/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*Licensed under the Apache License, Version 2.0 (the "License");
*you may not use this file except in compliance with the License.
*You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*Unless required by applicable law or agreed to in writing,
*software distributed under the License is distributed on an "AS IS" BASIS,
*WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
*either express or implied. See the License for the specific language governing permissions and limitations under the License
*/
package net.rubyeye.xmemcached.codec;
import net.rubyeye.xmemcached.command.Command;
import net.rubyeye.xmemcached.impl.MemcachedTCPSession;
import net.rubyeye.xmemcached.utils.ByteUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.code.yanf4j.buffer.IoBuffer;
import com.google.code.yanf4j.core.Session;
import com.google.code.yanf4j.core.CodecFactory.Decoder;
import com.google.code.yanf4j.util.ByteBufferMatcher;
import com.google.code.yanf4j.util.ShiftAndByteBufferMatcher;
/**
* Memcached protocol decoder
*
* @author dennis
*
*/
public class MemcachedDecoder implements Decoder {
public static final Logger log = LoggerFactory
.getLogger(MemcachedDecoder.class);
public MemcachedDecoder() {
super();
}
/**
* shift-and algorithm for ByteBuffer's match
*/
public static final ByteBufferMatcher SPLIT_MATCHER = new ShiftAndByteBufferMatcher(
IoBuffer.wrap(ByteUtils.SPLIT));
public Object decode(IoBuffer buffer, Session origSession) {
MemcachedTCPSession session = (MemcachedTCPSession) origSession;
if (session.getCurrentCommand() != null) {
return decode0(buffer, session);
} else {
session.takeCurrentCommand();
return decode0(buffer, session);
}
}
private Object decode0(IoBuffer buffer, MemcachedTCPSession session) {
if (session.getCurrentCommand().decode(session, buffer.buf())) {
final Command command = session.getCurrentCommand();
session.setCurrentCommand(null);
return command;
}
return null;
}
}