private byte[] ToBytes(bool withHeader = true)
{
var encoding = new ASCIIEncoding();
byte pktReadMode = 0x0;
var pktMessageId = KVPConvert.UShortToByte(Id);
var pktVarName = encoding.GetBytes(VarName);
var pktVarNameLength = KVPConvert.UShortToByte((short)VarName.Length);
var pktContentLength = KVPConvert.UShortToByte((short)(VarName.Length + 3));
if (withHeader)
{
var pkt = new byte[MessageLength];
pkt[0] = pktMessageId[1];
pkt[1] = pktMessageId[0];
pkt[2] = pktContentLength[1];
pkt[3] = pktContentLength[0];
pkt[4] = pktReadMode;
pkt[5] = pktVarNameLength[1];
pkt[6] = pktVarNameLength[0];
pktVarName.CopyTo(pkt, 7);
return(pkt);
}
else
{
var pkt = new byte[MessageLength - 4];
pkt[0] = pktReadMode;
pkt[1] = pktVarNameLength[1];
pkt[2] = pktVarNameLength[0];
pktVarName.CopyTo(pkt, 3);
return(pkt);
}
}
private byte[] ToBytes(bool withHeader = true)
{
var encoding = new ASCIIEncoding();
var pktMessageId = KVPConvert.UShortToByte(Id);
var pktVarValue = encoding.GetBytes(VarValue);
var pktVarValueLength = KVPConvert.UShortToByte((short)VarValue.Length);
var pktContentLength = KVPConvert.UShortToByte((short)ContentLength);
if (withHeader)
{
var pkt = new byte[MessageLength];
pkt[0] = pktMessageId[1];
pkt[1] = pktMessageId[0];
pkt[2] = pktContentLength[1];
pkt[3] = pktContentLength[0];
pkt[4] = KVPConvert.ModeToByte(Mode);
pkt[5] = pktVarValueLength[1];
pkt[6] = pktVarValueLength[0];
pktVarValue.CopyTo(pkt, 7);
pkt[7 + pktVarValue.Length] = 0x0;
pkt[7 + pktVarValue.Length + 1] = Convert.ToByte(Successful);
pkt[7 + pktVarValue.Length + 2] = Convert.ToByte(Successful);
return(pkt);
}
else
{
var pkt = new byte[MessageLength - 4];
pkt[0] = KVPConvert.ModeToByte(Mode);
pkt[1] = pktVarValueLength[1];
pkt[2] = pktVarValueLength[0];
pktVarValue.CopyTo(pkt, 3);
pkt[3 + pktVarValue.Length] = 0x0;
pkt[3 + pktVarValue.Length + 1] = Convert.ToByte(Successful);
pkt[3 + pktVarValue.Length + 2] = Convert.ToByte(Successful);
return(pkt);
}
}
/// <summary>
/// Tries to build an answer form the avavilable bytes.
/// </summary>
/// <param name="bytes">The available bytes as an IEnumerable.</param>
/// <param name="bytesCount">The number of bytes in the IEnumerable. Avoid unecessary enumerations.</param>
/// <param name="answer">The answer on success. An empty answer on failure.</param>
/// <returns>The status of the parsing process.</returns>
public static KVParsingStatus TryParse(IEnumerable <byte> bytes, int bytesCount, out KVAnswer answer)
{
answer = new KVAnswer();
if (bytes == null)
{
return(KVParsingStatus.NotEnoughBytes);
}
if (bytesCount < 4)
{
return(KVParsingStatus.NotEnoughBytes);
}
// get the enumerator to iterate byte by byte
// the using statement ensure that the enumerator is properly disposed so the lock is released ...
using (var enumerator = bytes.GetEnumerator())
{
// get the id
byte b0, b1;
enumerator.MoveNext();
b0 = enumerator.Current;
enumerator.MoveNext();
b1 = enumerator.Current;
answer.Id = KVPConvert.UByteToShort(new byte[2] {
b1, b0
});
// get the msg length
byte b2, b3;
enumerator.MoveNext();
b2 = enumerator.Current;
enumerator.MoveNext();
b3 = enumerator.Current;
var msgLength = KVPConvert.UByteToShort(new byte[2] {
b3, b2
});
// here we got a serious problem and the stream is corrupted
if (msgLength == 0)
{
return(KVParsingStatus.Empty);
}
if (bytesCount < msgLength + 4)
{
return(KVParsingStatus.NotEnoughBytes);
}
// get the msg bytes
var bmsg = new byte[msgLength];
for (int i = 0; i < msgLength; i++)
{
enumerator.MoveNext();
bmsg[i] = enumerator.Current;
}
answer.Mode = KVPConvert.ByteToMode(bmsg[0]);
if (answer.Mode == RWMode.UNDEF)
{
return(KVParsingStatus.InvalidRWStatus);
}
var varValueLength = KVPConvert.UByteToShort(new byte[2] {
bmsg[2], bmsg[1]
});
answer.VarValue = Encoding.ASCII.GetString(bmsg, 3, varValueLength);
var tail_0 = bmsg[msgLength - 1];
var tail_1 = bmsg[msgLength - 2];
var tail_2 = bmsg[msgLength - 3];
if (tail_0 != 0 && tail_1 != 1)
{
return(KVParsingStatus.InvalidTail);
}
if (tail_1 != 0 && tail_1 != 1)
{
return(KVParsingStatus.InvalidTail);
}
if (tail_2 != 0)
{
return(KVParsingStatus.InvalidTail);
}
if (tail_0 == 1 && tail_1 == 1)
{
answer.Successful = true;
}
else if (tail_0 == 0 && tail_1 == 0)
{
answer.Successful = false;
}
return(KVParsingStatus.Valid);
}
}
