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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/rayon/src/option.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/rayon/src/option.rs')
-rw-r--r-- | third_party/rust/rayon/src/option.rs | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/third_party/rust/rayon/src/option.rs b/third_party/rust/rayon/src/option.rs new file mode 100644 index 0000000000..0f56896f05 --- /dev/null +++ b/third_party/rust/rayon/src/option.rs @@ -0,0 +1,203 @@ +//! Parallel iterator types for [options][std::option] +//! +//! You will rarely need to interact with this module directly unless you need +//! to name one of the iterator types. +//! +//! [std::option]: https://doc.rust-lang.org/stable/std/option/ + +use crate::iter::plumbing::*; +use crate::iter::*; +use std::sync::atomic::{AtomicBool, Ordering}; + +/// A parallel iterator over the value in [`Some`] variant of an [`Option`]. +/// +/// The iterator yields one value if the [`Option`] is a [`Some`], otherwise none. +/// +/// This `struct` is created by the [`into_par_iter`] function. +/// +/// [`Option`]: https://doc.rust-lang.org/std/option/enum.Option.html +/// [`Some`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some +/// [`into_par_iter`]: ../iter/trait.IntoParallelIterator.html#tymethod.into_par_iter +#[derive(Debug, Clone)] +pub struct IntoIter<T: Send> { + opt: Option<T>, +} + +impl<T: Send> IntoParallelIterator for Option<T> { + type Item = T; + type Iter = IntoIter<T>; + + fn into_par_iter(self) -> Self::Iter { + IntoIter { opt: self } + } +} + +impl<T: Send> ParallelIterator for IntoIter<T> { + type Item = T; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where + C: UnindexedConsumer<Self::Item>, + { + self.drive(consumer) + } + + fn opt_len(&self) -> Option<usize> { + Some(self.len()) + } +} + +impl<T: Send> IndexedParallelIterator for IntoIter<T> { + fn drive<C>(self, consumer: C) -> C::Result + where + C: Consumer<Self::Item>, + { + let mut folder = consumer.into_folder(); + if let Some(item) = self.opt { + folder = folder.consume(item); + } + folder.complete() + } + + fn len(&self) -> usize { + match self.opt { + Some(_) => 1, + None => 0, + } + } + + fn with_producer<CB>(self, callback: CB) -> CB::Output + where + CB: ProducerCallback<Self::Item>, + { + callback.callback(OptionProducer { opt: self.opt }) + } +} + +/// A parallel iterator over a reference to the [`Some`] variant of an [`Option`]. +/// +/// The iterator yields one value if the [`Option`] is a [`Some`], otherwise none. +/// +/// This `struct` is created by the [`par_iter`] function. +/// +/// [`Option`]: https://doc.rust-lang.org/std/option/enum.Option.html +/// [`Some`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some +/// [`par_iter`]: ../iter/trait.IntoParallelRefIterator.html#tymethod.par_iter +#[derive(Debug)] +pub struct Iter<'a, T: Sync> { + inner: IntoIter<&'a T>, +} + +impl<'a, T: Sync> Clone for Iter<'a, T> { + fn clone(&self) -> Self { + Iter { + inner: self.inner.clone(), + } + } +} + +impl<'a, T: Sync> IntoParallelIterator for &'a Option<T> { + type Item = &'a T; + type Iter = Iter<'a, T>; + + fn into_par_iter(self) -> Self::Iter { + Iter { + inner: self.as_ref().into_par_iter(), + } + } +} + +delegate_indexed_iterator! { + Iter<'a, T> => &'a T, + impl<'a, T: Sync + 'a> +} + +/// A parallel iterator over a mutable reference to the [`Some`] variant of an [`Option`]. +/// +/// The iterator yields one value if the [`Option`] is a [`Some`], otherwise none. +/// +/// This `struct` is created by the [`par_iter_mut`] function. +/// +/// [`Option`]: https://doc.rust-lang.org/std/option/enum.Option.html +/// [`Some`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some +/// [`par_iter_mut`]: ../iter/trait.IntoParallelRefMutIterator.html#tymethod.par_iter_mut +#[derive(Debug)] +pub struct IterMut<'a, T: Send> { + inner: IntoIter<&'a mut T>, +} + +impl<'a, T: Send> IntoParallelIterator for &'a mut Option<T> { + type Item = &'a mut T; + type Iter = IterMut<'a, T>; + + fn into_par_iter(self) -> Self::Iter { + IterMut { + inner: self.as_mut().into_par_iter(), + } + } +} + +delegate_indexed_iterator! { + IterMut<'a, T> => &'a mut T, + impl<'a, T: Send + 'a> +} + +/// Private producer for an option +struct OptionProducer<T: Send> { + opt: Option<T>, +} + +impl<T: Send> Producer for OptionProducer<T> { + type Item = T; + type IntoIter = std::option::IntoIter<T>; + + fn into_iter(self) -> Self::IntoIter { + self.opt.into_iter() + } + + fn split_at(self, index: usize) -> (Self, Self) { + debug_assert!(index <= 1); + let none = OptionProducer { opt: None }; + if index == 0 { + (none, self) + } else { + (self, none) + } + } +} + +/// Collect an arbitrary `Option`-wrapped collection. +/// +/// If any item is `None`, then all previous items collected are discarded, +/// and it returns only `None`. +impl<C, T> FromParallelIterator<Option<T>> for Option<C> +where + C: FromParallelIterator<T>, + T: Send, +{ + fn from_par_iter<I>(par_iter: I) -> Self + where + I: IntoParallelIterator<Item = Option<T>>, + { + fn check<T>(found_none: &AtomicBool) -> impl Fn(&Option<T>) + '_ { + move |item| { + if item.is_none() { + found_none.store(true, Ordering::Relaxed); + } + } + } + + let found_none = AtomicBool::new(false); + let collection = par_iter + .into_par_iter() + .inspect(check(&found_none)) + .while_some() + .collect(); + + if found_none.load(Ordering::Relaxed) { + None + } else { + Some(collection) + } + } +} |