests/substring/mod.rs @@ -0,0 +1,232 @@ +/*! +This module defines tests and test helpers for substring implementations. +*/ + +use alloc::{ + boxed::Box, + format, + string::{String, ToString}, +}; + +pub(crate) mod naive; +#[macro_use] +pub(crate) mod prop; + +const SEEDS: &'static [Seed] = &[ + Seed::new("", "", Some(0), Some(0)), + Seed::new("", "a", Some(0), Some(1)), + Seed::new("", "ab", Some(0), Some(2)), + Seed::new("", "abc", Some(0), Some(3)), + Seed::new("a", "", None, None), + Seed::new("a", "a", Some(0), Some(0)), + Seed::new("a", "aa", Some(0), Some(1)), + Seed::new("a", "ba", Some(1), Some(1)), + Seed::new("a", "bba", Some(2), Some(2)), + Seed::new("a", "bbba", Some(3), Some(3)), + Seed::new("a", "bbbab", Some(3), Some(3)), + Seed::new("a", "bbbabb", Some(3), Some(3)), + Seed::new("a", "bbbabbb", Some(3), Some(3)), + Seed::new("a", "bbbbbb", None, None), + Seed::new("ab", "", None, None), + Seed::new("ab", "a", None, None), + Seed::new("ab", "b", None, None), + Seed::new("ab", "ab", Some(0), Some(0)), + Seed::new("ab", "aab", Some(1), Some(1)), + Seed::new("ab", "aaab", Some(2), Some(2)), + Seed::new("ab", "abaab", Some(0), Some(3)), + Seed::new("ab", "baaab", Some(3), Some(3)), + Seed::new("ab", "acb", None, None), + Seed::new("ab", "abba", Some(0), Some(0)), + Seed::new("abc", "ab", None, None), + Seed::new("abc", "abc", Some(0), Some(0)), + Seed::new("abc", "abcz", Some(0), Some(0)), + Seed::new("abc", "abczz", Some(0), Some(0)), + Seed::new("abc", "zabc", Some(1), Some(1)), + Seed::new("abc", "zzabc", Some(2), Some(2)), + Seed::new("abc", "azbc", None, None), + Seed::new("abc", "abzc", None, None), + Seed::new("abczdef", "abczdefzzzzzzzzzzzzzzzzzzzz", Some(0), Some(0)), + Seed::new("abczdef", "zzzzzzzzzzzzzzzzzzzzabczdef", Some(20), Some(20)), + Seed::new( + "xyz", + "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaxyz", + Some(32), + Some(32), + ), + Seed::new("\u{0}\u{15}", "\u{0}\u{15}\u{15}\u{0}", Some(0), Some(0)), + Seed::new("\u{0}\u{1e}", "\u{1e}\u{0}", None, None), +]; + +/// Runs a host of substring search tests. +/// +/// This has support for "partial" substring search implementations only work +/// for a subset of needles/haystacks. For example, the "packed pair" substring +/// search implementation only works for haystacks of some minimum length based +/// of the pair of bytes selected and the size of the vector used. +pub(crate) struct Runner { + fwd: Option< + Box<dyn FnMut(&[u8], &[u8]) -> Option<Option<usize>> + 'static>, + >, + rev: Option< + Box<dyn FnMut(&[u8], &[u8]) -> Option<Option<usize>> + 'static>, + >, +} + +impl Runner { + /// Create a new test runner for forward and reverse substring search + /// implementations. + pub(crate) fn new() -> Runner { + Runner { fwd: None, rev: None } + } + + /// Run all tests. This panics on the first failure. + /// + /// If the implementation being tested returns `None` for a particular + /// haystack/needle combination, then that test is skipped. + /// + /// This runs tests on both the forward and reverse implementations given. + /// If either (or both) are missing, then tests for that implementation are + /// skipped. + pub(crate) fn run(self) { + if let Some(mut fwd) = self.fwd { + for seed in SEEDS.iter() { + for t in seed.generate() { + match fwd(t.haystack.as_bytes(), t.needle.as_bytes()) { + None => continue, + Some(result) => { + assert_eq!( + t.fwd, result, + "FORWARD, needle: {:?}, haystack: {:?}", + t.needle, t.haystack, + ); + } + } + } + } + } + if let Some(mut rev) = self.rev { + for seed in SEEDS.iter() { + for t in seed.generate() { + match rev(t.haystack.as_bytes(), t.needle.as_bytes()) { + None => continue, + Some(result) => { + assert_eq!( + t.rev, result, + "REVERSE, needle: {:?}, haystack: {:?}", + t.needle, t.haystack, + ); + } + } + } + } + } + } + + /// Set the implementation for forward substring search. + /// + /// If the closure returns `None`, then it is assumed that the given + /// test cannot be applied to the particular implementation and it is + /// skipped. For example, if a particular implementation only supports + /// needles or haystacks for some minimum length. + /// + /// If this is not set, then forward substring search is not tested. + pub(crate) fn fwd( + mut self, + search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>> + 'static, + ) -> Runner { + self.fwd = Some(Box::new(search)); + self + } + + /// Set the implementation for reverse substring search. + /// + /// If the closure returns `None`, then it is assumed that the given + /// test cannot be applied to the particular implementation and it is + /// skipped. For example, if a particular implementation only supports + /// needles or haystacks for some minimum length. + /// + /// If this is not set, then reverse substring search is not tested. + pub(crate) fn rev( + mut self, + search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>> + 'static, + ) -> Runner { + self.rev = Some(Box::new(search)); + self + } +} + +/// A single substring test for forward and reverse searches. +#[derive(Clone, Debug)] +struct Test { + needle: String, + haystack: String, + fwd: Option<usize>, + rev: Option<usize>, +} + +/// A single substring test for forward and reverse searches. +/// +/// Each seed is valid on its own, but it also serves as a starting point +/// to generate more tests. Namely, we pad out the haystacks with other +/// characters so that we get more complete coverage. This is especially useful +/// for testing vector algorithms that tend to have weird special cases for +/// alignment and loop unrolling. +/// +/// Padding works by assuming certain characters never otherwise appear in a +/// needle or a haystack. Neither should contain a `#` character. +#[derive(Clone, Copy, Debug)] +struct Seed { + needle: &'static str, + haystack: &'static str, + fwd: Option<usize>, + rev: Option<usize>, +} + +impl Seed { + const MAX_PAD: usize = 34; + + const fn new( + needle: &'static str, + haystack: &'static str, + fwd: Option<usize>, + rev: Option<usize>, + ) -> Seed { + Seed { needle, haystack, fwd, rev } + } + + fn generate(self) -> impl Iterator<Item = Test> { + assert!(!self.needle.contains('#'), "needle must not contain '#'"); + assert!(!self.haystack.contains('#'), "haystack must not contain '#'"); + (0..=Seed::MAX_PAD) + // Generate tests for padding at the beginning of haystack. + .map(move |pad| { + let needle = self.needle.to_string(); + let prefix = "#".repeat(pad); + let haystack = format!("{}{}", prefix, self.haystack); + let fwd = if needle.is_empty() { + Some(0) + } else { + self.fwd.map(|i| pad + i) + }; + let rev = if needle.is_empty() { + Some(haystack.len()) + } else { + self.rev.map(|i| pad + i) + }; + Test { needle, haystack, fwd, rev } + }) + // Generate tests for padding at the end of haystack. + .chain((1..=Seed::MAX_PAD).map(move |pad| { + let needle = self.needle.to_string(); + let suffix = "#".repeat(pad); + let haystack = format!("{}{}", self.haystack, suffix); + let fwd = if needle.is_empty() { Some(0) } else { self.fwd }; + let rev = if needle.is_empty() { + Some(haystack.len()) + } else { + self.rev + }; + Test { needle, haystack, fwd, rev } + })) + } +} diff --git a/vendor/memchr/src/tests/substring/naive.rs b/vendor/memchr/src/tests/substring/naive.rs new file mode 100644 index 0000000..1bc6009 --- /dev/null +++ b/vendor/memchr/src/tests/substring/naive.rs @@ -0,0 +1,45 @@ +/*! +This module defines "naive" implementations of substring search. + +These are sometimes useful to compare with "real" substring implementations. +The idea is that they are so simple that they are unlikely to be incorrect. +*/ + +/// Naively search forwards for the given needle in the given haystack. +pub(crate) fn find(haystack: &[u8], needle: &[u8]) -> Option<usize> { + let end = haystack.len().checked_sub(needle.len()).map_or(0, |i| i + 1); + for i in 0..end { + if needle == &haystack[i..i + needle.len()] { + return Some(i); + } + } + None +} + +/// Naively search in reverse for the given needle in the given haystack. +pub(crate) fn rfind(haystack: &[u8], needle: &[u8]) -> Option<usize> { + let end = haystack.len().checked_sub(needle.len()).map_or(0, |i| i + 1); + for i in (0..end).rev() { + if needle == &haystack[i..i + needle.len()] { + return Some(i); + } + } + None +} + +#[cfg(test)] +mod tests { + use crate::tests::substring; + + use super::*; + + #[test] + fn forward() { + substring::Runner::new().fwd(|h, n| Some(find(h, n))).run() + } + + #[test] + fn reverse() { + substring::Runner::new().rev(|h, n| Some(rfind(h, n))).run() + } +} diff --git a/vendor/memchr/src/tests/substring/prop.rs b/vendor/memchr/src/tests/substring/prop.rs new file mode 100644 index 0000000..a8352ec --- /dev/null +++ b/vendor/memchr/src/tests/substring/prop.rs @@ -0,0 +1,126 @@ +/*! +This module defines a few quickcheck properties for substring search. + +It also provides a forward and reverse macro for conveniently defining +quickcheck tests that run these properties over any substring search +implementation. +*/ + +use crate::tests::substring::naive; + +/// $fwd is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the +/// routine returns `None`, then it's skipped, which is useful for substring +/// implementations that don't work for all inputs. +#[macro_export] +macro_rules! define_substring_forward_quickcheck { + ($fwd:expr) => { + #[cfg(not(miri))] + quickcheck::quickcheck! { + fn qc_fwd_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool { + crate::tests::substring::prop::prefix_is_substring(&bs, $fwd) + } + + fn qc_fwd_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool { + crate::tests::substring::prop::suffix_is_substring(&bs, $fwd) + } + + fn qc_fwd_matches_naive( + haystack: alloc::vec::Vec<u8>, + needle: alloc::vec::Vec<u8> + ) -> bool { + crate::tests::substring::prop::same_as_naive( + false, + &haystack, + &needle, + $fwd, + ) + } + } + }; +} + +/// $rev is a `impl FnMut(haystack, needle) -> Option<Option<usize>>`. When the +/// routine returns `None`, then it's skipped, which is useful for substring +/// implementations that don't work for all inputs. +#[macro_export] +macro_rules! define_substring_reverse_quickcheck { + ($rev:expr) => { + #[cfg(not(miri))] + quickcheck::quickcheck! { + fn qc_rev_prefix_is_substring(bs: alloc::vec::Vec<u8>) -> bool { + crate::tests::substring::prop::prefix_is_substring(&bs, $rev) + } + + fn qc_rev_suffix_is_substring(bs: alloc::vec::Vec<u8>) -> bool { + crate::tests::substring::prop::suffix_is_substring(&bs, $rev) + } + + fn qc_rev_matches_naive( + haystack: alloc::vec::Vec<u8>, + needle: alloc::vec::Vec<u8> + ) -> bool { + crate::tests::substring::prop::same_as_naive( + true, + &haystack, + &needle, + $rev, + ) + } + } + }; +} + +/// Check that every prefix of the given byte string is a substring. +pub(crate) fn prefix_is_substring( + bs: &[u8], + mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>, +) -> bool { + for i in 0..bs.len().saturating_sub(1) { + let prefix = &bs[..i]; + let result = match search(bs, prefix) { + None => continue, + Some(result) => result, + }; + if !result.is_some() { + return false; + } + } + true +} + +/// Check that every suffix of the given byte string is a substring. +pub(crate) fn suffix_is_substring( + bs: &[u8], + mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>, +) -> bool { + for i in 0..bs.len().saturating_sub(1) { + let suffix = &bs[i..]; + let result = match search(bs, suffix) { + None => continue, + Some(result) => result, + }; + if !result.is_some() { + return false; + } + } + true +} + +/// Check that naive substring search matches the result of the given search +/// algorithm. +pub(crate) fn same_as_naive( + reverse: bool, + haystack: &[u8], + needle: &[u8], + mut search: impl FnMut(&[u8], &[u8]) -> Option<Option<usize>>, +) -> bool { + let result = match search(haystack, needle) { + None => return true, + Some(result) => result, + }; + if reverse { + result == naive::rfind(haystack, needle) + } else { + result == naive::find(haystack, needle) + } +} |