Re: Logging Library-GSOC

[Vincent Torri]

On Mon, May 18, 2020 at 9:28 AM David Turner <address@hidden> wrote:
>
>
>
> Le lun. 18 mai 2020 à 09:03, Priyesh kumar <address@hidden> a écrit :
>>
>> Hey,
>> I wanted to ask that after selecting desirable external library how should I 
>> proceed:
>> 1. Should I stick to the existing debugging facility in which filtering of 
>> log messages is based on debug level comparisons of various FreeType's 
>> components and only use the external library to write log messages to file 
>> instead of stderr?
>> OR
>> 2. Most external libraries provide some log levels capabilities themselves, 
>> so,  should I think in direction of utilizing those. In case yes, then how 
>> should that be utilized?
>>
> I recommend not baking details of the logging library into the rest of 
> FreeType whenever possible. One thing that can be done is to send structured 
> logs from FreeType, i.e. instead of FT_Message() sending a string to whatever 
> log, the function could instead send a (component, level, message) tuple, 
> which would allow filtering externally (in the log library, through whatever 
> means are necessary). Also something useful when tracing is scoping traces 
> with start/stop events, but that would require new FT_TRACE_XXX() macros, so 
> should probably be considered a stretch goal. Just keep this in mind if you 
> intend to modify that part of the code.
>
>>
>> In the 2nd case, FreeType's logger will completely depend on the external 
>> library, and developers will also need to learn some new information to use 
>> the logger. And In the worst-case scenario, if the external library drops 
>> some functionality, we will need to make amendments to the logger.
>>
> I still don't know what the benefits of these external logging libraries will 
> be. Can you clarify what are we supposed to gain from this in practical 
> terms? Every dependency we add to the library becomes a maintenance burden, 
> so I would be in favor of the least coupling possible.
>

what about dlopen this external log lib ?

Vincent Torri