net.sf.ehcache.transaction.SoftLockHelper Maven / Gradle / Ivy
/**
* Copyright Terracotta, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.ehcache.transaction;
import net.sf.ehcache.Element;
import net.sf.ehcache.store.ElementValueComparator;
import net.sf.ehcache.store.Store;
/**
* A helper class containing the logic to commit or rollback a soft lock in a store.
*
* @author Ludovic Orban
*/
public class SoftLockHelper {
/**
* Commit a soft lock.
*
* @param softLock the soft lock to commit.
* @param underlyingStore the underlying store.
* @param comparator the element value comparator.
*/
public static void commit(SoftLock softLock, Store underlyingStore, ElementValueComparator comparator) {
Element e = underlyingStore.getQuiet(softLock.getKey());
if (e == null || !(e.getObjectValue() instanceof SoftLockID)) {
// the element can be null or not a soft lock if it was manually unpinned, see DEV-8308
return;
}
SoftLockID softLockId = (SoftLockID)e.getObjectValue();
// must unpin before replacing the softlock ID to avoid racily unpinning another transaction's element
if (!softLockId.wasPinned()) {
underlyingStore.setPinned(softLock.getKey(), false);
}
Element element = softLockId.getNewElement();
if (element != null) {
underlyingStore.replace(e, element, comparator);
} else {
underlyingStore.removeElement(e, comparator);
}
}
/**
* Rollback a soft lock.
*
* @param softLock the soft lock to commit.
* @param underlyingStore the underlying store.
* @param comparator the element value comparator.
* @see net.sf.ehcache.transaction.xa.commands.AbstractStoreCommand#rollback(net.sf.ehcache.store.Store, SoftLockManager, net.sf.ehcache.store.ElementValueComparator)
* phase 1 rollback of the 2PC implementation
*/
public static void rollback(SoftLock softLock, Store underlyingStore, ElementValueComparator comparator) {
Element e = underlyingStore.getQuiet(softLock.getKey());
if (e == null || !(e.getObjectValue() instanceof SoftLockID)) {
// the element can be null or not a soft lock if it was manually unpinned, see DEV-8308
return;
}
SoftLockID softLockId = (SoftLockID)e.getObjectValue();
// must unpin before replacing the softlock ID to avoid racily unpinning another transaction's element
if (!softLockId.wasPinned()) {
underlyingStore.setPinned(softLock.getKey(), false);
}
Element element = softLockId.getOldElement();
if (element != null) {
underlyingStore.replace(e, element, comparator);
} else {
underlyingStore.removeElement(e, comparator);
}
}
}