Re: [boost] [log] How to set/reset a channel-specific filter

Subject: Re: [boost] [log] How to set/reset a channel-specific filter
From: Andreas Huber (ahd6974-spamboostorgtrap_at_[hidden])
Date: 2010-03-16 13:22:21

"Andrey Semashev" <andrey.semashev_at_[hidden]> wrote in message 
news:4B9FAFD5.50409_at_gmail.com...
>> If we go with method a), we'd need a way to enumerate all global
>> loggers.
>
> Not sure why would you need to enumerate loggers. You could simply specify 
> all the channels in the filter, if their number is not very big.

Loggers are declared by thrird party code, so we have no idea about the 
number of loggers.

> If it is, you can create your own function that accepts the channel name 
> and then decides if it is enabled. This function can then be converted 
> into a filter like this:
>
>   bool is_channel_enabled(std::string const& chan_name);
>
>
>   sink->set_filter(
>     flt::attr< std::string >("Channel").satisfies(&is_channel_enabled)
>   );

Ok, that will certainly work for us, but I'd consider this a (small) hack, 
because we'd have to duplicate information that is presumably already 
present in Boost.Log.

More precisely, we want to provide a utility function where you pass in a 
logger and a severity and the function then modifies the global filter so 
that all records comming from the specified logger with a severity below the 
specified one will be discarded. Unless I'm missing something, this would 
require us keeping a global list of all loggers that have a filter applied, 
correct?

I assumed that somewhere Boost.Log keeps such a list anyway, so I'd rather 
use that one than build our own.

Thanks & Regards,

-- 
Andreas Huber
When replying by private email, please remove the words spam and trap
from the address shown in the header.