Re: [naviserver-devel] RFE: Expanding ns_log/ns_logctl

[Zoran V. <zv...@ar...>]

Am 25.06.2006 um 11:30 schrieb Gustaf Neumann:

> Well, i would not base the whole design decision on this fact, since
> also from the c-level one could call the tcl/xotcl log functions

Well, this is not the only reason (see below). I also believe it is
cleaner to have C-code not dependent (if possible) to any Tcl code.
By getting apropriate "hooks" into the log facility, one can handle
just about any situation with relative ease being it just C or just
Tcl or a combination.

At the moment, the way of expanding the log facility is pretty
inflexible. Currently you can overload internal log and flush
calls only. If one module redefines those log calls, another module
can junk its modifications by plugging into the same hook. Also, the
"default" operation of the log-facility is from that point, entirely
dependent on the overloading module. This is not very nice and the
idea is to improve on that as well. I will however not change that
behaviour as I do not really know wether somebody is using it or not.
What I'd do is to change the default way of handling the log entries
by adding a list of callbacks one can add and/or remote to/from.
The callbacks themselves can be written in C or in Tcl similar to the
filter callbacks we already use. This way, the current log processing
(a call to write(2...) will be implemented as yet-another-callback so
the entire beast will be completely generic. By addind more callbacks
one will not influence/replace the default processing, rather expand it!

I hope to get some code pretty soon and I will post diffs to
the list. This will then be much easier to understand.

Cheers
Zoran