/*
* Copyright (C) 2009 eXo Platform SAS.
*
* 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.exoplatform.services.jcr.impl.storage.jdbc.indexing;
import org.exoplatform.commons.utils.PropertyManager;
import org.exoplatform.services.jcr.datamodel.NodeDataIndexing;
import org.exoplatform.services.jcr.impl.core.query.NodeDataIndexingIterator;
import org.exoplatform.services.jcr.impl.storage.jdbc.JDBCStorageConnection;
import org.exoplatform.services.jcr.impl.storage.jdbc.db.GenericConnectionFactory;
import org.exoplatform.services.log.ExoLogger;
import org.exoplatform.services.log.Log;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import javax.jcr.RepositoryException;
/**
* Created by The eXo Platform SAS.
*
* Date: 1 02 2011
*
* Iterator for fetching NodeData from database with all properties and its values.
*
* @author <a href="mailto:anatoliy.bazko@exoplatform.com.ua">Anatoliy Bazko</a>
* @version $Id: JdbcIndexingDataIterator.java 34360 2010-11-11 11:11:11Z tolusha $
*/
public class JdbcNodeDataIndexingIterator implements NodeDataIndexingIterator
{
/**
* Connection factory. Allows to open jdbc storage connection.
*/
private final GenericConnectionFactory connFactory;
/**
* The amount of the rows which could be retrieved from database for once.
*/
private final int pageSize;
/**
* The current offset in database.
*/
private final AtomicInteger offset = new AtomicInteger(0);
/**
* Indicates if not all records have been read from database.
*/
private final AtomicBoolean hasNext = new AtomicBoolean(true);
/**
* The last node Id retrieved from the DB
*/
private final AtomicReference<String> lastNodeId = new AtomicReference<String>("");
/**
* The current page index
*/
private static final AtomicInteger page = new AtomicInteger();
/**
* Logger.
*/
protected static final Log LOG = ExoLogger.getLogger("exo.jcr.component.core.JdbcIndexingDataIterator");
/**
* Constructor JdbcIndexingDataIterator.
*
*/
public JdbcNodeDataIndexingIterator(GenericConnectionFactory connFactory, int pageSize) throws RepositoryException
{
this.connFactory = connFactory;
this.pageSize = pageSize;
}
/**
* {@inheritDoc}
*/
public List<NodeDataIndexing> next() throws RepositoryException
{
if (!hasNext())
{
// avoid unnecessary request to database
return new ArrayList<NodeDataIndexing>();
}
JDBCStorageConnection conn = (JDBCStorageConnection)connFactory.openConnection();
try
{
int currentOffset;
String currentLastNodeId;
int currentPage;
synchronized (this)
{
currentOffset = offset.getAndAdd(pageSize);
currentLastNodeId = lastNodeId.get();
currentPage = page.incrementAndGet();
}
long time = System.currentTimeMillis();
List<NodeDataIndexing> result = conn.getNodesAndProperties(currentLastNodeId, currentOffset, pageSize);
if (PropertyManager.isDevelopping())
{
LOG.info("Page = " + currentPage + " Offset = " + currentOffset + " LastNodeId = '" + currentLastNodeId
+ "', query time = " + (System.currentTimeMillis() - time) + " ms, from '"
+ (result.isEmpty() ? "unknown" : result.get(0).getIdentifier()) + "' to '"
+ (result.isEmpty() ? "unknown" : result.get(result.size() - 1).getIdentifier()) + "'");
}
hasNext.compareAndSet(true, result.size() == pageSize);
if (hasNext() && connFactory.isIDNeededForPaging())
{
synchronized (this)
{
lastNodeId.set(result.get(result.size() - 1).getIdentifier());
offset.set((page.get() - currentPage) * pageSize);
}
}
return result;
}
finally
{
conn.close();
}
}
/**
* {@inheritDoc}
*/
public boolean hasNext()
{
return hasNext.get();
}
}