Re: remove_duplicates() in builtin/fetch-pack.c is O(N^2)

On Thursday, May 24, 2012 07:04:34 pm Jeff King wrote:

On Thu, May 24, 2012 at 06:54:56PM -0600, Martin Fick 

wrote:

quoted

quoted

Yes, exclusively warm. And all of the refs were

We'd have to give some thought to potential race
conditions, though. Usually pack-refs isn't modifying
the ref, so it can just write out the value to the
packed-refs file, then delete the loose ref if nobody
has touched it since we wrote. But here we're combining
it with a modification, so I suspect there would be a
race with another process trying to modify it.

Yeah, I thought about that.  Could you just right the new 
packed-ref file with the new refs and the old refs which 
were in the file already, then just delete any loose refs 
which were ones which were just added by this operation, 
only if they have not changed?

This way, if someone else modifies one of the same refs, 
they could just win?

-Martin


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