On Thu, Jul 12, 2001 at 12:47:13PM +0200, Sander Striker wrote:
> [...]
> > what i suspect is happening in subversion [correct me if i'm
> > wrong, here!] is that they are writing their own server-code.
>
> You're wrong :)
wha-heeey :) i like being wrong :)
> subversion is going to use httpd with mod_dav as the server :)
... *enthusiastic*... omigud, i'm 25% way through mod_dav.c when
i looked at the LOC good _grief_. okay, that's irrelevent.
i get the idea.
> Wondering what the framework like socketserver.py looks like.
> Summary?
SocketServer.py is basically three sets of classes [with
specialisations of each] that you then 'mix' together to
get the required combination for your server.
set one:
BaseServer. specialisations: TCPServer and UDPServer
[i wrote a SQLTableReadingServer
where the 'request' is the data
_read_ from a queueing-table!]
Mixin. specialisations: ForkingMixIn and ThreadingMixIn.
[on the TODO list is a single-process
Mixin that keeps a list of all connections
*itself* and has to deal with them one-by-one
with all the associated blocking and select
problems etc. on a series of file descriptors]
Handlers. basically this allows you to 'Do' things to a
request. there are some pre-defined UDP and TCP request-handling
classes that you still have to over-ride functions to actually
_do_ something with the request socket, but at least it _gives_
you a per-connection socket.
the SocketServer framework basically provides a common API to
create, handle, finish and close requests. you don't have
to worry about how the request gets _to_ you: you only
have to provide methods to deal _with_ the request.
so you combine the above classes to get:
ThreadingUDPServer
ThreadingTCPServer
ForkingUDPServer
ForkingTCPServer
and, with the addition of BaseServer, i created
ForkingSQLTableReadingServer, which polls [yes, i know]
a SQL table, locks it, reads one entry, deletes it from
the table, unlocks the table,
creates a handler for it, passes the entry to the
handler, the handler Does Its Thing (in this case,
loads from a SQL table a python script named in the
request and runs it!)
now, whilst this level of genericity is probably excessive,
it was trivial to do, and it also provides the means to
*transparently* add... mmmm.... SSLServer and then
mix it in with Forking and Threading and you change *zero*
lines of code - ssl is all done for you.
redirection. loop-back testing. unix-domain-socket server.
even a TransactNamedPipe server - whatever you can dream up.
> It seems that the apache server framework can be extended
> with other protocols by just adding new modules and filters.
... what if people don't want to add new modules and new filters?
what if they want to go a separate route but take advantages
of the best bits of httpd's code, and share the results?
:)
luke
