mirror of git://gcc.gnu.org/git/gcc.git
840 lines
28 KiB
Java
840 lines
28 KiB
Java
/*
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* Written by Josh Bloch of Google Inc. and released to the public domain,
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* as explained at http://creativecommons.org/licenses/publicdomain.
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*/
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package java.util;
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import java.io.*;
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/**
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* Resizable-array implementation of the {@link Deque} interface. Array
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* deques have no capacity restrictions; they grow as necessary to support
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* usage. They are not thread-safe; in the absence of external
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* synchronization, they do not support concurrent access by multiple threads.
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* Null elements are prohibited. This class is likely to be faster than
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* {@link Stack} when used as a stack, and faster than {@link LinkedList}
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* when used as a queue.
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*
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* <p>Most <tt>ArrayDeque</tt> operations run in amortized constant time.
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* Exceptions include {@link #remove(Object) remove}, {@link
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* #removeFirstOccurrence removeFirstOccurrence}, {@link #removeLastOccurrence
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* removeLastOccurrence}, {@link #contains contains}, {@link #iterator
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* iterator.remove()}, and the bulk operations, all of which run in linear
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* time.
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*
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* <p>The iterators returned by this class's <tt>iterator</tt> method are
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* <i>fail-fast</i>: If the deque is modified at any time after the iterator
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* is created, in any way except through the iterator's own <tt>remove</tt>
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* method, the iterator will generally throw a {@link
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* ConcurrentModificationException}. Thus, in the face of concurrent
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* modification, the iterator fails quickly and cleanly, rather than risking
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* arbitrary, non-deterministic behavior at an undetermined time in the
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* future.
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*
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* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
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* as it is, generally speaking, impossible to make any hard guarantees in the
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* presence of unsynchronized concurrent modification. Fail-fast iterators
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* throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
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* Therefore, it would be wrong to write a program that depended on this
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* exception for its correctness: <i>the fail-fast behavior of iterators
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* should be used only to detect bugs.</i>
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*
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* <p>This class and its iterator implement all of the
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* <em>optional</em> methods of the {@link Collection} and {@link
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* Iterator} interfaces.
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*
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* <p>This class is a member of the
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* <a href="{@docRoot}/../technotes/guides/collections/index.html">
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* Java Collections Framework</a>.
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*
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* @author Josh Bloch and Doug Lea
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* @since 1.6
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* @param <E> the type of elements held in this collection
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*/
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public class ArrayDeque<E> extends AbstractCollection<E>
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implements Deque<E>, Cloneable, Serializable
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{
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/**
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* The array in which the elements of the deque are stored.
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* The capacity of the deque is the length of this array, which is
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* always a power of two. The array is never allowed to become
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* full, except transiently within an addX method where it is
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* resized (see doubleCapacity) immediately upon becoming full,
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* thus avoiding head and tail wrapping around to equal each
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* other. We also guarantee that all array cells not holding
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* deque elements are always null.
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*/
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private transient E[] elements;
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/**
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* The index of the element at the head of the deque (which is the
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* element that would be removed by remove() or pop()); or an
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* arbitrary number equal to tail if the deque is empty.
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*/
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private transient int head;
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/**
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* The index at which the next element would be added to the tail
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* of the deque (via addLast(E), add(E), or push(E)).
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*/
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private transient int tail;
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/**
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* The minimum capacity that we'll use for a newly created deque.
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* Must be a power of 2.
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*/
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private static final int MIN_INITIAL_CAPACITY = 8;
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// ****** Array allocation and resizing utilities ******
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/**
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* Allocate empty array to hold the given number of elements.
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*
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* @param numElements the number of elements to hold
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*/
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private void allocateElements(int numElements) {
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int initialCapacity = MIN_INITIAL_CAPACITY;
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// Find the best power of two to hold elements.
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// Tests "<=" because arrays aren't kept full.
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if (numElements >= initialCapacity) {
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initialCapacity = numElements;
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initialCapacity |= (initialCapacity >>> 1);
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initialCapacity |= (initialCapacity >>> 2);
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initialCapacity |= (initialCapacity >>> 4);
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initialCapacity |= (initialCapacity >>> 8);
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initialCapacity |= (initialCapacity >>> 16);
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initialCapacity++;
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if (initialCapacity < 0) // Too many elements, must back off
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initialCapacity >>>= 1;// Good luck allocating 2 ^ 30 elements
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}
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elements = (E[]) new Object[initialCapacity];
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}
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/**
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* Double the capacity of this deque. Call only when full, i.e.,
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* when head and tail have wrapped around to become equal.
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*/
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private void doubleCapacity() {
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assert head == tail;
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int p = head;
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int n = elements.length;
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int r = n - p; // number of elements to the right of p
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int newCapacity = n << 1;
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if (newCapacity < 0)
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throw new IllegalStateException("Sorry, deque too big");
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Object[] a = new Object[newCapacity];
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System.arraycopy(elements, p, a, 0, r);
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System.arraycopy(elements, 0, a, r, p);
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elements = (E[])a;
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head = 0;
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tail = n;
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}
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/**
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* Copies the elements from our element array into the specified array,
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* in order (from first to last element in the deque). It is assumed
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* that the array is large enough to hold all elements in the deque.
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*
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* @return its argument
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*/
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private <T> T[] copyElements(T[] a) {
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if (head < tail) {
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System.arraycopy(elements, head, a, 0, size());
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} else if (head > tail) {
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int headPortionLen = elements.length - head;
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System.arraycopy(elements, head, a, 0, headPortionLen);
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System.arraycopy(elements, 0, a, headPortionLen, tail);
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}
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return a;
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}
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/**
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* Constructs an empty array deque with an initial capacity
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* sufficient to hold 16 elements.
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*/
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public ArrayDeque() {
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elements = (E[]) new Object[16];
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}
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/**
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* Constructs an empty array deque with an initial capacity
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* sufficient to hold the specified number of elements.
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*
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* @param numElements lower bound on initial capacity of the deque
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*/
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public ArrayDeque(int numElements) {
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allocateElements(numElements);
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}
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/**
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* Constructs a deque containing the elements of the specified
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* collection, in the order they are returned by the collection's
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* iterator. (The first element returned by the collection's
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* iterator becomes the first element, or <i>front</i> of the
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* deque.)
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*
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* @param c the collection whose elements are to be placed into the deque
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* @throws NullPointerException if the specified collection is null
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*/
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public ArrayDeque(Collection<? extends E> c) {
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allocateElements(c.size());
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addAll(c);
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}
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// The main insertion and extraction methods are addFirst,
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// addLast, pollFirst, pollLast. The other methods are defined in
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// terms of these.
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/**
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* Inserts the specified element at the front of this deque.
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*
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* @param e the element to add
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* @throws NullPointerException if the specified element is null
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*/
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public void addFirst(E e) {
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if (e == null)
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throw new NullPointerException();
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elements[head = (head - 1) & (elements.length - 1)] = e;
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if (head == tail)
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doubleCapacity();
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}
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/**
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* Inserts the specified element at the end of this deque.
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*
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* <p>This method is equivalent to {@link #add}.
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*
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* @param e the element to add
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* @throws NullPointerException if the specified element is null
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*/
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public void addLast(E e) {
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if (e == null)
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throw new NullPointerException();
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elements[tail] = e;
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if ( (tail = (tail + 1) & (elements.length - 1)) == head)
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doubleCapacity();
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}
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/**
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* Inserts the specified element at the front of this deque.
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*
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* @param e the element to add
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* @return <tt>true</tt> (as specified by {@link Deque#offerFirst})
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* @throws NullPointerException if the specified element is null
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*/
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public boolean offerFirst(E e) {
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addFirst(e);
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return true;
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}
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/**
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* Inserts the specified element at the end of this deque.
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*
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* @param e the element to add
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* @return <tt>true</tt> (as specified by {@link Deque#offerLast})
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* @throws NullPointerException if the specified element is null
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*/
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public boolean offerLast(E e) {
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addLast(e);
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return true;
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}
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/**
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E removeFirst() {
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E x = pollFirst();
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if (x == null)
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throw new NoSuchElementException();
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return x;
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}
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/**
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E removeLast() {
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E x = pollLast();
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if (x == null)
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throw new NoSuchElementException();
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return x;
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}
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public E pollFirst() {
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int h = head;
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E result = elements[h]; // Element is null if deque empty
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if (result == null)
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return null;
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elements[h] = null; // Must null out slot
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head = (h + 1) & (elements.length - 1);
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return result;
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}
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public E pollLast() {
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int t = (tail - 1) & (elements.length - 1);
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E result = elements[t];
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if (result == null)
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return null;
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elements[t] = null;
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tail = t;
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return result;
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}
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/**
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E getFirst() {
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E x = elements[head];
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if (x == null)
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throw new NoSuchElementException();
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return x;
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}
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/**
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E getLast() {
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E x = elements[(tail - 1) & (elements.length - 1)];
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if (x == null)
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throw new NoSuchElementException();
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return x;
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}
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public E peekFirst() {
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return elements[head]; // elements[head] is null if deque empty
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}
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public E peekLast() {
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return elements[(tail - 1) & (elements.length - 1)];
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}
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/**
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* Removes the first occurrence of the specified element in this
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* deque (when traversing the deque from head to tail).
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* If the deque does not contain the element, it is unchanged.
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* More formally, removes the first element <tt>e</tt> such that
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* <tt>o.equals(e)</tt> (if such an element exists).
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* Returns <tt>true</tt> if this deque contained the specified element
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* (or equivalently, if this deque changed as a result of the call).
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*
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* @param o element to be removed from this deque, if present
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* @return <tt>true</tt> if the deque contained the specified element
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*/
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public boolean removeFirstOccurrence(Object o) {
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if (o == null)
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return false;
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int mask = elements.length - 1;
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int i = head;
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E x;
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while ( (x = elements[i]) != null) {
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if (o.equals(x)) {
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delete(i);
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return true;
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}
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i = (i + 1) & mask;
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}
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return false;
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}
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/**
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* Removes the last occurrence of the specified element in this
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* deque (when traversing the deque from head to tail).
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* If the deque does not contain the element, it is unchanged.
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* More formally, removes the last element <tt>e</tt> such that
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* <tt>o.equals(e)</tt> (if such an element exists).
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* Returns <tt>true</tt> if this deque contained the specified element
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* (or equivalently, if this deque changed as a result of the call).
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*
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* @param o element to be removed from this deque, if present
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* @return <tt>true</tt> if the deque contained the specified element
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*/
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public boolean removeLastOccurrence(Object o) {
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if (o == null)
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return false;
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int mask = elements.length - 1;
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int i = (tail - 1) & mask;
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E x;
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while ( (x = elements[i]) != null) {
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if (o.equals(x)) {
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delete(i);
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return true;
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}
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i = (i - 1) & mask;
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}
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return false;
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}
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// *** Queue methods ***
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/**
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* Inserts the specified element at the end of this deque.
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*
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* <p>This method is equivalent to {@link #addLast}.
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*
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* @param e the element to add
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* @return <tt>true</tt> (as specified by {@link Collection#add})
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* @throws NullPointerException if the specified element is null
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*/
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public boolean add(E e) {
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addLast(e);
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return true;
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}
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/**
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* Inserts the specified element at the end of this deque.
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*
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* <p>This method is equivalent to {@link #offerLast}.
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*
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* @param e the element to add
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* @return <tt>true</tt> (as specified by {@link Queue#offer})
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* @throws NullPointerException if the specified element is null
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*/
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public boolean offer(E e) {
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return offerLast(e);
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}
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/**
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* Retrieves and removes the head of the queue represented by this deque.
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*
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* This method differs from {@link #poll poll} only in that it throws an
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* exception if this deque is empty.
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*
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* <p>This method is equivalent to {@link #removeFirst}.
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*
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* @return the head of the queue represented by this deque
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E remove() {
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return removeFirst();
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}
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/**
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* Retrieves and removes the head of the queue represented by this deque
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* (in other words, the first element of this deque), or returns
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* <tt>null</tt> if this deque is empty.
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*
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* <p>This method is equivalent to {@link #pollFirst}.
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*
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* @return the head of the queue represented by this deque, or
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* <tt>null</tt> if this deque is empty
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*/
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public E poll() {
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return pollFirst();
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}
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/**
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* Retrieves, but does not remove, the head of the queue represented by
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* this deque. This method differs from {@link #peek peek} only in
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* that it throws an exception if this deque is empty.
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*
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* <p>This method is equivalent to {@link #getFirst}.
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*
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* @return the head of the queue represented by this deque
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E element() {
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return getFirst();
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}
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/**
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* Retrieves, but does not remove, the head of the queue represented by
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* this deque, or returns <tt>null</tt> if this deque is empty.
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*
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* <p>This method is equivalent to {@link #peekFirst}.
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*
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* @return the head of the queue represented by this deque, or
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* <tt>null</tt> if this deque is empty
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*/
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public E peek() {
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return peekFirst();
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}
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// *** Stack methods ***
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/**
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* Pushes an element onto the stack represented by this deque. In other
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* words, inserts the element at the front of this deque.
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*
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* <p>This method is equivalent to {@link #addFirst}.
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*
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* @param e the element to push
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* @throws NullPointerException if the specified element is null
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*/
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public void push(E e) {
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addFirst(e);
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}
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/**
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* Pops an element from the stack represented by this deque. In other
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* words, removes and returns the first element of this deque.
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*
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* <p>This method is equivalent to {@link #removeFirst()}.
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*
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* @return the element at the front of this deque (which is the top
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* of the stack represented by this deque)
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* @throws NoSuchElementException {@inheritDoc}
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*/
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public E pop() {
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return removeFirst();
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}
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private void checkInvariants() {
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assert elements[tail] == null;
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assert head == tail ? elements[head] == null :
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(elements[head] != null &&
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elements[(tail - 1) & (elements.length - 1)] != null);
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assert elements[(head - 1) & (elements.length - 1)] == null;
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}
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/**
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* Removes the element at the specified position in the elements array,
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* adjusting head and tail as necessary. This can result in motion of
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* elements backwards or forwards in the array.
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*
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* <p>This method is called delete rather than remove to emphasize
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* that its semantics differ from those of {@link List#remove(int)}.
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*
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* @return true if elements moved backwards
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*/
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private boolean delete(int i) {
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checkInvariants();
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final E[] elements = this.elements;
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final int mask = elements.length - 1;
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final int h = head;
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final int t = tail;
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final int front = (i - h) & mask;
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final int back = (t - i) & mask;
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// Invariant: head <= i < tail mod circularity
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if (front >= ((t - h) & mask))
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throw new ConcurrentModificationException();
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// Optimize for least element motion
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if (front < back) {
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if (h <= i) {
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System.arraycopy(elements, h, elements, h + 1, front);
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} else { // Wrap around
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System.arraycopy(elements, 0, elements, 1, i);
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elements[0] = elements[mask];
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System.arraycopy(elements, h, elements, h + 1, mask - h);
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}
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elements[h] = null;
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head = (h + 1) & mask;
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return false;
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} else {
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if (i < t) { // Copy the null tail as well
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System.arraycopy(elements, i + 1, elements, i, back);
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tail = t - 1;
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} else { // Wrap around
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System.arraycopy(elements, i + 1, elements, i, mask - i);
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elements[mask] = elements[0];
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System.arraycopy(elements, 1, elements, 0, t);
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tail = (t - 1) & mask;
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// *** Collection Methods ***
|
|
|
|
/**
|
|
* Returns the number of elements in this deque.
|
|
*
|
|
* @return the number of elements in this deque
|
|
*/
|
|
public int size() {
|
|
return (tail - head) & (elements.length - 1);
|
|
}
|
|
|
|
/**
|
|
* Returns <tt>true</tt> if this deque contains no elements.
|
|
*
|
|
* @return <tt>true</tt> if this deque contains no elements
|
|
*/
|
|
public boolean isEmpty() {
|
|
return head == tail;
|
|
}
|
|
|
|
/**
|
|
* Returns an iterator over the elements in this deque. The elements
|
|
* will be ordered from first (head) to last (tail). This is the same
|
|
* order that elements would be dequeued (via successive calls to
|
|
* {@link #remove} or popped (via successive calls to {@link #pop}).
|
|
*
|
|
* @return an iterator over the elements in this deque
|
|
*/
|
|
public Iterator<E> iterator() {
|
|
return new DeqIterator();
|
|
}
|
|
|
|
public Iterator<E> descendingIterator() {
|
|
return new DescendingIterator();
|
|
}
|
|
|
|
private class DeqIterator implements Iterator<E> {
|
|
/**
|
|
* Index of element to be returned by subsequent call to next.
|
|
*/
|
|
private int cursor = head;
|
|
|
|
/**
|
|
* Tail recorded at construction (also in remove), to stop
|
|
* iterator and also to check for comodification.
|
|
*/
|
|
private int fence = tail;
|
|
|
|
/**
|
|
* Index of element returned by most recent call to next.
|
|
* Reset to -1 if element is deleted by a call to remove.
|
|
*/
|
|
private int lastRet = -1;
|
|
|
|
public boolean hasNext() {
|
|
return cursor != fence;
|
|
}
|
|
|
|
public E next() {
|
|
if (cursor == fence)
|
|
throw new NoSuchElementException();
|
|
E result = elements[cursor];
|
|
// This check doesn't catch all possible comodifications,
|
|
// but does catch the ones that corrupt traversal
|
|
if (tail != fence || result == null)
|
|
throw new ConcurrentModificationException();
|
|
lastRet = cursor;
|
|
cursor = (cursor + 1) & (elements.length - 1);
|
|
return result;
|
|
}
|
|
|
|
public void remove() {
|
|
if (lastRet < 0)
|
|
throw new IllegalStateException();
|
|
if (delete(lastRet)) { // if left-shifted, undo increment in next()
|
|
cursor = (cursor - 1) & (elements.length - 1);
|
|
fence = tail;
|
|
}
|
|
lastRet = -1;
|
|
}
|
|
}
|
|
|
|
private class DescendingIterator implements Iterator<E> {
|
|
/*
|
|
* This class is nearly a mirror-image of DeqIterator, using
|
|
* tail instead of head for initial cursor, and head instead of
|
|
* tail for fence.
|
|
*/
|
|
private int cursor = tail;
|
|
private int fence = head;
|
|
private int lastRet = -1;
|
|
|
|
public boolean hasNext() {
|
|
return cursor != fence;
|
|
}
|
|
|
|
public E next() {
|
|
if (cursor == fence)
|
|
throw new NoSuchElementException();
|
|
cursor = (cursor - 1) & (elements.length - 1);
|
|
E result = elements[cursor];
|
|
if (head != fence || result == null)
|
|
throw new ConcurrentModificationException();
|
|
lastRet = cursor;
|
|
return result;
|
|
}
|
|
|
|
public void remove() {
|
|
if (lastRet < 0)
|
|
throw new IllegalStateException();
|
|
if (!delete(lastRet)) {
|
|
cursor = (cursor + 1) & (elements.length - 1);
|
|
fence = head;
|
|
}
|
|
lastRet = -1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns <tt>true</tt> if this deque contains the specified element.
|
|
* More formally, returns <tt>true</tt> if and only if this deque contains
|
|
* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>.
|
|
*
|
|
* @param o object to be checked for containment in this deque
|
|
* @return <tt>true</tt> if this deque contains the specified element
|
|
*/
|
|
public boolean contains(Object o) {
|
|
if (o == null)
|
|
return false;
|
|
int mask = elements.length - 1;
|
|
int i = head;
|
|
E x;
|
|
while ( (x = elements[i]) != null) {
|
|
if (o.equals(x))
|
|
return true;
|
|
i = (i + 1) & mask;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Removes a single instance of the specified element from this deque.
|
|
* If the deque does not contain the element, it is unchanged.
|
|
* More formally, removes the first element <tt>e</tt> such that
|
|
* <tt>o.equals(e)</tt> (if such an element exists).
|
|
* Returns <tt>true</tt> if this deque contained the specified element
|
|
* (or equivalently, if this deque changed as a result of the call).
|
|
*
|
|
* <p>This method is equivalent to {@link #removeFirstOccurrence}.
|
|
*
|
|
* @param o element to be removed from this deque, if present
|
|
* @return <tt>true</tt> if this deque contained the specified element
|
|
*/
|
|
public boolean remove(Object o) {
|
|
return removeFirstOccurrence(o);
|
|
}
|
|
|
|
/**
|
|
* Removes all of the elements from this deque.
|
|
* The deque will be empty after this call returns.
|
|
*/
|
|
public void clear() {
|
|
int h = head;
|
|
int t = tail;
|
|
if (h != t) { // clear all cells
|
|
head = tail = 0;
|
|
int i = h;
|
|
int mask = elements.length - 1;
|
|
do {
|
|
elements[i] = null;
|
|
i = (i + 1) & mask;
|
|
} while (i != t);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns an array containing all of the elements in this deque
|
|
* in proper sequence (from first to last element).
|
|
*
|
|
* <p>The returned array will be "safe" in that no references to it are
|
|
* maintained by this deque. (In other words, this method must allocate
|
|
* a new array). The caller is thus free to modify the returned array.
|
|
*
|
|
* <p>This method acts as bridge between array-based and collection-based
|
|
* APIs.
|
|
*
|
|
* @return an array containing all of the elements in this deque
|
|
*/
|
|
public Object[] toArray() {
|
|
return copyElements(new Object[size()]);
|
|
}
|
|
|
|
/**
|
|
* Returns an array containing all of the elements in this deque in
|
|
* proper sequence (from first to last element); the runtime type of the
|
|
* returned array is that of the specified array. If the deque fits in
|
|
* the specified array, it is returned therein. Otherwise, a new array
|
|
* is allocated with the runtime type of the specified array and the
|
|
* size of this deque.
|
|
*
|
|
* <p>If this deque fits in the specified array with room to spare
|
|
* (i.e., the array has more elements than this deque), the element in
|
|
* the array immediately following the end of the deque is set to
|
|
* <tt>null</tt>.
|
|
*
|
|
* <p>Like the {@link #toArray()} method, this method acts as bridge between
|
|
* array-based and collection-based APIs. Further, this method allows
|
|
* precise control over the runtime type of the output array, and may,
|
|
* under certain circumstances, be used to save allocation costs.
|
|
*
|
|
* <p>Suppose <tt>x</tt> is a deque known to contain only strings.
|
|
* The following code can be used to dump the deque into a newly
|
|
* allocated array of <tt>String</tt>:
|
|
*
|
|
* <pre>
|
|
* String[] y = x.toArray(new String[0]);</pre>
|
|
*
|
|
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
|
|
* <tt>toArray()</tt>.
|
|
*
|
|
* @param a the array into which the elements of the deque are to
|
|
* be stored, if it is big enough; otherwise, a new array of the
|
|
* same runtime type is allocated for this purpose
|
|
* @return an array containing all of the elements in this deque
|
|
* @throws ArrayStoreException if the runtime type of the specified array
|
|
* is not a supertype of the runtime type of every element in
|
|
* this deque
|
|
* @throws NullPointerException if the specified array is null
|
|
*/
|
|
public <T> T[] toArray(T[] a) {
|
|
int size = size();
|
|
if (a.length < size)
|
|
a = (T[])java.lang.reflect.Array.newInstance(
|
|
a.getClass().getComponentType(), size);
|
|
copyElements(a);
|
|
if (a.length > size)
|
|
a[size] = null;
|
|
return a;
|
|
}
|
|
|
|
// *** Object methods ***
|
|
|
|
/**
|
|
* Returns a copy of this deque.
|
|
*
|
|
* @return a copy of this deque
|
|
*/
|
|
public ArrayDeque<E> clone() {
|
|
try {
|
|
ArrayDeque<E> result = (ArrayDeque<E>) super.clone();
|
|
// Classpath local: we don't have Arrays.copyOf yet.
|
|
// result.elements = Arrays.copyOf(elements, elements.length);
|
|
result.elements = (E[]) elements.clone();
|
|
return result;
|
|
|
|
} catch (CloneNotSupportedException e) {
|
|
throw new AssertionError();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Appease the serialization gods.
|
|
*/
|
|
private static final long serialVersionUID = 2340985798034038923L;
|
|
|
|
/**
|
|
* Serialize this deque.
|
|
*
|
|
* @serialData The current size (<tt>int</tt>) of the deque,
|
|
* followed by all of its elements (each an object reference) in
|
|
* first-to-last order.
|
|
*/
|
|
private void writeObject(ObjectOutputStream s) throws IOException {
|
|
s.defaultWriteObject();
|
|
|
|
// Write out size
|
|
s.writeInt(size());
|
|
|
|
// Write out elements in order.
|
|
int mask = elements.length - 1;
|
|
for (int i = head; i != tail; i = (i + 1) & mask)
|
|
s.writeObject(elements[i]);
|
|
}
|
|
|
|
/**
|
|
* Deserialize this deque.
|
|
*/
|
|
private void readObject(ObjectInputStream s)
|
|
throws IOException, ClassNotFoundException {
|
|
s.defaultReadObject();
|
|
|
|
// Read in size and allocate array
|
|
int size = s.readInt();
|
|
allocateElements(size);
|
|
head = 0;
|
|
tail = size;
|
|
|
|
// Read in all elements in the proper order.
|
|
for (int i = 0; i < size; i++)
|
|
elements[i] = (E)s.readObject();
|
|
}
|
|
}
|