1 files changed, 252 insertions, 0 deletions
diff --git a/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs b/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs
new file mode 100644
index 0000000000..e8e50944ad
--- /dev/null
+++ b/third_party/rust/hashbrown/src/external_trait_impls/rayon/table.rs
@@ -0,0 +1,252 @@
+//! Rayon extensions for `HashTable`.
+
+use super::raw::{RawIntoParIter, RawParDrain, RawParIter};
+use crate::hash_table::HashTable;
+use crate::raw::{Allocator, Global};
+use core::fmt;
+use core::marker::PhantomData;
+use rayon::iter::plumbing::UnindexedConsumer;
+use rayon::iter::{IntoParallelIterator, ParallelIterator};
+
+/// Parallel iterator over shared references to entries in a map.
+///
+/// This iterator is created by the [`par_iter`] method on [`HashTable`]
+/// (provided by the [`IntoParallelRefIterator`] trait).
+/// See its documentation for more.
+///
+/// [`par_iter`]: /hashbrown/struct.HashTable.html#method.par_iter
+/// [`HashTable`]: /hashbrown/struct.HashTable.html
+/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html
+pub struct ParIter<'a, T> {
+    inner: RawParIter<T>,
+    marker: PhantomData<&'a T>,
+}
+
+impl<'a, T: Sync> ParallelIterator for ParIter<'a, T> {
+    type Item = &'a T;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        self.inner
+            .map(|x| unsafe { x.as_ref() })
+            .drive_unindexed(consumer)
+    }
+}
+
+impl<T> Clone for ParIter<'_, T> {
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn clone(&self) -> Self {
+        Self {
+            inner: self.inner.clone(),
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for ParIter<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let iter = unsafe { self.inner.iter() }.map(|x| unsafe { x.as_ref() });
+        f.debug_list().entries(iter).finish()
+    }
+}
+
+/// Parallel iterator over mutable references to entries in a map.
+///
+/// This iterator is created by the [`par_iter_mut`] method on [`HashTable`]
+/// (provided by the [`IntoParallelRefMutIterator`] trait).
+/// See its documentation for more.
+///
+/// [`par_iter_mut`]: /hashbrown/struct.HashTable.html#method.par_iter_mut
+/// [`HashTable`]: /hashbrown/struct.HashTable.html
+/// [`IntoParallelRefMutIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefMutIterator.html
+pub struct ParIterMut<'a, T> {
+    inner: RawParIter<T>,
+    marker: PhantomData<&'a mut T>,
+}
+
+impl<'a, T: Send> ParallelIterator for ParIterMut<'a, T> {
+    type Item = &'a mut T;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        self.inner
+            .map(|x| unsafe { x.as_mut() })
+            .drive_unindexed(consumer)
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for ParIterMut<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        ParIter {
+            inner: self.inner.clone(),
+            marker: PhantomData,
+        }
+        .fmt(f)
+    }
+}
+
+/// Parallel iterator over entries of a consumed map.
+///
+/// This iterator is created by the [`into_par_iter`] method on [`HashTable`]
+/// (provided by the [`IntoParallelIterator`] trait).
+/// See its documentation for more.
+///
+/// [`into_par_iter`]: /hashbrown/struct.HashTable.html#method.into_par_iter
+/// [`HashTable`]: /hashbrown/struct.HashTable.html
+/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html
+pub struct IntoParIter<T, A: Allocator = Global> {
+    inner: RawIntoParIter<T, A>,
+}
+
+impl<T: Send, A: Allocator + Send> ParallelIterator for IntoParIter<T, A> {
+    type Item = T;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        self.inner.drive_unindexed(consumer)
+    }
+}
+
+impl<T: fmt::Debug, A: Allocator> fmt::Debug for IntoParIter<T, A> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        ParIter {
+            inner: unsafe { self.inner.par_iter() },
+            marker: PhantomData,
+        }
+        .fmt(f)
+    }
+}
+
+/// Parallel draining iterator over entries of a map.
+///
+/// This iterator is created by the [`par_drain`] method on [`HashTable`].
+/// See its documentation for more.
+///
+/// [`par_drain`]: /hashbrown/struct.HashTable.html#method.par_drain
+/// [`HashTable`]: /hashbrown/struct.HashTable.html
+pub struct ParDrain<'a, T, A: Allocator = Global> {
+    inner: RawParDrain<'a, T, A>,
+}
+
+impl<T: Send, A: Allocator + Sync> ParallelIterator for ParDrain<'_, T, A> {
+    type Item = T;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        self.inner.drive_unindexed(consumer)
+    }
+}
+
+impl<T: fmt::Debug, A: Allocator> fmt::Debug for ParDrain<'_, T, A> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        ParIter {
+            inner: unsafe { self.inner.par_iter() },
+            marker: PhantomData,
+        }
+        .fmt(f)
+    }
+}
+
+impl<T: Send, A: Allocator> HashTable<T, A> {
+    /// Consumes (potentially in parallel) all values in an arbitrary order,
+    /// while preserving the map's allocated memory for reuse.
+    #[cfg_attr(feature = "inline-more", inline)]
+    pub fn par_drain(&mut self) -> ParDrain<'_, T, A> {
+        ParDrain {
+            inner: self.raw.par_drain(),
+        }
+    }
+}
+
+impl<T: Send, A: Allocator + Send> IntoParallelIterator for HashTable<T, A> {
+    type Item = T;
+    type Iter = IntoParIter<T, A>;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn into_par_iter(self) -> Self::Iter {
+        IntoParIter {
+            inner: self.raw.into_par_iter(),
+        }
+    }
+}
+
+impl<'a, T: Sync, A: Allocator> IntoParallelIterator for &'a HashTable<T, A> {
+    type Item = &'a T;
+    type Iter = ParIter<'a, T>;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn into_par_iter(self) -> Self::Iter {
+        ParIter {
+            inner: unsafe { self.raw.par_iter() },
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<'a, T: Send, A: Allocator> IntoParallelIterator for &'a mut HashTable<T, A> {
+    type Item = &'a mut T;
+    type Iter = ParIterMut<'a, T>;
+
+    #[cfg_attr(feature = "inline-more", inline)]
+    fn into_par_iter(self) -> Self::Iter {
+        ParIterMut {
+            inner: unsafe { self.raw.par_iter() },
+            marker: PhantomData,
+        }
+    }
+}
+
+#[cfg(test)]
+mod test_par_table {
+    use alloc::vec::Vec;
+    use core::sync::atomic::{AtomicUsize, Ordering};
+
+    use rayon::prelude::*;
+
+    use crate::{
+        hash_map::{make_hash, DefaultHashBuilder},
+        hash_table::HashTable,
+    };
+
+    #[test]
+    fn test_iterate() {
+        let hasher = DefaultHashBuilder::default();
+        let mut a = HashTable::new();
+        for i in 0..32 {
+            a.insert_unique(make_hash(&hasher, &i), i, |x| make_hash(&hasher, x));
+        }
+        let observed = AtomicUsize::new(0);
+        a.par_iter().for_each(|k| {
+            observed.fetch_or(1 << *k, Ordering::Relaxed);
+        });
+        assert_eq!(observed.into_inner(), 0xFFFF_FFFF);
+    }
+
+    #[test]
+    fn test_move_iter() {
+        let hasher = DefaultHashBuilder::default();
+        let hs = {
+            let mut hs = HashTable::new();
+
+            hs.insert_unique(make_hash(&hasher, &'a'), 'a', |x| make_hash(&hasher, x));
+            hs.insert_unique(make_hash(&hasher, &'b'), 'b', |x| make_hash(&hasher, x));
+
+            hs
+        };
+
+        let v = hs.into_par_iter().collect::<Vec<char>>();
+        assert!(v == ['a', 'b'] || v == ['b', 'a']);
+    }
+}