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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/rayon/src/iter/while_some.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/rayon/src/iter/while_some.rs')
-rw-r--r-- | vendor/rayon/src/iter/while_some.rs | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/while_some.rs b/vendor/rayon/src/iter/while_some.rs new file mode 100644 index 000000000..215047bc6 --- /dev/null +++ b/vendor/rayon/src/iter/while_some.rs @@ -0,0 +1,154 @@ +use super::plumbing::*; +use super::*; +use std::sync::atomic::{AtomicBool, Ordering}; + +/// `WhileSome` is an iterator that yields the `Some` elements of an iterator, +/// halting as soon as any `None` is produced. +/// +/// This struct is created by the [`while_some()`] method on [`ParallelIterator`] +/// +/// [`while_some()`]: trait.ParallelIterator.html#method.while_some +/// [`ParallelIterator`]: trait.ParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Debug, Clone)] +pub struct WhileSome<I: ParallelIterator> { + base: I, +} + +impl<I> WhileSome<I> +where + I: ParallelIterator, +{ + /// Creates a new `WhileSome` iterator. + pub(super) fn new(base: I) -> Self { + WhileSome { base } + } +} + +impl<I, T> ParallelIterator for WhileSome<I> +where + I: ParallelIterator<Item = Option<T>>, + T: Send, +{ + type Item = T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let full = AtomicBool::new(false); + let consumer1 = WhileSomeConsumer { + base: consumer, + full: &full, + }; + self.base.drive_unindexed(consumer1) + } +} + +/// //////////////////////////////////////////////////////////////////////// +/// Consumer implementation + +struct WhileSomeConsumer<'f, C> { + base: C, + full: &'f AtomicBool, +} + +impl<'f, T, C> Consumer<Option<T>> for WhileSomeConsumer<'f, C> +where + C: Consumer<T>, + T: Send, +{ + type Folder = WhileSomeFolder<'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); + ( + WhileSomeConsumer { base: left, ..self }, + WhileSomeConsumer { + base: right, + ..self + }, + reducer, + ) + } + + fn into_folder(self) -> Self::Folder { + WhileSomeFolder { + base: self.base.into_folder(), + full: self.full, + } + } + + fn full(&self) -> bool { + self.full.load(Ordering::Relaxed) || self.base.full() + } +} + +impl<'f, T, C> UnindexedConsumer<Option<T>> for WhileSomeConsumer<'f, C> +where + C: UnindexedConsumer<T>, + T: Send, +{ + fn split_off_left(&self) -> Self { + WhileSomeConsumer { + base: self.base.split_off_left(), + ..*self + } + } + + fn to_reducer(&self) -> Self::Reducer { + self.base.to_reducer() + } +} + +struct WhileSomeFolder<'f, C> { + base: C, + full: &'f AtomicBool, +} + +impl<'f, T, C> Folder<Option<T>> for WhileSomeFolder<'f, C> +where + C: Folder<T>, +{ + type Result = C::Result; + + fn consume(mut self, item: Option<T>) -> Self { + match item { + Some(item) => self.base = self.base.consume(item), + None => self.full.store(true, Ordering::Relaxed), + } + self + } + + fn consume_iter<I>(mut self, iter: I) -> Self + where + I: IntoIterator<Item = Option<T>>, + { + fn some<T>(full: &AtomicBool) -> impl Fn(&Option<T>) -> bool + '_ { + move |x| match *x { + Some(_) => !full.load(Ordering::Relaxed), + None => { + full.store(true, Ordering::Relaxed); + false + } + } + } + + self.base = self.base.consume_iter( + iter.into_iter() + .take_while(some(self.full)) + .map(Option::unwrap), + ); + self + } + + fn complete(self) -> C::Result { + self.base.complete() + } + + fn full(&self) -> bool { + self.full.load(Ordering::Relaxed) || self.base.full() + } +} |