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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_any.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_any.rs')
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+use super::plumbing::*;
+use super::*;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+/// `TakeAny` is an iterator that iterates over `n` elements from anywhere in `I`.
+/// This struct is created by the [`take_any()`] method on [`ParallelIterator`]
+///
+/// [`take_any()`]: trait.ParallelIterator.html#method.take_any
+/// [`ParallelIterator`]: trait.ParallelIterator.html
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Clone, Debug)]
+pub struct TakeAny<I: ParallelIterator> {
+ base: I,
+ count: usize,
+}
+
+impl<I> TakeAny<I>
+where
+ I: ParallelIterator,
+{
+ /// Creates a new `TakeAny` iterator.
+ pub(super) fn new(base: I, count: usize) -> Self {
+ TakeAny { base, count }
+ }
+}
+
+impl<I> ParallelIterator for TakeAny<I>
+where
+ I: ParallelIterator,
+{
+ type Item = I::Item;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ let consumer1 = TakeAnyConsumer {
+ base: consumer,
+ count: &AtomicUsize::new(self.count),
+ };
+ self.base.drive_unindexed(consumer1)
+ }
+}
+
+/// ////////////////////////////////////////////////////////////////////////
+/// Consumer implementation
+
+struct TakeAnyConsumer<'f, C> {
+ base: C,
+ count: &'f AtomicUsize,
+}
+
+impl<'f, T, C> Consumer<T> for TakeAnyConsumer<'f, C>
+where
+ C: Consumer<T>,
+ T: Send,
+{
+ type Folder = TakeAnyFolder<'f, C::Folder>;
+ type Reducer = C::Reducer;
+ type Result = C::Result;
+
+ fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
+ let (left, right, reducer) = self.base.split_at(index);
+ (
+ TakeAnyConsumer { base: left, ..self },
+ TakeAnyConsumer {
+ base: right,
+ ..self
+ },
+ reducer,
+ )
+ }
+
+ fn into_folder(self) -> Self::Folder {
+ TakeAnyFolder {
+ base: self.base.into_folder(),
+ count: self.count,
+ }
+ }
+
+ fn full(&self) -> bool {
+ self.count.load(Ordering::Relaxed) == 0 || self.base.full()
+ }
+}
+
+impl<'f, T, C> UnindexedConsumer<T> for TakeAnyConsumer<'f, C>
+where
+ C: UnindexedConsumer<T>,
+ T: Send,
+{
+ fn split_off_left(&self) -> Self {
+ TakeAnyConsumer {
+ base: self.base.split_off_left(),
+ ..*self
+ }
+ }
+
+ fn to_reducer(&self) -> Self::Reducer {
+ self.base.to_reducer()
+ }
+}
+
+struct TakeAnyFolder<'f, C> {
+ base: C,
+ count: &'f AtomicUsize,
+}
+
+fn checked_decrement(u: &AtomicUsize) -> bool {
+ u.fetch_update(Ordering::Relaxed, Ordering::Relaxed, |u| u.checked_sub(1))
+ .is_ok()
+}
+
+impl<'f, T, C> Folder<T> for TakeAnyFolder<'f, C>
+where
+ C: Folder<T>,
+{
+ type Result = C::Result;
+
+ fn consume(mut self, item: T) -> Self {
+ if checked_decrement(self.count) {
+ self.base = self.base.consume(item);
+ }
+ self
+ }
+
+ fn consume_iter<I>(mut self, iter: I) -> Self
+ where
+ I: IntoIterator<Item = T>,
+ {
+ self.base = self.base.consume_iter(
+ iter.into_iter()
+ .take_while(move |_| checked_decrement(self.count)),
+ );
+ self
+ }
+
+ fn complete(self) -> C::Result {
+ self.base.complete()
+ }
+
+ fn full(&self) -> bool {
+ self.count.load(Ordering::Relaxed) == 0 || self.base.full()
+ }
+}