ClearCommand.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2009 Red Hat Inc. and/or its affiliates and other
 * contributors as indicated by the @author tags. All rights reserved.
 * See the copyright.txt 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.infinispan.commands.write;

import org.infinispan.commands.AbstractFlagAffectedCommand;
import org.infinispan.commands.Visitor;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.container.entries.MVCCEntry;
import org.infinispan.context.Flag;
import org.infinispan.context.InvocationContext;
import org.infinispan.lifecycle.ComponentStatus;
import org.infinispan.notifications.cachelistener.CacheNotifier;

import java.util.Collections;
import java.util.Set;

/**
 * @author Mircea.Markus@jboss.com
 * @since 4.0
 */
public class ClearCommand extends AbstractFlagAffectedCommand implements WriteCommand {

   public static final byte COMMAND_ID = 5;
   CacheNotifier notifier;

   public ClearCommand() {
   }

   public ClearCommand(CacheNotifier notifier, Set<Flag> flags) {
      this.notifier = notifier;
      this.flags = flags;
   }

   public void init(CacheNotifier notifier) {
      this.notifier = notifier;
   }

   @Override
   public Object acceptVisitor(InvocationContext ctx, Visitor visitor) throws Throwable {
      return visitor.visitClearCommand(ctx, this);
   }

   @Override
   public Object perform(InvocationContext ctx) throws Throwable {
      for (CacheEntry e : ctx.getLookedUpEntries().values()) {
         if (e instanceof MVCCEntry) {
            MVCCEntry me = (MVCCEntry) e;
            Object k = me.getKey(), v = me.getValue();
            notifier.notifyCacheEntryRemoved(k, v, true, ctx);
            me.setRemoved(true);
            me.setValid(false);
            notifier.notifyCacheEntryRemoved(k, null, false, ctx);
         }
      }
      return null;
   }

   @Override
   public Object[] getParameters() {
      return new Object[]{flags};
   }

   @Override
   public byte getCommandId() {
      return COMMAND_ID;
   }

   @Override
   public void setParameters(int commandId, Object[] parameters) {
      if (commandId != COMMAND_ID) throw new IllegalStateException("Invalid command id");
      if (parameters.length > 0) {
         this.flags = (Set<Flag>) parameters[0];
      }
   }

   @Override
   public boolean shouldInvoke(InvocationContext ctx) {
      return true;
   }

   @Override
   public String toString() {
      return new StringBuilder()
            .append("ClearCommand{flags=")
            .append(flags)
            .append("}")
            .toString();
   }

   @Override
   public boolean isSuccessful() {
      return true;
   }

   @Override
   public boolean isConditional() {
      return false;
   }

   @Override
   public Set<Object> getAffectedKeys() {
      return Collections.emptySet();
   }

   @Override
   public boolean isReturnValueExpected() {
      return false;
   }

   @Override
   public boolean ignoreCommandOnStatus(ComponentStatus status) {
      return false;
   }
}