Re: [boost] [log] Boost.Log formal review closing down

Subject: Re: [boost] [log] Boost.Log formal review closing down
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2010-03-17 04:26:46

Hi, 

I though the review will continue until Sunday. 

Here is a a part of my review. I will continue this evening.

> - What is your evaluation of the design?

First say that in general I like the library general architecture. Going into details:

* Trivial log
Trivial log should be logged to std::cerr 
Trivial log should contain in the record message only the application part and the severity. If the user want line number, a timestamp, thread identifier the library need to let the user configure this trivial logger.

* Filters, Formatters and attributes:
An attribute is a different think than a filter. Filters contains attributes as part of its expressions.

attr< logging::severity_level >("Severity") should return the attribute value when called.

The following expression

attr< logging::severity_level >("Severity") >= logging::info

should return a filter. Can this make be possible and unanbigous?

Note that I have removed the trivial namespace which didn't add any information in the preceding expressions.

The same applies to formatters
fmt::stream
<< fmt::attr< unsigned int >("LineID")
<< ": <" << fmt::attr< logging::trivial::severity_level >("Severity")
<< "> " << fmt::message()

should be just written

fmt::stream
<< attr< unsigned int >("LineID")
<< ": <" << attr< logging::severity_level >("Severity")
<< "> " << message()

or even the library could provide some functions returning the predefined attrributes:

fmt::stream
<< line_id()
<< ": <" << severity_level()
<< "> " << message()

Specific formats could be written as

fmt::stream
<< (format("%08x") % line_id())<< ": <" << severity_level()<< "> " << message()

* Rotation on files.
Can rotation be based only on time? Can we rotate at 2:00AM every day?
How many rotation files are maintained? Can this number be configured?

Best,
Vicente