/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2006-2009 Sun Microsystems, Inc.
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* Portions Copyright 2011-2013 ForgeRock AS
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*/
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package org.opends.server.replication.server.changelog.je;
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import org.opends.messages.Message;
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import org.opends.server.replication.common.CSN;
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import org.opends.server.replication.protocol.UpdateMsg;
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import org.opends.server.replication.server.changelog.api.ChangelogException;
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import org.opends.server.replication.server.changelog.api.ReplicaDBCursor;
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import org.opends.server.replication.server.changelog.je.ReplicationDB.*;
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/**
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* Berkeley DB JE implementation of {@link ReplicaDBCursor}.
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*/
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public class JEReplicaDBCursor implements ReplicaDBCursor
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{
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private UpdateMsg currentChange = null;
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private ReplServerDBCursor cursor = null;
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private DbHandler dbHandler;
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private ReplicationDB db;
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private CSN lastNonNullCurrentCSN;
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/**
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* Creates a new {@link JEReplicaDBCursor}. All created cursor must be
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* released by the caller using the {@link #close()} method.
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*
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* @param db
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* The db where the cursor must be created.
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* @param startAfterCSN
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* The CSN after which the cursor must start.
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* @param dbHandler
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* The associated DbHandler.
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* @throws ChangelogException
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* if a database problem happened.
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*/
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public JEReplicaDBCursor(ReplicationDB db, CSN startAfterCSN,
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DbHandler dbHandler) throws ChangelogException
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{
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this.db = db;
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this.dbHandler = dbHandler;
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this.lastNonNullCurrentCSN = startAfterCSN;
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try
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{
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cursor = db.openReadCursor(startAfterCSN);
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}
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catch(Exception e)
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{
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// we didn't find it in the db
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cursor = null;
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}
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if (cursor == null)
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{
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// flush the queue into the db
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dbHandler.flush();
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// look again in the db
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cursor = db.openReadCursor(startAfterCSN);
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if (cursor == null)
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{
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throw new ChangelogException(Message.raw("no new change"));
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}
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}
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}
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/** {@inheritDoc} */
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@Override
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public UpdateMsg getChange()
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{
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return currentChange;
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}
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/** {@inheritDoc} */
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@Override
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public boolean next()
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{
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currentChange = cursor.next();
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if (currentChange != null)
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{
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lastNonNullCurrentCSN = currentChange.getCSN();
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}
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else
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{
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synchronized (this)
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{
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if (cursor != null)
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{
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cursor.close();
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cursor = null;
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}
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dbHandler.flush();
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try
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{
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cursor = db.openReadCursor(lastNonNullCurrentCSN);
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currentChange = cursor.next();
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if (currentChange != null)
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{
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lastNonNullCurrentCSN = currentChange.getCSN();
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}
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}
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catch(Exception e)
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{
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currentChange = null;
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}
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}
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}
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return currentChange != null;
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}
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/** {@inheritDoc} */
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@Override
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public void close()
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{
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synchronized (this)
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{
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if (cursor != null)
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{
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cursor.close();
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cursor = null;
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}
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this.dbHandler = null;
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this.db = null;
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}
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}
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/**
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* Called by the Gc when the object is garbage collected Release the internal
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* cursor in case the cursor was badly used and {@link #close()} was never
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* called.
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*/
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@Override
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protected void finalize()
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{
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close();
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}
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}
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