[cpp-netlib-devel] Binary message class

[<rhy...@gm...>]

Hi, all

Currently, the cpp-netlib is only text protocol oriented, since the 
underlying data storage facility is actually std::string (definitely 
will be replaced by std::basic_string<>). This maybe enough for 
protocols like http, but definitely not for binary protocols like socks. 
And, I would like to have a binary protocol friendly network framework. 
How about you guys? ;-)

For binary data processing abilities, I suggest the following:

 * reference counted binary buffer

    To avoid memory copies, reference counted binary buffer would help a 
lot.  I think boost::shared_ptr and boost::asio::basic_streambuf<> may 
help. The asio basic_streambuf<> template is automatically resizable and 
uses a vector<> for the underlying data storage. With Boost.Pool for 
memory management, I think it may be an excellent choice.

 * standard compliant marshalling/unmarshalling

    Binary messages should be constructed easily with 
marshalling/unmarshalling facilities. The library provides facilities to 
marshal/unmarshal basic data types such as different kinds of (unsigned) 
integers, string, sequence and array, and user can define their own 
overloaded marshal/unmarshal methods to deal with user defined data 
structures:

        namespace network {
            typedef basic_message<tag::binary_> bin_message;
        } // namespace network

        struct payload {
            ...
        };

        bin_message msg;
        payload p;
        uint32_t len = sizeof( payload )

        msg
            << source( ... )
            << dest( ... ) << dest( ... )
            << marshal( len ) << marshal( p );

    It also would be fine to have a standard compliant 
marshalling/demarshalling policy, may be CORBA CDR could be a choice?

In one word, I'd like to have a binary message class that plays the role 
of ACE_Message_Block and ACE_InputCDR/ACE_OutputCDR. What about your 
opinions, guys?

Cheers
Cheng