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

H.Merijn Brand wrote:
> On Tue, 02 Sep 2008 19:03:26 +0100, "Martin J. Evans"
> <[email protected]> wrote:
>
>   
>> 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:
>>     
>
> That is why I also support $ENV{DBD_TRACE}, in analogy with
> $ENV{DBI_TRACE}.
>  
>   
I would have to agree with $ENV{DBD_TRACE} It would be very useful for 
me while debugging connections as well.
>> 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.
>>     
>
>