/*
 * JBoss, Home of Professional Open Source
 * Copyright 2010 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.client.hotrod.impl.operations;

import java.util.concurrent.atomic.AtomicInteger;

import net.jcip.annotations.Immutable;

import org.infinispan.client.hotrod.Flag;
import org.infinispan.client.hotrod.impl.protocol.Codec;
import org.infinispan.client.hotrod.impl.protocol.HeaderParams;
import org.infinispan.client.hotrod.impl.protocol.HotRodConstants;
import org.infinispan.client.hotrod.impl.transport.Transport;

/**
 * Generic Hot Rod operation. It is aware of {@link org.infinispan.client.hotrod.Flag}s and it is targeted against a
 * cache name. This base class encapsulates the knowledge of writing and reading a header, as described in the
 * <a href="http://community.jboss.org/wiki/HotRodProtocol">Hot Rod protocol specification</a>
 *
 * @author Mircea.Markus@jboss.com
 * @since 4.1
 */
@Immutable
public abstract class HotRodOperation implements HotRodConstants {

   protected final Flag[] flags;

   protected final byte[] cacheName;

   protected final AtomicInteger topologyId;
   
   private final Codec codec;

   private static final byte NO_TX = 0;
   private static final byte XA_TX = 1;

   protected HotRodOperation(Codec codec, Flag[] flags, byte[] cacheName, AtomicInteger topologyId) {
      this.flags = flags;
      this.cacheName = cacheName;
      this.topologyId = topologyId;
      this.codec = codec;
   }

   public abstract Object execute();

   protected final HeaderParams writeHeader(Transport transport, short operationCode) {
      HeaderParams params = new HeaderParams()
            .opCode(operationCode).cacheName(cacheName).flags(flags)
            .clientIntel(CLIENT_INTELLIGENCE_HASH_DISTRIBUTION_AWARE)
            .topologyId(topologyId).txMarker(NO_TX);
      return codec.writeHeader(transport, params);
   }

   /**
    * Magic	| Message Id | Op code | Status | Topology Change Marker
    */
   protected short readHeaderAndValidate(Transport transport, HeaderParams params) {
      return codec.readHeader(transport, params);
   }

}