Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 236 insertions, 0 deletions

diff --git a/third_party/rust/rayon/src/iter/fold_chunks.rs b/third_party/rust/rayon/src/iter/fold_chunks.rs
new file mode 100644
index 0000000000..185fb1a65d
--- /dev/null
+++ b/third_party/rust/rayon/src/iter/fold_chunks.rs
@@ -0,0 +1,236 @@
+use std::fmt::{self, Debug};
+
+use super::chunks::ChunkProducer;
+use super::plumbing::*;
+use super::*;
+use crate::math::div_round_up;
+
+/// `FoldChunks` is an iterator that groups elements of an underlying iterator and applies a
+/// function over them, producing a single value for each group.
+///
+/// This struct is created by the [`fold_chunks()`] method on [`IndexedParallelIterator`]
+///
+/// [`fold_chunks()`]: trait.IndexedParallelIterator.html#method.fold_chunks
+/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Clone)]
+pub struct FoldChunks<I, ID, F>
+where
+    I: IndexedParallelIterator,
+{
+    base: I,
+    chunk_size: usize,
+    fold_op: F,
+    identity: ID,
+}
+
+impl<I: IndexedParallelIterator + Debug, ID, F> Debug for FoldChunks<I, ID, F> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Fold")
+            .field("base", &self.base)
+            .field("chunk_size", &self.chunk_size)
+            .finish()
+    }
+}
+
+impl<I, ID, U, F> FoldChunks<I, ID, F>
+where
+    I: IndexedParallelIterator,
+    ID: Fn() -> U + Send + Sync,
+    F: Fn(U, I::Item) -> U + Send + Sync,
+    U: Send,
+{
+    /// Creates a new `FoldChunks` iterator
+    pub(super) fn new(base: I, chunk_size: usize, identity: ID, fold_op: F) -> Self {
+        FoldChunks {
+            base,
+            chunk_size,
+            identity,
+            fold_op,
+        }
+    }
+}
+
+impl<I, ID, U, F> ParallelIterator for FoldChunks<I, ID, F>
+where
+    I: IndexedParallelIterator,
+    ID: Fn() -> U + Send + Sync,
+    F: Fn(U, I::Item) -> U + Send + Sync,
+    U: Send,
+{
+    type Item = U;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<U>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        Some(self.len())
+    }
+}
+
+impl<I, ID, U, F> IndexedParallelIterator for FoldChunks<I, ID, F>
+where
+    I: IndexedParallelIterator,
+    ID: Fn() -> U + Send + Sync,
+    F: Fn(U, I::Item) -> U + Send + Sync,
+    U: Send,
+{
+    fn len(&self) -> usize {
+        div_round_up(self.base.len(), self.chunk_size)
+    }
+
+    fn drive<C>(self, consumer: C) -> C::Result
+    where
+        C: Consumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn with_producer<CB>(self, callback: CB) -> CB::Output
+    where
+        CB: ProducerCallback<Self::Item>,
+    {
+        let len = self.base.len();
+        return self.base.with_producer(Callback {
+            chunk_size: self.chunk_size,
+            len,
+            identity: self.identity,
+            fold_op: self.fold_op,
+            callback,
+        });
+
+        struct Callback<CB, ID, F> {
+            chunk_size: usize,
+            len: usize,
+            identity: ID,
+            fold_op: F,
+            callback: CB,
+        }
+
+        impl<T, CB, ID, U, F> ProducerCallback<T> for Callback<CB, ID, F>
+        where
+            CB: ProducerCallback<U>,
+            ID: Fn() -> U + Send + Sync,
+            F: Fn(U, T) -> U + Send + Sync,
+        {
+            type Output = CB::Output;
+
+            fn callback<P>(self, base: P) -> CB::Output
+            where
+                P: Producer<Item = T>,
+            {
+                let identity = &self.identity;
+                let fold_op = &self.fold_op;
+                let fold_iter = move |iter: P::IntoIter| iter.fold(identity(), fold_op);
+                let producer = ChunkProducer::new(self.chunk_size, self.len, base, fold_iter);
+                self.callback.callback(producer)
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use std::ops::Add;
+
+    #[test]
+    fn check_fold_chunks() {
+        let words = "bishbashbosh!"
+            .chars()
+            .collect::<Vec<_>>()
+            .into_par_iter()
+            .fold_chunks(4, String::new, |mut s, c| {
+                s.push(c);
+                s
+            })
+            .collect::<Vec<_>>();
+
+        assert_eq!(words, vec!["bish", "bash", "bosh", "!"]);
+    }
+
+    // 'closure' values for tests below
+    fn id() -> i32 {
+        0
+    }
+    fn sum<T, U>(x: T, y: U) -> T
+    where
+        T: Add<U, Output = T>,
+    {
+        x + y
+    }
+
+    #[test]
+    #[should_panic(expected = "chunk_size must not be zero")]
+    fn check_fold_chunks_zero_size() {
+        let _: Vec<i32> = vec![1, 2, 3]
+            .into_par_iter()
+            .fold_chunks(0, id, sum)
+            .collect();
+    }
+
+    #[test]
+    fn check_fold_chunks_even_size() {
+        assert_eq!(
+            vec![1 + 2 + 3, 4 + 5 + 6, 7 + 8 + 9],
+            (1..10)
+                .into_par_iter()
+                .fold_chunks(3, id, sum)
+                .collect::<Vec<i32>>()
+        );
+    }
+
+    #[test]
+    fn check_fold_chunks_empty() {
+        let v: Vec<i32> = vec![];
+        let expected: Vec<i32> = vec![];
+        assert_eq!(
+            expected,
+            v.into_par_iter()
+                .fold_chunks(2, id, sum)
+                .collect::<Vec<i32>>()
+        );
+    }
+
+    #[test]
+    fn check_fold_chunks_len() {
+        assert_eq!(4, (0..8).into_par_iter().fold_chunks(2, id, sum).len());
+        assert_eq!(3, (0..9).into_par_iter().fold_chunks(3, id, sum).len());
+        assert_eq!(3, (0..8).into_par_iter().fold_chunks(3, id, sum).len());
+        assert_eq!(1, (&[1]).par_iter().fold_chunks(3, id, sum).len());
+        assert_eq!(0, (0..0).into_par_iter().fold_chunks(3, id, sum).len());
+    }
+
+    #[test]
+    fn check_fold_chunks_uneven() {
+        let cases: Vec<(Vec<u32>, usize, Vec<u32>)> = vec![
+            ((0..5).collect(), 3, vec![0 + 1 + 2, 3 + 4]),
+            (vec![1], 5, vec![1]),
+            ((0..4).collect(), 3, vec![0 + 1 + 2, 3]),
+        ];
+
+        for (i, (v, n, expected)) in cases.into_iter().enumerate() {
+            let mut res: Vec<u32> = vec![];
+            v.par_iter()
+                .fold_chunks(n, || 0, sum)
+                .collect_into_vec(&mut res);
+            assert_eq!(expected, res, "Case {} failed", i);
+
+            res.truncate(0);
+            v.into_par_iter()
+                .fold_chunks(n, || 0, sum)
+                .rev()
+                .collect_into_vec(&mut res);
+            assert_eq!(
+                expected.into_iter().rev().collect::<Vec<u32>>(),
+                res,
+                "Case {} reversed failed",
+                i
+            );
+        }
+    }
+}