--- jsr166/src/main/java/util/PriorityQueue.java	2013/01/19 18:11:56	1.84
+++ jsr166/src/main/java/util/PriorityQueue.java	2016/11/30 03:31:47	1.113
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,10 +24,8 @@
  */
 
 package java.util;
-import java.util.stream.Stream;
-import java.util.Spliterator;
-import java.util.stream.Streams;
-import java.util.function.Block;
+
+import java.util.function.Consumer;
 
 /**
  * An unbounded priority {@linkplain Queue queue} based on a priority heap.
@@ -56,7 +54,8 @@ import java.util.function.Block;
  * <p>This class and its iterator implement all of the
  * <em>optional</em> methods of the {@link Collection} and {@link
  * Iterator} interfaces.  The Iterator provided in method {@link
- * #iterator()} is <em>not</em> guaranteed to traverse the elements of
+ * #iterator()} and the Spliterator provided in method {@link #spliterator()}
+ * are <em>not</em> guaranteed to traverse the elements of
  * the priority queue in any particular order. If you need ordered
  * traversal, consider using {@code Arrays.sort(pq.toArray())}.
  *
@@ -67,7 +66,7 @@ import java.util.function.Block;
  * java.util.concurrent.PriorityBlockingQueue} class.
  *
  * <p>Implementation note: this implementation provides
- * O(log(n)) time for the enqueing and dequeing methods
+ * O(log(n)) time for the enqueuing and dequeuing methods
  * ({@code offer}, {@code poll}, {@code remove()} and {@code add});
  * linear time for the {@code remove(Object)} and {@code contains(Object)}
  * methods; and constant time for the retrieval methods
@@ -79,7 +78,7 @@ import java.util.function.Block;
  *
  * @since 1.5
  * @author Josh Bloch, Doug Lea
- * @param <E> the type of elements held in this collection
+ * @param <E> the type of elements held in this queue
  */
 public class PriorityQueue<E> extends AbstractQueue<E>
     implements java.io.Serializable {
@@ -101,7 +100,7 @@ public class PriorityQueue<E> extends Ab
     /**
      * The number of elements in the priority queue.
      */
-    private int size = 0;
+    int size;
 
     /**
      * The comparator, or null if priority queue uses elements'
@@ -113,7 +112,7 @@ public class PriorityQueue<E> extends Ab
      * The number of times this priority queue has been
      * <i>structurally modified</i>.  See AbstractList for gory details.
      */
-    transient int modCount = 0; // non-private to simplify nested class access
+    transient int modCount;     // non-private to simplify nested class access
 
     /**
      * Creates a {@code PriorityQueue} with the default initial
@@ -138,6 +137,19 @@ public class PriorityQueue<E> extends Ab
     }
 
     /**
+     * Creates a {@code PriorityQueue} with the default initial capacity and
+     * whose elements are ordered according to the specified comparator.
+     *
+     * @param  comparator the comparator that will be used to order this
+     *         priority queue.  If {@code null}, the {@linkplain Comparable
+     *         natural ordering} of the elements will be used.
+     * @since 1.8
+     */
+    public PriorityQueue(Comparator<? super E> comparator) {
+        this(DEFAULT_INITIAL_CAPACITY, comparator);
+    }
+
+    /**
      * Creates a {@code PriorityQueue} with the specified initial capacity
      * that orders its elements according to the specified comparator.
      *
@@ -247,8 +259,8 @@ public class PriorityQueue<E> extends Ab
             a = Arrays.copyOf(a, a.length, Object[].class);
         int len = a.length;
         if (len == 1 || this.comparator != null)
-            for (int i = 0; i < len; i++)
-                if (a[i] == null)
+            for (Object e : a)
+                if (e == null)
                     throw new NullPointerException();
         this.queue = a;
         this.size = a.length;
@@ -326,11 +338,8 @@ public class PriorityQueue<E> extends Ab
         int i = size;
         if (i >= queue.length)
             grow(i + 1);
+        siftUp(i, e);
         size = i + 1;
-        if (i == 0)
-            queue[0] = e;
-        else
-            siftUp(i, e);
         return true;
     }
 
@@ -395,7 +404,7 @@ public class PriorityQueue<E> extends Ab
      * @return {@code true} if this queue contains the specified element
      */
     public boolean contains(Object o) {
-        return indexOf(o) != -1;
+        return indexOf(o) >= 0;
     }
 
     /**
@@ -437,7 +446,7 @@ public class PriorityQueue<E> extends Ab
      * The following code can be used to dump the queue into a newly
      * allocated array of {@code String}:
      *
-     *  <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
+     * <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
      *
      * Note that {@code toArray(new Object[0])} is identical in function to
      * {@code toArray()}.
@@ -453,6 +462,7 @@ public class PriorityQueue<E> extends Ab
      */
     @SuppressWarnings("unchecked")
     public <T> T[] toArray(T[] a) {
+        final int size = this.size;
         if (a.length < size)
             // Make a new array of a's runtime type, but my contents:
             return (T[]) Arrays.copyOf(queue, size, a.getClass());
@@ -477,7 +487,7 @@ public class PriorityQueue<E> extends Ab
          * Index (into queue array) of element to be returned by
          * subsequent call to next.
          */
-        private int cursor = 0;
+        private int cursor;
 
         /**
          * Index of element returned by most recent call to next,
@@ -497,13 +507,13 @@ public class PriorityQueue<E> extends Ab
          * We expect that most iterations, even those involving removals,
          * will not need to store elements in this field.
          */
-        private ArrayDeque<E> forgetMeNot = null;
+        private ArrayDeque<E> forgetMeNot;
 
         /**
          * Element returned by the most recent call to next iff that
          * element was drawn from the forgetMeNot list.
          */
-        private E lastRetElt = null;
+        private E lastRetElt;
 
         /**
          * The modCount value that the iterator believes that the backing
@@ -542,7 +552,7 @@ public class PriorityQueue<E> extends Ab
                     cursor--;
                 else {
                     if (forgetMeNot == null)
-                        forgetMeNot = new ArrayDeque<E>();
+                        forgetMeNot = new ArrayDeque<>();
                     forgetMeNot.add(moved);
                 }
             } else if (lastRetElt != null) {
@@ -597,7 +607,7 @@ public class PriorityQueue<E> extends Ab
      * avoid missing traversing elements.
      */
     @SuppressWarnings("unchecked")
-    private E removeAt(int i) {
+    E removeAt(int i) {
         // assert i >= 0 && i < size;
         modCount++;
         int s = --size;
@@ -717,6 +727,7 @@ public class PriorityQueue<E> extends Ab
     /**
      * Establishes the heap invariant (described above) in the entire tree,
      * assuming nothing about the order of the elements prior to the call.
+     * This classic algorithm due to Floyd (1964) is known to be O(size).
      */
     @SuppressWarnings("unchecked")
     private void heapify() {
@@ -740,10 +751,11 @@ public class PriorityQueue<E> extends Ab
     /**
      * Saves this queue to a stream (that is, serializes it).
      *
+     * @param s the stream
+     * @throws java.io.IOException if an I/O error occurs
      * @serialData The length of the array backing the instance is
      *             emitted (int), followed by all of its elements
      *             (each an {@code Object}) in the proper order.
-     * @param s the stream
      */
     private void writeObject(java.io.ObjectOutputStream s)
         throws java.io.IOException {
@@ -763,6 +775,9 @@ public class PriorityQueue<E> extends Ab
      * (that is, deserializes it).
      *
      * @param s the stream
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found
+     * @throws java.io.IOException if an I/O error occurs
      */
     private void readObject(java.io.ObjectInputStream s)
         throws java.io.IOException, ClassNotFoundException {
@@ -783,91 +798,108 @@ public class PriorityQueue<E> extends Ab
         heapify();
     }
 
-    // wrapping constructor in method avoids transient javac problems
-    final PriorityQueueSpliterator<E> spliterator(int origin, int fence,
-                                                  int expectedModCount) {
-        return new PriorityQueueSpliterator<E>(this, origin, fence,
-                                               expectedModCount);
-    }
-
-    public Stream<E> stream() {
-        int flags = Streams.STREAM_IS_SIZED;
-        return Streams.stream
-            (() -> spliterator(0, size, modCount), flags);
-    }
-    public Stream<E> parallelStream() {
-        int flags = Streams.STREAM_IS_SIZED;
-        return Streams.parallelStream
-            (() -> spliterator(0, size, modCount), flags);
-    }
-
-    /** Index-based split-by-two Spliterator */
-    static final class PriorityQueueSpliterator<E>
-        implements Spliterator<E>, Iterator<E> {
-        private final PriorityQueue<E> pq;
-        private int index;           // current index, modified on advance/split
-        private final int fence;     // one past last index
-        private final int expectedModCount; // for comodification checks
-
-        /** Create new spliterator covering the given  range */
-        PriorityQueueSpliterator(PriorityQueue<E> pq, int origin, int fence,
-                             int expectedModCount) {
-            this.pq = pq; this.index = origin; this.fence = fence;
+    /**
+     * Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
+     * and <em>fail-fast</em> {@link Spliterator} over the elements in this
+     * queue. The spliterator does not traverse elements in any particular order
+     * (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported).
+     *
+     * <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
+     * {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}.
+     * Overriding implementations should document the reporting of additional
+     * characteristic values.
+     *
+     * @return a {@code Spliterator} over the elements in this queue
+     * @since 1.8
+     */
+    public final Spliterator<E> spliterator() {
+        return new PriorityQueueSpliterator(0, -1, 0);
+    }
+
+    final class PriorityQueueSpliterator implements Spliterator<E> {
+        /*
+         * This is very similar to ArrayList Spliterator, except for
+         * extra null checks.
+         */
+        private int index;            // current index, modified on advance/split
+        private int fence;            // -1 until first use
+        private int expectedModCount; // initialized when fence set
+
+        /** Creates new spliterator covering the given range. */
+        PriorityQueueSpliterator(int origin, int fence, int expectedModCount) {
+            this.index = origin;
+            this.fence = fence;
             this.expectedModCount = expectedModCount;
         }
 
-        public PriorityQueueSpliterator<E> trySplit() {
-            int lo = index, mid = (lo + fence) >>> 1;
+        private int getFence() { // initialize fence to size on first use
+            int hi;
+            if ((hi = fence) < 0) {
+                expectedModCount = modCount;
+                hi = fence = size;
+            }
+            return hi;
+        }
+
+        public PriorityQueueSpliterator trySplit() {
+            int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
             return (lo >= mid) ? null :
-                new PriorityQueueSpliterator<E>(pq, lo, index = mid,
-                                            expectedModCount);
+                new PriorityQueueSpliterator(lo, index = mid, expectedModCount);
         }
 
-        public void forEach(Block<? super E> block) {
-            Object[] a; int i, hi; // hoist accesses and checks from loop
-            if (block == null)
+        @SuppressWarnings("unchecked")
+        public void forEachRemaining(Consumer<? super E> action) {
+            int i, hi, mc; // hoist accesses and checks from loop
+            final Object[] a;
+            if (action == null)
                 throw new NullPointerException();
-            if ((a = pq.queue).length >= (hi = fence) &&
-                (i = index) >= 0 && i < hi) {
-                index = hi;
-                do {
-                    @SuppressWarnings("unchecked") E e = (E) a[i];
-                    block.accept(e);
-                } while (++i < hi);
-                if (pq.modCount != expectedModCount)
-                    throw new ConcurrentModificationException();
+            if ((a = queue) != null) {
+                if ((hi = fence) < 0) {
+                    mc = modCount;
+                    hi = size;
+                }
+                else
+                    mc = expectedModCount;
+                if ((i = index) >= 0 && (index = hi) <= a.length) {
+                    for (E e;; ++i) {
+                        if (i < hi) {
+                            if ((e = (E) a[i]) == null) // must be CME
+                                break;
+                            action.accept(e);
+                        }
+                        else if (modCount != mc)
+                            break;
+                        else
+                            return;
+                    }
+                }
             }
+            throw new ConcurrentModificationException();
         }
 
-        public boolean tryAdvance(Block<? super E> block) {
-            if (index >= 0 && index < fence) {
-                if (pq.modCount != expectedModCount)
+        public boolean tryAdvance(Consumer<? super E> action) {
+            if (action == null)
+                throw new NullPointerException();
+            int hi = getFence(), lo = index;
+            if (lo >= 0 && lo < hi) {
+                index = lo + 1;
+                @SuppressWarnings("unchecked") E e = (E)queue[lo];
+                if (e == null)
+                    throw new ConcurrentModificationException();
+                action.accept(e);
+                if (modCount != expectedModCount)
                     throw new ConcurrentModificationException();
-                @SuppressWarnings("unchecked") E e =
-                    (E)pq.queue[index++];
-                block.accept(e);
                 return true;
             }
             return false;
         }
 
-        public long estimateSize() { return (long)(fence - index); }
-        public boolean hasExactSize() { return true; }
-        public boolean hasExactSplits() { return true; }
-
-        // Iterator support
-        public Iterator<E> iterator() { return this; }
-        public void remove() { throw new UnsupportedOperationException(); }
-        public boolean hasNext() { return index >= 0 && index < fence; }
+        public long estimateSize() {
+            return getFence() - index;
+        }
 
-        public E next() {
-            if (index < 0 || index >= fence)
-                throw new NoSuchElementException();
-            if (pq.modCount != expectedModCount)
-                throw new ConcurrentModificationException();
-            @SuppressWarnings("unchecked") E e =
-                (E) pq.queue[index++];
-            return e;
+        public int characteristics() {
+            return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL;
         }
     }
 }