From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- vendor/rayon/src/iter/multizip.rs | 338 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 338 insertions(+) create mode 100644 vendor/rayon/src/iter/multizip.rs (limited to 'vendor/rayon/src/iter/multizip.rs') diff --git a/vendor/rayon/src/iter/multizip.rs b/vendor/rayon/src/iter/multizip.rs new file mode 100644 index 000000000..8e36d08a2 --- /dev/null +++ b/vendor/rayon/src/iter/multizip.rs @@ -0,0 +1,338 @@ +use super::plumbing::*; +use super::*; + +/// `MultiZip` is an iterator that zips up a tuple of parallel iterators to +/// produce tuples of their items. +/// +/// It is created by calling `into_par_iter()` on a tuple of types that +/// implement `IntoParallelIterator`, or `par_iter()`/`par_iter_mut()` with +/// types that are iterable by reference. +/// +/// The implementation currently support tuples up to length 12. +/// +/// # Examples +/// +/// ``` +/// use rayon::prelude::*; +/// +/// // This will iterate `r` by mutable reference, like `par_iter_mut()`, while +/// // ranges are all iterated by value like `into_par_iter()`. +/// // Note that the zipped iterator is only as long as the shortest input. +/// let mut r = vec![0; 3]; +/// (&mut r, 1..10, 10..100, 100..1000).into_par_iter() +/// .for_each(|(r, x, y, z)| *r = x * y + z); +/// +/// assert_eq!(&r, &[1 * 10 + 100, 2 * 11 + 101, 3 * 12 + 102]); +/// ``` +/// +/// For a group that should all be iterated by reference, you can use a tuple reference. +/// +/// ``` +/// use rayon::prelude::*; +/// +/// let xs: Vec<_> = (1..10).collect(); +/// let ys: Vec<_> = (10..100).collect(); +/// let zs: Vec<_> = (100..1000).collect(); +/// +/// // Reference each input separately with `IntoParallelIterator`: +/// let r1: Vec<_> = (&xs, &ys, &zs).into_par_iter() +/// .map(|(x, y, z)| x * y + z) +/// .collect(); +/// +/// // Reference them all together with `IntoParallelRefIterator`: +/// let r2: Vec<_> = (xs, ys, zs).par_iter() +/// .map(|(x, y, z)| x * y + z) +/// .collect(); +/// +/// assert_eq!(r1, r2); +/// ``` +/// +/// Mutable references to a tuple will work similarly. +/// +/// ``` +/// use rayon::prelude::*; +/// +/// let mut xs: Vec<_> = (1..4).collect(); +/// let mut ys: Vec<_> = (-4..-1).collect(); +/// let mut zs = vec![0; 3]; +/// +/// // Mutably reference each input separately with `IntoParallelIterator`: +/// (&mut xs, &mut ys, &mut zs).into_par_iter().for_each(|(x, y, z)| { +/// *z += *x + *y; +/// std::mem::swap(x, y); +/// }); +/// +/// assert_eq!(xs, (vec![-4, -3, -2])); +/// assert_eq!(ys, (vec![1, 2, 3])); +/// assert_eq!(zs, (vec![-3, -1, 1])); +/// +/// // Mutably reference them all together with `IntoParallelRefMutIterator`: +/// let mut tuple = (xs, ys, zs); +/// tuple.par_iter_mut().for_each(|(x, y, z)| { +/// *z += *x + *y; +/// std::mem::swap(x, y); +/// }); +/// +/// assert_eq!(tuple, (vec![1, 2, 3], vec![-4, -3, -2], vec![-6, -2, 2])); +/// ``` +#[derive(Debug, Clone)] +pub struct MultiZip { + tuple: T, +} + +// These macros greedily consume 4 or 2 items first to achieve log2 nesting depth. +// For example, 5 => 4,1 => (2,2),1. +// +// The tuples go up to 12, so we might want to greedily consume 8 too, but +// the depth works out the same if we let that expand on the right: +// 9 => 4,5 => (2,2),(4,1) => (2,2),((2,2),1) +// 12 => 4,8 => (2,2),(4,4) => (2,2),((2,2),(2,2)) +// +// But if we ever increase to 13, we would want to split 8,5 rather than 4,9. + +macro_rules! reduce { + ($a:expr, $b:expr, $c:expr, $d:expr, $( $x:expr ),+ => $fn:path) => { + reduce!(reduce!($a, $b, $c, $d => $fn), + reduce!($( $x ),+ => $fn) + => $fn) + }; + ($a:expr, $b:expr, $( $x:expr ),+ => $fn:path) => { + reduce!(reduce!($a, $b => $fn), + reduce!($( $x ),+ => $fn) + => $fn) + }; + ($a:expr, $b:expr => $fn:path) => { $fn($a, $b) }; + ($a:expr => $fn:path) => { $a }; +} + +macro_rules! nest { + ($A:tt, $B:tt, $C:tt, $D:tt, $( $X:tt ),+) => { + (nest!($A, $B, $C, $D), nest!($( $X ),+)) + }; + ($A:tt, $B:tt, $( $X:tt ),+) => { + (($A, $B), nest!($( $X ),+)) + }; + ($A:tt, $B:tt) => { ($A, $B) }; + ($A:tt) => { $A }; +} + +macro_rules! flatten { + ($( $T:ident ),+) => {{ + #[allow(non_snake_case)] + fn flatten<$( $T ),+>(nest!($( $T ),+) : nest!($( $T ),+)) -> ($( $T, )+) { + ($( $T, )+) + } + flatten + }}; +} + +macro_rules! multizip_impls { + ($( + $Tuple:ident { + $(($idx:tt) -> $T:ident)+ + } + )+) => { + $( + impl<$( $T, )+> IntoParallelIterator for ($( $T, )+) + where + $( + $T: IntoParallelIterator, + $T::Iter: IndexedParallelIterator, + )+ + { + type Item = ($( $T::Item, )+); + type Iter = MultiZip<($( $T::Iter, )+)>; + + fn into_par_iter(self) -> Self::Iter { + MultiZip { + tuple: ( $( self.$idx.into_par_iter(), )+ ), + } + } + } + + impl<'a, $( $T, )+> IntoParallelIterator for &'a ($( $T, )+) + where + $( + $T: IntoParallelRefIterator<'a>, + $T::Iter: IndexedParallelIterator, + )+ + { + type Item = ($( $T::Item, )+); + type Iter = MultiZip<($( $T::Iter, )+)>; + + fn into_par_iter(self) -> Self::Iter { + MultiZip { + tuple: ( $( self.$idx.par_iter(), )+ ), + } + } + } + + impl<'a, $( $T, )+> IntoParallelIterator for &'a mut ($( $T, )+) + where + $( + $T: IntoParallelRefMutIterator<'a>, + $T::Iter: IndexedParallelIterator, + )+ + { + type Item = ($( $T::Item, )+); + type Iter = MultiZip<($( $T::Iter, )+)>; + + fn into_par_iter(self) -> Self::Iter { + MultiZip { + tuple: ( $( self.$idx.par_iter_mut(), )+ ), + } + } + } + + impl<$( $T, )+> ParallelIterator for MultiZip<($( $T, )+)> + where + $( $T: IndexedParallelIterator, )+ + { + type Item = ($( $T::Item, )+); + + fn drive_unindexed(self, consumer: CONSUMER) -> CONSUMER::Result + where + CONSUMER: UnindexedConsumer, + { + self.drive(consumer) + } + + fn opt_len(&self) -> Option { + Some(self.len()) + } + } + + impl<$( $T, )+> IndexedParallelIterator for MultiZip<($( $T, )+)> + where + $( $T: IndexedParallelIterator, )+ + { + fn drive(self, consumer: CONSUMER) -> CONSUMER::Result + where + CONSUMER: Consumer, + { + reduce!($( self.tuple.$idx ),+ => IndexedParallelIterator::zip) + .map(flatten!($( $T ),+)) + .drive(consumer) + } + + fn len(&self) -> usize { + reduce!($( self.tuple.$idx.len() ),+ => Ord::min) + } + + fn with_producer(self, callback: CB) -> CB::Output + where + CB: ProducerCallback, + { + reduce!($( self.tuple.$idx ),+ => IndexedParallelIterator::zip) + .map(flatten!($( $T ),+)) + .with_producer(callback) + } + } + )+ + } +} + +multizip_impls! { + Tuple1 { + (0) -> A + } + Tuple2 { + (0) -> A + (1) -> B + } + Tuple3 { + (0) -> A + (1) -> B + (2) -> C + } + Tuple4 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + } + Tuple5 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + } + Tuple6 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + } + Tuple7 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + } + Tuple8 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + (7) -> H + } + Tuple9 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + (7) -> H + (8) -> I + } + Tuple10 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + (7) -> H + (8) -> I + (9) -> J + } + Tuple11 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + (7) -> H + (8) -> I + (9) -> J + (10) -> K + } + Tuple12 { + (0) -> A + (1) -> B + (2) -> C + (3) -> D + (4) -> E + (5) -> F + (6) -> G + (7) -> H + (8) -> I + (9) -> J + (10) -> K + (11) -> L + } +} -- cgit v1.2.3