Re: Taking trace () to the next level ...

H.Merijn Brand wrote:
>  On Tue, 2 Sep 2008 11:15:20 +0100, Tim Bunce <[email protected]>
>  wrote:
>
> > On Mon, Sep 01, 2008 at 05:01:40PM -0700, Jonathan Leffler wrote:
> >> On Mon, Sep 1, 2008 at 3:30 PM, Tim Bunce <[email protected]>
> >> wrote:
> >>
> >>> On Mon, Sep 01, 2008 at 01:31:57PM +0200, H.Merijn Brand wrote:
> >>>
> >>>
> >>>
> >>>
> >>>> On Sun, 31 Aug 2008 23:56:43 +0100, Tim Bunce
> >>>> <[email protected]> wrote:
> >>>>
> >>>>> Having said all that, I can see some value in having a
> >>>>> separate driver trace level. I suggest a few of the "middle
> >>>>>  16 bits" are given over to
> >>>> IMHO 4 bits will do (0..15). If that is correct, I'll also
> >>>> change the levels to leave the basic levels 1 and 2 alone.
> >>> Actually I'd rather squeeze the levels concept down to 0..7 for
> >>>  both DBI and DBD levels in order to make two more flag bits
> >>> available and to encourage greater use of flags.
> >> FWIW, DBD::Informix uses trace levels from about 3 to 9 (leaving
> >> 1 and 2 for DBI output only).
> >>
> >> Whether that matters is another issue, but 4 bits would be
> >> preferred (though three is not the end of the world).  Unless you
> >>  have a use for those 2 bits at the back of your mind...
> > Although it looks like the trace level range is being reduced, it's
> >  effectively being increased. It's just that instead of a single
> > range you'd now have two.
> >
> > The current highest levels of driver internals tracing would then
> > be controlled via the DBD trace level. Something like this:
> >
> > $h->trace("2,-6"); # DBI trace level 2, DBD trace level 6
> >
> > That gives you more control because you can enable higher levels of
> >  DBD tracing without being swamped by higher levels of DBI tracing.
> >
> >
> >
>
>  Sounds ok
>
> > You could/should also define some trace flags for specific topics
> > to give finer control. Something like this:
> >
> > $h->trace("2,-4,ix_charset");
>
>  We will need some extra macro's to get the dbd level and the flags
>  Any suggestions?
>

I like what I'm reading in this thread. As others have said I would find 
it beneficial to be able to trace DBD::ODBC without getting DBI tracing. 
In an attempt to get DBD::ODBC tracing without DBI tracing I moved some 
tracing to trace flags. Unfortunately, this had a rather unfortunate 
side effect. I created an odbcconnection trace flag and put all my 
connection tracing under that. The problem is the only way to set the 
flag before connecting :-( is:

use DBD::ODBC;
DBI->trace(DBD::ODBC->parse_trace_flags('odbcconnection|odbcunicode');

The current trace macros allow tracing if a flag is set, tracing if a 
flag is set and the trace level is at least N, and tracing if the level 
is at least N but NOT tracing if a flag is set OR the level is at least 
N. I'd find the latter greatly beneficial for the above reason.

Martin