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* as indicated by the @author tags. See the copyright.txt file 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
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*/
package org.jboss.cache.commands.remote;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jboss.cache.DataContainer;
import org.jboss.cache.Fqn;
import org.jboss.cache.InvocationContext;
import org.jboss.cache.buddyreplication.BuddyFqnTransformer;
import org.jboss.cache.buddyreplication.BuddyManager;
import org.jboss.cache.commands.CommandsFactory;
import org.jboss.cache.commands.ReplicableCommand;
import org.jboss.cache.commands.write.EvictCommand;
import org.jboss.cache.commands.write.RemoveNodeCommand;
import org.jboss.cache.interceptors.InterceptorChain;
import org.jboss.cache.transaction.GlobalTransaction;
import org.jboss.cache.transaction.TransactionTable;
import java.util.List;
/**
* Data gravitation cleanup handler. Primarily used by the {@link org.jboss.cache.interceptors.DataGravitatorInterceptor}.
* This is not a {@link org.jboss.cache.commands.VisitableCommand} and hence
* not passed up the {@link org.jboss.cache.interceptors.base.CommandInterceptor} chain.
* <p/>
*
* @author Mircea.Markus@jboss.com
* @since 2.2
*/
public class DataGravitationCleanupCommand implements ReplicableCommand
{
public static final int METHOD_ID = 34;
private static final Log log = LogFactory.getLog(DataGravitationCleanupCommand.class);
private static final boolean trace = log.isTraceEnabled();
/* dependencies */
private BuddyManager buddyManager;
private TransactionTable transactionTable;
private InterceptorChain invoker;
private CommandsFactory commandsFactory;
private DataContainer dataContainer;
/* parameters */
private GlobalTransaction globalTransaction;
private Fqn fqn;
private Fqn backup;
private BuddyFqnTransformer buddyFqnTransformer;
public DataGravitationCleanupCommand(Fqn primary, Fqn backup)
{
this.fqn = primary;
this.backup = backup;
}
public DataGravitationCleanupCommand()
{
}
public void initialize(BuddyManager buddyManager, InterceptorChain invoker, TransactionTable transactionTable,
CommandsFactory commandsFactory, DataContainer dataContainer, BuddyFqnTransformer buddyFqnTransformer)
{
this.buddyManager = buddyManager;
this.invoker = invoker;
this.transactionTable = transactionTable;
this.commandsFactory = commandsFactory;
this.dataContainer = dataContainer;
this.buddyFqnTransformer = buddyFqnTransformer;
}
/**
* Performs a cleanup on nodes that would have been previously gravitated away from the current cache instance.
*/
public Object perform(InvocationContext ctx) throws Throwable
{
if (buddyManager.isDataGravitationRemoveOnFind())
{
if (trace)
log.trace("DataGravitationCleanup: Removing primary (" + fqn + ") and backup (" + backup + ")");
GlobalTransaction gtx = transactionTable.getCurrentTransaction();
if (!executeRemove(gtx, fqn))
{
// only attempt to clean up the backup if the primary did not exist - a waste of a call otherwise.
Object result = executeRemove(gtx, backup);
if (wasNodeRemoved(result))
{
cleanEmptyDeadRegion(gtx, backup);
}
else
{
// JBCACHE-1530 -- check for race where node was moved to a
// xxx:DEAD region just after we returned it as a GravitateResult
List<Fqn<?>> deadFqns = buddyManager.getNewlyDeadBackupFqns(backup);
if (deadFqns != null)
{
for (Fqn<?> dead : deadFqns)
{
result = executeRemove(gtx, dead);
if (wasNodeRemoved(result))
{
cleanEmptyDeadRegion(gtx, dead);
break;
}
}
}
}
}
else
{
if (trace) log.trace("Managed to remove primary (" + fqn + "). Not bothering with backups.");
}
}
else
{
if (trace)
log.trace("DataGravitationCleanup: Evicting primary (" + fqn + ") and backup (" + backup + ")");
evictNode(fqn);
evictNode(backup);
}
return null;
}
private void cleanEmptyDeadRegion(GlobalTransaction gtx, Fqn backupFqn) throws Throwable
{
// if this is a DIRECT child of a DEAD buddy backup region, then remove the empty dead region structural node.
Fqn deadBackupRootFqn = null;
if (buddyFqnTransformer.isDeadBackupFqn(backupFqn) && buddyFqnTransformer.isDeadBackupRoot(backup.getAncestor(backupFqn.size() - 2))
&& !dataContainer.hasChildren((deadBackupRootFqn = backupFqn.getParent())))
{
if (trace) log.trace("Removing dead backup region " + deadBackupRootFqn);
executeRemove(gtx, deadBackupRootFqn);
// now check the grand parent and see if we are free of versions
deadBackupRootFqn = deadBackupRootFqn.getParent();
if (!dataContainer.hasChildren(deadBackupRootFqn))
{
if (trace) log.trace("Removing dead backup region " + deadBackupRootFqn);
executeRemove(gtx, deadBackupRootFqn);
}
}
}
/**
* Returns true if such a node was removed.
*/
private boolean executeRemove(GlobalTransaction gtx, Fqn toRemove) throws Throwable
{
Object result;
RemoveNodeCommand removeBackupCommand = commandsFactory.buildRemoveNodeCommand(gtx, toRemove);
InvocationContext ctx = invoker.getInvocationContext();
ctx.getOptionOverrides().setCacheModeLocal(true);
result = invoker.invoke(ctx, removeBackupCommand);
return result != null && (Boolean) result;
}
private boolean wasNodeRemoved(Object result)
{
return result != null && (Boolean) result;
}
private void evictNode(Fqn fqn) throws Throwable
{
if (dataContainer.exists(fqn))
{
List<Fqn> toEvict = dataContainer.getNodesForEviction(fqn, true);
for (Fqn aFqn : toEvict)
{
EvictCommand evictFqnCommand = commandsFactory.buildEvictFqnCommand(aFqn);
invoker.invoke(evictFqnCommand);
}
}
else
{
if (trace) log.trace("Not evicting " + fqn + " as it doesn't exist");
}
}
public int getCommandId()
{
return METHOD_ID;
}
public Fqn getBackup()
{
return backup;
}
public GlobalTransaction getGlobalTransaction()
{
return globalTransaction;
}
public void setGlobalTransaction(GlobalTransaction gtx)
{
this.globalTransaction = gtx;
}
public Fqn getFqn()
{
return fqn;
}
public Object[] getParameters()
{
return new Object[]{fqn, backup}; //To change body of implemented methods use File | Settings | File Templates.
}
public void setParameters(int commandId, Object[] args)
{
fqn = (Fqn) args[0];
backup = (Fqn) args[1];
}
@Override
public boolean equals(Object o)
{
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
if (!super.equals(o)) return false;
DataGravitationCleanupCommand that = (DataGravitationCleanupCommand) o;
if (backup != null ? !backup.equals(that.backup) : that.backup != null) return false;
if (globalTransaction != null ? !globalTransaction.equals(that.globalTransaction) : that.globalTransaction != null)
return false;
return true;
}
@Override
public int hashCode()
{
int result = super.hashCode();
result = 31 * result + (globalTransaction != null ? globalTransaction.hashCode() : 0);
result = 31 * result + (backup != null ? backup.hashCode() : 0);
return result;
}
@Override
public String toString()
{
return "DataGravitationCleanupCommand{" +
"fqn=" + fqn +
", backup=" + backup +
'}';
}
}