/**
* Copyright (C) 2010-2012, FuseSource Corp. All rights reserved.
*
* http://fusesource.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 org.fusesource.mqtt.codec;
import java.io.IOException;
import java.net.ProtocolException;
import org.fusesource.hawtbuf.Buffer;
import org.fusesource.hawtbuf.DataByteArrayInputStream;
import org.fusesource.hawtbuf.DataByteArrayOutputStream;
import org.fusesource.hawtbuf.UTF8Buffer;
import org.fusesource.mqtt.client.QoS;
/**
* <p>
* </p>
*
* @author <a href="http://hiramchirino.com">Hiram Chirino</a>
*/
public class MessageSupport {
/**
* All command objects implement this interface.
*/
static public interface Message {
public byte messageType();
public Message decode(MQTTFrame frame) throws ProtocolException;
public MQTTFrame encode();
}
/**
* All command objects that can get acked implement this interface.
*/
static public interface Acked extends Message {
public boolean dup();
public Acked dup(boolean dup);
public QoS qos();
public short messageId();
public Acked messageId(short messageId);
}
static protected UTF8Buffer readUTF(DataByteArrayInputStream is) throws ProtocolException {
int size = is.readShort();
Buffer buffer = is.readBuffer(size);
if (buffer == null || buffer.length != size) {
throw new ProtocolException("Invalid message encoding");
}
return buffer.utf8();
}
static protected void writeUTF(DataByteArrayOutputStream os, Buffer buffer) throws IOException {
os.writeShort(buffer.length);
os.write(buffer);
}
static abstract public class AckBase {
short messageId;
abstract byte messageType();
protected AckBase decode(MQTTFrame frame) throws ProtocolException {
assert(frame.buffers.length == 1);
DataByteArrayInputStream is = new DataByteArrayInputStream(frame.buffers[0]);
messageId = is.readShort();
return this;
}
public MQTTFrame encode() {
try {
DataByteArrayOutputStream os = new DataByteArrayOutputStream(2);
os.writeShort(messageId);
MQTTFrame frame = new MQTTFrame();
frame.commandType(messageType());
return frame.buffer(os.toBuffer());
} catch (IOException e) {
throw new RuntimeException("The impossible happened");
}
}
public short messageId() {
return messageId;
}
protected AckBase messageId(short messageId) {
this.messageId = messageId;
return this;
}
@Override
public String toString() {
return getClass().getSimpleName()+"{" +
"messageId=" + messageId +
'}';
}
}
static abstract public class EmptyBase {
abstract byte messageType();
protected EmptyBase decode(MQTTFrame frame) throws ProtocolException {
return this;
}
public MQTTFrame encode() {
return new MQTTFrame().commandType(messageType());
}
}
/**
* <p>
* </p>
*
* @author <a href="http://hiramchirino.com">Hiram Chirino</a>
*/
static public class HeaderBase {
protected byte header;
protected byte header() {
return header;
}
protected HeaderBase header(byte header) {
this.header = header;
return this;
}
protected byte messageType() {
return (byte) ((header & 0xF0) >>> 4);
}
protected HeaderBase commandType(int type) {
this.header &= 0x0F;
this.header |= (type << 4) & 0xF0;
return this;
}
protected QoS qos() {
return QoS.values()[((header & 0x06) >>> 1)];
}
protected HeaderBase qos(QoS qos) {
this.header &= 0xF9;
this.header |= (qos.ordinal() << 1) & 0x06;
return this;
}
protected boolean dup() {
return (header & 0x08) > 0;
}
protected HeaderBase dup(boolean dup) {
if(dup) {
this.header |= 0x08;
} else {
this.header &= 0xF7;
}
return this;
}
protected boolean retain() {
return (header & 0x01) > 0;
}
protected HeaderBase retain(boolean retain) {
if(retain) {
this.header |= 0x01;
} else {
this.header &= 0xFE;
}
return this;
}
}
}