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//! This module contains the parallel iterator types for heaps
//! (`BinaryHeap<T>`). You will rarely need to interact with it directly
//! unless you have need to name one of the iterator types.
use std::collections::BinaryHeap;
use crate::iter::plumbing::*;
use crate::iter::*;
use crate::vec;
/// Parallel iterator over a binary heap
#[derive(Debug, Clone)]
pub struct IntoIter<T: Ord + Send> {
inner: vec::IntoIter<T>,
}
impl<T: Ord + Send> IntoParallelIterator for BinaryHeap<T> {
type Item = T;
type Iter = IntoIter<T>;
fn into_par_iter(self) -> Self::Iter {
IntoIter {
inner: Vec::from(self).into_par_iter(),
}
}
}
delegate_indexed_iterator! {
IntoIter<T> => T,
impl<T: Ord + Send>
}
/// Parallel iterator over an immutable reference to a binary heap
#[derive(Debug)]
pub struct Iter<'a, T: Ord + Sync> {
inner: vec::IntoIter<&'a T>,
}
impl<'a, T: Ord + Sync> Clone for Iter<'a, T> {
fn clone(&self) -> Self {
Iter {
inner: self.inner.clone(),
}
}
}
into_par_vec! {
&'a BinaryHeap<T> => Iter<'a, T>,
impl<'a, T: Ord + Sync>
}
delegate_indexed_iterator! {
Iter<'a, T> => &'a T,
impl<'a, T: Ord + Sync + 'a>
}
// `BinaryHeap` doesn't have a mutable `Iterator`
/// Draining parallel iterator that moves out of a binary heap,
/// but keeps the total capacity.
#[derive(Debug)]
pub struct Drain<'a, T: Ord + Send> {
heap: &'a mut BinaryHeap<T>,
}
impl<'a, T: Ord + Send> ParallelDrainFull for &'a mut BinaryHeap<T> {
type Iter = Drain<'a, T>;
type Item = T;
fn par_drain(self) -> Self::Iter {
Drain { heap: self }
}
}
impl<'a, T: Ord + Send> ParallelIterator for Drain<'a, T> {
type Item = T;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
bridge(self, consumer)
}
fn opt_len(&self) -> Option<usize> {
Some(self.len())
}
}
impl<'a, T: Ord + Send> IndexedParallelIterator for Drain<'a, T> {
fn drive<C>(self, consumer: C) -> C::Result
where
C: Consumer<Self::Item>,
{
bridge(self, consumer)
}
fn len(&self) -> usize {
self.heap.len()
}
fn with_producer<CB>(self, callback: CB) -> CB::Output
where
CB: ProducerCallback<Self::Item>,
{
super::DrainGuard::new(self.heap)
.par_drain(..)
.with_producer(callback)
}
}
impl<'a, T: Ord + Send> Drop for Drain<'a, T> {
fn drop(&mut self) {
if !self.heap.is_empty() {
// We must not have produced, so just call a normal drain to remove the items.
self.heap.drain();
}
}
}