Subject: Re: [boost] [log] Comments
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2010-03-16 11:54:53
On 03/16/2010 02:19 PM, Stewart, Robert wrote:
> That reminds me. Seeing the strings in the library's interface such
> as proposed above make me nervous. In our environment, logging has
> to be very low latency in the calling thread. Checking to see
> whether a severity/component is enabled has to be very fast.
> Strings, such as those appearing in the suggestion above, imply
> higher latency than ideal.
>
> It would be really nice to have a string-to-ID mapping whereby the
> attribute names can be turned into identifiers that can be used
> thereafter for constant time lookup. In the example above, an extern
> std::size_t, say, would hold the ID for "Severity" and another for
> "Channel." Then, the macro would reference those std::size_t's
> rather than the strings, making all uses of that macro much faster.
>
> Adding support for that approach would, most likely, increase the API
> by adding overloads to various functions because the simpler,
> string-based approach may be adequate for many applications.
That looks like a possible optimization, although I'm not sure the final
outcome will be positive. That approach should be well benchmarked
before inclusion.