You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

264 lines
9.4 KiB
C#

9 months ago
/*
Copyright (c) 2013, 2014 Paolo Patierno
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
and Eclipse Distribution License v1.0 which accompany this distribution.
The Eclipse Public License is available at
http://www.eclipse.org/legal/epl-v10.html
and the Eclipse Distribution License is available at
http://www.eclipse.org/org/documents/edl-v10.php.
Contributors:
Paolo Patierno - initial API and implementation and/or initial documentation
*/
using System;
using System.Collections.Generic;
using System.Collections;
using System.Text;
using uPLibrary.Networking.M2Mqtt.Exceptions;
namespace uPLibrary.Networking.M2Mqtt.Messages
{
/// <summary>
/// Class for SUBSCRIBE message from client to broker
/// </summary>
public class MqttMsgSubscribe : MqttMsgBase
{
#region Properties...
/// <summary>
/// List of topics to subscribe
/// </summary>
public string[] Topics
{
get { return this.topics; }
set { this.topics = value; }
}
/// <summary>
/// List of QOS Levels related to topics
/// </summary>
public byte[] QoSLevels
{
get { return this.qosLevels; }
set { this.qosLevels = value; }
}
#endregion
// topics to subscribe
string[] topics;
// QOS levels related to topics
byte[] qosLevels;
/// <summary>
/// Constructor
/// </summary>
public MqttMsgSubscribe()
{
this.type = MQTT_MSG_SUBSCRIBE_TYPE;
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="topics">List of topics to subscribe</param>
/// <param name="qosLevels">List of QOS Levels related to topics</param>
public MqttMsgSubscribe(string[] topics, byte[] qosLevels)
{
this.type = MQTT_MSG_SUBSCRIBE_TYPE;
this.topics = topics;
this.qosLevels = qosLevels;
// SUBSCRIBE message uses QoS Level 1 (not "officially" in 3.1.1)
this.qosLevel = QOS_LEVEL_AT_LEAST_ONCE;
}
/// <summary>
/// Parse bytes for a SUBSCRIBE message
/// </summary>
/// <param name="fixedHeaderFirstByte">First fixed header byte</param>
/// <param name="protocolVersion">Protocol Version</param>
/// <param name="channel">Channel connected to the broker</param>
/// <returns>SUBSCRIBE message instance</returns>
public static MqttMsgSubscribe Parse(byte fixedHeaderFirstByte, byte protocolVersion, IMqttNetworkChannel channel)
{
byte[] buffer;
int index = 0;
byte[] topicUtf8;
int topicUtf8Length;
MqttMsgSubscribe msg = new MqttMsgSubscribe();
if (protocolVersion == MqttMsgConnect.PROTOCOL_VERSION_V3_1_1)
{
// [v3.1.1] check flag bits
if ((fixedHeaderFirstByte & MSG_FLAG_BITS_MASK) != MQTT_MSG_SUBSCRIBE_FLAG_BITS)
throw new MqttClientException(MqttClientErrorCode.InvalidFlagBits);
}
// get remaining length and allocate buffer
int remainingLength = MqttMsgBase.decodeRemainingLength(channel);
buffer = new byte[remainingLength];
// read bytes from socket...
int received = channel.Receive(buffer);
if (protocolVersion == MqttMsgConnect.PROTOCOL_VERSION_V3_1)
{
// only 3.1.0
// 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);
// retain flag not used
msg.retain = false;
}
// message id
msg.messageId = (ushort)((buffer[index++] << 8) & 0xFF00);
msg.messageId |= (buffer[index++]);
// payload contains topics and QoS levels
// NOTE : before, I don't know how many topics will be in the payload (so use List)
IList<String> tmpTopics = new List<String>();
IList<byte> tmpQosLevels = new List<byte>();
do
{
// topic name
topicUtf8Length = ((buffer[index++] << 8) & 0xFF00);
topicUtf8Length |= buffer[index++];
topicUtf8 = new byte[topicUtf8Length];
Array.Copy(buffer, index, topicUtf8, 0, topicUtf8Length);
index += topicUtf8Length;
tmpTopics.Add(new String(Encoding.UTF8.GetChars(topicUtf8)));
// QoS level
tmpQosLevels.Add(buffer[index++]);
} while (index < remainingLength);
// copy from list to array
msg.topics = new string[tmpTopics.Count];
msg.qosLevels = new byte[tmpQosLevels.Count];
for (int i = 0; i < tmpTopics.Count; i++)
{
msg.topics[i] = (string)tmpTopics[i];
msg.qosLevels[i] = (byte)tmpQosLevels[i];
}
return msg;
}
public override byte[] GetBytes(byte protocolVersion)
{
int fixedHeaderSize = 0;
int varHeaderSize = 0;
int payloadSize = 0;
int remainingLength = 0;
byte[] buffer;
int index = 0;
// topics list empty
if ((this.topics == null) || (this.topics.Length == 0))
throw new MqttClientException(MqttClientErrorCode.TopicsEmpty);
// qos levels list empty
if ((this.qosLevels == null) || (this.qosLevels.Length == 0))
throw new MqttClientException(MqttClientErrorCode.QosLevelsEmpty);
// topics and qos levels lists length don't match
if (this.topics.Length != this.qosLevels.Length)
throw new MqttClientException(MqttClientErrorCode.TopicsQosLevelsNotMatch);
// message identifier
varHeaderSize += MESSAGE_ID_SIZE;
int topicIdx = 0;
byte[][] topicsUtf8 = new byte[this.topics.Length][];
for (topicIdx = 0; topicIdx < this.topics.Length; topicIdx++)
{
// check topic length
if ((this.topics[topicIdx].Length < MIN_TOPIC_LENGTH) || (this.topics[topicIdx].Length > MAX_TOPIC_LENGTH))
throw new MqttClientException(MqttClientErrorCode.TopicLength);
topicsUtf8[topicIdx] = Encoding.UTF8.GetBytes(this.topics[topicIdx]);
payloadSize += 2; // topic size (MSB, LSB)
payloadSize += topicsUtf8[topicIdx].Length;
payloadSize++; // byte for QoS
}
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
if (protocolVersion == MqttMsgConnect.PROTOCOL_VERSION_V3_1_1)
buffer[index++] = (MQTT_MSG_SUBSCRIBE_TYPE << MSG_TYPE_OFFSET) | MQTT_MSG_SUBSCRIBE_FLAG_BITS; // [v.3.1.1]
else
{
buffer[index] = (byte)((MQTT_MSG_SUBSCRIBE_TYPE << MSG_TYPE_OFFSET) |
(this.qosLevel << QOS_LEVEL_OFFSET));
buffer[index] |= this.dupFlag ? (byte)(1 << DUP_FLAG_OFFSET) : (byte)0x00;
index++;
}
// encode remaining length
index = this.encodeRemainingLength(remainingLength, buffer, index);
// check message identifier assigned (SUBSCRIBE uses QoS Level 1, so message id is mandatory)
if (this.messageId == 0)
throw new MqttClientException(MqttClientErrorCode.WrongMessageId);
buffer[index++] = (byte)((messageId >> 8) & 0x00FF); // MSB
buffer[index++] = (byte)(messageId & 0x00FF); // LSB
topicIdx = 0;
for (topicIdx = 0; topicIdx < this.topics.Length; topicIdx++)
{
// topic name
buffer[index++] = (byte)((topicsUtf8[topicIdx].Length >> 8) & 0x00FF); // MSB
buffer[index++] = (byte)(topicsUtf8[topicIdx].Length & 0x00FF); // LSB
Array.Copy(topicsUtf8[topicIdx], 0, buffer, index, topicsUtf8[topicIdx].Length);
index += topicsUtf8[topicIdx].Length;
// requested QoS
buffer[index++] = this.qosLevels[topicIdx];
}
return buffer;
}
public override string ToString()
{
#if TRACE
return this.GetTraceString(
"SUBSCRIBE",
new object[] { "messageId", "topics", "qosLevels" },
new object[] { this.messageId, this.topics, this.qosLevels });
#else
return base.ToString();
#endif
}
}
}