Re: fact-import: failed to apply delta

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 10, 2009, 22:30 UTC
Message-ID: <7vprhqkjrr.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20090210213612.GW30949@spearce.org>

"Shawn O. Pearce" <spearce@spearce.org> writes:

Show 20 quoted lines

> Daniel Barkalow <barkalow@iabervon.org> wrote:
>> On Tue, 10 Feb 2009, Shawn O. Pearce wrote:
>> > 
>> > We should dump the cached_objects table in sha1_file.c during
>> > a checkpoint in fast-import.
>> 
>> No, that one's keyed by sha1, and doesn't get collisions; it's the 
>> delta_base_cache that's the issue; it's keyed by struct packed_git * and 
>> offset.
>
> Uh, yea, I realize that after I sent the message.  Does this patch
> fix it for you?
>
> --8<--
> Clear the delta base cache during fast-import checkpoint
>
> Otherwise we may reuse the same memory address for a totally
> different "struct packed_git", and a previously cached object from
> the prior occupant might be returned when trying to unpack an object
> from the new pack.

Can this be made more automatic?

For example if you do this every time a new pack is installed to sha1_file(), like in add_packed_git() perhaps, wouldn't that be much less error prone?