using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using uPLibrary.Networking.M2Mqtt.Exceptions;
namespace uPLibrary.Networking.M2Mqtt.Messages
{
///
/// Class for PUBREC message from broker to client
///
public class MqttMsgPubrec : MqttMsgBase
{
///
/// Constructor
///
public MqttMsgPubrec()
{
this.type = MQTT_MSG_PUBREC_TYPE;
}
public override byte[] GetBytes(byte protocolVersion)
{
int fixedHeaderSize = 0;
int varHeaderSize = 0;
int payloadSize = 0;
int remainingLength = 0;
byte[] buffer;
int index = 0;
// message identifier
varHeaderSize += MESSAGE_ID_SIZE;
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_PUBREC_TYPE << MSG_TYPE_OFFSET) | MQTT_MSG_PUBREC_FLAG_BITS; // [v.3.1.1]
else
buffer[index++] = (MQTT_MSG_PUBREC_TYPE << MSG_TYPE_OFFSET);
// encode remaining length
index = this.encodeRemainingLength(remainingLength, buffer, index);
// get message identifier
buffer[index++] = (byte)((this.messageId >> 8) & 0x00FF); // MSB
buffer[index++] = (byte)(this.messageId & 0x00FF); // LSB
return buffer;
}
///
/// Parse bytes for a PUBREC message
///
/// First fixed header byte
/// Protocol Version
/// Channel connected to the broker
/// PUBREC message instance
public static MqttMsgPubrec Parse(byte fixedHeaderFirstByte, byte protocolVersion, IMqttNetworkChannel channel)
{
byte[] buffer;
int index = 0;
MqttMsgPubrec msg = new MqttMsgPubrec();
if (protocolVersion == MqttMsgConnect.PROTOCOL_VERSION_V3_1_1)
{
// [v3.1.1] check flag bits
if ((fixedHeaderFirstByte & MSG_FLAG_BITS_MASK) != MQTT_MSG_PUBREC_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...
channel.Receive(buffer);
// message id
msg.messageId = (ushort)((buffer[index++] << 8) & 0xFF00);
msg.messageId |= (buffer[index++]);
return msg;
}
public override string ToString()
{
#if TRACE
return this.GetTraceString(
"PUBREC",
new object[] { "messageId" },
new object[] { this.messageId });
#else
return base.ToString();
#endif
}
}
}