protected virtual void RaiseObisDataEvent(ObisData data)
{
// Raise the event in a thread-safe manner using the ?. operator.
ObisDataEvent?.Invoke(this, new ObisDataEventArgs(data.Raw, data.Code, data.Value, data.Unit));
}
private async Task <bool> ReadObisMessageAsync()
{
var code = new StringBuilder();
var value = new StringBuilder();
var unit = new StringBuilder();
var raw = new StringBuilder();
var obisdata = new List <ObisData>();
var state = ParseState.OBIS_BLOCK_START;
while (!_token.IsCancellationRequested && (state != ParseState.STOPPARSING))
{
var data = await _reader.ReadByteAsync();
_hexDump.DumpByte(HexDumpMode.BytesIn, data);
switch (state)
{
case ParseState.OBIS_BLOCK_START:
if (data == Constants.FrameStart)
{
state = ParseState.OBIS_CODE;
}
break;
case ParseState.OBIS_CODE:
if (data == Constants.EndMessage)
{
state = ParseState.OBIS_BLOCK_END;
break;
}
if ((char)data == '(')
{
raw.Append((char)data);
state = ParseState.OBIS_VALUE;
break;
}
if (code.Length < Constants.ObisCodeMaxLength)
{
raw.Append((char)data);
code.Append((char)data);
}
else
{
throw new Exception();
}
break;
case ParseState.OBIS_VALUE:
if ((char)data == '*')
{
raw.Append((char)data);
state = ParseState.OBIS_UNIT;
break;
}
if ((char)data == ')')
{
raw.Append((char)data);
state = ParseState.OBIS_ITEM_END;
break;
}
if (value.Length < Constants.ObisValueMaxLength)
{
raw.Append((char)data);
value.Append((char)data);
}
else
{
throw new Exception();
}
break;
case ParseState.OBIS_UNIT:
if ((char)data == ')')
{
raw.Append((char)data);
state = ParseState.OBIS_ITEM_END;
break;
}
if (unit.Length < Constants.ObisUnitMaxLength)
{
raw.Append((char)data);
unit.Append((char)data);
}
else
{
throw new Exception();
}
break;
case ParseState.OBIS_ITEM_END:
if (data == Constants.CR)
{
continue;
}
if (data == Constants.LF)
{
var item = new ObisData(raw.ToString(), code.ToString(), value.ToString(), unit.ToString());
obisdata.Add(item);
RaiseObisDataEvent(item);
raw.Clear();
code.Clear();
value.Clear();
unit.Clear();
state = ParseState.OBIS_CODE;
break;
}
break;
case ParseState.OBIS_BLOCK_END:
if (data == Constants.CR || data == Constants.LF)
{
continue;
}
if (data == Constants.FrameEnd)
{
state = ParseState.STOPPARSING;
break;
}
throw new Exception(); // unexpected character
default:
break;
}
}
return(true);
}
