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Diffstat (limited to 'vendor/rayon/src/iter/reduce.rs')
-rw-r--r-- | vendor/rayon/src/iter/reduce.rs | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/vendor/rayon/src/iter/reduce.rs b/vendor/rayon/src/iter/reduce.rs new file mode 100644 index 0000000..321b5dd --- /dev/null +++ b/vendor/rayon/src/iter/reduce.rs @@ -0,0 +1,116 @@ +use super::plumbing::*; +use super::ParallelIterator; + +pub(super) fn reduce<PI, R, ID, T>(pi: PI, identity: ID, reduce_op: R) -> T +where + PI: ParallelIterator<Item = T>, + R: Fn(T, T) -> T + Sync, + ID: Fn() -> T + Sync, + T: Send, +{ + let consumer = ReduceConsumer { + identity: &identity, + reduce_op: &reduce_op, + }; + pi.drive_unindexed(consumer) +} + +struct ReduceConsumer<'r, R, ID> { + identity: &'r ID, + reduce_op: &'r R, +} + +impl<'r, R, ID> Copy for ReduceConsumer<'r, R, ID> {} + +impl<'r, R, ID> Clone for ReduceConsumer<'r, R, ID> { + fn clone(&self) -> Self { + *self + } +} + +impl<'r, R, ID, T> Consumer<T> for ReduceConsumer<'r, R, ID> +where + R: Fn(T, T) -> T + Sync, + ID: Fn() -> T + Sync, + T: Send, +{ + type Folder = ReduceFolder<'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 { + ReduceFolder { + reduce_op: self.reduce_op, + item: (self.identity)(), + } + } + + fn full(&self) -> bool { + false + } +} + +impl<'r, R, ID, T> UnindexedConsumer<T> for ReduceConsumer<'r, R, ID> +where + R: Fn(T, T) -> T + Sync, + ID: Fn() -> T + Sync, + T: Send, +{ + fn split_off_left(&self) -> Self { + *self + } + + fn to_reducer(&self) -> Self::Reducer { + *self + } +} + +impl<'r, R, ID, T> Reducer<T> for ReduceConsumer<'r, R, ID> +where + R: Fn(T, T) -> T + Sync, +{ + fn reduce(self, left: T, right: T) -> T { + (self.reduce_op)(left, right) + } +} + +struct ReduceFolder<'r, R, T> { + reduce_op: &'r R, + item: T, +} + +impl<'r, R, T> Folder<T> for ReduceFolder<'r, R, T> +where + R: Fn(T, T) -> T, +{ + type Result = T; + + fn consume(self, item: T) -> Self { + ReduceFolder { + reduce_op: self.reduce_op, + item: (self.reduce_op)(self.item, item), + } + } + + fn consume_iter<I>(self, iter: I) -> Self + where + I: IntoIterator<Item = T>, + { + ReduceFolder { + reduce_op: self.reduce_op, + item: iter.into_iter().fold(self.item, self.reduce_op), + } + } + + fn complete(self) -> T { + self.item + } + + fn full(&self) -> bool { + false + } +} |