On Wed, 15 Sep 2004 07:48:15 -0400, Hugo Duncan wrote
Spend a few days off line and you suddenly miss a whole conversation :-( It's going to take a while to catch up...
Well, I've been involved and I still not caught up...
Recent IOstreams discussion has indeed been very interesting, espescially as I am finally getting round to implementing buffers and filters for giallo (boost.sockets). At the moment I am leaning towards ACE style message buffer, using the apache filter idea of flush/eos/eoc control (but trying to avoid any knowledge of the underlying resource).
Are you talking about the ACE Message Block / ACE Message Queue stuff? http://www.dre.vanderbilt.edu/Doxygen/Current/html/ace/classACE__Message__Bl... http://www.dre.vanderbilt.edu/Doxygen/Current/html/ace/classACE__Message__Qu... If so, I'm really hoping we can do better. I understand that the key desire here is to avoid lots of copying and I agree with that. But, honestly I think at the socket boundary layer we really just want an IOStream that I can read/write to and control the send/recv. The reason is that typically I want / need to make one transformation at the process boundary anyway. So, for example, when I recieve an inbound message I'm going to unserialize whatever it is into a native structure. So I have to allocate (or take from a pool) and go field by field thru the data anyway realizing it into the native structure. Then I process the data. I'll never make any copies in the processing core b/c I'm going to pass around shared_ptr's or something. Going outbound I've built up a complex structure that needs to be serialized into a buffer that gets sent after I'm done. I'm passing this all around using smart pointers until I get to the socket stream and it's ready to go outbound. So if I'm writing some network code, I'm thinkin I just want to use boost.serialize to do the serialization and it needs a stream to do that. And actually, I'm curious if the file descriptor wrapper in the IOStream library wouldn't pretty much take care of it? The only exception I can think of is if the data is to be 'multicast' down 2 TCP connections...
So where is giallo today (apart from being temporarily broken on gcc due to mpl changes)?
...snip lots of good status info...
There is a streambuf implementation, but I have not found a way to implement this without it degenerating to a thread per connection model.
I would think it would tend to be a streambuf per connection regardless of the threading? Anyway, glad you're back -- I hope between all the interested parties we can get enough momentum to sustain things to the point of actually producing a boost library for demultipexing and sockets.... Jeff