public UInt8T this[int index]
{
get
{
#if DEBUG
if (index < 0 || index >= DataLength)
{
throw new ArgumentOutOfRangeException(nameof(index), index, $"Value \"index\" should be greater equal than 0 and less than {DataLength}");
}
#endif
UInt8T retVal;
lock (atomicityLock)
{
retVal = rawFrame[HeaderLength + index];
}
return(retVal);
}
set
{
#if DEBUG
if (index < 0 || index >= DataLength)
{
throw new ArgumentOutOfRangeException(nameof(index), index, $"Value \"index\" should be greater equal than 0 and less than {DataLength}");
}
#endif
lock (atomicityLock)
{
byte oldValue = rawFrame[HeaderLength + index];
if (oldValue == value)
{
goto DoNothing;
}
UInt16T oldChecksum = 0;
oldChecksum[1] = rawFrame[rawFrame[2] - 2];
oldChecksum[0] = rawFrame[rawFrame[2] - 1];
rawFrame[HeaderLength + index] = value;
unchecked
{
if (value > oldValue)
{
oldChecksum = (ushort)(oldChecksum + (value - oldValue));
}
else
{
oldChecksum = (ushort)(oldChecksum - (oldValue - value));
}
}
rawFrame[rawFrame[2] - 2] = oldChecksum[1];
rawFrame[rawFrame[2] - 1] = oldChecksum[0];
}
DoNothing:
return;
}
}
public ProtoFrame(byte length, byte messageId)
{
DataLength = (byte)(length - HeaderLength - ChecksumLength);
rawFrame[0] = SyncCode0;
rawFrame[1] = SyncCode1;
rawFrame[2] = length;
rawFrame[3] = messageId;
UInt16T checksum = 0;
for (int i = 0; i < (HeaderLength - 1); i++)
{
checksum += rawFrame[i];
}
rawFrame[4] = checksum[0];
checksum += rawFrame[4];
rawFrame[rawFrame[2] - 2] = checksum[1];
rawFrame[rawFrame[2] - 1] = checksum[0];
}