Re: logging enhancements, take 2

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 01:02 PM 10/9/00 -0400, Gary Williams wrote:
>Here's what I have for libldap:
>
>The following is added to print.c.  Similar changes would be made in modules
>for the other libraries (liblber, libavl, etc.)  A static variable holding the
>address of an external logging routine, and functions that can set and get the
>address.  The debugging macro would then check the external function and use it
>if it's been set, otherwise use the existing logging routine.

I suggest a slight twist...

It would be nice if could always use the macro:
        LDAP_LOG( subsys, level, fmt, ...)  /* preferred */
or
        LDAP_LOG(( subsys, level, fmt, ...))

no matter which subsys we were in... but than inside each
subsystem requiring independent logging (-lldap -llber),
this would use an internal such as ber_int_logger() instead of
the full lutil logger.  OpenLDAP applications would call call
lutil_log_initialize() to (amongst other things) install the
full logger, lutil_int_logger().

It's best to use a function to do the switching (using an
internal hook), then to expose the hook, hence, I suggest:
        #define LDAP_LOG ber_pvt_logger  /* preferred */
or
        #define LDAP_LOG(x) ( ber_pvt_logger x )

and let ber_pvt_logger() determine whether or not to use
ber_int_logger() or lutil_int_logger() (as installed via the hook).

As far as the hook...
>static void (*ldap_logProc) LDAP_P(( char *subsys, int level, char *fmt, ... ));

That's reasonable prototype, but the hook needs to be -llber and
should be named per conventions, i.e:
  static void (*ber_int_log_proc)( const char *subsys, int level,
        const char *fmt, ... )

And should be set using:
  ber_set_option( NULL, LBER_OPT_LOG_PROC, (void*) lutil_int_logger )

from lutil_log_initialize()

[contrary to what I might have said previously] I would suggest that
the default logger (lber_int_logger) use a global log level (as this
is simpler to implement) which could be accessed via either
LBER_OPT_DEBUG or LDAP_OPT_DEBUG (LDAP_OPT_DEBUG would set LBER_OPT_DEBUG).
This means that a non-OpenLDAP application setting TRACE gets TRACE
across all subsystems (-lldap and -llber).  I don't have much problem
with this.

>If this is acceptable, I'll proceed putting it in all the libraries and updating the
>configuration routines and command lines to accept logging configuration. 

For command line, reuse -d.