Re: Sha1 lookup and GIT_USE_LOOKUP
- From
- Marc Pegon <pegon.marc@gmail.com>
- Date
- Jun 9, 2011, 09:24 UTC
- Message-ID
- <BANLkTi=b+WKy2_9VeEw5B0QqodHfVJs2XQ@mail.gmail.com>
- In-Reply-To
- <7v62og2lw1.fsf@alter.siamese.dyndns.org>
On Wed, Jun 8, 2011 at 8:55 PM, Junio C Hamano <gitster@pobox.com> wrote:
Show 19 quoted lines
> Marc Pegon <pegon.marc@gmail.com> writes: > >> Since this environment variable is not set by default, git will always >> use a simple binary search, won't it ? > > Yes. > >> Also, when searching for a sha1 given a sha1 prefix, among packed >> objects, find_short_packed_object also does a simple binary search. >> Wouldn't it be simpler to just use the sha1_entry_pos method ? > > Unknown ;-). > > The environment variable is there exactly for people like you who are > interested in finding out which one yields better performance by > benchmarking. Once we can get a convincing result, we can either > deprecate the more involved sha1_entry_pos() if it turns out to be not > worth it, or we can always use it if it turns out to be significantly > better.
Perhaps we could compare the two methods by counting for each one the average number of iterations it takes to find an object in a pack. But anyways, I guess GIT_USE_LOOKUP should also have an influence on the method used to find an object given a sha1 prefix, and the code that does a simple binary search should not be duplicated as it is now, right ?
> Thanks. >