/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch licenses this
* file to you 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 org.elasticsearch.memcached.netty;
import org.elasticsearch.Version;
import org.elasticsearch.common.Unicode;
import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.netty.buffer.ChannelBuffer;
import org.elasticsearch.common.netty.buffer.ChannelBuffers;
import org.elasticsearch.common.netty.channel.Channel;
import org.elasticsearch.common.netty.channel.ChannelHandlerContext;
import org.elasticsearch.common.netty.channel.ExceptionEvent;
import org.elasticsearch.common.netty.handler.codec.frame.FrameDecoder;
import org.elasticsearch.memcached.MemcachedRestRequest;
import org.elasticsearch.rest.RestRequest;
import java.io.StreamCorruptedException;
import java.util.regex.Pattern;
/**
*/
public class MemcachedDecoder extends FrameDecoder {
private final ESLogger logger;
private final Pattern lineSplit = Pattern.compile(" +");
public static final byte CR = 13;
public static final byte LF = 10;
public static final byte[] CRLF = new byte[]{CR, LF};
private volatile StringBuffer sb = new StringBuffer();
private volatile MemcachedRestRequest request;
private volatile boolean ending = false;
public MemcachedDecoder(ESLogger logger) {
super(false);
this.logger = logger;
}
@Override
protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
MemcachedRestRequest request = this.request;
if (request == null) {
buffer.markReaderIndex();
if (buffer.readableBytes() < 1) {
return null;
}
short magic = buffer.readUnsignedByte();
if (magic == 0x80) {
if (buffer.readableBytes() < 23) {
buffer.resetReaderIndex(); // but back magic
return null;
}
short opcode = buffer.readUnsignedByte();
short keyLength = buffer.readShort();
short extraLength = buffer.readUnsignedByte();
short dataType = buffer.readUnsignedByte(); // unused
short reserved = buffer.readShort(); // unused
int totalBodyLength = buffer.readInt();
int opaque = buffer.readInt();
long cas = buffer.readLong();
// we want the whole of totalBodyLength; otherwise, keep waiting.
if (buffer.readableBytes() < totalBodyLength) {
buffer.resetReaderIndex();
return null;
}
buffer.skipBytes(extraLength); // get extras, can be empty
if (opcode == 0x00) { // GET
byte[] key = new byte[keyLength];
buffer.readBytes(key);
String uri = Unicode.fromBytes(key);
request = new MemcachedRestRequest(RestRequest.Method.GET, uri, key, -1, true);
request.setOpaque(opaque);
return request;
} else if (opcode == 0x04) { // DELETE
byte[] key = new byte[keyLength];
buffer.readBytes(key);
String uri = Unicode.fromBytes(key);
request = new MemcachedRestRequest(RestRequest.Method.DELETE, uri, key, -1, true);
request.setOpaque(opaque);
return request;
} else if (opcode == 0x01/* || opcode == 0x11*/) { // SET
byte[] key = new byte[keyLength];
buffer.readBytes(key);
String uri = Unicode.fromBytes(key);
// the remainder of the message -- that is, totalLength - (keyLength + extraLength) should be the payload
int size = totalBodyLength - keyLength - extraLength;
request = new MemcachedRestRequest(RestRequest.Method.POST, uri, key, size, true);
request.setOpaque(opaque);
byte[] data = new byte[size];
buffer.readBytes(data, 0, size);
request.setData(data);
request.setQuiet(opcode == 0x11);
return request;
} else if (opcode == 0x0A || opcode == 0x10) { // NOOP or STATS
// TODO once we support setQ we need to wait for them to flush
ChannelBuffer writeBuffer = ChannelBuffers.dynamicBuffer(24);
writeBuffer.writeByte(0x81); // magic
writeBuffer.writeByte(opcode); // opcode
writeBuffer.writeShort(0); // key length
writeBuffer.writeByte(0); // extra length = flags + expiry
writeBuffer.writeByte(0); // data type unused
writeBuffer.writeShort(0x0000); // OK
writeBuffer.writeInt(0); // data length
writeBuffer.writeInt(opaque); // opaque
writeBuffer.writeLong(0); // cas
channel.write(writeBuffer);
return MemcachedDispatcher.IGNORE_REQUEST;
} else if (opcode == 0x07) { // QUIT
channel.disconnect();
} else {
logger.error("Unsupported opcode [0x{}], ignoring and closing connection", Integer.toHexString(opcode));
channel.disconnect();
return null;
}
} else {
buffer.resetReaderIndex(); // reset to get to the first byte
// need to read a header
boolean done = false;
StringBuffer sb = this.sb;
int readableBytes = buffer.readableBytes();
for (int i = 0; i < readableBytes; i++) {
byte next = buffer.readByte();
if (!ending && next == CR) {
ending = true;
} else if (ending && next == LF) {
ending = false;
done = true;
break;
} else if (ending) {
logger.error("Corrupt stream, expected LF, found [0x{}]", Integer.toHexString(next));
throw new StreamCorruptedException("Expecting LF after CR");
} else {
sb.append((char) next);
}
}
if (!done) {
// let's keep the buffer and bytes read
// buffer.discardReadBytes();
buffer.markReaderIndex();
return null;
}
String[] args = lineSplit.split(sb);
// we read the text, clear it
sb.setLength(0);
String cmd = args[0];
if ("get".equals(cmd)) {
request = new MemcachedRestRequest(RestRequest.Method.GET, args[1], null, -1, false);
if (args.length > 3) {
request.setData(Unicode.fromStringAsBytes(args[2]));
}
return request;
} else if ("delete".equals(cmd)) {
request = new MemcachedRestRequest(RestRequest.Method.DELETE, args[1], null, -1, false);
// if (args.length > 3) {
// request.setData(Unicode.fromStringAsBytes(args[2]));
// }
return request;
} else if ("set".equals(cmd)) {
this.request = new MemcachedRestRequest(RestRequest.Method.POST, args[1], null, Integer.parseInt(args[4]), false);
buffer.markReaderIndex();
} else if ("version".equals(cmd)) { // sent as a noop
byte[] bytes = Version.CURRENT.toString().getBytes();
ChannelBuffer writeBuffer = ChannelBuffers.dynamicBuffer(bytes.length);
writeBuffer.writeBytes(bytes);
channel.write(writeBuffer);
return MemcachedDispatcher.IGNORE_REQUEST;
} else if ("quit".equals(cmd)) {
if (channel.isConnected()) { // we maybe in the process of clearing the queued bits
channel.disconnect();
}
} else {
logger.error("Unsupported command [{}], ignoring and closing connection", cmd);
if (channel.isConnected()) { // we maybe in the process of clearing the queued bits
channel.disconnect();
}
return null;
}
}
} else {
if (buffer.readableBytes() < (request.getDataSize() + 2)) {
return null;
}
byte[] data = new byte[request.getDataSize()];
buffer.readBytes(data, 0, data.length);
byte next = buffer.readByte();
if (next == CR) {
next = buffer.readByte();
if (next == LF) {
request.setData(data);
// reset
this.request = null;
return request;
} else {
this.request = null;
throw new StreamCorruptedException("Expecting separator after data block");
}
} else {
this.request = null;
throw new StreamCorruptedException("Expecting separator after data block");
}
}
return null;
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
this.request = null;
this.ending = false;
this.sb.setLength(0);
if (ctx.getChannel().isConnected()) {
ctx.getChannel().disconnect();
}
logger.error("caught exception on memcached decoder", e);
}
}