31 Mar
2009
31 Mar
'09
12:38 p.m.
On Mar 30, 2009 at 23:21, Daniel-Constantin Mierla <miconda(a)gmail.com> wrote:
Hello,
it became a trend to add anchors to each header used by some module to
sip_msg structure. While the average is 15 headers per SIP message (some
without anchors in the sip_msg), sip_msg has over 35.
Many of these are used only once, e.g., presence related headers are
used by router as endpoint, not as a proxy. Intended to endpoint are
subject, supported, unsupported, and perhaps others... Keeping them and
cloning in TM when proxying makes no sense. They are not used for routing.
I think would be good to replace some anchors or at least for future the
addition of anchors with functions like:
get_hdr_xyz(sip_msg) - that will take care of parsing and return the
right hdr_field structure.
I fully agree. I tried this once before, but hit some opposition :-)
The problem with lots of anchors is that each one uses 8 bytes on a
64-bit system and they add up (clone in tm a.s.o.).
I would keep anchors only for the headers that are use a lot and that
are used more then once per message processing cycle (e.g. if Foo is
used only once by one module, it shouldn't get an anchor/shortcut).
On another hand I propose to add sortcut to body (start and length) - in
this case if there is a correction done by the parser, will be in effect
everywhere. Looking now in the code, there are functions that extract
body in different ways, some correcting the length by skipping \r, \n at
the end.
Why isn't get_body() enough?
The message end is always at msg->buf+msg->len (but we can write a
function or extend get_body() to return the len too).
Andrei