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-rw-r--r--vendor/rayon/src/iter/while_some.rs154
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+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()
+ }
+}