Re: hashmap vs khash? Re: [PATCH] packfile.c: speed up loading lots of packfiles.

> Colin Stolley <cstolley@runbox.com> wrote:
>> When loading packfiles on start-up, we traverse the internal packfile
>> list once per file to avoid reloading packfiles that have already
>> been loaded. This check runs in quadratic time, so for poorly
>> maintained repos with a large number of packfiles, it can be pretty
>> slow.
>
> Cool!  Thanks for looking into this, and I've been having
> trouble in that department with big alternates files.
>
>> Add a hashmap containing the packfile names as we load them so that
>> the average runtime cost of checking for already-loaded packs becomes
>> constant.
>
> Btw, would you have time to do a comparison against khash?
>
> AFAIK hashmap predates khash in git; and hashmap was optimized
> for removal.   Removals don't seem to be a problem for pack
> loading.
>
> I'm interested in exploring the removing of hashmap entirely in
> favor of khash to keep our codebase smaller and easier-to-learn.
> khash shows up more in other projects, and ought to have better
> cache-locality.