diff options
Diffstat (limited to 'vendor/rayon/src/iter/try_reduce.rs')
-rw-r--r-- | vendor/rayon/src/iter/try_reduce.rs | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/try_reduce.rs b/vendor/rayon/src/iter/try_reduce.rs new file mode 100644 index 0000000..35a724c --- /dev/null +++ b/vendor/rayon/src/iter/try_reduce.rs @@ -0,0 +1,131 @@ +use super::plumbing::*; +use super::ParallelIterator; +use super::Try; + +use std::ops::ControlFlow::{self, Break, Continue}; +use std::sync::atomic::{AtomicBool, Ordering}; + +pub(super) fn try_reduce<PI, R, ID, T>(pi: PI, identity: ID, reduce_op: R) -> T +where + PI: ParallelIterator<Item = T>, + R: Fn(T::Output, T::Output) -> T + Sync, + ID: Fn() -> T::Output + Sync, + T: Try + Send, +{ + let full = AtomicBool::new(false); + let consumer = TryReduceConsumer { + identity: &identity, + reduce_op: &reduce_op, + full: &full, + }; + pi.drive_unindexed(consumer) +} + +struct TryReduceConsumer<'r, R, ID> { + identity: &'r ID, + reduce_op: &'r R, + full: &'r AtomicBool, +} + +impl<'r, R, ID> Copy for TryReduceConsumer<'r, R, ID> {} + +impl<'r, R, ID> Clone for TryReduceConsumer<'r, R, ID> { + fn clone(&self) -> Self { + *self + } +} + +impl<'r, R, ID, T> Consumer<T> for TryReduceConsumer<'r, R, ID> +where + R: Fn(T::Output, T::Output) -> T + Sync, + ID: Fn() -> T::Output + Sync, + T: Try + Send, +{ + type Folder = TryReduceFolder<'r, R, T>; + type Reducer = Self; + type Result = T; + + fn split_at(self, _index: usize) -> (Self, Self, Self) { + (self, self, self) + } + + fn into_folder(self) -> Self::Folder { + TryReduceFolder { + reduce_op: self.reduce_op, + control: Continue((self.identity)()), + full: self.full, + } + } + + fn full(&self) -> bool { + self.full.load(Ordering::Relaxed) + } +} + +impl<'r, R, ID, T> UnindexedConsumer<T> for TryReduceConsumer<'r, R, ID> +where + R: Fn(T::Output, T::Output) -> T + Sync, + ID: Fn() -> T::Output + Sync, + T: Try + Send, +{ + fn split_off_left(&self) -> Self { + *self + } + + fn to_reducer(&self) -> Self::Reducer { + *self + } +} + +impl<'r, R, ID, T> Reducer<T> for TryReduceConsumer<'r, R, ID> +where + R: Fn(T::Output, T::Output) -> T + Sync, + T: Try, +{ + fn reduce(self, left: T, right: T) -> T { + match (left.branch(), right.branch()) { + (Continue(left), Continue(right)) => (self.reduce_op)(left, right), + (Break(r), _) | (_, Break(r)) => T::from_residual(r), + } + } +} + +struct TryReduceFolder<'r, R, T: Try> { + reduce_op: &'r R, + control: ControlFlow<T::Residual, T::Output>, + full: &'r AtomicBool, +} + +impl<'r, R, T> Folder<T> for TryReduceFolder<'r, R, T> +where + R: Fn(T::Output, T::Output) -> T, + T: Try, +{ + type Result = T; + + fn consume(mut self, item: T) -> Self { + let reduce_op = self.reduce_op; + self.control = match (self.control, item.branch()) { + (Continue(left), Continue(right)) => reduce_op(left, right).branch(), + (control @ Break(_), _) | (_, control @ Break(_)) => control, + }; + if let Break(_) = self.control { + self.full.store(true, Ordering::Relaxed); + } + self + } + + fn complete(self) -> T { + match self.control { + Continue(c) => T::from_output(c), + Break(r) => T::from_residual(r), + } + } + + fn full(&self) -> bool { + match self.control { + Break(_) => true, + _ => self.full.load(Ordering::Relaxed), + } + } +} |