Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

3 files changed, 675 insertions, 0 deletions

diff --git a/vendor/rayon/src/iter/collect/consumer.rs b/vendor/rayon/src/iter/collect/consumer.rs
new file mode 100644
index 0000000..acd67df
--- /dev/null
+++ b/vendor/rayon/src/iter/collect/consumer.rs
@@ -0,0 +1,186 @@
+use super::super::plumbing::*;
+use crate::SendPtr;
+use std::marker::PhantomData;
+use std::ptr;
+use std::slice;
+
+pub(super) struct CollectConsumer<'c, T: Send> {
+    /// See `CollectResult` for explanation of why this is not a slice
+    start: SendPtr<T>,
+    len: usize,
+    marker: PhantomData<&'c mut T>,
+}
+
+impl<T: Send> CollectConsumer<'_, T> {
+    /// Create a collector for `len` items in the unused capacity of the vector.
+    pub(super) fn appender(vec: &mut Vec<T>, len: usize) -> CollectConsumer<'_, T> {
+        let start = vec.len();
+        assert!(vec.capacity() - start >= len);
+
+        // SAFETY: We already made sure to have the additional space allocated.
+        // The pointer is derived from `Vec` directly, not through a `Deref`,
+        // so it has provenance over the whole allocation.
+        unsafe { CollectConsumer::new(vec.as_mut_ptr().add(start), len) }
+    }
+}
+
+impl<'c, T: Send + 'c> CollectConsumer<'c, T> {
+    /// The target memory is considered uninitialized, and will be
+    /// overwritten without reading or dropping existing values.
+    unsafe fn new(start: *mut T, len: usize) -> Self {
+        CollectConsumer {
+            start: SendPtr(start),
+            len,
+            marker: PhantomData,
+        }
+    }
+}
+
+/// CollectResult represents an initialized part of the target slice.
+///
+/// This is a proxy owner of the elements in the slice; when it drops,
+/// the elements will be dropped, unless its ownership is released before then.
+#[must_use]
+pub(super) struct CollectResult<'c, T> {
+    /// This pointer and length has the same representation as a slice,
+    /// but retains the provenance of the entire array so that we can merge
+    /// these regions together in `CollectReducer`.
+    start: SendPtr<T>,
+    total_len: usize,
+    /// The current initialized length after `start`
+    initialized_len: usize,
+    /// Lifetime invariance guarantees that the data flows from consumer to result,
+    /// especially for the `scope_fn` callback in `Collect::with_consumer`.
+    invariant_lifetime: PhantomData<&'c mut &'c mut [T]>,
+}
+
+unsafe impl<'c, T> Send for CollectResult<'c, T> where T: Send {}
+
+impl<'c, T> CollectResult<'c, T> {
+    /// The current length of the collect result
+    pub(super) fn len(&self) -> usize {
+        self.initialized_len
+    }
+
+    /// Release ownership of the slice of elements, and return the length
+    pub(super) fn release_ownership(mut self) -> usize {
+        let ret = self.initialized_len;
+        self.initialized_len = 0;
+        ret
+    }
+}
+
+impl<'c, T> Drop for CollectResult<'c, T> {
+    fn drop(&mut self) {
+        // Drop the first `self.initialized_len` elements, which have been recorded
+        // to be initialized by the folder.
+        unsafe {
+            ptr::drop_in_place(slice::from_raw_parts_mut(
+                self.start.0,
+                self.initialized_len,
+            ));
+        }
+    }
+}
+
+impl<'c, T: Send + 'c> Consumer<T> for CollectConsumer<'c, T> {
+    type Folder = CollectResult<'c, T>;
+    type Reducer = CollectReducer;
+    type Result = CollectResult<'c, T>;
+
+    fn split_at(self, index: usize) -> (Self, Self, CollectReducer) {
+        let CollectConsumer { start, len, .. } = self;
+
+        // Produce new consumers.
+        // SAFETY: This assert checks that `index` is a valid offset for `start`
+        unsafe {
+            assert!(index <= len);
+            (
+                CollectConsumer::new(start.0, index),
+                CollectConsumer::new(start.0.add(index), len - index),
+                CollectReducer,
+            )
+        }
+    }
+
+    fn into_folder(self) -> Self::Folder {
+        // Create a result/folder that consumes values and writes them
+        // into the region after start. The initial result has length 0.
+        CollectResult {
+            start: self.start,
+            total_len: self.len,
+            initialized_len: 0,
+            invariant_lifetime: PhantomData,
+        }
+    }
+
+    fn full(&self) -> bool {
+        false
+    }
+}
+
+impl<'c, T: Send + 'c> Folder<T> for CollectResult<'c, T> {
+    type Result = Self;
+
+    fn consume(mut self, item: T) -> Self {
+        assert!(
+            self.initialized_len < self.total_len,
+            "too many values pushed to consumer"
+        );
+
+        // SAFETY: The assert above is a bounds check for this write, and we
+        // avoid assignment here so we do not drop an uninitialized T.
+        unsafe {
+            // Write item and increase the initialized length
+            self.start.0.add(self.initialized_len).write(item);
+            self.initialized_len += 1;
+        }
+
+        self
+    }
+
+    fn complete(self) -> Self::Result {
+        // NB: We don't explicitly check that the local writes were complete,
+        // but Collect will assert the total result length in the end.
+        self
+    }
+
+    fn full(&self) -> bool {
+        false
+    }
+}
+
+/// Pretend to be unindexed for `special_collect_into_vec`,
+/// but we should never actually get used that way...
+impl<'c, T: Send + 'c> UnindexedConsumer<T> for CollectConsumer<'c, T> {
+    fn split_off_left(&self) -> Self {
+        unreachable!("CollectConsumer must be indexed!")
+    }
+    fn to_reducer(&self) -> Self::Reducer {
+        CollectReducer
+    }
+}
+
+/// CollectReducer combines adjacent chunks; the result must always
+/// be contiguous so that it is one combined slice.
+pub(super) struct CollectReducer;
+
+impl<'c, T> Reducer<CollectResult<'c, T>> for CollectReducer {
+    fn reduce(
+        self,
+        mut left: CollectResult<'c, T>,
+        right: CollectResult<'c, T>,
+    ) -> CollectResult<'c, T> {
+        // Merge if the CollectResults are adjacent and in left to right order
+        // else: drop the right piece now and total length will end up short in the end,
+        // when the correctness of the collected result is asserted.
+        unsafe {
+            let left_end = left.start.0.add(left.initialized_len);
+            if left_end == right.start.0 {
+                left.total_len += right.total_len;
+                left.initialized_len += right.release_ownership();
+            }
+            left
+        }
+    }
+}
diff --git a/vendor/rayon/src/iter/collect/mod.rs b/vendor/rayon/src/iter/collect/mod.rs
new file mode 100644
index 0000000..4044a68
--- /dev/null
+++ b/vendor/rayon/src/iter/collect/mod.rs
@@ -0,0 +1,116 @@
+use super::{IndexedParallelIterator, ParallelIterator};
+
+mod consumer;
+use self::consumer::CollectConsumer;
+use self::consumer::CollectResult;
+use super::unzip::unzip_indexed;
+
+mod test;
+
+/// Collects the results of the exact iterator into the specified vector.
+///
+/// This is called by `IndexedParallelIterator::collect_into_vec`.
+pub(super) fn collect_into_vec<I, T>(pi: I, v: &mut Vec<T>)
+where
+    I: IndexedParallelIterator<Item = T>,
+    T: Send,
+{
+    v.truncate(0); // clear any old data
+    let len = pi.len();
+    collect_with_consumer(v, len, |consumer| pi.drive(consumer));
+}
+
+/// Collects the results of the iterator into the specified vector.
+///
+/// Technically, this only works for `IndexedParallelIterator`, but we're faking a
+/// bit of specialization here until Rust can do that natively.  Callers are
+/// using `opt_len` to find the length before calling this, and only exact
+/// iterators will return anything but `None` there.
+///
+/// Since the type system doesn't understand that contract, we have to allow
+/// *any* `ParallelIterator` here, and `CollectConsumer` has to also implement
+/// `UnindexedConsumer`.  That implementation panics `unreachable!` in case
+/// there's a bug where we actually do try to use this unindexed.
+pub(super) fn special_extend<I, T>(pi: I, len: usize, v: &mut Vec<T>)
+where
+    I: ParallelIterator<Item = T>,
+    T: Send,
+{
+    collect_with_consumer(v, len, |consumer| pi.drive_unindexed(consumer));
+}
+
+/// Unzips the results of the exact iterator into the specified vectors.
+///
+/// This is called by `IndexedParallelIterator::unzip_into_vecs`.
+pub(super) fn unzip_into_vecs<I, A, B>(pi: I, left: &mut Vec<A>, right: &mut Vec<B>)
+where
+    I: IndexedParallelIterator<Item = (A, B)>,
+    A: Send,
+    B: Send,
+{
+    // clear any old data
+    left.truncate(0);
+    right.truncate(0);
+
+    let len = pi.len();
+    collect_with_consumer(right, len, |right_consumer| {
+        let mut right_result = None;
+        collect_with_consumer(left, len, |left_consumer| {
+            let (left_r, right_r) = unzip_indexed(pi, left_consumer, right_consumer);
+            right_result = Some(right_r);
+            left_r
+        });
+        right_result.unwrap()
+    });
+}
+
+/// Create a consumer on the slice of memory we are collecting into.
+///
+/// The consumer needs to be used inside the scope function, and the
+/// complete collect result passed back.
+///
+/// This method will verify the collect result, and panic if the slice
+/// was not fully written into. Otherwise, in the successful case,
+/// the vector is complete with the collected result.
+fn collect_with_consumer<T, F>(vec: &mut Vec<T>, len: usize, scope_fn: F)
+where
+    T: Send,
+    F: FnOnce(CollectConsumer<'_, T>) -> CollectResult<'_, T>,
+{
+    // Reserve space for `len` more elements in the vector,
+    vec.reserve(len);
+
+    // Create the consumer and run the callback for collection.
+    let result = scope_fn(CollectConsumer::appender(vec, len));
+
+    // The `CollectResult` represents a contiguous part of the slice, that has
+    // been written to. On unwind here, the `CollectResult` will be dropped. If
+    // some producers on the way did not produce enough elements, partial
+    // `CollectResult`s may have been dropped without being reduced to the final
+    // result, and we will see that as the length coming up short.
+    //
+    // Here, we assert that added length is fully initialized. This is checked
+    // by the following assert, which verifies if a complete `CollectResult`
+    // was produced; if the length is correct, it is necessarily covering the
+    // target slice. Since we know that the consumer cannot have escaped from
+    // `drive` (by parametricity, essentially), we know that any stores that
+    // will happen, have happened. Unless some code is buggy, that means we
+    // should have seen `len` total writes.
+    let actual_writes = result.len();
+    assert!(
+        actual_writes == len,
+        "expected {} total writes, but got {}",
+        len,
+        actual_writes
+    );
+
+    // Release the result's mutable borrow and "proxy ownership"
+    // of the elements, before the vector takes it over.
+    result.release_ownership();
+
+    let new_len = vec.len() + len;
+
+    unsafe {
+        vec.set_len(new_len);
+    }
+}
diff --git a/vendor/rayon/src/iter/collect/test.rs b/vendor/rayon/src/iter/collect/test.rs
new file mode 100644
index 0000000..97bec3f
--- /dev/null
+++ b/vendor/rayon/src/iter/collect/test.rs
@@ -0,0 +1,373 @@
+#![cfg(test)]
+#![allow(unused_assignments)]
+
+// These tests are primarily targeting "abusive" producers that will
+// try to drive the "collect consumer" incorrectly. These should
+// result in panics.
+
+use super::collect_with_consumer;
+use crate::iter::plumbing::*;
+use rayon_core::join;
+
+use std::fmt;
+use std::panic;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::thread::Result as ThreadResult;
+
+/// Promises to produce 2 items, but then produces 3.  Does not do any
+/// splits at all.
+#[test]
+#[should_panic(expected = "too many values")]
+fn produce_too_many_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 2, |consumer| {
+        let mut folder = consumer.into_folder();
+        folder = folder.consume(22);
+        folder = folder.consume(23);
+        folder = folder.consume(24);
+        unreachable!("folder does not complete")
+    });
+}
+
+/// Produces fewer items than promised. Does not do any
+/// splits at all.
+#[test]
+#[should_panic(expected = "expected 5 total writes, but got 2")]
+fn produce_fewer_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 5, |consumer| {
+        let mut folder = consumer.into_folder();
+        folder = folder.consume(22);
+        folder = folder.consume(23);
+        folder.complete()
+    });
+}
+
+// Complete is not called by the consumer. Hence,the collection vector is not fully initialized.
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 2")]
+fn left_produces_items_with_no_complete() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3);
+        right_folder.complete()
+    });
+}
+
+// Complete is not called by the right consumer. Hence,the
+// collection vector is not fully initialized.
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 2")]
+fn right_produces_items_with_no_complete() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3);
+        left_folder.complete()
+    });
+}
+
+// Complete is not called by the consumer. Hence,the collection vector is not fully initialized.
+#[test]
+#[cfg_attr(not(panic = "unwind"), ignore)]
+fn produces_items_with_no_complete() {
+    let counter = DropCounter::default();
+    let mut v = vec![];
+    let panic_result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        collect_with_consumer(&mut v, 2, |consumer| {
+            let mut folder = consumer.into_folder();
+            folder = folder.consume(counter.element());
+            folder = folder.consume(counter.element());
+            panic!("folder does not complete");
+        });
+    }));
+    assert!(v.is_empty());
+    assert_is_panic_with_message(&panic_result, "folder does not complete");
+    counter.assert_drop_count();
+}
+
+// The left consumer produces too many items while the right
+// consumer produces correct number.
+#[test]
+#[should_panic(expected = "too many values")]
+fn left_produces_too_many_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1).consume(2);
+        right_folder = right_folder.consume(2).consume(3);
+        let _ = right_folder.complete();
+        unreachable!("folder does not complete");
+    });
+}
+
+// The right consumer produces too many items while the left
+// consumer produces correct number.
+#[test]
+#[should_panic(expected = "too many values")]
+fn right_produces_too_many_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3).consume(4);
+        let _ = left_folder.complete();
+        unreachable!("folder does not complete");
+    });
+}
+
+// The left consumer produces fewer items while the right
+// consumer produces correct number.
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 1")]
+fn left_produces_fewer_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let reducer = consumer.to_reducer();
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0);
+        right_folder = right_folder.consume(2).consume(3);
+        let left_result = left_folder.complete();
+        let right_result = right_folder.complete();
+        reducer.reduce(left_result, right_result)
+    });
+}
+
+// The left and right consumer produce the correct number but
+// only left result is returned
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 2")]
+fn only_left_result() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3);
+        let left_result = left_folder.complete();
+        let _ = right_folder.complete();
+        left_result
+    });
+}
+
+// The left and right consumer produce the correct number but
+// only right result is returned
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 2")]
+fn only_right_result() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3);
+        let _ = left_folder.complete();
+        right_folder.complete()
+    });
+}
+
+// The left and right consumer produce the correct number but reduce
+// in the wrong order.
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 2")]
+fn reducer_does_not_preserve_order() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let reducer = consumer.to_reducer();
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2).consume(3);
+        let left_result = left_folder.complete();
+        let right_result = right_folder.complete();
+        reducer.reduce(right_result, left_result)
+    });
+}
+
+// The right consumer produces fewer items while the left
+// consumer produces correct number.
+#[test]
+#[should_panic(expected = "expected 4 total writes, but got 3")]
+fn right_produces_fewer_items() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let reducer = consumer.to_reducer();
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let mut left_folder = left_consumer.into_folder();
+        let mut right_folder = right_consumer.into_folder();
+        left_folder = left_folder.consume(0).consume(1);
+        right_folder = right_folder.consume(2);
+        let left_result = left_folder.complete();
+        let right_result = right_folder.complete();
+        reducer.reduce(left_result, right_result)
+    });
+}
+
+// The left consumer panics and the right stops short, like `panic_fuse()`.
+// We should get the left panic without finishing `collect_with_consumer`.
+#[test]
+#[should_panic(expected = "left consumer panic")]
+fn left_panics() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let reducer = consumer.to_reducer();
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let (left_result, right_result) = join(
+            || {
+                let mut left_folder = left_consumer.into_folder();
+                left_folder = left_folder.consume(0);
+                panic!("left consumer panic");
+            },
+            || {
+                let mut right_folder = right_consumer.into_folder();
+                right_folder = right_folder.consume(2);
+                right_folder.complete() // early return
+            },
+        );
+        reducer.reduce(left_result, right_result)
+    });
+    unreachable!();
+}
+
+// The right consumer panics and the left stops short, like `panic_fuse()`.
+// We should get the right panic without finishing `collect_with_consumer`.
+#[test]
+#[should_panic(expected = "right consumer panic")]
+fn right_panics() {
+    let mut v = vec![];
+    collect_with_consumer(&mut v, 4, |consumer| {
+        let reducer = consumer.to_reducer();
+        let (left_consumer, right_consumer, _) = consumer.split_at(2);
+        let (left_result, right_result) = join(
+            || {
+                let mut left_folder = left_consumer.into_folder();
+                left_folder = left_folder.consume(0);
+                left_folder.complete() // early return
+            },
+            || {
+                let mut right_folder = right_consumer.into_folder();
+                right_folder = right_folder.consume(2);
+                panic!("right consumer panic");
+            },
+        );
+        reducer.reduce(left_result, right_result)
+    });
+    unreachable!();
+}
+
+// The left consumer produces fewer items while the right
+// consumer produces correct number; check that created elements are dropped
+#[test]
+#[cfg_attr(not(panic = "unwind"), ignore)]
+fn left_produces_fewer_items_drops() {
+    let counter = DropCounter::default();
+    let mut v = vec![];
+    let panic_result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        collect_with_consumer(&mut v, 4, |consumer| {
+            let reducer = consumer.to_reducer();
+            let (left_consumer, right_consumer, _) = consumer.split_at(2);
+            let mut left_folder = left_consumer.into_folder();
+            let mut right_folder = right_consumer.into_folder();
+            left_folder = left_folder.consume(counter.element());
+            right_folder = right_folder
+                .consume(counter.element())
+                .consume(counter.element());
+            let left_result = left_folder.complete();
+            let right_result = right_folder.complete();
+            reducer.reduce(left_result, right_result)
+        });
+    }));
+    assert!(v.is_empty());
+    assert_is_panic_with_message(&panic_result, "expected 4 total writes, but got 1");
+    counter.assert_drop_count();
+}
+
+/// This counter can create elements, and then count and verify
+/// the number of which have actually been dropped again.
+#[derive(Default)]
+struct DropCounter {
+    created: AtomicUsize,
+    dropped: AtomicUsize,
+}
+
+struct Element<'a>(&'a AtomicUsize);
+
+impl DropCounter {
+    fn created(&self) -> usize {
+        self.created.load(Ordering::SeqCst)
+    }
+
+    fn dropped(&self) -> usize {
+        self.dropped.load(Ordering::SeqCst)
+    }
+
+    fn element(&self) -> Element<'_> {
+        self.created.fetch_add(1, Ordering::SeqCst);
+        Element(&self.dropped)
+    }
+
+    fn assert_drop_count(&self) {
+        assert_eq!(
+            self.created(),
+            self.dropped(),
+            "Expected {} dropped elements, but found {}",
+            self.created(),
+            self.dropped()
+        );
+    }
+}
+
+impl<'a> Drop for Element<'a> {
+    fn drop(&mut self) {
+        self.0.fetch_add(1, Ordering::SeqCst);
+    }
+}
+
+/// Assert that the result from catch_unwind is a panic that contains expected message
+fn assert_is_panic_with_message<T>(result: &ThreadResult<T>, expected: &str)
+where
+    T: fmt::Debug,
+{
+    match result {
+        Ok(value) => {
+            panic!(
+                "assertion failure: Expected panic, got successful {:?}",
+                value
+            );
+        }
+        Err(error) => {
+            let message_str = error.downcast_ref::<&'static str>().cloned();
+            let message_string = error.downcast_ref::<String>().map(String::as_str);
+            if let Some(message) = message_str.or(message_string) {
+                if !message.contains(expected) {
+                    panic!(
+                        "assertion failure: Expected {:?}, but found panic with {:?}",
+                        expected, message
+                    );
+                }
+            // assertion passes
+            } else {
+                panic!(
+                    "assertion failure: Expected {:?}, but found panic with unknown value",
+                    expected
+                );
+            }
+        }
+    }
+}