/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
* or http://forgerock.org/license/CDDLv1.0.html.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at legal-notices/CDDLv1_0.txt.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2009 Sun Microsystems, Inc.
* Portions Copyright 2011-2015 ForgeRock AS
*/
package org.opends.server.replication.plugin;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.TreeMap;
import org.opends.server.replication.common.CSN;
import org.opends.server.replication.common.CSNGenerator;
import org.opends.server.replication.protocol.LDAPUpdateMsg;
import org.opends.server.replication.protocol.ReplicaOfflineMsg;
import org.opends.server.replication.protocol.UpdateMsg;
import org.opends.server.replication.service.ReplicationDomain;
import org.opends.server.types.operation.PluginOperation;
/**
* This class is used to store the list of local operations currently
* in progress and not yet committed in the database.
* <p>
* It is used to make sure that operations are sent to the Replication Server
* in the order defined by their CSN. It is also used to update the ServerState
* at the appropriate time.
* <p>
* An object of this class is instantiated for each ReplicationDomain.
*/
class PendingChanges
{
/** A map used to store the pending changes. */
private final TreeMap<CSN, PendingChange> pendingChanges = new TreeMap<>();
/**
* The {@link CSNGenerator} to use to create new unique CSNs
* for each operation done on the replication domain.
*/
private final CSNGenerator csnGenerator;
/** The ReplicationDomain that will be used to send UpdateMsg. */
private final ReplicationDomain domain;
private boolean recoveringOldChanges;
/**
* Creates a new PendingChanges using the provided CSNGenerator.
*
* @param csnGenerator The CSNGenerator to use to create new unique CSNs.
* @param domain The ReplicationDomain that will be used to send UpdateMsg.
*/
PendingChanges(CSNGenerator csnGenerator, ReplicationDomain domain)
{
this.csnGenerator = csnGenerator;
this.domain = domain;
}
/**
* Remove and return an update form the pending changes list.
*
* @param csn
* The CSN of the update to remove.
*/
synchronized void remove(CSN csn)
{
pendingChanges.remove(csn);
}
/**
* Returns the number of update currently in the list.
*
* @return The number of update currently in the list.
*/
int size()
{
return pendingChanges.size();
}
/**
* Mark an update message as committed.
*
* @param csn The CSN of the update message that must be set as committed.
* @param msg The message associated to the update.
*/
private synchronized void commit(CSN csn, LDAPUpdateMsg msg)
{
final PendingChange curChange = pendingChanges.get(csn);
if (curChange == null)
{
throw new NoSuchElementException();
}
curChange.setCommitted(true);
curChange.setMsg(msg);
}
/**
* Add a new UpdateMsg to the pending list from the provided local operation.
*
* @param operation The local operation for which an UpdateMsg must
* be added in the pending list.
* @return The CSN now associated to the operation.
*/
synchronized CSN putLocalOperation(PluginOperation operation)
{
final CSN csn = csnGenerator.newCSN();
if (!operation.isSynchronizationOperation())
{
pendingChanges.put(csn, new PendingChange(csn, operation, null));
}
return csn;
}
/**
* Add a replica offline message to the pending list.
*/
public synchronized void putReplicaOfflineMsg()
{
final CSN offlineCSN = csnGenerator.newCSN();
final PendingChange pendingChange =
new PendingChange(offlineCSN, null, new ReplicaOfflineMsg(offlineCSN));
pendingChange.setCommitted(true);
pendingChanges.put(offlineCSN, pendingChange);
pushCommittedChanges();
}
/**
* Push all committed local changes to the replicationServer service.
*/
synchronized void pushCommittedChanges()
{
// peek the oldest change
Entry<CSN, PendingChange> firstEntry = pendingChanges.firstEntry();
if (firstEntry == null)
{
return;
}
PendingChange firstChange = firstEntry.getValue();
while (firstChange != null && firstChange.isCommitted())
{
final PluginOperation op = firstChange.getOp();
final UpdateMsg msg = firstChange.getMsg();
if (msg instanceof LDAPUpdateMsg
&& op != null
&& !op.isSynchronizationOperation())
{
if (!recoveringOldChanges)
{
domain.publish(msg);
}
else
{
// do not push updates until the RS catches up.
// @see #setRecovering(boolean)
domain.getServerState().update(msg.getCSN());
}
}
else if (msg instanceof ReplicaOfflineMsg)
{
domain.publish(msg);
}
// false warning: firstEntry will not be null if firstChange is not null
pendingChanges.remove(firstEntry.getKey());
// peek the oldest change
firstEntry = pendingChanges.firstEntry();
firstChange = firstEntry != null ? firstEntry.getValue() : null;
}
}
/**
* Mark an update message as committed, then
* push all committed local changes to the replicationServer service
* in a single atomic operation.
*
* @param csn The CSN of the update message that must be set as committed.
* @param msg The message associated to the update.
*/
synchronized void commitAndPushCommittedChanges(CSN csn, LDAPUpdateMsg msg)
{
commit(csn, msg);
pushCommittedChanges();
}
/**
* Set the PendingChangesList structure in a mode where it is waiting for the
* RS to receive all the previous changes to be sent before starting to
* process the changes normally. In this mode, The Domain does not publish the
* changes from the pendingChanges because there are older changes that need
* to be published before.
*
* @param recovering
* The recovering status that must be set.
*/
public void setRecovering(boolean recovering)
{
recoveringOldChanges = recovering;
}
/**
* Allows to update the recovery situation by comparing the CSN of the last
* change that was sent to the ReplicationServer with the CSN of the last
* operation that was taken out of the PendingChanges list. If the two match
* then the recovery is completed and normal procedure can restart. Otherwise
* the RSUpdater thread must continue to look for older changes and no changes
* can be committed from the pendingChanges list.
*
* @param recovered
* The CSN of the last change that was published to the
* ReplicationServer.
* @return A boolean indicating if the recovery is completed (false) or must
* continue (true).
*/
synchronized boolean recoveryUntil(CSN recovered)
{
final CSN lastLocalChange = domain.getLastLocalChange();
if (recovered != null && recovered.isNewerThanOrEqualTo(lastLocalChange))
{
recoveringOldChanges = false;
}
return recoveringOldChanges;
}
}