| /******************************************************************************* |
| * Copyright (c) 2009 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.utility.internal.iterables; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| |
| import org.eclipse.jpt.utility.internal.StringTools; |
| import org.eclipse.jpt.utility.internal.iterators.CloneIterator; |
| |
| /** |
| * A <code>FixedCloneIterable</code> returns an iterator on a static copy of a |
| * collection, allowing for concurrent access to the original collection. A |
| * copy of the collection is created at construction time. |
| * As a result, the contents of the collection will be the same with |
| * every call to <code>#iterable()</code>. |
| * <p> |
| * The original collection passed to the <code>FixedCloneIterable</code>'s |
| * constructor should be synchronized (e.g. java.util.Vector); |
| * otherwise you run the risk of a corrupted collection. |
| * <p> |
| * By default, the iterator returned by a <code>FixedCloneIterable</code> does not |
| * support the <code>#remove()</code> operation; this is because it does not |
| * have access to the original collection. But if the <code>FixedCloneIterable</code> |
| * is supplied with an <code>CloneIterator.Mutator</code> it will delegate the |
| * <code>#remove()</code> operation to the <code>Mutator</code>. |
| * |
| * @see CloneIterator |
| */ |
| public class FixedCloneIterable<E> |
| implements Iterable<E> |
| { |
| private final Object[] array; |
| private final CloneIterator.Mutator<E> mutator; |
| |
| |
| // ********** constructors ********** |
| |
| /** |
| * Construct a static iterable for the specified collection. |
| * The <code>#remove()</code> method will not be supported |
| * by the <code>Iterator</code> returned by <code>#iterable()</code>. |
| */ |
| public FixedCloneIterable(Collection<? extends E> collection) { |
| this(collection, CloneIterator.Mutator.ReadOnly.<E>instance()); |
| } |
| |
| /** |
| * Construct a static iterable for the specified collection. |
| * Use the specified mutator to remove objects from the |
| * original collection. |
| */ |
| public FixedCloneIterable(Collection<? extends E> collection, CloneIterator.Mutator<E> mutator) { |
| super(); |
| this.array = collection.toArray(); |
| this.mutator = mutator; |
| } |
| |
| |
| // ********** Iterable implementation ********** |
| |
| public Iterator<E> iterator() { |
| return new LocalCloneIterator<E>(this.mutator, this.array); |
| } |
| |
| @Override |
| public String toString() { |
| return StringTools.buildToStringFor(this); |
| } |
| |
| |
| // ********** clone iterator ********** |
| |
| /** |
| * provide access to "internal" constructor |
| */ |
| protected static class LocalCloneIterator<E> extends CloneIterator<E> { |
| protected LocalCloneIterator(Mutator<E> mutator, Object[] array) { |
| super(mutator, array); |
| } |
| } |
| |
| } |