Re: [jamboost] header cacheing, etc.

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-05-24 10:35:47

At 08:25 AM 5/24/2002, David Abrahams wrote:

>I was getting tired of waiting for builds to start, especially when I was
>building over my slow wireless LAN connection, so I grabbed Matt
>Armstrong's improvements on Craig McPheeters' header cacheing patches 
(and
>a few other things) for jam_src. I made some mistakes with the checkin, 
so
>they're sitting on the end of the RC_1_28_0 branch, though I think that 
tag
>didn't get moved. The right way to get them is by checking out the
>"header-cache" tag in jam_src:
>
> cvs update -rheader-cache tools/build/jam_src
>
>In my experience (cursory tests) the patch slows things down slightly
>unless you set the HCACHEFILE variable to point at the cache dependency
>file you want it to use, in which case after the first build, you get an
>enormous speedup.

Will there be documentation on how to create the cache dependency file? Or 
is it something that is created automatically? If automatic, is there any 
reason a default HCACHEFILE couldn't be supplied?

Overall jam improves regression testing speed so much it isn't very 
gracious to complain about header scanning, but when just working with one 
regression test any speedup it will be much appreciated.

Thanks to all those involved!

--Beman