Early review of std.logger

[ilya-stromberg]

On Monday, 21 October 2013 at 06:27:39 UTC, SomeDude wrote:
> On Thursday, 17 October 2013 at 07:34:28 UTC, qznc wrote:
>> On Thursday, 17 October 2013 at 02:13:12 UTC, Eric Anderton 
>> wrote:
>>> The strength of this is that it would allow us to freely 
>>> integrate D libraries that use std.logger, yet filter their 
>>> log output from *outside* the library through the std.logger 
>>> API.
>>
>> This is one of the most important aspects in my opinion.
>> Std.logger should be easy to use, so library writers are
>> encouraged to use it. Compare this with the "unittest" keyword,
>> which makes it easy to write some simple tests. Of course,
>> flexibility to use complex machinery for using the 
>> messages/tests
>> is necessary. Just like we can hook up more advanced unit 
>> testing
>> frameworks, we should be able to hook up more advanced logging
>> machinery. The advanced stuff is not for Phobos though. 
>> Advanced
>> stuff for unittests is for example, parallel execution and
>> graphical reports. Advanced stuff for logging is for example 
>> log
>> rotation and networking.
>
> There is no contradiction. Complex log libraries become 
> (relatively) complex when one wants to use their advanced 
> features, but are as simple as the others when one wants to use 
> them simply.
> That's why in the Java world nearly everyone uses Log4j instead 
> of the official JEE API.
>
> In practive, you really want a powerful logging facility.
> Another feature I used once in a project, was to log to RAM. We 
> decided to log TRACE logs in production in order to catch a 
> rare bug, but of course, it would output too many logs. So we 
> decided to log everything in RAM and keep the last 1000 logs. 
> Whenever there would be an exception or a CRITICAL log, the 
> whole 1000 logs would be dumped on disk. That feature proved 
> very useful.

+1
Also, it would be useful to use buffered asynchronous logger 
(mentioned above).
It will help to trace and save all logs, but should be fast for 
production usage.