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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rayon/src/iter/take.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/rayon/src/iter/take.rs')
-rw-r--r--vendor/rayon/src/iter/take.rs86
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diff --git a/vendor/rayon/src/iter/take.rs b/vendor/rayon/src/iter/take.rs
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+use super::plumbing::*;
+use super::*;
+use std::cmp::min;
+
+/// `Take` is an iterator that iterates over the first `n` elements.
+/// This struct is created by the [`take()`] method on [`IndexedParallelIterator`]
+///
+/// [`take()`]: trait.IndexedParallelIterator.html#method.take
+/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Debug, Clone)]
+pub struct Take<I> {
+ base: I,
+ n: usize,
+}
+
+impl<I> Take<I>
+where
+ I: IndexedParallelIterator,
+{
+ /// Creates a new `Take` iterator.
+ pub(super) fn new(base: I, n: usize) -> Self {
+ let n = min(base.len(), n);
+ Take { base, n }
+ }
+}
+
+impl<I> ParallelIterator for Take<I>
+where
+ I: IndexedParallelIterator,
+{
+ type Item = I::Item;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ bridge(self, consumer)
+ }
+
+ fn opt_len(&self) -> Option<usize> {
+ Some(self.len())
+ }
+}
+
+impl<I> IndexedParallelIterator for Take<I>
+where
+ I: IndexedParallelIterator,
+{
+ fn len(&self) -> usize {
+ self.n
+ }
+
+ fn drive<C: Consumer<Self::Item>>(self, consumer: C) -> C::Result {
+ bridge(self, consumer)
+ }
+
+ fn with_producer<CB>(self, callback: CB) -> CB::Output
+ where
+ CB: ProducerCallback<Self::Item>,
+ {
+ return self.base.with_producer(Callback {
+ callback,
+ n: self.n,
+ });
+
+ struct Callback<CB> {
+ callback: CB,
+ n: usize,
+ }
+
+ impl<T, CB> ProducerCallback<T> for Callback<CB>
+ where
+ CB: ProducerCallback<T>,
+ {
+ type Output = CB::Output;
+ fn callback<P>(self, base: P) -> CB::Output
+ where
+ P: Producer<Item = T>,
+ {
+ let (producer, _) = base.split_at(self.n);
+ self.callback.callback(producer)
+ }
+ }
+ }
+}