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Diffstat (limited to 'vendor/rayon/src/iter/chain.rs')
| -rw-r--r-- | vendor/rayon/src/iter/chain.rs | 268 |
1 files changed, 0 insertions, 268 deletions
diff --git a/vendor/rayon/src/iter/chain.rs b/vendor/rayon/src/iter/chain.rs deleted file mode 100644 index 48fce07..0000000 --- a/vendor/rayon/src/iter/chain.rs +++ /dev/null @@ -1,268 +0,0 @@ -use super::plumbing::*; -use super::*; -use rayon_core::join; -use std::cmp; -use std::iter; - -/// `Chain` is an iterator that joins `b` after `a` in one continuous iterator. -/// This struct is created by the [`chain()`] method on [`ParallelIterator`] -/// -/// [`chain()`]: trait.ParallelIterator.html#method.chain -/// [`ParallelIterator`]: trait.ParallelIterator.html -#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] -#[derive(Debug, Clone)] -pub struct Chain<A, B> -where - A: ParallelIterator, - B: ParallelIterator<Item = A::Item>, -{ - a: A, - b: B, -} - -impl<A, B> Chain<A, B> -where - A: ParallelIterator, - B: ParallelIterator<Item = A::Item>, -{ - /// Creates a new `Chain` iterator. - pub(super) fn new(a: A, b: B) -> Self { - Chain { a, b } - } -} - -impl<A, B> ParallelIterator for Chain<A, B> -where - A: ParallelIterator, - B: ParallelIterator<Item = A::Item>, -{ - type Item = A::Item; - - fn drive_unindexed<C>(self, consumer: C) -> C::Result - where - C: UnindexedConsumer<Self::Item>, - { - let Chain { a, b } = self; - - // If we returned a value from our own `opt_len`, then the collect consumer in particular - // will balk at being treated like an actual `UnindexedConsumer`. But when we do know the - // length, we can use `Consumer::split_at` instead, and this is still harmless for other - // truly-unindexed consumers too. - let (left, right, reducer) = if let Some(len) = a.opt_len() { - consumer.split_at(len) - } else { - let reducer = consumer.to_reducer(); - (consumer.split_off_left(), consumer, reducer) - }; - - let (a, b) = join(|| a.drive_unindexed(left), || b.drive_unindexed(right)); - reducer.reduce(a, b) - } - - fn opt_len(&self) -> Option<usize> { - self.a.opt_len()?.checked_add(self.b.opt_len()?) - } -} - -impl<A, B> IndexedParallelIterator for Chain<A, B> -where - A: IndexedParallelIterator, - B: IndexedParallelIterator<Item = A::Item>, -{ - fn drive<C>(self, consumer: C) -> C::Result - where - C: Consumer<Self::Item>, - { - let Chain { a, b } = self; - let (left, right, reducer) = consumer.split_at(a.len()); - let (a, b) = join(|| a.drive(left), || b.drive(right)); - reducer.reduce(a, b) - } - - fn len(&self) -> usize { - self.a.len().checked_add(self.b.len()).expect("overflow") - } - - fn with_producer<CB>(self, callback: CB) -> CB::Output - where - CB: ProducerCallback<Self::Item>, - { - let a_len = self.a.len(); - return self.a.with_producer(CallbackA { - callback, - a_len, - b: self.b, - }); - - struct CallbackA<CB, B> { - callback: CB, - a_len: usize, - b: B, - } - - impl<CB, B> ProducerCallback<B::Item> for CallbackA<CB, B> - where - B: IndexedParallelIterator, - CB: ProducerCallback<B::Item>, - { - type Output = CB::Output; - - fn callback<A>(self, a_producer: A) -> Self::Output - where - A: Producer<Item = B::Item>, - { - self.b.with_producer(CallbackB { - callback: self.callback, - a_len: self.a_len, - a_producer, - }) - } - } - - struct CallbackB<CB, A> { - callback: CB, - a_len: usize, - a_producer: A, - } - - impl<CB, A> ProducerCallback<A::Item> for CallbackB<CB, A> - where - A: Producer, - CB: ProducerCallback<A::Item>, - { - type Output = CB::Output; - - fn callback<B>(self, b_producer: B) -> Self::Output - where - B: Producer<Item = A::Item>, - { - let producer = ChainProducer::new(self.a_len, self.a_producer, b_producer); - self.callback.callback(producer) - } - } - } -} - -/// //////////////////////////////////////////////////////////////////////// - -struct ChainProducer<A, B> -where - A: Producer, - B: Producer<Item = A::Item>, -{ - a_len: usize, - a: A, - b: B, -} - -impl<A, B> ChainProducer<A, B> -where - A: Producer, - B: Producer<Item = A::Item>, -{ - fn new(a_len: usize, a: A, b: B) -> Self { - ChainProducer { a_len, a, b } - } -} - -impl<A, B> Producer for ChainProducer<A, B> -where - A: Producer, - B: Producer<Item = A::Item>, -{ - type Item = A::Item; - type IntoIter = ChainSeq<A::IntoIter, B::IntoIter>; - - fn into_iter(self) -> Self::IntoIter { - ChainSeq::new(self.a.into_iter(), self.b.into_iter()) - } - - fn min_len(&self) -> usize { - cmp::max(self.a.min_len(), self.b.min_len()) - } - - fn max_len(&self) -> usize { - cmp::min(self.a.max_len(), self.b.max_len()) - } - - fn split_at(self, index: usize) -> (Self, Self) { - if index <= self.a_len { - let a_rem = self.a_len - index; - let (a_left, a_right) = self.a.split_at(index); - let (b_left, b_right) = self.b.split_at(0); - ( - ChainProducer::new(index, a_left, b_left), - ChainProducer::new(a_rem, a_right, b_right), - ) - } else { - let (a_left, a_right) = self.a.split_at(self.a_len); - let (b_left, b_right) = self.b.split_at(index - self.a_len); - ( - ChainProducer::new(self.a_len, a_left, b_left), - ChainProducer::new(0, a_right, b_right), - ) - } - } - - fn fold_with<F>(self, mut folder: F) -> F - where - F: Folder<A::Item>, - { - folder = self.a.fold_with(folder); - if folder.full() { - folder - } else { - self.b.fold_with(folder) - } - } -} - -/// //////////////////////////////////////////////////////////////////////// -/// Wrapper for Chain to implement ExactSizeIterator - -struct ChainSeq<A, B> { - chain: iter::Chain<A, B>, -} - -impl<A, B> ChainSeq<A, B> { - fn new(a: A, b: B) -> ChainSeq<A, B> - where - A: ExactSizeIterator, - B: ExactSizeIterator<Item = A::Item>, - { - ChainSeq { chain: a.chain(b) } - } -} - -impl<A, B> Iterator for ChainSeq<A, B> -where - A: Iterator, - B: Iterator<Item = A::Item>, -{ - type Item = A::Item; - - fn next(&mut self) -> Option<Self::Item> { - self.chain.next() - } - - fn size_hint(&self) -> (usize, Option<usize>) { - self.chain.size_hint() - } -} - -impl<A, B> ExactSizeIterator for ChainSeq<A, B> -where - A: ExactSizeIterator, - B: ExactSizeIterator<Item = A::Item>, -{ -} - -impl<A, B> DoubleEndedIterator for ChainSeq<A, B> -where - A: DoubleEndedIterator, - B: DoubleEndedIterator<Item = A::Item>, -{ - fn next_back(&mut self) -> Option<Self::Item> { - self.chain.next_back() - } -} |