Re: Summer of Code - Cached Packs/Object Lists

From: Shawn O. Pearce <spearce@spearce.org>
Date: Mar 23, 2009, 01:59 UTC
Message-ID: <20090323015936.GM23521@spearce.org>
In-Reply-To: <fsmi80et2dp57f5bdxUYAxe124vaj_firegpg@mail.gmail.com>

Please line wrap your email at something useful to others when quoting, like 70-72 characters per line.

thisnukes4u@gmail.com wrote:

Show 6 quoted lines

> I am particularly interested in the packfile caching project
> mentioned on the wiki, but I have a couple of questions:
>
> 1.  Would it be possible to implement both the packfile and
> object list caching mechanisms, or might would one interfere with
> the other in some way?

You could do both. But I think most people on the list will argue that doing both is overkill and only one is necessary, and further, that only the one that offers the "biggest bank for the buck" should be implemented.

Whole pack file caching has been discussed on list a few times as a nice feature to have, but it raises some issues of cache management, not to mention the issue I posed about it being relatively useless on frequently changing repositories.

> 2.  With just a quick perusal of the daemon source, I noticed
> that it shells out to the upload-pack command. Where would it be
> appropriate to implement such a caching mechanism, in the daemon
> proper, the upload-pack code, or would both need to be updated?

The daemon doesn't get enough data from the client in order to perform any sort of caching.

So the caching has to happen in upload-pack, and/or pack-objects. (upload-pack forks out to pack-objects to create the pack file to send to the client)

-- 
Shawn.