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* Copyright 2000 - 2008, Red Hat Middleware LLC, and individual contributors
* 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
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.cache.commands.write;
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.InternalNode;
import org.jboss.cache.InvocationContext;
import org.jboss.cache.NodeSPI;
import org.jboss.cache.commands.Visitor;
import org.jboss.cache.commands.read.AbstractDataCommand;
import org.jboss.cache.mvcc.ReadCommittedNode;
import org.jboss.cache.notifications.Notifier;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
/**
* Implements functionality defined by {@link org.jboss.cache.Cache#evict(org.jboss.cache.Fqn)}
*
* @author Mircea.Markus@jboss.com
* @since 2.2
*/
public class EvictCommand extends AbstractDataCommand
{
public static final int METHOD_ID = 8;
public static final int VERSIONED_METHOD_ID = 9;
private boolean recursive = false;
protected Notifier notifier;
protected static final Log log = LogFactory.getLog(EvictCommand.class);
protected static final boolean trace = log.isTraceEnabled();
private List<Fqn> nodesToEvict;
public EvictCommand(Fqn fqn)
{
this.fqn = fqn;
}
public EvictCommand()
{
}
public void initialize(Notifier notifier, DataContainer dataContainer)
{
super.initialize(dataContainer);
this.notifier = notifier;
}
public List<Fqn> getNodesToEvict()
{
return nodesToEvict;
}
public void setNodesToEvict(List<Fqn> nodesToEvict)
{
this.nodesToEvict = nodesToEvict;
}
/**
* Evicts a node.
* <p/>
* See {@link org.jboss.cache.interceptors.EvictionInterceptor#visitEvictFqnCommand(org.jboss.cache.InvocationContext , EvictCommand)}
* which is where the return value is used
*
* @return true if the node was removed from the tree or if it is resident. Returns false if the node still exists; i.e. was only data removed because it still has children.
*/
public Object perform(InvocationContext ctx)
{
NodeSPI node = lookupForEviction(ctx, fqn);
if (node == null || node.isDeleted())
{
return false;
}
else if (node.isResident())
{
return true;
}
else if (recursive)
{
Collection<Fqn> nodesToEvict = getRecursiveEvictionNodes();
for (Fqn aFqn : nodesToEvict)
{
evictNode(aFqn, ctx, lookupForEviction(ctx, aFqn));
}
return !nodesToEvict.isEmpty();
}
else
{
return evictNode(fqn, ctx, node);
}
}
protected Collection<Fqn> getRecursiveEvictionNodes()
{
Collections.sort(nodesToEvict);
Collections.reverse(nodesToEvict);
return nodesToEvict;
}
protected boolean evictNode(Fqn fqn, InvocationContext ctx, NodeSPI node)
{
notifier.notifyNodeEvicted(fqn, true, ctx);
try
{
if (node == null) return true;
if (node.hasChildrenDirect() || fqn.isRoot())
{
if (trace) log.trace("removing DATA as node has children: evict(" + fqn + ")");
node.clearDataDirect();
node.setDataLoaded(false);
return false;
}
else
{
if (trace) log.trace("removing NODE as it is a leaf: evict(" + fqn + ")");
InternalNode parentNode = lookupInAllScopes(ctx, fqn.getParent());
if (parentNode != null)
{
parentNode.removeChild(fqn.getLastElement());
parentNode.setChildrenLoaded(false);
}
node.setValid(false, false);
node.markAsDeleted(true);
node.setDataLoaded(false);
node.getDelegationTarget().clear();
return true;
}
}
finally
{
notifier.notifyNodeEvicted(fqn, false, ctx);
}
}
private InternalNode lookupInAllScopes(InvocationContext ctx, Fqn fqn)
{
ReadCommittedNode nodeSPI = (ReadCommittedNode) lookupForEviction(ctx, fqn);
if (nodeSPI == null)
{
return dataContainer.peekInternalNode(fqn, true);
}
return nodeSPI.getDelegationTarget();
}
protected NodeSPI lookupForEviction(InvocationContext ctx, Fqn fqn)
{
return ctx.lookUpNode(fqn);
}
public Object acceptVisitor(InvocationContext ctx, Visitor visitor) throws Throwable
{
return visitor.visitEvictFqnCommand(ctx, this);
}
public int getCommandId()
{
return METHOD_ID;
}
public boolean isRecursive()
{
return recursive;
}
public void setRecursive(boolean recursive)
{
this.recursive = recursive;
}
@Override
public Object[] getParameters()
{
throw new UnsupportedOperationException(getClass().getSimpleName() + " is not meant to be marshalled and replicated!");
}
@Override
public void setParameters(int commandId, Object[] args)
{
throw new UnsupportedOperationException(getClass().getSimpleName() + " is not meant to be marshalled and replicated!");
}
@Override
public String toString()
{
return getClass().getSimpleName() + "{" +
"fqn=" + fqn +
", recursive=" + recursive +
"}";
}
public void rollback()
{
// this is a no-op.
}
}