diff options
Diffstat (limited to 'vendor/rayon/src/iter/skip_any_while.rs')
-rw-r--r-- | vendor/rayon/src/iter/skip_any_while.rs | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/skip_any_while.rs b/vendor/rayon/src/iter/skip_any_while.rs new file mode 100644 index 0000000..28b9e59 --- /dev/null +++ b/vendor/rayon/src/iter/skip_any_while.rs @@ -0,0 +1,166 @@ +use super::plumbing::*; +use super::*; +use std::fmt; +use std::sync::atomic::{AtomicBool, Ordering}; + +/// `SkipAnyWhile` is an iterator that skips over elements from anywhere in `I` +/// until the callback returns `false`. +/// This struct is created by the [`skip_any_while()`] method on [`ParallelIterator`] +/// +/// [`skip_any_while()`]: trait.ParallelIterator.html#method.skip_any_while +/// [`ParallelIterator`]: trait.ParallelIterator.html +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +#[derive(Clone)] +pub struct SkipAnyWhile<I: ParallelIterator, P> { + base: I, + predicate: P, +} + +impl<I: ParallelIterator + fmt::Debug, P> fmt::Debug for SkipAnyWhile<I, P> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("SkipAnyWhile") + .field("base", &self.base) + .finish() + } +} + +impl<I, P> SkipAnyWhile<I, P> +where + I: ParallelIterator, +{ + /// Creates a new `SkipAnyWhile` iterator. + pub(super) fn new(base: I, predicate: P) -> Self { + SkipAnyWhile { base, predicate } + } +} + +impl<I, P> ParallelIterator for SkipAnyWhile<I, P> +where + I: ParallelIterator, + P: Fn(&I::Item) -> bool + Sync + Send, +{ + type Item = I::Item; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + let consumer1 = SkipAnyWhileConsumer { + base: consumer, + predicate: &self.predicate, + skipping: &AtomicBool::new(true), + }; + self.base.drive_unindexed(consumer1) + } +} + +/// //////////////////////////////////////////////////////////////////////// +/// Consumer implementation + +struct SkipAnyWhileConsumer<'p, C, P> { + base: C, + predicate: &'p P, + skipping: &'p AtomicBool, +} + +impl<'p, T, C, P> Consumer<T> for SkipAnyWhileConsumer<'p, C, P> +where + C: Consumer<T>, + P: Fn(&T) -> bool + Sync, +{ + type Folder = SkipAnyWhileFolder<'p, C::Folder, P>; + 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); + ( + SkipAnyWhileConsumer { base: left, ..self }, + SkipAnyWhileConsumer { + base: right, + ..self + }, + reducer, + ) + } + + fn into_folder(self) -> Self::Folder { + SkipAnyWhileFolder { + base: self.base.into_folder(), + predicate: self.predicate, + skipping: self.skipping, + } + } + + fn full(&self) -> bool { + self.base.full() + } +} + +impl<'p, T, C, P> UnindexedConsumer<T> for SkipAnyWhileConsumer<'p, C, P> +where + C: UnindexedConsumer<T>, + P: Fn(&T) -> bool + Sync, +{ + fn split_off_left(&self) -> Self { + SkipAnyWhileConsumer { + base: self.base.split_off_left(), + ..*self + } + } + + fn to_reducer(&self) -> Self::Reducer { + self.base.to_reducer() + } +} + +struct SkipAnyWhileFolder<'p, C, P> { + base: C, + predicate: &'p P, + skipping: &'p AtomicBool, +} + +fn skip<T>(item: &T, skipping: &AtomicBool, predicate: &impl Fn(&T) -> bool) -> bool { + if !skipping.load(Ordering::Relaxed) { + return false; + } + if predicate(item) { + return true; + } + skipping.store(false, Ordering::Relaxed); + false +} + +impl<'p, T, C, P> Folder<T> for SkipAnyWhileFolder<'p, C, P> +where + C: Folder<T>, + P: Fn(&T) -> bool + 'p, +{ + type Result = C::Result; + + fn consume(mut self, item: T) -> Self { + if !skip(&item, self.skipping, self.predicate) { + 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() + .skip_while(move |x| skip(x, self.skipping, self.predicate)), + ); + self + } + + fn complete(self) -> C::Result { + self.base.complete() + } + + fn full(&self) -> bool { + self.base.full() + } +} |