/*
M2Mqtt - MQTT Client Library for .Net
Copyright (c) 2014, Paolo Patierno, All rights reserved.
This library 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 3.0 of the License, or (at your option) any later version.
This library 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 library.
*/
using System;
using System.Text;
using uPLibrary.Networking.M2Mqtt.Exceptions;
namespace uPLibrary.Networking.M2Mqtt.Messages
{
///
/// Class for PUBLISH message from client to broker
///
public class MqttMsgPublish : MqttMsgBase
{
#region Properties...
///
/// Message topic
///
public string Topic
{
get { return this.topic; }
set { this.topic = value; }
}
///
/// Message data
///
public byte[] Message
{
get { return this.message; }
set { this.message = value; }
}
///
/// Message identifier
///
public ushort MessageId
{
get { return this.messageId; }
set { this.messageId = value; }
}
#endregion
// message topic
private string topic;
// message data
private byte[] message;
// message identifier
ushort messageId;
///
/// Constructor
///
public MqttMsgPublish()
{
this.type = MQTT_MSG_PUBLISH_TYPE;
}
///
/// Constructor
///
/// Message topic
/// Message data
public MqttMsgPublish(string topic, byte[] message) :
this(topic, message, false, QOS_LEVEL_AT_MOST_ONCE, false)
{
}
///
/// Constructor
///
/// Message topic
/// Message data
/// Duplicate flag
/// Quality of Service level
/// Retain flag
public MqttMsgPublish(string topic,
byte[] message,
bool dupFlag,
byte qosLevel,
bool retain) : base()
{
this.type = MQTT_MSG_PUBLISH_TYPE;
this.topic = topic;
this.message = message;
this.dupFlag = dupFlag;
this.qosLevel = qosLevel;
this.retain = retain;
this.messageId = 0;
}
public override byte[] GetBytes()
{
int fixedHeaderSize = 0;
int varHeaderSize = 0;
int payloadSize = 0;
int remainingLength = 0;
byte[] buffer;
int index = 0;
// topic can't contain wildcards
if ((this.topic.IndexOf('#') != -1) || (this.topic.IndexOf('+') != -1))
throw new MqttClientException(MqttClientErrorCode.TopicWildcard);
// check topic length
if ((this.topic.Length < MIN_TOPIC_LENGTH) || (this.topic.Length > MAX_TOPIC_LENGTH))
throw new MqttClientException(MqttClientErrorCode.TopicLength);
byte[] topicUtf8 = Encoding.UTF8.GetBytes(this.topic);
// topic name
varHeaderSize += topicUtf8.Length + 2;
// message id is valid only with QOS level 1 or QOS level 2
if ((this.qosLevel == QOS_LEVEL_AT_LEAST_ONCE) ||
(this.qosLevel == QOS_LEVEL_EXACTLY_ONCE))
{
varHeaderSize += MESSAGE_ID_SIZE;
}
// check on message with zero length
if (this.message != null)
// message data
payloadSize += this.message.Length;
remainingLength += (varHeaderSize + payloadSize);
// first byte of fixed header
fixedHeaderSize = 1;
int temp = remainingLength;
// increase fixed header size based on remaining length
// (each remaining length byte can encode until 128)
do
{
fixedHeaderSize++;
temp = temp / 128;
} while (temp > 0);
// allocate buffer for message
buffer = new byte[fixedHeaderSize + varHeaderSize + payloadSize];
// first fixed header byte
buffer[index] = (byte)((MQTT_MSG_PUBLISH_TYPE << MSG_TYPE_OFFSET) |
(this.qosLevel << QOS_LEVEL_OFFSET));
buffer[index] |= this.dupFlag ? (byte)(1 << DUP_FLAG_OFFSET) : (byte)0x00;
buffer[index] |= this.retain ? (byte)(1 << RETAIN_FLAG_OFFSET) : (byte)0x00;
index++;
// encode remaining length
index = this.encodeRemainingLength(remainingLength, buffer, index);
// topic name
buffer[index++] = (byte)((topicUtf8.Length >> 8) & 0x00FF); // MSB
buffer[index++] = (byte)(topicUtf8.Length & 0x00FF); // LSB
Array.Copy(topicUtf8, 0, buffer, index, topicUtf8.Length);
index += topicUtf8.Length;
// message id is valid only with QOS level 1 or QOS level 2
if ((this.qosLevel == QOS_LEVEL_AT_LEAST_ONCE) ||
(this.qosLevel == QOS_LEVEL_EXACTLY_ONCE))
{
// check message identifier assigned
if (this.messageId == 0)
throw new MqttClientException(MqttClientErrorCode.WrongMessageId);
buffer[index++] = (byte)((this.messageId >> 8) & 0x00FF); // MSB
buffer[index++] = (byte)(this.messageId & 0x00FF); // LSB
}
// check on message with zero length
if (this.message != null)
{
// message data
Array.Copy(this.message, 0, buffer, index, this.message.Length);
index += this.message.Length;
}
return buffer;
}
///
/// Parse bytes for a PUBLISH message
///
/// First fixed header byte
/// Channel connected to the broker
/// PUBLISH message instance
public static MqttMsgPublish Parse(byte fixedHeaderFirstByte, IMqttNetworkChannel channel)
{
byte[] buffer;
int index = 0;
byte[] topicUtf8;
int topicUtf8Length;
MqttMsgPublish msg = new MqttMsgPublish();
// get remaining length and allocate buffer
int remainingLength = MqttMsgBase.decodeRemainingLength(channel);
buffer = new byte[remainingLength];
// read bytes from socket...
int received = channel.Receive(buffer);
// topic name
topicUtf8Length = ((buffer[index++] << 8) & 0xFF00);
topicUtf8Length |= buffer[index++];
topicUtf8 = new byte[topicUtf8Length];
Array.Copy(buffer, index, topicUtf8, 0, topicUtf8Length);
index += topicUtf8Length;
msg.topic = new String(Encoding.UTF8.GetChars(topicUtf8));
// read QoS level from fixed header
msg.qosLevel = (byte)((fixedHeaderFirstByte & QOS_LEVEL_MASK) >> QOS_LEVEL_OFFSET);
// read DUP flag from fixed header
msg.dupFlag = (((fixedHeaderFirstByte & DUP_FLAG_MASK) >> DUP_FLAG_OFFSET) == 0x01);
// read retain flag from fixed header
msg.retain = (((fixedHeaderFirstByte & RETAIN_FLAG_MASK) >> RETAIN_FLAG_OFFSET) == 0x01);
// message id is valid only with QOS level 1 or QOS level 2
if ((msg.qosLevel == QOS_LEVEL_AT_LEAST_ONCE) ||
(msg.qosLevel == QOS_LEVEL_EXACTLY_ONCE))
{
// message id
msg.messageId = (ushort)((buffer[index++] << 8) & 0xFF00);
msg.messageId |= (buffer[index++]);
}
// get payload with message data
int messageSize = remainingLength - index;
int remaining = messageSize;
int messageOffset = 0;
msg.message = new byte[messageSize];
// BUG FIX 26/07/2013 : receiving large payload
// copy first part of payload data received
Array.Copy(buffer, index, msg.message, messageOffset, received - index);
remaining -= (received - index);
messageOffset += (received - index);
// if payload isn't finished
while (remaining > 0)
{
// receive other payload data
received = channel.Receive(buffer);
Array.Copy(buffer, 0, msg.message, messageOffset, received);
remaining -= received;
messageOffset += received;
}
return msg;
}
}
}