Re: [PATCH] Handle deltified object correctly in git-*-pull family.

From: McMullan, Jason <jason.mcmullan@timesys.com>
Date: Jun 2, 2005, 17:03 UTC
Message-ID: <1117731830.32257.52.camel@jmcmullan.timesys>
In-Reply-To: <7v4qcg906f.fsf_-_@assigned-by-dhcp.cox.net>

On Thu, 2005-06-02 at 09:46 -0700, Junio C Hamano wrote:

Show 9 quoted lines

> When a remote repository is deltified, we need to get the
> objects that a deltified object we want to obtain is based upon.
> The initial parts of each retrieved SHA1 file is inflated and
> inspected to see if it is deltified, and its base object is
> asked from the remote side when it is.  Since this partial
> inflation and inspection has a small performance hit, it can
> optionally be skipped by giving -d flag to git-*-pull commands.
> This flag should be used only when the remote repository is
> known to have no deltified objects.

Eww. Don't you want to attempt to get the referenced sha1 *before* you stick the delta blob into the repository?

Otherwise, if a transfer fails, there's no good way to recover your database through the git-*pull interfaces, ie:

Try to pull session 1:
  pull tree a
    pull delta b (references blob c)
    pull blob c -> fails!

Try to pull session 2:
  pull tree a
    delta b - Found in database!
    ...

Or do I not understand your code properly?

(I'm working on a similar piece of code for my git-daemon protocol,
 which is why I'm worried about this issue)

-- 
Jason McMullan <jason.mcmullan@timesys.com>
TimeSys Corporation