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Jon Smirl said: | Once an object reference hits a pack file it is very likely that | following references will hit the same pack file. So first place to | look for an object is the same place the previous object was found. This is indeed a good heuristic so here it is. The search always start with the pack where the last object lookup succeeded. If the wanted object is not available there then the search continues with the normal pack ordering. To test this I split the Linux repository into 66 packs and performed a "time git-rev-list --objects --all > /dev/null". Best results are as follows: Pack Sort w/o this patch w/ this patch ------------------------------------------------------------- recent objects last 26.4s 20.9s recent objects first 24.9s 18.4s This shows that the pack order based on object age has some influence, but that the last-used-pack heuristic is even more significant in reducing object lookup. Signed-off-by: Nicolas Pitre <nico@cam.org> --- Note: the --max-pack-size to git-repack currently produces packs with old objects after those containing recent objects. The pack sort based on filesystem timestamp is therefore backward for those. This needs to be fixed of course, but at least it made me think about this variable for the test. Signed-off-by: Junio C Hamano <junkio@cox.net>
//////////////////////////////////////////////////////////////// GIT - the stupid content tracker //////////////////////////////////////////////////////////////// "git" can mean anything, depending on your mood. - random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant. - stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang. - "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room. - "goddamn idiotic truckload of sh*t": when it breaks Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals. Git is an Open Source project covered by the GNU General Public License. It was originally written by Linus Torvalds with help of a group of hackers around the net. It is currently maintained by Junio C Hamano. Please read the file INSTALL for installation instructions. See Documentation/tutorial.txt to get started, then see Documentation/everyday.txt for a useful minimum set of commands, and "man git-commandname" for documentation of each command. CVS users may also want to read Documentation/cvs-migration.txt. Many Git online resources are accessible from http://git.or.cz/ including full documentation and Git related tools. The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org. To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at http://marc.theaimsgroup.com/?l=git and other archival sites. The messages titled "A note from the maintainer", "What's in git.git (stable)" and "What's cooking in git.git (topics)" and the discussion following them on the mailing list give a good reference for project status, development direction and remaining tasks.