/// <summary>
/// Reads an MQTT string from the underlying stream.
/// </summary>
/// <param name="stream">The stream to read the string from.</param>
/// <returns>The Mqtt String.</returns>
public static string ReadMqttString(this Stream stringStream)
{
// read and check the length
var lengthBytes = new byte[2];
int bytesRead = stringStream.Read(lengthBytes, 0, 2);
if (bytesRead < 2)
{
throw new ArgumentException(
"The stream did not have enough bytes to describe the length of the string",
"stringStream");
}
System.Text.Encoding enc = new MqttEncoding();
short stringLength = (short)enc.GetCharCount(lengthBytes);
// read the bytes from the string, validate we have enough etc.
var stringBytes = new byte[stringLength];
bytesRead = stringStream.Read(stringBytes, 0, stringLength);
if (bytesRead < stringLength)
{
throw new ArgumentException("stream",
String.Format("The stream did not have enough bytes to match the defined string length {0}", stringLength));
}
return enc.GetString(stringBytes);
}
/// <summary>
/// Reads an MQTT string from the underlying stream.
/// </summary>
/// <param name="stringStream">The stream to read the string from.</param>
/// <returns>The Mqtt String.</returns>
public static string ReadMqttString(this Stream stringStream)
{
// read and check the length
var lengthBytes = new byte[2];
var bytesRead = stringStream.Read(lengthBytes, 0, 2);
if (bytesRead < 2)
{
throw new ArgumentException(
"The stream did not have enough bytes to describe the length of the string",
"stringStream");
}
System.Text.Encoding enc = new MqttEncoding();
var stringLength = (ushort)enc.GetCharCount(lengthBytes);
// read the bytes from the string, validate we have enough etc.
var stringBytes = new byte[stringLength];
var readBuffer = new byte[1 << 10]; // 1KB read buffer
var totalRead = 0;
// Keep reading until we have all. Intentionally synchronous
while (totalRead < stringLength) {
var remainingBytes = stringLength - totalRead;
var nextReadSize = remainingBytes > readBuffer.Length ? readBuffer.Length : remainingBytes;
bytesRead = stringStream.Read(readBuffer, 0, nextReadSize);
Array.Copy(readBuffer, 0, stringBytes, totalRead, bytesRead);
totalRead += bytesRead;
}
return enc.GetString(stringBytes);
}
internal override int GetWriteLength()
{
int length = 0;
MqttEncoding enc = new MqttEncoding();
length += enc.GetByteCount(ClientIdentifier);
if (this.variableHeader.ConnectFlags.WillFlag)
{
length += enc.GetByteCount(WillTopic);
length += enc.GetByteCount(WillMessage);
}
return length;
}
/// <summary>
/// Gets the length of the write data when WriteTo will be called.
/// </summary>
/// <returns>The length of data witten by the call to GetWriteLength</returns>
public virtual int GetWriteLength() {
int headerLength = 0;
var enc = new MqttEncoding();
if ((WriteFlags & ReadWriteFlags.ProtocolName) == ReadWriteFlags.ProtocolName) {
headerLength += enc.GetByteCount(ProtocolName);
}
if ((WriteFlags & ReadWriteFlags.ProtocolVersion) == ReadWriteFlags.ProtocolVersion) {
headerLength += sizeof (byte);
}
if ((WriteFlags & ReadWriteFlags.ConnectFlags) == ReadWriteFlags.ConnectFlags) {
headerLength += MqttConnectFlags.GetWriteLength();
}
if ((WriteFlags & ReadWriteFlags.KeepAlive) == ReadWriteFlags.KeepAlive) {
headerLength += sizeof (short);
}
if ((WriteFlags & ReadWriteFlags.ReturnCode) == ReadWriteFlags.ReturnCode) {
headerLength += sizeof (byte);
}
if ((WriteFlags & ReadWriteFlags.TopicName) == ReadWriteFlags.TopicName) {
headerLength += enc.GetByteCount(TopicName.ToString());
}
if ((WriteFlags & ReadWriteFlags.MessageIdentifier) == ReadWriteFlags.MessageIdentifier) {
headerLength += sizeof (short);
}
return headerLength;
}
/// <summary>
/// Writes the MQTT string.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="stringToWrite">The string to write.</param>
public static void WriteMqttString(this Stream stringStream, string stringToWrite)
{
System.Text.Encoding enc = new MqttEncoding();
byte[] stringBytes = enc.GetBytes(stringToWrite);
stringStream.Write(stringBytes, 0, stringBytes.Length);
}
/// <summary>
/// Gets the length of the payload in bytes when written to a stream.
/// </summary>
/// <returns>The length of the payload in bytes.</returns>
internal override int GetWriteLength() {
int length = 0;
var enc = new MqttEncoding();
foreach (var sub in subscriptions) {
length += enc.GetByteCount(sub.Key);
length += sizeof (MqttQos);
}
return length;
}
/// <summary>
/// Gets the length of the payload in bytes when written to a stream.
/// </summary>
/// <returns>The length of the payload in bytes.</returns>
internal override int GetWriteLength() {
int length = 0;
var enc = new MqttEncoding();
foreach (var topic in subscriptions) {
length += enc.GetByteCount(topic);
}
return length;
}
