/******************************************************************************* | |
* Copyright (c) 1998, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* Oracle - initial API and implementation from Oracle TopLink | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.identitymaps; | |
import java.util.*; | |
/** | |
* Used to allow iterating over a maps cache keys. | |
*/ | |
public class IdentityMapKeyEnumeration implements Enumeration { | |
protected FullIdentityMap map; | |
protected Iterator cacheKeysIterator; | |
protected CacheKey nextKey; | |
protected boolean shouldCheckReadLocks; | |
public IdentityMapKeyEnumeration(FullIdentityMap map) { | |
this(map, true); | |
} | |
public IdentityMapKeyEnumeration(FullIdentityMap map, boolean shouldCheckReadLocks) { | |
this.map = map; | |
this.shouldCheckReadLocks = shouldCheckReadLocks; | |
this.cacheKeysIterator = map.getCacheKeys().values().iterator(); | |
} | |
public boolean hasMoreElements() { | |
this.nextKey = getNextCacheKey(); | |
return this.nextKey != null; | |
} | |
public Object nextElement() { | |
if (this.nextKey == null) { | |
throw new NoSuchElementException("IdentityMapKeyEnumeration nextElement"); | |
} | |
// The read lock check is for avoidance of half built objects being returned. | |
// bug 275724: Added shouldCheckReadLocks to avoid the read lock check when invalidating. | |
if (shouldCheckReadLocks) { | |
this.nextKey.checkReadLock(); | |
} | |
return this.nextKey; | |
} | |
protected CacheKey getNextCacheKey() { | |
CacheKey key = null; | |
while (this.cacheKeysIterator.hasNext() && (key == null)) { | |
key = (CacheKey)this.cacheKeysIterator.next(); | |
} | |
return key; | |
} | |
public boolean getShouldCheckReadLocks() { | |
return this.shouldCheckReadLocks; | |
} | |
public void setShouldCheckReadLocks(boolean shouldCheckReadLocks) { | |
this.shouldCheckReadLocks = shouldCheckReadLocks; | |
} | |
} |