/*
* JBoss, Home of Professional Open Source
* Copyright 2010 Red Hat Inc. and/or its affiliates and other
* contributors as indicated by the @author tags. All rights reserved.
* See the copyright.txt in the distribution for a full listing of
* individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.infinispan.lucene.locking;
import org.apache.lucene.store.Lock;
import org.infinispan.Cache;
import org.infinispan.context.Flag;
import org.infinispan.lucene.FileCacheKey;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
/**
* Inter-IndexWriter Lucene index lock based on Infinispan.
* This implementation is not bound to and does not need a TransactionManager,
* is more suited for large batch work and index optimization.
*
* @since 4.0
* @author Sanne Grinovero
* @see org.apache.lucene.store.Lock
*/
@SuppressWarnings("unchecked")
class BaseLuceneLock extends Lock {
private static final Log log = LogFactory.getLog(BaseLuceneLock.class);
private final Cache<Object, Object> noCacheStoreCache;
private final String lockName;
private final String indexName;
private final FileCacheKey keyOfLock;
BaseLuceneLock(Cache<?, ?> cache, String indexName, String lockName) {
this.noCacheStoreCache = (Cache<Object, Object>) cache.getAdvancedCache().withFlags(Flag.SKIP_CACHE_STORE, Flag.SKIP_CACHE_LOAD, Flag.SKIP_INDEXING);
this.lockName = lockName;
this.indexName = indexName;
this.keyOfLock = new FileCacheKey(indexName, lockName);
}
/**
* {@inheritDoc}
*/
@Override
public boolean obtain() {
Object previousValue = noCacheStoreCache.putIfAbsent(keyOfLock, keyOfLock);
if (previousValue == null) {
if (log.isTraceEnabled()) {
log.tracef("Lock: %s acquired for index: %s", lockName, indexName);
}
// we own the lock:
return true;
} else {
if (log.isTraceEnabled()) {
log.tracef("Lock: %s not aquired for index: %s, was taken already.", lockName, indexName);
}
return false;
}
}
/**
* {@inheritDoc}
*/
@Override
public void release() {
clearLock();
}
/**
* Used by Lucene at Directory creation: we expect the lock to not exist in this case.
*/
public void clearLock() {
Object previousValue = noCacheStoreCache.remove(keyOfLock);
if (previousValue!=null && log.isTraceEnabled()) {
log.tracef("Lock removed for index: %s", indexName);
}
}
@Override
public boolean isLocked() {
boolean locked = noCacheStoreCache.containsKey(keyOfLock);
return locked;
}
}