/**
* 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();
if (session.getCurrentCommand() == null) return null;
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;
}
}
private Command newMergedCommand(
final Map<Object, Command> mergeCommands,
int mergeCount,
final CommandCollector commandCollector,
final CommandType commandType) {
if (protocol == Protocol.Text) {
String resultKey = (String) commandCollector.getResult();
byte[] keyBytes = ByteUtils.getBytes(resultKey);
byte[] cmdBytes = commandType == CommandType.GET_ONE ? Constants.GET : Constants.GETS;
final byte[] buf = new byte[cmdBytes.length + 3 + keyBytes.length];
ByteUtils.setArguments(buf, 0, cmdBytes, keyBytes);
TextGetOneCommand cmd = new TextGetOneCommand(resultKey, keyBytes, commandType, null);
cmd.setMergeCommands(mergeCommands);
cmd.setWriteFuture(new FutureImpl<Boolean>());
cmd.setMergeCount(mergeCount);
cmd.setIoBuffer(IoBuffer.wrap(buf));
return cmd;
} else {
BinaryGetMultiCommand result = (BinaryGetMultiCommand) commandCollector.getResult();
result.setMergeCount(mergeCount);
result.setMergeCommands(mergeCommands);
return result;
}
}
public Object getResult() {
byte[] buf = new byte[totalBytes];
int offset = 0;
for (IoBuffer buffer : bufferList) {
byte[] ba = buffer.array();
System.arraycopy(ba, 0, buf, offset, ba.length);
offset += ba.length;
}
BinaryGetMultiCommand resultCommand =
new BinaryGetMultiCommand(null, CommandType.GET_MANY, new CountDownLatch(1));
resultCommand.setIoBuffer(IoBuffer.wrap(buf));
return resultCommand;
}
@Override
public final void encode() {
int size = Constants.DELETE.length + 1 + this.keyBytes.length + Constants.CRLF.length;
if (isNoreply()) {
size += 8;
}
byte[] buf = new byte[size];
if (isNoreply()) {
ByteUtils.setArguments(buf, 0, Constants.DELETE, this.keyBytes, Constants.NO_REPLY);
} else {
ByteUtils.setArguments(buf, 0, Constants.DELETE, this.keyBytes);
}
this.ioBuffer = IoBuffer.wrap(buf);
}
/**
* �峰�涓��琛�
*
* @param buffer
*/
public static final String nextLine(ByteBuffer buffer) {
if (buffer == null) {
return null;
}
/**
* 娴��琛ㄦ���� Shift-And绠���归� >BM绠���归���� > �寸��归� > KMP�归�锛�
* 濡��浣���村ソ��缓璁��璇�mail缁��([email protected])
*/
int index =
MemcachedDecoder.SPLIT_MATCHER.matchFirst(
com.google.code.yanf4j.buffer.IoBuffer.wrap(buffer));
if (index >= 0) {
int limit = buffer.limit();
buffer.limit(index);
byte[] bytes = new byte[buffer.remaining()];
buffer.get(bytes);
buffer.limit(limit);
buffer.position(index + ByteUtils.SPLIT.remaining());
return getString(bytes);
}
return null;
}
@SuppressWarnings("unchecked")
private final Command mergeBuffer(
final Command firstCommand,
final Queue writeQueue,
final Queue<Command> executingCmds,
final int sendBufferSize) {
Command lastCommand = firstCommand; // ��苟������涓�ommand
Command nextCmd = (Command) writeQueue.peek();
if (nextCmd == null) {
return lastCommand;
}
final List<Command> commands = getLocalList();
final ByteBuffer firstBuffer = firstCommand.getIoBuffer().buf();
int totalBytes = firstBuffer.remaining();
commands.add(firstCommand);
boolean wasFirst = true;
while (totalBytes + nextCmd.getIoBuffer().remaining() <= sendBufferSize
&& (nextCmd = (Command) writeQueue.peek()) != null) {
if (nextCmd.getStatus() == OperationStatus.WRITING) {
break;
}
if (nextCmd.isCancel()) {
writeQueue.remove();
continue;
}
nextCmd.setStatus(OperationStatus.WRITING);
writeQueue.remove();
if (wasFirst) {
wasFirst = false;
}
// if it is get_one command,try to merge get commands
if ((nextCmd.getCommandType() == CommandType.GET_ONE
|| nextCmd.getCommandType() == CommandType.GETS_ONE)
&& optimiezeGet) {
nextCmd = mergeGetCommands(nextCmd, writeQueue, executingCmds, nextCmd.getCommandType());
}
commands.add(nextCmd);
lastCommand = nextCmd;
totalBytes += nextCmd.getIoBuffer().remaining();
if (totalBytes > sendBufferSize) {
break;
}
}
if (commands.size() > 1) {
byte[] buf = new byte[totalBytes];
int offset = 0;
for (Command command : commands) {
byte[] ba = command.getIoBuffer().array();
System.arraycopy(ba, 0, buf, offset, ba.length);
offset += ba.length;
if (command != lastCommand
&& (!command.isNoreply() || command instanceof BaseBinaryCommand)) {
executingCmds.add(command);
}
}
lastCommand.setIoBuffer(IoBuffer.wrap(buf));
}
return lastCommand;
}