Re: [boost] Re: Logging Library -- Formal Review Request

From: John Torjo (john.lists_at_[hidden])
Date: 2005-05-19 11:28:02

Hi Darryl,

Sorry for the late reply...

> 
> 
> I think you (or anyone) should be able to implement levels by changing the
> manager only, although I guess that depends on what "implement levels" really
> means.
> 
> I also think appenders/modifers should be able to be removed as well as added.
> It seems to me that the manager should deal with appender add/remove (or
> connect/disconnect if you prefer) in a way similar to enable/disable (or levels).

Yup, you are correct.

> 
> However, to be able to do that appenders (or connections to them) need to be
> comparable. It should be possible to write a manager to do this (eg one that
> indexes appenders by name), but the logger interface won't let me.
> 
> Given the various requests/discussion surrounding exactly how some parts of
> logging should best be done, I still think the simplified manager-log_impl
> interface I proposed previously, where the manager provides an
> appender/modifier vector to the log_impl, has both performance advantages
> and allows more flexibility in manager implementation/features. However,
> it probably isn't general or clean enough an interface, and this could
> be addressed by providing a concept something like the following, to
> replace the (not customisable at present) logger_impl.

I really like the sink concept. I could do something like:

get_sink("app.*").set_level(LEVEL_DEBUG);
get_sink("app.*").add_appender(some_appender);
get_sink("app.*").del_appender(some_appender);

The easiest way to implement deletion of appenders/modifiers, is to 
allow naming them. Once an appender has a name, when you say:

get_sink("app.*").del_appender( "my_cool_appender");

it will remove it. This will remove all appenders with that name.
I think this would be quite an easy to use solution.

What do you think?

Best,
John

-- 
John Torjo,    Contributing editor, C/C++ Users Journal
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