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From: Jeff King <peff@peff.net>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
Subject: Re: Bringing a bit more sanity to $GIT_DIR/objects/info/alternates?
Date: Tue, 7 Aug 2012 02:16:16 -0400	[thread overview]
Message-ID: <20120807061616.GC13222@sigill.intra.peff.net> (raw)
In-Reply-To: <501E3F04.4050902@alum.mit.edu>

On Sun, Aug 05, 2012 at 11:38:12AM +0200, Michael Haggerty wrote:

> I have some other crazy ideas for making the concept even more powerful:
> 
> * Support remote alternate repositories.  Local repository obtains
> missing objects from the remote as needed.  This would probably be
> insanely inefficient without also supporting...
> 
> * Lazy copying of "borrowed" objects to the local repository.  Any
> object fetched from the alternate object store is copied to the local
> object store.
> 
> Together, I think that these two features would give fully-functional
> shallow clones.

You might be interested in looking at my rough (_very_ rough) experiment
with object db "hooks":

  https://github.com/peff/git/commits/jk/external-odb

The basic idea is to have helper programs that basically have two
commands: give a list of sha1s you can provide, and fetch a specific
object by sha1. That's enough for the low levels of git to fall-back to
a helper on an object lookup failure, and copy the object to a local
cache. Managing the cache could be done externally by helper-specific
code.

Sorry, there's no documentation on the format or behavior, and most of
the changes are in one big patch. If you're interested and find it
unreadable, I can try to clean it up.

-Peff

  parent reply	other threads:[~2012-08-07  6:16 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-05  4:56 Bringing a bit more sanity to $GIT_DIR/objects/info/alternates? Junio C Hamano
2012-08-05  9:38 ` Michael Haggerty
2012-08-05 19:01   ` Junio C Hamano
2012-08-07  6:16   ` Jeff King [this message]
2012-08-06 21:55 ` Junio C Hamano
2012-08-08  1:42 ` Sascha Cunz
2012-08-11  9:35 ` Hallvard Breien Furuseth
2012-08-27 22:39 ` Oswald Buddenhagen
2012-08-28 19:19   ` GC of alternate object store (was: Bringing a bit more sanity to $GIT_DIR/objects/info/alternates?) Hallvard Breien Furuseth
2012-08-29  7:42     ` Oswald Buddenhagen
2012-08-29 15:52       ` GC of alternate object store Junio C Hamano
2012-08-30  9:53         ` Oswald Buddenhagen
2012-08-30 16:03           ` Junio C Hamano
2012-08-31 16:26             ` Oswald Buddenhagen
2012-08-31 19:18               ` Dan Johnson
2012-08-31 19:45                 ` Junio C Hamano
2012-09-01  4:25                   ` [PATCH] fetch --all: pass --tags/--no-tags through to each remote Dan Johnson
2012-09-01 11:22                     ` Jeff King
2012-09-01 11:25                       ` [PATCH 1/2] argv-array: add pop function Jeff King
2012-09-01 11:27                       ` [PATCH 2/2] fetch: use argv_array instead of hand-building arrays Jeff King
2012-09-01 14:34                         ` Jens Lehmann
2012-09-01 15:27                           ` [PATCH] submodule: " Jens Lehmann
2012-09-01 11:32                       ` [PATCH] fetch --all: pass --tags/--no-tags through to each remote Jeff King
2012-09-01 11:34                         ` [PATCH 3/2] argv-array: fix bogus cast when freeing array Jeff King
2012-09-05 21:22                       ` [PATCHv2] fetch --all: pass --tags/--no-tags through to each remote Dan Johnson
2012-09-07 17:07                         ` Junio C Hamano

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