1 /* 2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.util.stream; 26 27 import java.util.LongSummaryStatistics; 28 import java.util.Objects; 29 import java.util.OptionalDouble; 30 import java.util.OptionalLong; 31 import java.util.PrimitiveIterator; 32 import java.util.Spliterator; 33 import java.util.Spliterators; 34 import java.util.function.BiConsumer; 35 import java.util.function.BinaryOperator; 36 import java.util.function.IntFunction; 37 import java.util.function.LongBinaryOperator; 38 import java.util.function.LongConsumer; 39 import java.util.function.LongFunction; 40 import java.util.function.LongPredicate; 41 import java.util.function.LongToDoubleFunction; 42 import java.util.function.LongToIntFunction; 43 import java.util.function.LongUnaryOperator; 44 import java.util.function.ObjLongConsumer; 45 import java.util.function.Supplier; 46 47 /** 48 * Abstract base class for an intermediate pipeline stage or pipeline source 49 * stage implementing whose elements are of type {@code long}. 50 * 51 * @param <E_IN> type of elements in the upstream source 52 * @since 1.8 53 */ 54 abstract class LongPipeline<E_IN> 55 extends AbstractPipeline<E_IN, Long, LongStream> 56 implements LongStream { 57 58 /** 59 * Constructor for the head of a stream pipeline. 60 * 61 * @param source {@code Supplier<Spliterator>} describing the stream source 62 * @param sourceFlags the source flags for the stream source, described in 63 * {@link StreamOpFlag} 64 * @param parallel {@code true} if the pipeline is parallel 65 */ 66 LongPipeline(Supplier<? extends Spliterator<Long>> source, 67 int sourceFlags, boolean parallel) { 68 super(source, sourceFlags, parallel); 69 } 70 71 /** 72 * Constructor for the head of a stream pipeline. 73 * 74 * @param source {@code Spliterator} describing the stream source 75 * @param sourceFlags the source flags for the stream source, described in 76 * {@link StreamOpFlag} 77 * @param parallel {@code true} if the pipeline is parallel 78 */ 79 LongPipeline(Spliterator<Long> source, 80 int sourceFlags, boolean parallel) { 81 super(source, sourceFlags, parallel); 82 } 83 84 /** 85 * Constructor for appending an intermediate operation onto an existing pipeline. 86 * 87 * @param upstream the upstream element source. 88 * @param opFlags the operation flags 89 */ 90 LongPipeline(AbstractPipeline<?, E_IN, ?> upstream, int opFlags) { 91 super(upstream, opFlags); 92 } 93 94 /** 95 * Adapt a {@code Sink<Long> to an {@code LongConsumer}, ideally simply 96 * by casting. 97 */ 98 private static LongConsumer adapt(Sink<Long> sink) { 99 if (sink instanceof LongConsumer) { 100 return (LongConsumer) sink; 101 } else { 102 if (Tripwire.ENABLED) 103 Tripwire.trip(AbstractPipeline.class, 104 "using LongStream.adapt(Sink<Long> s)"); 105 return sink::accept; 106 } 107 } 108 109 /** 110 * Adapt a {@code Spliterator<Long>} to a {@code Spliterator.OfLong}. 111 * 112 * @implNote 113 * The implementation attempts to cast to a Spliterator.OfLong, and throws 114 * an exception if this cast is not possible. 115 */ 116 private static Spliterator.OfLong adapt(Spliterator<Long> s) { 117 if (s instanceof Spliterator.OfLong) { 118 return (Spliterator.OfLong) s; 119 } else { 120 if (Tripwire.ENABLED) 121 Tripwire.trip(AbstractPipeline.class, 122 "using LongStream.adapt(Spliterator<Long> s)"); 123 throw new UnsupportedOperationException("LongStream.adapt(Spliterator<Long> s)"); 124 } 125 } 126 127 128 // Shape-specific methods 129 130 @Override 131 final StreamShape getOutputShape() { 132 return StreamShape.LONG_VALUE; 133 } 134 135 @Override 136 final <P_IN> Node<Long> evaluateToNode(PipelineHelper<Long> helper, 137 Spliterator<P_IN> spliterator, 138 boolean flattenTree, 139 IntFunction<Long[]> generator) { 140 return Nodes.collectLong(helper, spliterator, flattenTree); 141 } 142 143 @Override 144 final <P_IN> Spliterator<Long> wrap(PipelineHelper<Long> ph, 145 Supplier<Spliterator<P_IN>> supplier, 146 boolean isParallel) { 147 return new StreamSpliterators.LongWrappingSpliterator<>(ph, supplier, isParallel); 148 } 149 150 @Override 151 final Spliterator.OfLong lazySpliterator(Supplier<? extends Spliterator<Long>> supplier) { 152 return new StreamSpliterators.DelegatingSpliterator.OfLong((Supplier<Spliterator.OfLong>) supplier); 153 } 154 155 @Override 156 final void forEachWithCancel(Spliterator<Long> spliterator, Sink<Long> sink) { 157 Spliterator.OfLong spl = adapt(spliterator); 158 LongConsumer adaptedSink = adapt(sink); 159 do { } while (!sink.cancellationRequested() && spl.tryAdvance(adaptedSink)); 160 } 161 162 @Override 163 final Node.Builder<Long> makeNodeBuilder(long exactSizeIfKnown, IntFunction<Long[]> generator) { 164 return Nodes.longBuilder(exactSizeIfKnown); 165 } 166 167 168 // LongStream 169 170 @Override 171 public final PrimitiveIterator.OfLong iterator() { 172 return Spliterators.iterator(spliterator()); 173 } 174 175 @Override 176 public final Spliterator.OfLong spliterator() { 177 return adapt(super.spliterator()); 178 } 179 180 // Stateless intermediate ops from LongStream 181 182 @Override 183 public final DoubleStream asDoubleStream() { 184 return new DoublePipeline.StatelessOp<Long>(this, StreamShape.LONG_VALUE, 185 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { 186 @Override 187 Sink<Long> opWrapSink(int flags, Sink<Double> sink) { 188 return new Sink.ChainedLong(sink) { 189 @Override 190 public void accept(long t) { 191 downstream.accept((double) t); 192 } 193 }; 194 } 195 }; 196 } 197 198 @Override 199 public final Stream<Long> boxed() { 200 return mapToObj(Long::valueOf); 201 } 202 203 @Override 204 public final LongStream map(LongUnaryOperator mapper) { 205 Objects.requireNonNull(mapper); 206 return new StatelessOp<Long>(this, StreamShape.LONG_VALUE, 207 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { 208 @Override 209 Sink<Long> opWrapSink(int flags, Sink<Long> sink) { 210 return new Sink.ChainedLong(sink) { 211 @Override 212 public void accept(long t) { 213 downstream.accept(mapper.applyAsLong(t)); 214 } 215 }; 216 } 217 }; 218 } 219 220 @Override 221 public final <U> Stream<U> mapToObj(LongFunction<? extends U> mapper) { 222 Objects.requireNonNull(mapper); 223 return new ReferencePipeline.StatelessOp<Long, U>(this, StreamShape.LONG_VALUE, 224 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { 225 @Override 226 Sink<Long> opWrapSink(int flags, Sink<U> sink) { 227 return new Sink.ChainedLong(sink) { 228 @Override 229 public void accept(long t) { 230 downstream.accept(mapper.apply(t)); 231 } 232 }; 233 } 234 }; 235 } 236 237 @Override 238 public final IntStream mapToInt(LongToIntFunction mapper) { 239 Objects.requireNonNull(mapper); 240 return new IntPipeline.StatelessOp<Long>(this, StreamShape.LONG_VALUE, 241 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { 242 @Override 243 Sink<Long> opWrapSink(int flags, Sink<Integer> sink) { 244 return new Sink.ChainedLong(sink) { 245 @Override 246 public void accept(long t) { 247 downstream.accept(mapper.applyAsInt(t)); 248 } 249 }; 250 } 251 }; 252 } 253 254 @Override 255 public final DoubleStream mapToDouble(LongToDoubleFunction mapper) { 256 Objects.requireNonNull(mapper); 257 return new DoublePipeline.StatelessOp<Long>(this, StreamShape.LONG_VALUE, 258 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT) { 259 @Override 260 Sink<Long> opWrapSink(int flags, Sink<Double> sink) { 261 return new Sink.ChainedLong(sink) { 262 @Override 263 public void accept(long t) { 264 downstream.accept(mapper.applyAsDouble(t)); 265 } 266 }; 267 } 268 }; 269 } 270 271 @Override 272 public final LongStream flatMap(LongFunction<? extends LongStream> mapper) { 273 return new StatelessOp<Long>(this, StreamShape.LONG_VALUE, 274 StreamOpFlag.NOT_SORTED | StreamOpFlag.NOT_DISTINCT | StreamOpFlag.NOT_SIZED) { 275 @Override 276 Sink<Long> opWrapSink(int flags, Sink<Long> sink) { 277 return new Sink.ChainedLong(sink) { 278 @Override 279 public void begin(long size) { 280 downstream.begin(-1); 281 } 282 283 @Override 284 public void accept(long t) { 285 // We can do better that this too; optimize for depth=0 case and just grab spliterator and forEach it 286 LongStream result = mapper.apply(t); 287 if (result != null) 288 result.sequential().forEach(i -> downstream.accept(i)); 289 } 290 }; 291 } 292 }; 293 } 294 295 @Override 296 public LongStream unordered() { 297 if (!isOrdered()) 298 return this; 299 return new StatelessOp<Long>(this, StreamShape.LONG_VALUE, StreamOpFlag.NOT_ORDERED) { 300 @Override 301 Sink<Long> opWrapSink(int flags, Sink<Long> sink) { 302 return sink; 303 } 304 }; 305 } 306 307 @Override 308 public final LongStream filter(LongPredicate predicate) { 309 Objects.requireNonNull(predicate); 310 return new StatelessOp<Long>(this, StreamShape.LONG_VALUE, 311 StreamOpFlag.NOT_SIZED) { 312 @Override 313 Sink<Long> opWrapSink(int flags, Sink<Long> sink) { 314 return new Sink.ChainedLong(sink) { 315 @Override 316 public void begin(long size) { 317 downstream.begin(-1); 318 } 319 320 @Override 321 public void accept(long t) { 322 if (predicate.test(t)) 323 downstream.accept(t); 324 } 325 }; 326 } 327 }; 328 } 329 330 @Override 331 public final LongStream peek(LongConsumer consumer) { 332 Objects.requireNonNull(consumer); 333 return new StatelessOp<Long>(this, StreamShape.LONG_VALUE, 334 0) { 335 @Override 336 Sink<Long> opWrapSink(int flags, Sink<Long> sink) { 337 return new Sink.ChainedLong(sink) { 338 @Override 339 public void accept(long t) { 340 consumer.accept(t); 341 downstream.accept(t); 342 } 343 }; 344 } 345 }; 346 } 347 348 // Stateful intermediate ops from LongStream 349 350 private LongStream slice(long skip, long limit) { 351 return SliceOps.makeLong(this, skip, limit); 352 } 353 354 @Override 355 public final LongStream limit(long maxSize) { 356 if (maxSize < 0) 357 throw new IllegalArgumentException(Long.toString(maxSize)); 358 return slice(0, maxSize); 359 } 360 361 @Override 362 public final LongStream substream(long startingOffset) { 363 if (startingOffset < 0) 364 throw new IllegalArgumentException(Long.toString(startingOffset)); 365 if (startingOffset == 0) 366 return this; 367 else 368 return slice(startingOffset, -1); 369 } 370 371 @Override 372 public final LongStream substream(long startingOffset, long endingOffset) { 373 if (startingOffset < 0 || endingOffset < startingOffset) 374 throw new IllegalArgumentException(String.format("substream(%d, %d)", startingOffset, endingOffset)); 375 return slice(startingOffset, endingOffset - startingOffset); 376 } 377 378 @Override 379 public final LongStream sorted() { 380 return SortedOps.makeLong(this); 381 } 382 383 @Override 384 public final LongStream distinct() { 385 // While functional and quick to implement, this approach is not very efficient. 386 // An efficient version requires a long-specific map/set implementation. 387 return boxed().distinct().mapToLong(i -> (long) i); 388 } 389 390 // Terminal ops from LongStream 391 392 @Override 393 public void forEach(LongConsumer action) { 394 evaluate(ForEachOps.makeLong(action, false)); 395 } 396 397 @Override 398 public void forEachOrdered(LongConsumer action) { 399 evaluate(ForEachOps.makeLong(action, true)); 400 } 401 402 @Override 403 public final long sum() { 404 // use better algorithm to compensate for intermediate overflow? 405 return reduce(0, Long::sum); 406 } 407 408 @Override 409 public final OptionalLong min() { 410 return reduce(Math::min); 411 } 412 413 @Override 414 public final OptionalLong max() { 415 return reduce(Math::max); 416 } 417 418 @Override 419 public final OptionalDouble average() { 420 long[] avg = collect(() -> new long[2], 421 (ll, i) -> { 422 ll[0]++; 423 ll[1] += i; 424 }, 425 (ll, rr) -> { 426 ll[0] += rr[0]; 427 ll[1] += rr[1]; 428 }); 429 return avg[0] > 0 430 ? OptionalDouble.of((double) avg[1] / avg[0]) 431 : OptionalDouble.empty(); 432 } 433 434 @Override 435 public final long count() { 436 return map(e -> 1L).sum(); 437 } 438 439 @Override 440 public final LongSummaryStatistics summaryStatistics() { 441 return collect(LongSummaryStatistics::new, LongSummaryStatistics::accept, 442 LongSummaryStatistics::combine); 443 } 444 445 @Override 446 public final long reduce(long identity, LongBinaryOperator op) { 447 return evaluate(ReduceOps.makeLong(identity, op)); 448 } 449 450 @Override 451 public final OptionalLong reduce(LongBinaryOperator op) { 452 return evaluate(ReduceOps.makeLong(op)); 453 } 454 455 @Override 456 public final <R> R collect(Supplier<R> resultFactory, 457 ObjLongConsumer<R> accumulator, 458 BiConsumer<R, R> combiner) { 459 BinaryOperator<R> operator = (left, right) -> { 460 combiner.accept(left, right); 461 return left; 462 }; 463 return evaluate(ReduceOps.makeLong(resultFactory, accumulator, operator)); 464 } 465 466 @Override 467 public final boolean anyMatch(LongPredicate predicate) { 468 return evaluate(MatchOps.makeLong(predicate, MatchOps.MatchKind.ANY)); 469 } 470 471 @Override 472 public final boolean allMatch(LongPredicate predicate) { 473 return evaluate(MatchOps.makeLong(predicate, MatchOps.MatchKind.ALL)); 474 } 475 476 @Override 477 public final boolean noneMatch(LongPredicate predicate) { 478 return evaluate(MatchOps.makeLong(predicate, MatchOps.MatchKind.NONE)); 479 } 480 481 @Override 482 public final OptionalLong findFirst() { 483 return evaluate(FindOps.makeLong(true)); 484 } 485 486 @Override 487 public final OptionalLong findAny() { 488 return evaluate(FindOps.makeLong(false)); 489 } 490 491 @Override 492 public final long[] toArray() { 493 return Nodes.flattenLong((Node.OfLong) evaluateToArrayNode(Long[]::new)) 494 .asPrimitiveArray(); 495 } 496 497 498 // 499 500 /** 501 * Source stage of a LongPipeline. 502 * 503 * @param <E_IN> type of elements in the upstream source 504 * @since 1.8 505 */ 506 static class Head<E_IN> extends LongPipeline<E_IN> { 507 /** 508 * Constructor for the source stage of a LongStream. 509 * 510 * @param source {@code Supplier<Spliterator>} describing the stream 511 * source 512 * @param sourceFlags the source flags for the stream source, described 513 * in {@link StreamOpFlag} 514 * @param parallel {@code true} if the pipeline is parallel 515 */ 516 Head(Supplier<? extends Spliterator<Long>> source, 517 int sourceFlags, boolean parallel) { 518 super(source, sourceFlags, parallel); 519 } 520 521 /** 522 * Constructor for the source stage of a LongStream. 523 * 524 * @param source {@code Spliterator} describing the stream source 525 * @param sourceFlags the source flags for the stream source, described 526 * in {@link StreamOpFlag} 527 * @param parallel {@code true} if the pipeline is parallel 528 */ 529 Head(Spliterator<Long> source, 530 int sourceFlags, boolean parallel) { 531 super(source, sourceFlags, parallel); 532 } 533 534 @Override 535 final boolean opIsStateful() { 536 throw new UnsupportedOperationException(); 537 } 538 539 @Override 540 final Sink<E_IN> opWrapSink(int flags, Sink<Long> sink) { 541 throw new UnsupportedOperationException(); 542 } 543 544 // Optimized sequential terminal operations for the head of the pipeline 545 546 @Override 547 public void forEach(LongConsumer action) { 548 if (!isParallel()) { 549 adapt(sourceStageSpliterator()).forEachRemaining(action); 550 } else { 551 super.forEach(action); 552 } 553 } 554 555 @Override 556 public void forEachOrdered(LongConsumer action) { 557 if (!isParallel()) { 558 adapt(sourceStageSpliterator()).forEachRemaining(action); 559 } else { 560 super.forEachOrdered(action); 561 } 562 } 563 } 564 565 /** Base class for a stateless intermediate stage of a LongStream. 566 * 567 * @param <E_IN> type of elements in the upstream source 568 * @since 1.8 569 */ 570 abstract static class StatelessOp<E_IN> extends LongPipeline<E_IN> { 571 /** 572 * Construct a new LongStream by appending a stateless intermediate 573 * operation to an existing stream. 574 * @param upstream The upstream pipeline stage 575 * @param inputShape The stream shape for the upstream pipeline stage 576 * @param opFlags Operation flags for the new stage 577 */ 578 StatelessOp(AbstractPipeline<?, E_IN, ?> upstream, 579 StreamShape inputShape, 580 int opFlags) { 581 super(upstream, opFlags); 582 assert upstream.getOutputShape() == inputShape; 583 } 584 585 @Override 586 final boolean opIsStateful() { 587 return false; 588 } 589 } 590 591 /** 592 * Base class for a stateful intermediate stage of a LongStream. 593 * 594 * @param <E_IN> type of elements in the upstream source 595 * @since 1.8 596 */ 597 abstract static class StatefulOp<E_IN> extends LongPipeline<E_IN> { 598 /** 599 * Construct a new LongStream by appending a stateful intermediate 600 * operation to an existing stream. 601 * @param upstream The upstream pipeline stage 602 * @param inputShape The stream shape for the upstream pipeline stage 603 * @param opFlags Operation flags for the new stage 604 */ 605 StatefulOp(AbstractPipeline<?, E_IN, ?> upstream, 606 StreamShape inputShape, 607 int opFlags) { 608 super(upstream, opFlags); 609 assert upstream.getOutputShape() == inputShape; 610 } 611 612 @Override 613 final boolean opIsStateful() { 614 return true; 615 } 616 617 @Override 618 abstract <P_IN> Node<Long> opEvaluateParallel(PipelineHelper<Long> helper, 619 Spliterator<P_IN> spliterator, 620 IntFunction<Long[]> generator); 621 } 622 }