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| 1 | +use super::plumbing::*; |
| 2 | +use super::*; |
| 3 | + |
| 4 | +use std::cmp; |
| 5 | + |
| 6 | +/// `MultiZip` is an iterator that zips up a tuple of parallel iterators to |
| 7 | +/// produce tuples of their items. |
| 8 | +/// |
| 9 | +/// It is created by calling `into_par_iter()` on a tuple of types that |
| 10 | +/// implement `IntoParallelIterator`, or `par_iter()`/`par_iter_mut()` with |
| 11 | +/// types that are iterable by reference. |
| 12 | +/// |
| 13 | +/// The implementation currently support tuples up to length 12. |
| 14 | +/// |
| 15 | +/// # Examples |
| 16 | +/// |
| 17 | +/// ``` |
| 18 | +/// use rayon::prelude::*; |
| 19 | +/// |
| 20 | +/// // This will iterate `r` by mutable reference, like `par_iter_mut()`, while |
| 21 | +/// // ranges are all iterated by value like `into_par_iter()`. |
| 22 | +/// // Note that the zipped iterator is only as long as the shortest input. |
| 23 | +/// let mut r = vec![0; 3]; |
| 24 | +/// (&mut r, 1..10, 10..100, 100..1000).into_par_iter() |
| 25 | +/// .for_each(|(r, x, y, z)| *r = x * y + z); |
| 26 | +/// |
| 27 | +/// assert_eq!(&r, &[1 * 10 + 100, 2 * 11 + 101, 3 * 12 + 102]); |
| 28 | +/// ``` |
| 29 | +/// |
| 30 | +/// For a group that should all be iterated by reference, you can use a tuple reference. |
| 31 | +/// |
| 32 | +/// ``` |
| 33 | +/// use rayon::prelude::*; |
| 34 | +/// |
| 35 | +/// let xs: Vec<_> = (1..10).collect(); |
| 36 | +/// let ys: Vec<_> = (10..100).collect(); |
| 37 | +/// let zs: Vec<_> = (100..1000).collect(); |
| 38 | +/// |
| 39 | +/// // Reference each input separately with `IntoParallelIterator`: |
| 40 | +/// let r1: Vec<_> = (&xs, &ys, &zs).into_par_iter() |
| 41 | +/// .map(|(x, y, z)| x * y + z) |
| 42 | +/// .collect(); |
| 43 | +/// |
| 44 | +/// // Reference them all together with `IntoParallelRefIterator`: |
| 45 | +/// let r2: Vec<_> = (xs, ys, zs).par_iter() |
| 46 | +/// .map(|(x, y, z)| x * y + z) |
| 47 | +/// .collect(); |
| 48 | +/// |
| 49 | +/// assert_eq!(r1, r2); |
| 50 | +/// ``` |
| 51 | +/// |
| 52 | +/// Mutable references to a tuple will work similarly. |
| 53 | +/// |
| 54 | +/// ``` |
| 55 | +/// use rayon::prelude::*; |
| 56 | +/// |
| 57 | +/// let mut xs: Vec<_> = (1..4).collect(); |
| 58 | +/// let mut ys: Vec<_> = (-4..-1).collect(); |
| 59 | +/// let mut zs = vec![0; 3]; |
| 60 | +/// |
| 61 | +/// // Mutably reference each input separately with `IntoParallelIterator`: |
| 62 | +/// (&mut xs, &mut ys, &mut zs).into_par_iter().for_each(|(x, y, z)| { |
| 63 | +/// *z += *x + *y; |
| 64 | +/// std::mem::swap(x, y); |
| 65 | +/// }); |
| 66 | +/// |
| 67 | +/// assert_eq!(xs, (vec![-4, -3, -2])); |
| 68 | +/// assert_eq!(ys, (vec![1, 2, 3])); |
| 69 | +/// assert_eq!(zs, (vec![-3, -1, 1])); |
| 70 | +/// |
| 71 | +/// // Mutably reference them all together with `IntoParallelRefMutIterator`: |
| 72 | +/// let mut tuple = (xs, ys, zs); |
| 73 | +/// tuple.par_iter_mut().for_each(|(x, y, z)| { |
| 74 | +/// *z += *x + *y; |
| 75 | +/// std::mem::swap(x, y); |
| 76 | +/// }); |
| 77 | +/// |
| 78 | +/// assert_eq!(tuple, (vec![1, 2, 3], vec![-4, -3, -2], vec![-6, -2, 2])); |
| 79 | +/// ``` |
| 80 | +#[derive(Debug, Clone)] |
| 81 | +pub struct MultiZip<T> { |
| 82 | + tuple: T, |
| 83 | +} |
| 84 | + |
| 85 | +macro_rules! zip { |
| 86 | + ($first:expr, $( $iter:expr, )*) => { |
| 87 | + $first $( .zip($iter) )* |
| 88 | + }; |
| 89 | +} |
| 90 | + |
| 91 | +macro_rules! min { |
| 92 | + ($x:expr,) => { $x }; |
| 93 | + ($x:expr, $( $y:expr, )+) => { cmp::min($x, min!($( $y, )+)) }; |
| 94 | +} |
| 95 | + |
| 96 | +macro_rules! flatten { |
| 97 | + (|$a:tt : $A:tt| -> ($( $X:ident, )+) { $tuple:tt };) => {{ |
| 98 | + fn flatten<$( $X ),+>($a : $A) -> ($( $X, )*) { |
| 99 | + $tuple |
| 100 | + } |
| 101 | + flatten |
| 102 | + }}; |
| 103 | + (|$a:tt : $A:tt| -> ($( $X:ident, )+) { ($( $x:ident, )+) }; |
| 104 | + $B:ident, $( $T:ident, )*) => { |
| 105 | + flatten!(|($a, b): ($A, $B)| -> ($( $X, )+ $B,) { ($( $x, )+ b,) }; $( $T, )*) |
| 106 | + }; |
| 107 | + ($A:ident, $( $T:ident, )*) => { |
| 108 | + flatten!(|a: $A| -> ($A,) { (a,) }; $( $T, )*) |
| 109 | + }; |
| 110 | +} |
| 111 | + |
| 112 | +macro_rules! multizip_impls { |
| 113 | + ($( |
| 114 | + $Tuple:ident { |
| 115 | + $(($idx:tt) -> $T:ident)+ |
| 116 | + } |
| 117 | + )+) => { |
| 118 | + $( |
| 119 | + impl<$( $T, )+> IntoParallelIterator for ($( $T, )+) |
| 120 | + where |
| 121 | + $( |
| 122 | + $T: IntoParallelIterator, |
| 123 | + $T::Iter: IndexedParallelIterator, |
| 124 | + )+ |
| 125 | + { |
| 126 | + type Item = ($( $T::Item, )+); |
| 127 | + type Iter = MultiZip<($( $T::Iter, )+)>; |
| 128 | + |
| 129 | + fn into_par_iter(self) -> Self::Iter { |
| 130 | + MultiZip { |
| 131 | + tuple: ( $( self.$idx.into_par_iter(), )+ ), |
| 132 | + } |
| 133 | + } |
| 134 | + } |
| 135 | + |
| 136 | + impl<'a, $( $T, )+> IntoParallelIterator for &'a ($( $T, )+) |
| 137 | + where |
| 138 | + $( |
| 139 | + $T: IntoParallelRefIterator<'a>, |
| 140 | + $T::Iter: IndexedParallelIterator, |
| 141 | + )+ |
| 142 | + { |
| 143 | + type Item = ($( $T::Item, )+); |
| 144 | + type Iter = MultiZip<($( $T::Iter, )+)>; |
| 145 | + |
| 146 | + fn into_par_iter(self) -> Self::Iter { |
| 147 | + MultiZip { |
| 148 | + tuple: ( $( self.$idx.par_iter(), )+ ), |
| 149 | + } |
| 150 | + } |
| 151 | + } |
| 152 | + |
| 153 | + impl<'a, $( $T, )+> IntoParallelIterator for &'a mut ($( $T, )+) |
| 154 | + where |
| 155 | + $( |
| 156 | + $T: IntoParallelRefMutIterator<'a>, |
| 157 | + $T::Iter: IndexedParallelIterator, |
| 158 | + )+ |
| 159 | + { |
| 160 | + type Item = ($( $T::Item, )+); |
| 161 | + type Iter = MultiZip<($( $T::Iter, )+)>; |
| 162 | + |
| 163 | + fn into_par_iter(self) -> Self::Iter { |
| 164 | + MultiZip { |
| 165 | + tuple: ( $( self.$idx.par_iter_mut(), )+ ), |
| 166 | + } |
| 167 | + } |
| 168 | + } |
| 169 | + |
| 170 | + impl<$( $T, )+> ParallelIterator for MultiZip<($( $T, )+)> |
| 171 | + where |
| 172 | + $( $T: IndexedParallelIterator, )+ |
| 173 | + { |
| 174 | + type Item = ($( $T::Item, )+); |
| 175 | + |
| 176 | + fn drive_unindexed<CONSUMER>(self, consumer: CONSUMER) -> CONSUMER::Result |
| 177 | + where |
| 178 | + CONSUMER: UnindexedConsumer<Self::Item>, |
| 179 | + { |
| 180 | + self.drive(consumer) |
| 181 | + } |
| 182 | + |
| 183 | + fn opt_len(&self) -> Option<usize> { |
| 184 | + Some(self.len()) |
| 185 | + } |
| 186 | + } |
| 187 | + |
| 188 | + impl<$( $T, )+> IndexedParallelIterator for MultiZip<($( $T, )+)> |
| 189 | + where |
| 190 | + $( $T: IndexedParallelIterator, )+ |
| 191 | + { |
| 192 | + fn drive<CONSUMER>(self, consumer: CONSUMER) -> CONSUMER::Result |
| 193 | + where |
| 194 | + CONSUMER: Consumer<Self::Item>, |
| 195 | + { |
| 196 | + zip!($( self.tuple.$idx, )+) |
| 197 | + .map(flatten!($( $T, )+)) |
| 198 | + .drive(consumer) |
| 199 | + } |
| 200 | + |
| 201 | + fn len(&self) -> usize { |
| 202 | + min!($( self.tuple.$idx.len(), )+) |
| 203 | + } |
| 204 | + |
| 205 | + fn with_producer<CB>(self, callback: CB) -> CB::Output |
| 206 | + where |
| 207 | + CB: ProducerCallback<Self::Item>, |
| 208 | + { |
| 209 | + zip!($( self.tuple.$idx, )+) |
| 210 | + .map(flatten!($( $T, )+)) |
| 211 | + .with_producer(callback) |
| 212 | + } |
| 213 | + } |
| 214 | + )+ |
| 215 | + } |
| 216 | +} |
| 217 | + |
| 218 | +multizip_impls! { |
| 219 | + Tuple1 { |
| 220 | + (0) -> A |
| 221 | + } |
| 222 | + Tuple2 { |
| 223 | + (0) -> A |
| 224 | + (1) -> B |
| 225 | + } |
| 226 | + Tuple3 { |
| 227 | + (0) -> A |
| 228 | + (1) -> B |
| 229 | + (2) -> C |
| 230 | + } |
| 231 | + Tuple4 { |
| 232 | + (0) -> A |
| 233 | + (1) -> B |
| 234 | + (2) -> C |
| 235 | + (3) -> D |
| 236 | + } |
| 237 | + Tuple5 { |
| 238 | + (0) -> A |
| 239 | + (1) -> B |
| 240 | + (2) -> C |
| 241 | + (3) -> D |
| 242 | + (4) -> E |
| 243 | + } |
| 244 | + Tuple6 { |
| 245 | + (0) -> A |
| 246 | + (1) -> B |
| 247 | + (2) -> C |
| 248 | + (3) -> D |
| 249 | + (4) -> E |
| 250 | + (5) -> F |
| 251 | + } |
| 252 | + Tuple7 { |
| 253 | + (0) -> A |
| 254 | + (1) -> B |
| 255 | + (2) -> C |
| 256 | + (3) -> D |
| 257 | + (4) -> E |
| 258 | + (5) -> F |
| 259 | + (6) -> G |
| 260 | + } |
| 261 | + Tuple8 { |
| 262 | + (0) -> A |
| 263 | + (1) -> B |
| 264 | + (2) -> C |
| 265 | + (3) -> D |
| 266 | + (4) -> E |
| 267 | + (5) -> F |
| 268 | + (6) -> G |
| 269 | + (7) -> H |
| 270 | + } |
| 271 | + Tuple9 { |
| 272 | + (0) -> A |
| 273 | + (1) -> B |
| 274 | + (2) -> C |
| 275 | + (3) -> D |
| 276 | + (4) -> E |
| 277 | + (5) -> F |
| 278 | + (6) -> G |
| 279 | + (7) -> H |
| 280 | + (8) -> I |
| 281 | + } |
| 282 | + Tuple10 { |
| 283 | + (0) -> A |
| 284 | + (1) -> B |
| 285 | + (2) -> C |
| 286 | + (3) -> D |
| 287 | + (4) -> E |
| 288 | + (5) -> F |
| 289 | + (6) -> G |
| 290 | + (7) -> H |
| 291 | + (8) -> I |
| 292 | + (9) -> J |
| 293 | + } |
| 294 | + Tuple11 { |
| 295 | + (0) -> A |
| 296 | + (1) -> B |
| 297 | + (2) -> C |
| 298 | + (3) -> D |
| 299 | + (4) -> E |
| 300 | + (5) -> F |
| 301 | + (6) -> G |
| 302 | + (7) -> H |
| 303 | + (8) -> I |
| 304 | + (9) -> J |
| 305 | + (10) -> K |
| 306 | + } |
| 307 | + Tuple12 { |
| 308 | + (0) -> A |
| 309 | + (1) -> B |
| 310 | + (2) -> C |
| 311 | + (3) -> D |
| 312 | + (4) -> E |
| 313 | + (5) -> F |
| 314 | + (6) -> G |
| 315 | + (7) -> H |
| 316 | + (8) -> I |
| 317 | + (9) -> J |
| 318 | + (10) -> K |
| 319 | + (11) -> L |
| 320 | + } |
| 321 | +} |
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