net.sf.ehcache.transaction.ReadCommittedSoftLockFactoryImpl Maven / Gradle / Ivy

/**
 *  Copyright 2003-2010 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.transaction.local.LocalTransactionContext;

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * A SoftLockFactory implementation which creates soft locks with Read-Committed isolation level
 *
 * @author Ludovic Orban
 */
public class ReadCommittedSoftLockFactoryImpl implements SoftLockFactory {

    private static final Object MARKER = new Object();

    private final String cacheManagerName;
    private final String cacheName;

    // actually all we need would be a ConcurrentSet...
    private final ConcurrentMap newKeyLocks = new ConcurrentHashMap();

    private final ConcurrentMap allLocks = new ConcurrentHashMap();

    /**
     * Create a new ReadCommittedSoftLockFactoryImpl instance for a cache
     * @param cacheManagerName the name of the cache manager
     * @param cacheName the name of the cache
     */
    public ReadCommittedSoftLockFactoryImpl(String cacheManagerName, String cacheName) {
        this.cacheManagerName = cacheManagerName;
        this.cacheName = cacheName;
    }

    /**
     * Get the cache manager name
     * @return the cache manager name
     */
    String getCacheManagerName() {
        return cacheManagerName;
    }

    /**
     * Get the cache name
     * @return the cache name
     */
    String getCacheName() {
        return cacheName;
    }

    /**
     * {@inheritDoc}
     */
    public SoftLock createSoftLock(TransactionID transactionID, Object key, Element newElement, Element oldElement, boolean pinned) {
        ReadCommittedSoftLockImpl softLock = new ReadCommittedSoftLockImpl(this, transactionID, key, newElement, oldElement, pinned);

        allLocks.put(softLock, MARKER);

        if (oldElement == null) {
            newKeyLocks.put(softLock, MARKER);
        }
        return softLock;
    }

    /**
     * Get a lock
     * @param transactionId the lock transaction ID
     * @param key the lock key
     * @return the lock, or null if there is no lock created with this transaction ID and key
     */
    ReadCommittedSoftLockImpl getLock(TransactionID transactionId, Object key) {
        for (ReadCommittedSoftLockImpl readCommittedSoftLock : allLocks.keySet()) {
            if (readCommittedSoftLock.getTransactionID().equals(transactionId) && readCommittedSoftLock.getKey().equals(key)) {
                return readCommittedSoftLock;
            }
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public Set