Hi Alwyn, On 5/20/07, Alwyn Schoeman <[EMAIL PROTECTED]> wrote:
I agree with mat-29. In order for DemuxingProtocolCodecFactory to call a specific Decoder or Encoder, it will need to know what the type of the message is.
Each MessageDecoder can determine if the incoming data is for itself or not. DemuxingProtocolCodecFactory calls MessageDecoder.decodable() to find an appripriate MessageDecoder.
Question is, how does it know?
It calls decodable() of all registered MessageDecoders.
Does it assume a specific value at a specific offset in the data stream?
No. Your MessageDecoder.decodable() decides.
Does it call all the Decoders in sequence until a Decoder acknowledges that it is meant for it? (Hope not)
Yes, but it doesn't perform that bad.
Assume you have to handle different messages from different established protocols (cannot redesign), how would you handle that?
If those protocols are all implemented with DemuxingProtocolCodecFactory, you can register all MessageDecoder implementations and that's all. If you want to disable all MessageDecoders from one protocol once a message from the other protocol is received, you can take care of it in your IoHandler implementation. Trustin -- what we call human nature is actually human habit -- http://gleamynode.net/ -- PGP Key ID: 0x0255ECA6
