| /******************************************************************************* |
| * 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>LiveCloneIterable</code> returns an iterator on a current copy of a |
| * collection, allowing for concurrent access to the original collection. A |
| * copy of the collection is created every time {@link #iterator()} is |
| * called. As a result, the contents of the collection can be different with |
| * each call to {@link #iterator()} (i.e. it is "live"). |
| * <p> |
| * The original collection passed to the <code>LiveCloneIterable</code>'s |
| * constructor should be thread-safe (e.g. {@link java.util.Vector}); |
| * otherwise you run the risk of a corrupted collection. |
| * <p> |
| * By default, the iterator returned by a <code>LiveCloneIterable</code> does not |
| * support the {@link Iterator#remove()} operation; this is because it does not |
| * have access to the original collection. But if the <code>LiveCloneIterable</code> |
| * is supplied with an {@link CloneIterator.Remover} it will delegate the |
| * {@link Iterator#remove()} operation to the <code>Remover</code>. |
| * Alternatively, a subclass can override the iterable's {@link #remove(Object)} |
| * method. |
| * |
| * @param <E> the type of elements returned by the iterable's iterator |
| * |
| * @see CloneIterator |
| * @see SnapshotCloneIterable |
| */ |
| public class LiveCloneIterable<E> |
| extends CloneIterable<E> |
| { |
| private final Collection<? extends E> collection; |
| |
| |
| // ********** constructors ********** |
| |
| /** |
| * Construct a "live" iterable for the specified collection. |
| * The {@link Iterator#remove()} operation will not be supported |
| * by the iterator returned by {@link #iterator()} |
| * unless a subclass overrides them iterable's {@link #remove(Object)} |
| * method. |
| */ |
| public LiveCloneIterable(Collection<? extends E> collection) { |
| super(); |
| this.collection = collection; |
| } |
| |
| /** |
| * Construct a "live" iterable for the specified collection. |
| * The specified remover will be used by any generated iterators to |
| * remove objects from the original collection. |
| */ |
| public LiveCloneIterable(Collection<? extends E> collection, CloneIterator.Remover<E> remover) { |
| super(remover); |
| this.collection = collection; |
| } |
| |
| |
| // ********** Iterable implementation ********** |
| |
| public Iterator<E> iterator() { |
| return new CloneIterator<E>(this.collection, this.remover); |
| } |
| |
| @Override |
| public String toString() { |
| return StringTools.buildToStringFor(this, this.collection); |
| } |
| |
| } |