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Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.80 by jsr166, Wed Jan 16 01:59:47 2013 UTC vs.
Revision 1.85 by jsr166, Sat Jan 19 18:18:10 2013 UTC

# Line 1 | Line 1
1   /*
2 < * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
2 > * Copyright (c) 2003, 2012, 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.  Sun designates this
7 > * published by the Free Software Foundation.  Oracle designates this
8   * particular file as subject to the "Classpath" exception as provided
9 < * by Sun in the LICENSE file that accompanied this code.
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
# Line 24 | Line 24
24   */
25  
26   package java.util;
27 + import java.util.stream.Stream;
28 + import java.util.Spliterator;
29 + import java.util.stream.Streams;
30 + import java.util.function.Block;
31  
32   /**
33   * An unbounded priority {@linkplain Queue queue} based on a priority heap.
# Line 63 | Line 67 | package java.util;
67   * java.util.concurrent.PriorityBlockingQueue} class.
68   *
69   * <p>Implementation note: this implementation provides
70 < * O(log(n)) time for the enqueuing and dequeuing methods
70 > * O(log(n)) time for the enqueing and dequeing methods
71   * ({@code offer}, {@code poll}, {@code remove()} and {@code add});
72   * linear time for the {@code remove(Object)} and {@code contains(Object)}
73   * methods; and constant time for the retrieval methods
# Line 77 | Line 81 | package java.util;
81   * @author Josh Bloch, Doug Lea
82   * @param <E> the type of elements held in this collection
83   */
80 – @SuppressWarnings("unchecked")
84   public class PriorityQueue<E> extends AbstractQueue<E>
85      implements java.io.Serializable {
86  
# Line 93 | Line 96 | public class PriorityQueue<E> extends Ab
96       * heap and each descendant d of n, n <= d.  The element with the
97       * lowest value is in queue[0], assuming the queue is nonempty.
98       */
99 <    private transient Object[] queue;
99 >    transient Object[] queue; // non-private to simplify nested class access
100  
101      /**
102       * The number of elements in the priority queue.
# Line 110 | Line 113 | public class PriorityQueue<E> extends Ab
113       * The number of times this priority queue has been
114       * <i>structurally modified</i>.  See AbstractList for gory details.
115       */
116 <    private transient int modCount = 0;
116 >    transient int modCount = 0; // non-private to simplify nested class access
117  
118      /**
119       * Creates a {@code PriorityQueue} with the default initial
# Line 331 | Line 334 | public class PriorityQueue<E> extends Ab
334          return true;
335      }
336  
337 +    @SuppressWarnings("unchecked")
338      public E peek() {
339          return (size == 0) ? null : (E) queue[0];
340      }
# Line 447 | Line 451 | public class PriorityQueue<E> extends Ab
451       *         this queue
452       * @throws NullPointerException if the specified array is null
453       */
454 +    @SuppressWarnings("unchecked")
455      public <T> T[] toArray(T[] a) {
456 +        final int size = this.size;
457          if (a.length < size)
458              // Make a new array of a's runtime type, but my contents:
459              return (T[]) Arrays.copyOf(queue, size, a.getClass());
# Line 512 | Line 518 | public class PriorityQueue<E> extends Ab
518                  (forgetMeNot != null && !forgetMeNot.isEmpty());
519          }
520  
521 +        @SuppressWarnings("unchecked")
522          public E next() {
523              if (expectedModCount != modCount)
524                  throw new ConcurrentModificationException();
# Line 564 | Line 571 | public class PriorityQueue<E> extends Ab
571          size = 0;
572      }
573  
574 +    @SuppressWarnings("unchecked")
575      public E poll() {
576          if (size == 0)
577              return null;
# Line 589 | Line 597 | public class PriorityQueue<E> extends Ab
597       * position before i. This fact is used by iterator.remove so as to
598       * avoid missing traversing elements.
599       */
600 +    @SuppressWarnings("unchecked")
601      private E removeAt(int i) {
602          // assert i >= 0 && i < size;
603          modCount++;
# Line 627 | Line 636 | public class PriorityQueue<E> extends Ab
636              siftUpComparable(k, x);
637      }
638  
639 +    @SuppressWarnings("unchecked")
640      private void siftUpComparable(int k, E x) {
641          Comparable<? super E> key = (Comparable<? super E>) x;
642          while (k > 0) {
# Line 640 | Line 650 | public class PriorityQueue<E> extends Ab
650          queue[k] = key;
651      }
652  
653 +    @SuppressWarnings("unchecked")
654      private void siftUpUsingComparator(int k, E x) {
655          while (k > 0) {
656              int parent = (k - 1) >>> 1;
# Line 667 | Line 678 | public class PriorityQueue<E> extends Ab
678              siftDownComparable(k, x);
679      }
680  
681 +    @SuppressWarnings("unchecked")
682      private void siftDownComparable(int k, E x) {
683          Comparable<? super E> key = (Comparable<? super E>)x;
684          int half = size >>> 1;        // loop while a non-leaf
# Line 685 | Line 697 | public class PriorityQueue<E> extends Ab
697          queue[k] = key;
698      }
699  
700 +    @SuppressWarnings("unchecked")
701      private void siftDownUsingComparator(int k, E x) {
702          int half = size >>> 1;
703          while (k < half) {
# Line 706 | Line 719 | public class PriorityQueue<E> extends Ab
719       * Establishes the heap invariant (described above) in the entire tree,
720       * assuming nothing about the order of the elements prior to the call.
721       */
722 +    @SuppressWarnings("unchecked")
723      private void heapify() {
724          for (int i = (size >>> 1) - 1; i >= 0; i--)
725              siftDown(i, (E) queue[i]);
# Line 730 | Line 744 | public class PriorityQueue<E> extends Ab
744       * @serialData The length of the array backing the instance is
745       *             emitted (int), followed by all of its elements
746       *             (each an {@code Object}) in the proper order.
747 +     * @param s the stream
748       */
749      private void writeObject(java.io.ObjectOutputStream s)
750          throws java.io.IOException {
# Line 745 | Line 760 | public class PriorityQueue<E> extends Ab
760      }
761  
762      /**
763 <     * Reconstitutes this queue from a stream (that is, deserializes it).
763 >     * Reconstitutes the {@code PriorityQueue} instance from a stream
764 >     * (that is, deserializes it).
765 >     *
766 >     * @param s the stream
767       */
768      private void readObject(java.io.ObjectInputStream s)
769          throws java.io.IOException, ClassNotFoundException {
# Line 765 | Line 783 | public class PriorityQueue<E> extends Ab
783          // spec has never explained what that might be.
784          heapify();
785      }
786 +
787 +    // wrapping constructor in method avoids transient javac problems
788 +    final PriorityQueueSpliterator<E> spliterator(int origin, int fence,
789 +                                                  int expectedModCount) {
790 +        return new PriorityQueueSpliterator<E>(this, origin, fence,
791 +                                               expectedModCount);
792 +    }
793 +
794 +    public Stream<E> stream() {
795 +        int flags = Streams.STREAM_IS_SIZED;
796 +        return Streams.stream
797 +            (() -> spliterator(0, size, modCount), flags);
798 +    }
799 +    public Stream<E> parallelStream() {
800 +        int flags = Streams.STREAM_IS_SIZED;
801 +        return Streams.parallelStream
802 +            (() -> spliterator(0, size, modCount), flags);
803 +    }
804 +
805 +    /** Index-based split-by-two Spliterator */
806 +    static final class PriorityQueueSpliterator<E>
807 +        implements Spliterator<E>, Iterator<E> {
808 +        private final PriorityQueue<E> pq;
809 +        private int index;           // current index, modified on advance/split
810 +        private final int fence;     // one past last index
811 +        private final int expectedModCount; // for comodification checks
812 +
813 +        /** Create new spliterator covering the given  range */
814 +        PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence,
815 +                             int expectedModCount) {
816 +            this.pq = pq; this.index = origin; this.fence = fence;
817 +            this.expectedModCount = expectedModCount;
818 +        }
819 +
820 +        public PriorityQueueSpliterator<E> trySplit() {
821 +            int lo = index, mid = (lo + fence) >>> 1;
822 +            return (lo >= mid) ? null :
823 +                new PriorityQueueSpliterator<E>(pq, lo, index = mid,
824 +                                            expectedModCount);
825 +        }
826 +
827 +        public void forEach(Block<? super E> block) {
828 +            Object[] a; int i, hi; // hoist accesses and checks from loop
829 +            if (block == null)
830 +                throw new NullPointerException();
831 +            if ((a = pq.queue).length >= (hi = fence) &&
832 +                (i = index) >= 0 && i < hi) {
833 +                index = hi;
834 +                do {
835 +                    @SuppressWarnings("unchecked") E e = (E) a[i];
836 +                    block.accept(e);
837 +                } while (++i < hi);
838 +                if (pq.modCount != expectedModCount)
839 +                    throw new ConcurrentModificationException();
840 +            }
841 +        }
842 +
843 +        public boolean tryAdvance(Block<? super E> block) {
844 +            if (index >= 0 && index < fence) {
845 +                if (pq.modCount != expectedModCount)
846 +                    throw new ConcurrentModificationException();
847 +                @SuppressWarnings("unchecked") E e =
848 +                    (E)pq.queue[index++];
849 +                block.accept(e);
850 +                return true;
851 +            }
852 +            return false;
853 +        }
854 +
855 +        public long estimateSize() { return (long)(fence - index); }
856 +        public boolean hasExactSize() { return true; }
857 +        public boolean hasExactSplits() { return true; }
858 +
859 +        // Iterator support
860 +        public Iterator<E> iterator() { return this; }
861 +        public void remove() { throw new UnsupportedOperationException(); }
862 +        public boolean hasNext() { return index >= 0 && index < fence; }
863 +
864 +        public E next() {
865 +            if (index < 0 || index >= fence)
866 +                throw new NoSuchElementException();
867 +            if (pq.modCount != expectedModCount)
868 +                throw new ConcurrentModificationException();
869 +            @SuppressWarnings("unchecked") E e =
870 +                (E) pq.queue[index++];
871 +            return e;
872 +        }
873 +    }
874   }

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