diff options
Diffstat (limited to 'vendor/rayon/src/iter/find.rs')
-rw-r--r-- | vendor/rayon/src/iter/find.rs | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/find.rs b/vendor/rayon/src/iter/find.rs new file mode 100644 index 0000000..b16ee84 --- /dev/null +++ b/vendor/rayon/src/iter/find.rs @@ -0,0 +1,120 @@ +use super::plumbing::*; +use super::*; +use std::sync::atomic::{AtomicBool, Ordering}; + +pub(super) fn find<I, P>(pi: I, find_op: P) -> Option<I::Item> +where + I: ParallelIterator, + P: Fn(&I::Item) -> bool + Sync, +{ + let found = AtomicBool::new(false); + let consumer = FindConsumer::new(&find_op, &found); + pi.drive_unindexed(consumer) +} + +struct FindConsumer<'p, P> { + find_op: &'p P, + found: &'p AtomicBool, +} + +impl<'p, P> FindConsumer<'p, P> { + fn new(find_op: &'p P, found: &'p AtomicBool) -> Self { + FindConsumer { find_op, found } + } +} + +impl<'p, T, P: 'p> Consumer<T> for FindConsumer<'p, P> +where + T: Send, + P: Fn(&T) -> bool + Sync, +{ + type Folder = FindFolder<'p, T, P>; + type Reducer = FindReducer; + type Result = Option<T>; + + fn split_at(self, _index: usize) -> (Self, Self, Self::Reducer) { + (self.split_off_left(), self, FindReducer) + } + + fn into_folder(self) -> Self::Folder { + FindFolder { + find_op: self.find_op, + found: self.found, + item: None, + } + } + + fn full(&self) -> bool { + self.found.load(Ordering::Relaxed) + } +} + +impl<'p, T, P: 'p> UnindexedConsumer<T> for FindConsumer<'p, P> +where + T: Send, + P: Fn(&T) -> bool + Sync, +{ + fn split_off_left(&self) -> Self { + FindConsumer::new(self.find_op, self.found) + } + + fn to_reducer(&self) -> Self::Reducer { + FindReducer + } +} + +struct FindFolder<'p, T, P> { + find_op: &'p P, + found: &'p AtomicBool, + item: Option<T>, +} + +impl<'p, T, P> Folder<T> for FindFolder<'p, T, P> +where + P: Fn(&T) -> bool + 'p, +{ + type Result = Option<T>; + + fn consume(mut self, item: T) -> Self { + if (self.find_op)(&item) { + self.found.store(true, Ordering::Relaxed); + self.item = Some(item); + } + self + } + + fn consume_iter<I>(mut self, iter: I) -> Self + where + I: IntoIterator<Item = T>, + { + fn not_full<T>(found: &AtomicBool) -> impl Fn(&T) -> bool + '_ { + move |_| !found.load(Ordering::Relaxed) + } + + self.item = iter + .into_iter() + // stop iterating if another thread has found something + .take_while(not_full(self.found)) + .find(self.find_op); + if self.item.is_some() { + self.found.store(true, Ordering::Relaxed) + } + self + } + + fn complete(self) -> Self::Result { + self.item + } + + fn full(&self) -> bool { + self.found.load(Ordering::Relaxed) + } +} + +struct FindReducer; + +impl<T> Reducer<Option<T>> for FindReducer { + fn reduce(self, left: Option<T>, right: Option<T>) -> Option<T> { + left.or(right) + } +} |