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Comparing jsr166/src/main/java/util/ArrayList.java (file contents):
Revision 1.7 by dl, Sat Nov 26 17:35:19 2005 UTC vs.
Revision 1.23 by jsr166, Sun Jan 7 07:38:27 2007 UTC

# Line 1 | Line 1
1   /*
2   * %W% %E%
3   *
4 < * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
4 > * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
5   * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6   */
7  
8   package java.util;
9 – import java.util.*; // for javadoc (till 6280605 is fixed)
9  
10   /**
11   * Resizable-array implementation of the <tt>List</tt> interface.  Implements
# Line 67 | Line 66 | import java.util.*; // for javadoc (till
66   * should be used only to detect bugs.</i><p>
67   *
68   * This class is a member of the
69 < * <a href="{@docRoot}/../guide/collections/index.html">
69 > * <a href="{@docRoot}/../technotes/guides/collections/index.html">
70   * Java Collections Framework</a>.
71   *
72   * @author  Josh Bloch
# Line 123 | Line 122 | public class ArrayList<E> extends Abstra
122      /**
123       * Constructs a list containing the elements of the specified
124       * collection, in the order they are returned by the collection's
125 <     * iterator.  The <tt>ArrayList</tt> instance has an initial capacity of
127 <     * 110% the size of the specified collection.
125 >     * iterator.
126       *
127       * @param c the collection whose elements are to be placed into this list
128       * @throws NullPointerException if the specified collection is null
129       */
130      public ArrayList(Collection<? extends E> c) {
133 –        int size = c.size();
134 –        // 10% for growth
135 –        int cap = ((size/10)+1)*11;
136 –        if (cap > 0) {
137 –            Object[] a = new Object[cap];
138 –            a[size] = a[size+1] = UNALLOCATED;
139 –            Object[] b = c.toArray(a);
140 –            if (b[size] == null && b[size+1] == UNALLOCATED) {
141 –                b[size+1] = null;
142 –                elementData = b;
143 –                this.size = size;
144 –                return;
145 –            }
146 –        }
147 –        initFromConcurrentlyMutating(c);
148 –    }
149 –
150 –    private void initFromConcurrentlyMutating(Collection<? extends E> c) {
131          elementData = c.toArray();
132          size = elementData.length;
133          // c.toArray might (incorrectly) not return Object[] (see 6260652)
# Line 155 | Line 135 | public class ArrayList<E> extends Abstra
135              elementData = Arrays.copyOf(elementData, size, Object[].class);
136      }
137  
158 –    private final static Object UNALLOCATED = new Object();
159 –
138      /**
139       * Trims the capacity of this <tt>ArrayList</tt> instance to be the
140       * list's current size.  An application can use this operation to minimize
# Line 189 | Line 167 | public class ArrayList<E> extends Abstra
167       * @param minCapacity the desired minimum capacity
168       */
169      private void growArray(int minCapacity) {
170 <        if (minCapacity < 0) throw new OutOfMemoryError(); // int overflow
170 >        if (minCapacity < 0) // overflow
171 >            throw new OutOfMemoryError();
172          int oldCapacity = elementData.length;
173          // Double size if small; else grow by 50%
174 <        int newCapacity = ((oldCapacity < 64)?
175 <                           (oldCapacity * 2):
176 <                           ((oldCapacity * 3)/2));
174 >        int newCapacity = ((oldCapacity < 64) ?
175 >                           ((oldCapacity + 1) * 2) :
176 >                           ((oldCapacity / 2) * 3));
177 >        if (newCapacity < 0) // overflow
178 >            newCapacity = Integer.MAX_VALUE;
179          if (newCapacity < minCapacity)
180              newCapacity = minCapacity;
181          elementData = Arrays.copyOf(elementData, newCapacity);
# Line 346 | Line 327 | public class ArrayList<E> extends Abstra
327      /**
328       * Throws an appropriate exception for indexing errors.
329       */
330 <    private static void rangeException(int i, int s) {
330 >    private static void indexOutOfBounds(int i, int s) {
331          throw new IndexOutOfBoundsException("Index: " + i + ", Size: " + s);
332      }
333  
# Line 359 | Line 340 | public class ArrayList<E> extends Abstra
340       */
341      public E get(int index) {
342          if (index >= size)
343 <            rangeException(index, size);
344 <        return (E)elementData[index];
343 >            indexOutOfBounds(index, size);
344 >        return (E) elementData[index];
345      }
346  
347      /**
# Line 374 | Line 355 | public class ArrayList<E> extends Abstra
355       */
356      public E set(int index, E element) {
357          if (index >= size)
358 <            rangeException(index, size);
378 <
358 >            indexOutOfBounds(index, size);
359          E oldValue = (E) elementData[index];
360          elementData[index] = element;
361          return oldValue;
# Line 388 | Line 368 | public class ArrayList<E> extends Abstra
368       * @return <tt>true</tt> (as specified by {@link Collection#add})
369       */
370      public boolean add(E e) {
371 <        ++modCount;
371 >        modCount++;
372          int s = size;
373          if (s >= elementData.length)
374              growArray(s + 1);
375          elementData[s] = e;
376 <        size = s + 1;
377 <        return true;
376 >        size = s + 1;
377 >        return true;
378      }
379  
380      /**
# Line 409 | Line 389 | public class ArrayList<E> extends Abstra
389      public void add(int index, E element) {
390          int s = size;
391          if (index > s || index < 0)
392 <            rangeException(index, s);
393 <        ++modCount;
392 >            indexOutOfBounds(index, s);
393 >        modCount++;
394          if (s >= elementData.length)
395              growArray(s + 1);
396 <        System.arraycopy(elementData, index,
397 <                         elementData, index + 1, s - index);
396 >        System.arraycopy(elementData, index,
397 >                         elementData, index + 1, s - index);
398          elementData[index] = element;
399          size = s + 1;
400      }
# Line 430 | Line 410 | public class ArrayList<E> extends Abstra
410       */
411      public E remove(int index) {
412          int s = size - 1;
413 <        if (index < 0 || index > s)
414 <            rangeException(index, size);
413 >        if (index > s)
414 >            indexOutOfBounds(index, size);
415          modCount++;
416 <        E oldValue = (E)elementData[index];
416 >        E oldValue = (E) elementData[index];
417          int numMoved = s - index;
418          if (numMoved > 0)
419 <            System.arraycopy(elementData, index + 1,
420 <                             elementData, index, numMoved);
421 <        elementData[s] = null; // forget removed element
422 <        size = s;
419 >            System.arraycopy(elementData, index + 1,
420 >                             elementData, index, numMoved);
421 >        elementData[s] = null;
422 >        size = s;
423          return oldValue;
424      }
425  
# Line 539 | Line 519 | public class ArrayList<E> extends Abstra
519       */
520      public boolean addAll(int index, Collection<? extends E> c) {
521          if (index > size || index < 0)
522 <            throw new IndexOutOfBoundsException(
543 <                "Index: " + index + ", Size: " + size);
522 >            indexOutOfBounds(index, size);
523  
524          Object[] a = c.toArray();
525          int numNew = a.length;
# Line 602 | Line 581 | public class ArrayList<E> extends Abstra
581          for (int i=0; i<size; i++)
582              s.writeObject(elementData[i]);
583  
584 <        if (modCount != expectedModCount) {
584 >        if (expectedModCount != modCount) {
585              throw new ConcurrentModificationException();
586          }
587  
# Line 625 | Line 604 | public class ArrayList<E> extends Abstra
604          for (int i=0; i<size; i++)
605              a[i] = s.readObject();
606      }
628 –
629 –
630 –    /**
631 –     * Returns a list-iterator of the elements in this list (in proper
632 –     * sequence), starting at the specified position in the list.
633 –     * Obeys the general contract of <tt>List.listIterator(int)</tt>.<p>
634 –     *
635 –     * The list-iterator is <i>fail-fast</i>: if the list is structurally
636 –     * modified at any time after the Iterator is created, in any way except
637 –     * through the list-iterator's own <tt>remove</tt> or <tt>add</tt>
638 –     * methods, the list-iterator will throw a
639 –     * <tt>ConcurrentModificationException</tt>.  Thus, in the face of
640 –     * concurrent modification, the iterator fails quickly and cleanly, rather
641 –     * than risking arbitrary, non-deterministic behavior at an undetermined
642 –     * time in the future.
643 –     *
644 –     * @param index index of the first element to be returned from the
645 –     *              list-iterator (by a call to <tt>next</tt>)
646 –     * @return a ListIterator of the elements in this list (in proper
647 –     *         sequence), starting at the specified position in the list
648 –     * @throws IndexOutOfBoundsException {@inheritDoc}
649 –     * @see List#listIterator(int)
650 –     */
651 –    public ListIterator<E> listIterator(int index) {
652 –        if (index < 0 || index > size)
653 –            throw new IndexOutOfBoundsException("Index: "+index);
654 –        return new ArrayListIterator(index);
655 –    }
656 –
657 –    /**
658 –     * Returns an iterator over the elements in this list in proper sequence.
659 –     *
660 –     * @return an iterator over the elements in this list in proper sequence
661 –     */
662 –    public Iterator<E> iterator() {
663 –        return new ArrayListIterator(0);
664 –    }
665 –
666 –    /**
667 –     * A streamlined version of AbstractList.Itr
668 –     */
669 –    final class ArrayListIterator implements ListIterator<E> {
670 –        int cursor;           // index of next element to return;
671 –        int lastRet;          // index of last element, or -1 if no such
672 –        int expectedModCount; // to check for CME
673 –
674 –        ArrayListIterator(int index) {
675 –            cursor = index;
676 –            lastRet = -1;
677 –            expectedModCount = modCount;
678 –        }
679 –
680 –        public boolean hasNext() {
681 –            return cursor < size;
682 –        }
683 –
684 –        public boolean hasPrevious() {
685 –            return cursor > 0;
686 –        }
687 –
688 –        public int nextIndex() {
689 –            return cursor;
690 –        }
691 –
692 –        public int previousIndex() {
693 –            return cursor - 1;
694 –        }
695 –
696 –        public E next() {
697 –            if (expectedModCount == modCount) {
698 –                int i = cursor;
699 –                if (i < size) {
700 –                    try {
701 –                        E e = (E)elementData[i];
702 –                        lastRet = i;
703 –                        cursor = i + 1;
704 –                        return e;
705 –                    } catch (IndexOutOfBoundsException fallthrough) {
706 –                    }
707 –                }
708 –            }
709 –            // Prefer reporting CME if applicable on failures
710 –            if (expectedModCount == modCount)
711 –                throw new NoSuchElementException();
712 –            throw new ConcurrentModificationException();
713 –        }
714 –
715 –        public E previous() {
716 –            if (expectedModCount == modCount) {
717 –                int i = cursor - 1;
718 –                if (i < size) {
719 –                    try {
720 –                        E e = (E)elementData[i];
721 –                        lastRet = i;
722 –                        cursor = i;
723 –                        return e;
724 –                    } catch (IndexOutOfBoundsException fallthrough) {
725 –                    }
726 –                }
727 –            }
728 –            if (expectedModCount == modCount)
729 –                throw new NoSuchElementException();
730 –            throw new ConcurrentModificationException();
731 –        }
732 –
733 –        public void remove() {
734 –            if (lastRet < 0)
735 –                throw new IllegalStateException();
736 –            if (modCount != expectedModCount)
737 –                throw new ConcurrentModificationException();
738 –            ArrayList.this.remove(lastRet);
739 –            if (lastRet < cursor)
740 –                cursor--;
741 –            lastRet = -1;
742 –            expectedModCount = modCount;
743 –        }
744 –
745 –        public void set(E e) {
746 –            if (lastRet < 0)
747 –                throw new IllegalStateException();
748 –            if (modCount != expectedModCount)
749 –                throw new ConcurrentModificationException();
750 –            ArrayList.this.set(lastRet, e);
751 –            expectedModCount = modCount;
752 –        }
753 –
754 –        public void add(E e) {
755 –            if (modCount != expectedModCount)
756 –                throw new ConcurrentModificationException();
757 –            ArrayList.this.add(cursor++, e);
758 –            lastRet = -1;
759 –            expectedModCount = modCount;
760 –        }
761 –    }
762 –
607   }

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