| 1 | package async |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "reflect" |
| 6 | |
| 7 | "go.bigb.es/auxilia/fn" |
| 8 | ) |
| 9 | |
| 10 | func select1[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 11 | if len(inp) != 1 { |
| 12 | panic("async: select1 called with wrong number of channels") |
| 13 | } |
| 14 | select { |
| 15 | case <-ctx.Done(): |
| 16 | return -1, fn.Zero[T](), false |
| 17 | case val, ok := <-inp[0]: |
| 18 | return 0, val, ok |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | func select2[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 23 | if len(inp) != 2 { |
| 24 | panic("async: select2 called with wrong number of channels") |
| 25 | } |
| 26 | select { |
| 27 | case <-ctx.Done(): |
| 28 | return -1, fn.Zero[T](), false |
| 29 | case val, ok := <-inp[0]: |
| 30 | return 0, val, ok |
| 31 | case val, ok := <-inp[1]: |
| 32 | return 1, val, ok |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | func select3[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 37 | if len(inp) != 3 { |
| 38 | panic("async: select3 called with wrong number of channels") |
| 39 | } |
| 40 | select { |
| 41 | case <-ctx.Done(): |
| 42 | return -1, fn.Zero[T](), false |
| 43 | case val, ok := <-inp[0]: |
| 44 | return 0, val, ok |
| 45 | case val, ok := <-inp[1]: |
| 46 | return 1, val, ok |
| 47 | case val, ok := <-inp[2]: |
| 48 | return 2, val, ok |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | func select4[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 53 | if len(inp) != 4 { |
| 54 | panic("async: select4 called with wrong number of channels") |
| 55 | } |
| 56 | select { |
| 57 | case <-ctx.Done(): |
| 58 | return -1, fn.Zero[T](), false |
| 59 | case val, ok := <-inp[0]: |
| 60 | return 0, val, ok |
| 61 | case val, ok := <-inp[1]: |
| 62 | return 1, val, ok |
| 63 | case val, ok := <-inp[2]: |
| 64 | return 2, val, ok |
| 65 | case val, ok := <-inp[3]: |
| 66 | return 3, val, ok |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | func select5[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 71 | if len(inp) != 5 { |
| 72 | panic("async: select5 called with wrong number of channels") |
| 73 | } |
| 74 | select { |
| 75 | case <-ctx.Done(): |
| 76 | return -1, fn.Zero[T](), false |
| 77 | case val, ok := <-inp[0]: |
| 78 | return 0, val, ok |
| 79 | case val, ok := <-inp[1]: |
| 80 | return 1, val, ok |
| 81 | case val, ok := <-inp[2]: |
| 82 | return 2, val, ok |
| 83 | case val, ok := <-inp[3]: |
| 84 | return 3, val, ok |
| 85 | case val, ok := <-inp[4]: |
| 86 | return 4, val, ok |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | func select6[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 91 | if len(inp) != 6 { |
| 92 | panic("async: select6 called with wrong number of channels") |
| 93 | } |
| 94 | select { |
| 95 | case <-ctx.Done(): |
| 96 | return -1, fn.Zero[T](), false |
| 97 | case val, ok := <-inp[0]: |
| 98 | return 0, val, ok |
| 99 | case val, ok := <-inp[1]: |
| 100 | return 1, val, ok |
| 101 | case val, ok := <-inp[2]: |
| 102 | return 2, val, ok |
| 103 | case val, ok := <-inp[3]: |
| 104 | return 3, val, ok |
| 105 | case val, ok := <-inp[4]: |
| 106 | return 4, val, ok |
| 107 | case val, ok := <-inp[5]: |
| 108 | return 5, val, ok |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | func select7[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 113 | if len(inp) != 7 { |
| 114 | panic("async: select7 called with wrong number of channels") |
| 115 | } |
| 116 | select { |
| 117 | case <-ctx.Done(): |
| 118 | return -1, fn.Zero[T](), false |
| 119 | case val, ok := <-inp[0]: |
| 120 | return 0, val, ok |
| 121 | case val, ok := <-inp[1]: |
| 122 | return 1, val, ok |
| 123 | case val, ok := <-inp[2]: |
| 124 | return 2, val, ok |
| 125 | case val, ok := <-inp[3]: |
| 126 | return 3, val, ok |
| 127 | case val, ok := <-inp[4]: |
| 128 | return 4, val, ok |
| 129 | case val, ok := <-inp[5]: |
| 130 | return 5, val, ok |
| 131 | case val, ok := <-inp[6]: |
| 132 | return 6, val, ok |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | func select8[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 137 | if len(inp) != 8 { |
| 138 | panic("async: select8 called with wrong number of channels") |
| 139 | } |
| 140 | select { |
| 141 | case <-ctx.Done(): |
| 142 | return -1, fn.Zero[T](), false |
| 143 | case val, ok := <-inp[0]: |
| 144 | return 0, val, ok |
| 145 | case val, ok := <-inp[1]: |
| 146 | return 1, val, ok |
| 147 | case val, ok := <-inp[2]: |
| 148 | return 2, val, ok |
| 149 | case val, ok := <-inp[3]: |
| 150 | return 3, val, ok |
| 151 | case val, ok := <-inp[4]: |
| 152 | return 4, val, ok |
| 153 | case val, ok := <-inp[5]: |
| 154 | return 5, val, ok |
| 155 | case val, ok := <-inp[6]: |
| 156 | return 6, val, ok |
| 157 | case val, ok := <-inp[7]: |
| 158 | return 7, val, ok |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | func select9[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 163 | if len(inp) != 9 { |
| 164 | panic("async: select9 called with wrong number of channels") |
| 165 | } |
| 166 | select { |
| 167 | case <-ctx.Done(): |
| 168 | return -1, fn.Zero[T](), false |
| 169 | case val, ok := <-inp[0]: |
| 170 | return 0, val, ok |
| 171 | case val, ok := <-inp[1]: |
| 172 | return 1, val, ok |
| 173 | case val, ok := <-inp[2]: |
| 174 | return 2, val, ok |
| 175 | case val, ok := <-inp[3]: |
| 176 | return 3, val, ok |
| 177 | case val, ok := <-inp[4]: |
| 178 | return 4, val, ok |
| 179 | case val, ok := <-inp[5]: |
| 180 | return 5, val, ok |
| 181 | case val, ok := <-inp[6]: |
| 182 | return 6, val, ok |
| 183 | case val, ok := <-inp[7]: |
| 184 | return 7, val, ok |
| 185 | case val, ok := <-inp[8]: |
| 186 | return 8, val, ok |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | func select10[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 191 | if len(inp) != 10 { |
| 192 | panic("async: select10 called with wrong number of channels") |
| 193 | } |
| 194 | select { |
| 195 | case <-ctx.Done(): |
| 196 | return -1, fn.Zero[T](), false |
| 197 | case val, ok := <-inp[0]: |
| 198 | return 0, val, ok |
| 199 | case val, ok := <-inp[1]: |
| 200 | return 1, val, ok |
| 201 | case val, ok := <-inp[2]: |
| 202 | return 2, val, ok |
| 203 | case val, ok := <-inp[3]: |
| 204 | return 3, val, ok |
| 205 | case val, ok := <-inp[4]: |
| 206 | return 4, val, ok |
| 207 | case val, ok := <-inp[5]: |
| 208 | return 5, val, ok |
| 209 | case val, ok := <-inp[6]: |
| 210 | return 6, val, ok |
| 211 | case val, ok := <-inp[7]: |
| 212 | return 7, val, ok |
| 213 | case val, ok := <-inp[8]: |
| 214 | return 8, val, ok |
| 215 | case val, ok := <-inp[9]: |
| 216 | return 9, val, ok |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | func select11[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 221 | if len(inp) != 11 { |
| 222 | panic("async: select11 called with wrong number of channels") |
| 223 | } |
| 224 | select { |
| 225 | case <-ctx.Done(): |
| 226 | return -1, fn.Zero[T](), false |
| 227 | case val, ok := <-inp[0]: |
| 228 | return 0, val, ok |
| 229 | case val, ok := <-inp[1]: |
| 230 | return 1, val, ok |
| 231 | case val, ok := <-inp[2]: |
| 232 | return 2, val, ok |
| 233 | case val, ok := <-inp[3]: |
| 234 | return 3, val, ok |
| 235 | case val, ok := <-inp[4]: |
| 236 | return 4, val, ok |
| 237 | case val, ok := <-inp[5]: |
| 238 | return 5, val, ok |
| 239 | case val, ok := <-inp[6]: |
| 240 | return 6, val, ok |
| 241 | case val, ok := <-inp[7]: |
| 242 | return 7, val, ok |
| 243 | case val, ok := <-inp[8]: |
| 244 | return 8, val, ok |
| 245 | case val, ok := <-inp[9]: |
| 246 | return 9, val, ok |
| 247 | case val, ok := <-inp[10]: |
| 248 | return 10, val, ok |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | func select12[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 253 | if len(inp) != 12 { |
| 254 | panic("async: select12 called with wrong number of channels") |
| 255 | } |
| 256 | select { |
| 257 | case <-ctx.Done(): |
| 258 | return -1, fn.Zero[T](), false |
| 259 | case val, ok := <-inp[0]: |
| 260 | return 0, val, ok |
| 261 | case val, ok := <-inp[1]: |
| 262 | return 1, val, ok |
| 263 | case val, ok := <-inp[2]: |
| 264 | return 2, val, ok |
| 265 | case val, ok := <-inp[3]: |
| 266 | return 3, val, ok |
| 267 | case val, ok := <-inp[4]: |
| 268 | return 4, val, ok |
| 269 | case val, ok := <-inp[5]: |
| 270 | return 5, val, ok |
| 271 | case val, ok := <-inp[6]: |
| 272 | return 6, val, ok |
| 273 | case val, ok := <-inp[7]: |
| 274 | return 7, val, ok |
| 275 | case val, ok := <-inp[8]: |
| 276 | return 8, val, ok |
| 277 | case val, ok := <-inp[9]: |
| 278 | return 9, val, ok |
| 279 | case val, ok := <-inp[10]: |
| 280 | return 10, val, ok |
| 281 | case val, ok := <-inp[11]: |
| 282 | return 11, val, ok |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | func select13[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 287 | if len(inp) != 13 { |
| 288 | panic("async: select13 called with wrong number of channels") |
| 289 | } |
| 290 | select { |
| 291 | case <-ctx.Done(): |
| 292 | return -1, fn.Zero[T](), false |
| 293 | case val, ok := <-inp[0]: |
| 294 | return 0, val, ok |
| 295 | case val, ok := <-inp[1]: |
| 296 | return 1, val, ok |
| 297 | case val, ok := <-inp[2]: |
| 298 | return 2, val, ok |
| 299 | case val, ok := <-inp[3]: |
| 300 | return 3, val, ok |
| 301 | case val, ok := <-inp[4]: |
| 302 | return 4, val, ok |
| 303 | case val, ok := <-inp[5]: |
| 304 | return 5, val, ok |
| 305 | case val, ok := <-inp[6]: |
| 306 | return 6, val, ok |
| 307 | case val, ok := <-inp[7]: |
| 308 | return 7, val, ok |
| 309 | case val, ok := <-inp[8]: |
| 310 | return 8, val, ok |
| 311 | case val, ok := <-inp[9]: |
| 312 | return 9, val, ok |
| 313 | case val, ok := <-inp[10]: |
| 314 | return 10, val, ok |
| 315 | case val, ok := <-inp[11]: |
| 316 | return 11, val, ok |
| 317 | case val, ok := <-inp[12]: |
| 318 | return 12, val, ok |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | func select14[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 323 | if len(inp) != 14 { |
| 324 | panic("async: select14 called with wrong number of channels") |
| 325 | } |
| 326 | select { |
| 327 | case <-ctx.Done(): |
| 328 | return -1, fn.Zero[T](), false |
| 329 | case val, ok := <-inp[0]: |
| 330 | return 0, val, ok |
| 331 | case val, ok := <-inp[1]: |
| 332 | return 1, val, ok |
| 333 | case val, ok := <-inp[2]: |
| 334 | return 2, val, ok |
| 335 | case val, ok := <-inp[3]: |
| 336 | return 3, val, ok |
| 337 | case val, ok := <-inp[4]: |
| 338 | return 4, val, ok |
| 339 | case val, ok := <-inp[5]: |
| 340 | return 5, val, ok |
| 341 | case val, ok := <-inp[6]: |
| 342 | return 6, val, ok |
| 343 | case val, ok := <-inp[7]: |
| 344 | return 7, val, ok |
| 345 | case val, ok := <-inp[8]: |
| 346 | return 8, val, ok |
| 347 | case val, ok := <-inp[9]: |
| 348 | return 9, val, ok |
| 349 | case val, ok := <-inp[10]: |
| 350 | return 10, val, ok |
| 351 | case val, ok := <-inp[11]: |
| 352 | return 11, val, ok |
| 353 | case val, ok := <-inp[12]: |
| 354 | return 12, val, ok |
| 355 | case val, ok := <-inp[13]: |
| 356 | return 13, val, ok |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | func select15[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 361 | if len(inp) != 15 { |
| 362 | panic("async: select15 called with wrong number of channels") |
| 363 | } |
| 364 | select { |
| 365 | case <-ctx.Done(): |
| 366 | return -1, fn.Zero[T](), false |
| 367 | case val, ok := <-inp[0]: |
| 368 | return 0, val, ok |
| 369 | case val, ok := <-inp[1]: |
| 370 | return 1, val, ok |
| 371 | case val, ok := <-inp[2]: |
| 372 | return 2, val, ok |
| 373 | case val, ok := <-inp[3]: |
| 374 | return 3, val, ok |
| 375 | case val, ok := <-inp[4]: |
| 376 | return 4, val, ok |
| 377 | case val, ok := <-inp[5]: |
| 378 | return 5, val, ok |
| 379 | case val, ok := <-inp[6]: |
| 380 | return 6, val, ok |
| 381 | case val, ok := <-inp[7]: |
| 382 | return 7, val, ok |
| 383 | case val, ok := <-inp[8]: |
| 384 | return 8, val, ok |
| 385 | case val, ok := <-inp[9]: |
| 386 | return 9, val, ok |
| 387 | case val, ok := <-inp[10]: |
| 388 | return 10, val, ok |
| 389 | case val, ok := <-inp[11]: |
| 390 | return 11, val, ok |
| 391 | case val, ok := <-inp[12]: |
| 392 | return 12, val, ok |
| 393 | case val, ok := <-inp[13]: |
| 394 | return 13, val, ok |
| 395 | case val, ok := <-inp[14]: |
| 396 | return 14, val, ok |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | func select16[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 401 | if len(inp) != 16 { |
| 402 | panic("async: select16 called with wrong number of channels") |
| 403 | } |
| 404 | select { |
| 405 | case <-ctx.Done(): |
| 406 | return -1, fn.Zero[T](), false |
| 407 | case val, ok := <-inp[0]: |
| 408 | return 0, val, ok |
| 409 | case val, ok := <-inp[1]: |
| 410 | return 1, val, ok |
| 411 | case val, ok := <-inp[2]: |
| 412 | return 2, val, ok |
| 413 | case val, ok := <-inp[3]: |
| 414 | return 3, val, ok |
| 415 | case val, ok := <-inp[4]: |
| 416 | return 4, val, ok |
| 417 | case val, ok := <-inp[5]: |
| 418 | return 5, val, ok |
| 419 | case val, ok := <-inp[6]: |
| 420 | return 6, val, ok |
| 421 | case val, ok := <-inp[7]: |
| 422 | return 7, val, ok |
| 423 | case val, ok := <-inp[8]: |
| 424 | return 8, val, ok |
| 425 | case val, ok := <-inp[9]: |
| 426 | return 9, val, ok |
| 427 | case val, ok := <-inp[10]: |
| 428 | return 10, val, ok |
| 429 | case val, ok := <-inp[11]: |
| 430 | return 11, val, ok |
| 431 | case val, ok := <-inp[12]: |
| 432 | return 12, val, ok |
| 433 | case val, ok := <-inp[13]: |
| 434 | return 13, val, ok |
| 435 | case val, ok := <-inp[14]: |
| 436 | return 14, val, ok |
| 437 | case val, ok := <-inp[15]: |
| 438 | return 15, val, ok |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | func selectReflect[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 443 | cases := make([]reflect.SelectCase, len(inp)+1) |
| 444 | cases[0] = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(ctx.Done())} |
| 445 | for i, c := range inp { |
| 446 | cases[i+1] = reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(c)} |
| 447 | } |
| 448 | i, val, ok := reflect.Select(cases) |
| 449 | if i == 0 { |
| 450 | return -1, fn.Zero[T](), false |
| 451 | } |
| 452 | return i - 1, val.Interface().(T), ok |
| 453 | } |
| 454 | |
| 455 | // SelectSlice waits for the first channel in inp to become ready, or for ctx |
| 456 | // to be cancelled. Returns the index of the ready channel (-1 on cancellation), |
| 457 | // the received value, and whether the channel was open. |
| 458 | func SelectSlice[T any](ctx context.Context, inp []<-chan T) (int, T, bool) { |
| 459 | switch len(inp) { |
| 460 | case 0: |
| 461 | panic("async: SelectSlice called with empty slice") |
| 462 | case 1: |
| 463 | return select1(ctx, inp) |
| 464 | case 2: |
| 465 | return select2(ctx, inp) |
| 466 | case 3: |
| 467 | return select3(ctx, inp) |
| 468 | case 4: |
| 469 | return select4(ctx, inp) |
| 470 | case 5: |
| 471 | return select5(ctx, inp) |
| 472 | case 6: |
| 473 | return select6(ctx, inp) |
| 474 | case 7: |
| 475 | return select7(ctx, inp) |
| 476 | case 8: |
| 477 | return select8(ctx, inp) |
| 478 | case 9: |
| 479 | return select9(ctx, inp) |
| 480 | case 10: |
| 481 | return select10(ctx, inp) |
| 482 | case 11: |
| 483 | return select11(ctx, inp) |
| 484 | case 12: |
| 485 | return select12(ctx, inp) |
| 486 | case 13: |
| 487 | return select13(ctx, inp) |
| 488 | case 14: |
| 489 | return select14(ctx, inp) |
| 490 | case 15: |
| 491 | return select15(ctx, inp) |
| 492 | case 16: |
| 493 | return select16(ctx, inp) |
| 494 | default: |
| 495 | return selectReflect(ctx, inp) |
| 496 | } |
| 497 | } |
| 498 | |
| 499 | // SelectSliceBi is like [SelectSlice] but accepts bidirectional channels. |
| 500 | func SelectSliceBi[T any](ctx context.Context, inp []chan T) (int, T, bool) { |
| 501 | out := make([]<-chan T, len(inp)) |
| 502 | for i, c := range inp { |
| 503 | out[i] = c |
| 504 | } |
| 505 | return SelectSlice(ctx, out) |
| 506 | } |
| 507 | |