[Spirit-general] Re: SLOW RUN-TIME: How to further optimize my spirit parser?

[Joel de G. <jo...@bo...>]

Martin Wille wrote:
> Joel de Guzman wrote:

> I created a trivial test program, used it with Boost 1.33.0,  and it 
> turned out to use the memory mapped implementation as intended. So, 
> Hartmut's patch definitely fixed the problem and the fix still works.
> 
> I suspect Matthew was using an older version of Spirit.
> 
> 
> Regarding the speed: profiling seems to indicate that the slowest part 
> of file_iterator is its dtor. Unfortunately, improving the speed of the 
> dtor isn't too easy. The dtor doesn't have any code; its execution time 
> is dominated by the execution time for the dtor of a shared_ptr member. 
> A way to improve that speed would be to add a policy to file_iterator 
> that would allow the user to specify that the file_iterator is used only 
> inside a single thread. In that case, a thread-unsafe (and therefore 
> much faster) implementation for a reference counting pointer could be 
> used. Without adding a policy, we could use the Spirit threading flags 
> for that.

The challenge would be to make this as fast as loading a vector
in memory and parsing from there; or something close. Is this
possible?

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net