user/sven/git.git/diff-lib.c, branch v1.6.4.5

Merge branch 'jc/cache-tree'

2009-06-21T04:47:30Z

* jc/cache-tree: Avoid "diff-index --cached" optimization under --find-copies-harder Optimize "diff-index --cached" using cache-tree t4007: modernize the style cache-tree.c::cache_tree_find(): simplify internal API write-tree --ignore-cache-tree

Avoid "diff-index --cached" optimization under --find-copies-harder

2009-05-25T18:35:29Z

When find-copies-harder is in effect, the diff frontends are expected to feed all paths, not just changed paths, to the diffcore, so that copy sources can be picked up. In such a case, not descending into subtrees using the cache-tree information is simply wrong. Signed-off-by: Junio C Hamano

Optimize "diff-index --cached" using cache-tree

2009-05-25T18:35:29Z

When running "diff-index --cached" after making a change to only a small portion of the index, there is no point unpacking unchanged subtrees into the index recursively, only to find that all entries match anyway. Tweak unpack_trees() logic that is used to read in the tree object to catch the case where the tree entry we are looking at matches the index as a whole by looking at the cache-tree. As an exercise, after modifying a few paths in the kernel tree, here are a few numbers on my Athlon 64X2 3800+: (without patch, hot cache) $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.07user 0.02system 0:00.09elapsed 102%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+9407minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.00system 0:00.02elapsed 103%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+2446minor)pagefaults 0swaps Cold cache numbers are very impressive, but it does not matter very much in practice: (without patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time git diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.06user 0.17system 0:10.26elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 247032inputs+0outputs (1172major+8237minor)pagefaults 0swaps (with patch, cold cache) $ su root sh -c 'echo 3 >/proc/sys/vm/drop_caches' $ /usr/bin/time ../git.git/git-diff --cached --raw :100644 100644 b57e1f5... e69de29... M Makefile :100644 000000 8c86b72... 0000000... D arch/x86/Makefile :000000 100644 0000000... e69de29... A arche 0.02user 0.01system 0:01.01elapsed 3%CPU (0avgtext+0avgdata 0maxresident)k 18440inputs+0outputs (79major+2369minor)pagefaults 0swaps This of course helps "git status" as well. (without patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.17user 0.18system 0:00.35elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+10970minor)pagefaults 0swaps (with patch, hot cache) $ /usr/bin/time ../git.git/git-status >/dev/null 0.10user 0.16system 0:00.27elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+5336outputs (0major+3921minor)pagefaults 0swaps Signed-off-by: Junio C Hamano

Merge branch 'lt/maint-diff-reduce-lstat'

2009-05-23T08:40:33Z

* lt/maint-diff-reduce-lstat: Teach 'git checkout' to preload the index contents Avoid unnecessary 'lstat()' calls in 'get_stat_data()'

Avoid unnecessary 'lstat()' calls in 'get_stat_data()'

2009-05-10T03:42:19Z

When we ask get_stat_data() to get the mode and size of an index entry, we can avoid the lstat() call if we have marked the index entry as being uptodate due to earlier lstat() calls. This avoids a lot of unnecessary lstat() calls in eg 'git checkout', where the last phase shows the differences to the working tree (requiring a diff), but earlier phases have already verified the index. On the kernel repo (with a fast machine and everything cached), this changes timings of a nul 'git checkout' from - Before (best of ten): 0.14user 0.05system 0:00.19elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+13237minor)pagefaults 0swaps - After 0.11user 0.03system 0:00.15elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+13235minor)pagefaults 0swaps so it can obviously be noticeable, although equally obviously it's not a show-stopper on this particular machine. The difference is likely larger on slower machines, or with operating systems that don't do as good a job of name caching. Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano

Merge branch 'kb/checkout-optim'

2009-03-18T01:54:31Z

* kb/checkout-optim: Revert "lstat_cache(): print a warning if doing ping-pong between cache types" checkout bugfix: use stat.mtime instead of stat.ctime in two places Makefile: Set compiler switch for USE_NSEC Create USE_ST_TIMESPEC and turn it on for Darwin Not all systems use st_[cm]tim field for ns resolution file timestamp Record ns-timestamps if possible, but do not use it without USE_NSEC write_index(): update index_state->timestamp after flushing to disk verify_uptodate(): add ce_uptodate(ce) test make USE_NSEC work as expected fix compile error when USE_NSEC is defined check_updates(): effective removal of cache entries marked CE_REMOVE lstat_cache(): print a warning if doing ping-pong between cache types show_patch_diff(): remove a call to fstat() write_entry(): use fstat() instead of lstat() when file is open write_entry(): cleanup of some duplicated code create_directories(): remove some memcpy() and strchr() calls unlink_entry(): introduce schedule_dir_for_removal() lstat_cache(): swap func(length, string) into func(string, length) lstat_cache(): generalise longest_match_lstat_cache() lstat_cache(): small cleanup and optimisation

Generalize and libify index_is_dirty() to index_differs_from(...)

2009-02-11T06:25:39Z

index_is_dirty() in builtin-revert.c checks if the index is dirty. This patch generalizes this function to check if the index differs from a revision, i.e. the former index_is_dirty() behavior can now be achieved by index_differs_from("HEAD", 0). The second argument "diff_flags" allows to set further diff option flags like DIFF_OPT_IGNORE_SUBMODULES. See DIFF_OPT_* macros in diff.h for a list. index_differs_from() seems to be useful for more than builtin-revert.c, so it is moved into diff-lib.c and also used in builtin-commit.c. Yet to mention: - "rev.abbrev = 0;" can be safely removed. This has no impact on performance or functioning of neither setup_revisions() nor run_diff_index(). - rev.pending.objects is free()d because this fixes a leak. (Also see 295dd2ad "Fix memory leak in traverse_commit_list") Mentored-by: Daniel Barkalow Mentored-by: Christian Couder Signed-off-by: Stephan Beyer Signed-off-by: Junio C Hamano

lstat_cache(): swap func(length, string) into func(string, length)

2009-02-10T04:59:26Z

Swap function argument pair (length, string) into (string, length) to conform with the commonly used order inside the GIT source code. Also, add a note about this fact into the coding guidelines. Signed-off-by: Kjetil Barvik Signed-off-by: Junio C Hamano

Cleanup of unused symcache variable inside diff-lib.c

2009-01-11T23:56:55Z

Commit c40641b77b0274186fd1b327d5dc3246f814aaaf, 'Optimize symlink/directory detection' by Linus Torvalds, removed the 'char *symcache' parameter to the has_symlink_leading_path() function. This made all variables currently named 'symcache' inside diff-lib.c unnecessary. This also let us throw away the 'struct oneway_unpack_data', and instead directly use the 'struct rev_info *revs' member, which was the only member left after removal of the 'symcache[] array' member. The 'struct oneway_unpack_data' was introduced by the following commit: 948dd346 "diff-files: careful when inspecting work tree items" Impact: cleanup PATH_MAX bytes less memory stack usage in some cases Signed-off-by: Kjetil Barvik Signed-off-by: Junio C Hamano

diff: vary default prefix depending on what are compared

2008-08-31T03:53:24Z

With a new configuration "diff.mnemonicprefix", "git diff" shows the differences between various combinations of preimage and postimage trees with prefixes different from the standard "a/" and "b/". Hopefully this will make the distinction stand out for some people. "git diff" compares the (i)ndex and the (w)ork tree; "git diff HEAD" compares a (c)ommit and the (w)ork tree; "git diff --cached" compares a (c)ommit and the (i)ndex; "git-diff HEAD:file1 file2" compares an (o)bject and a (w)ork tree entity; "git diff --no-index a b" compares two non-git things (1) and (2). Because these mnemonics now have meanings, they are swapped when reverse diff is in effect and this feature is enabled. Signed-off-by: Junio C Hamano