Re: [boost] logging v1.4 - some comments

From: John Torjo (john.lists_at_[hidden])
Date: 2005-08-22 12:01:53

Darryl Green wrote:

> Darryl Green <darryl.green <at> aanet.com.au> writes:
> 
> 
>>I think what is needed is a set of connections (logs connect to 
>>appenders/modifiers) ordered by the log name which may include wildcards. Log 
>>name (segments) containing wildcards should be ordered before exact names so 
>>the more specific rules override the less specific ones.
>>
> 
> 
> I'm putting together an alternate manager to implement something like the above.
> 
> The semantics will be that you specify logging rules like:
> 
> // create/register (but don't connect to any logs) an appender
> log_appender("display") = write_to_cout;
> log_appender("bazfile") = write_to_file("baz.log");
> 
> manipulate_logs("foo.bar.*")
>    .connect_appender("display");
> 
> manipulate_logs("foo.bar.baz")
>    .disconnect_appender("display")
>    .connect_appender("bazfile")
> 
> // one can delete the actual appender
> // which will disconnect it first!
> log_appender("display").erase();
> 
> The connecting/disconnecting of appenders maintains a (per appender) set of 
> rules for matching logs. The size of the rule set is bounded (assuming the set 
> of log names is) by removing redundant rules whenever a modification to the 
> rule set is made. The rules are applied in the order they are specified.
> 

This does indeed look easier. I want to update the log manager to allow 
for this, but I don't think I'll have the time to do it, before the 
formal review (30 Sept).

> Clearly this means changing manipulate_logs, and changing the manager 
> concept/interface. I'm finding it hard to see how a really "alternate" manager 
> could be written given the rather restrictive set of required interfaces. I 
> think manipulate_logs() should simply provide access to completely manager 
> defined functionality.
> 
> I also find the manipulation of logs by specifying the pattern to match a 
> number of logs, then applying a number of appenders to them to be less than 
> appealing, I think the "inverse" interface should also be provided ie.
> 
> appender("display")
>    .connect("foo.bar.*")
>    .disconnect("foo.bar.baz");
> appender("bazfile")
>    .connect("foo.bar.baz");
> 
> Would have the same result as the manipulate_logs lines above.
> 

Yup, this makes sense as well.

Best,
John

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