0ae91be0e1
Currently the only caller of peel_ref is show-ref, which is using this function to show the peeled tag information if it is available from an existing packed-refs file. The call happens during the for_each_ref callback function, so we have the proper struct ref_list already on the call stack but it is not easily available to return the peeled information to the caller. We now save the current struct ref_list item before calling back into the callback function so that future calls to peel_ref from within the callback function can quickly access the current ref. Doing so will save us an lstat() per ref processed as we no longer have to check the filesystem to see if the ref exists as a loose file or is packed. This current ref caching also saves a linear scan of the cached packed refs list. As a micro-optimization we test the address of the passed ref name against the current_ref->name before we go into the much more costly strcmp(). Nearly any caller of peel_ref will be passing us the same string do_for_each_ref passed them, which is current_ref->name. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
//////////////////////////////////////////////////////////////// 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.