/*
 * 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.index.IndexWriter;
import org.apache.lucene.store.LockFactory;
import org.infinispan.Cache;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;

/**
 * Default factory for locks obtained in <code>InfinispanDirectory</code>,
 * this factory produces instances of <code>BaseLuceneLock</code>.
 * 
 * @since 4.0
 * @author Sanne Grinovero
 * @see org.infinispan.lucene.InfinispanDirectory
 * @see org.infinispan.lucene.locking.BaseLuceneLock
 */
@SuppressWarnings("unchecked")
public class BaseLockFactory extends LockFactory {

   private static final Log log = LogFactory.getLog(BaseLockFactory.class);
   static final String DEF_LOCK_NAME = IndexWriter.WRITE_LOCK_NAME;

   private final Cache<?, ?> cache;
   private final String indexName;
   private final BaseLuceneLock defLock;

   public BaseLockFactory(Cache<?, ?> cache, String indexName) {
      this.cache = cache;
      this.indexName = indexName;
      defLock = new BaseLuceneLock(cache, indexName, DEF_LOCK_NAME);
   }

   /**
    * {@inheritDoc}
    */
   @Override
   public BaseLuceneLock makeLock(String lockName) {
      BaseLuceneLock lock;
      //It appears Lucene always uses the same name so we give locks
      //having this name a special treatment:
      if (DEF_LOCK_NAME.equals(lockName)) {
         lock = defLock;
      }
      else {
         // this branch is never taken with current Lucene version.
         lock = new BaseLuceneLock(cache, indexName, lockName);
      }
      if (log.isTraceEnabled()) {
         log.tracef("Lock prepared, not acquired: %s for index %s", lockName, indexName);
      }
      return lock;
   }

   /**
    * {@inheritDoc}
    */
   @Override
   public void clearLock(String lockName) {
      //Same special care as above for locks named DEF_LOCK_NAME:
      if (DEF_LOCK_NAME.equals(lockName)) {
         defLock.clearLock();
      }
      else {
         new BaseLuceneLock(cache, indexName, lockName).clearLock();
      }
      if (log.isTraceEnabled()) {
         log.tracef("Removed lock: %s for index %s", lockName, indexName);
      }
   }
   
}