protected override bool DoDecode(ByteBuffer input, IProtocolDecoderOutput output) { MessageDecoderResult result; if (_currentDecoder == null) { IMessageDecoder[] decoders = _decoders; int undecodables = 0; for (int i = decoders.Length - 1; i >= 0; i --) { IMessageDecoder decoder = decoders[i]; int limit = input.Limit; int pos = input.Position; try { result = decoder.Decodable(input); } finally { input.Position = pos; input.Limit = limit; } if (result == MessageDecoderResult.OK) { _currentDecoder = decoder; break; } else if(result == MessageDecoderResult.NOT_OK) { undecodables ++; } else if (result != MessageDecoderResult.NEED_DATA) { throw new Exception("Unexpected decode result (see your decodable()): " + result); } } if (undecodables == _decoders.Length) { // Throw an exception if all decoders cannot decode data. input.Position = input.Limit; // Skip data throw new ProtocolDecoderException( "No appropriate message decoder: " + input.GetHexDump()); } if (_currentDecoder == null) { // Decoder is not determined yet (i.e. we need more data) return false; } } result = _currentDecoder.Decode(input, output); if (result == MessageDecoderResult.OK) { _currentDecoder = null; return true; } else if (result == MessageDecoderResult.NEED_DATA) { return false; } else if (result == MessageDecoderResult.NOT_OK) { throw new ProtocolDecoderException("Message decoder returned NOT_OK."); } else { throw new Exception("Unexpected decode result (see your decode()): " + result); } }