git/cache.h, branch v2.10.2

Merge branch 'jk/fetch-quick-tag-following' into maint

2016-10-28T16:01:17Z

When fetching from a remote that has many tags that are irrelevant to branches we are following, we used to waste way too many cycles when checking if the object pointed at by a tag (that we are not going to fetch!) exists in our repository too carefully. * jk/fetch-quick-tag-following: fetch: use "quick" has_sha1_file for tag following

fetch: use "quick" has_sha1_file for tag following

2016-10-14T18:31:32Z

When we auto-follow tags in a fetch, we look at all of the tags advertised by the remote and fetch ones where we don't already have the tag, but we do have the object it peels to. This involves a lot of calls to has_sha1_file(), some of which we can reasonably expect to fail. Since 45e8a74 (has_sha1_file: re-check pack directory before giving up, 2013-08-30), this may cause many calls to reprepare_packed_git(), which is potentially expensive. This has gone unnoticed for several years because it requires a fairly unique setup to matter: 1. You need to have a lot of packs on the client side to make reprepare_packed_git() expensive (the most expensive part is finding duplicates in an unsorted list, which is currently quadratic). 2. You need a large number of tag refs on the server side that are candidates for auto-following (i.e., that the client doesn't have). Each one triggers a re-read of the pack directory. 3. Under normal circumstances, the client would auto-follow those tags and after one large fetch, (2) would no longer be true. But if those tags point to history which is disconnected from what the client otherwise fetches, then it will never auto-follow, and those candidates will impact it on every fetch. So when all three are true, each fetch pays an extra O(nr_tags * nr_packs^2) cost, mostly in string comparisons on the pack names. This was exacerbated by 47bf4b0 (prepare_packed_git_one: refactor duplicate-pack check, 2014-06-30) which uses a slightly more expensive string check, under the assumption that the duplicate check doesn't happen very often (and it shouldn't; the real problem here is how often we are calling reprepare_packed_git()). This patch teaches fetch to use HAS_SHA1_QUICK to sacrifice accuracy for speed, in cases where we might be racy with a simultaneous repack. This is similar to the fix in 0eeb077 (index-pack: avoid excessive re-reading of pack directory, 2015-06-09). As with that case, it's OK for has_sha1_file() occasionally say "no I don't have it" when we do, because the worst case is not a corruption, but simply that we may fail to auto-follow a tag that points to it. Here are results from the included perf script, which sets up a situation similar to the one described above: Test HEAD^ HEAD ---------------------------------------------------------- 5550.4: fetch 11.21(10.42+0.78) 0.08(0.04+0.02) -99.3% Reported-by: Vegard Nossum Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'tg/add-chmod+x-fix' into maint

2016-09-29T23:49:47Z

"git add --chmod=+x " added recently only toggled the executable bit for paths that are either new or modified. This has been corrected to flip the executable bit for all paths that match the given pathspec. * tg/add-chmod+x-fix: t3700-add: do not check working tree file mode without POSIXPERM t3700-add: create subdirectory gently add: modify already added files when --chmod is given read-cache: introduce chmod_index_entry update-index: add test for chmod flags

Merge branch 'rs/hex2chr' into maint

2016-09-19T20:51:43Z

Code cleanup. * rs/hex2chr: introduce hex2chr() for converting two hexadecimal digits to a character

add: modify already added files when --chmod is given

2016-09-15T19:13:54Z

When the chmod option was added to git add, it was hooked up to the diff machinery, meaning that it only works when the version in the index differs from the version on disk. As the option was supposed to mirror the chmod option in update-index, which always changes the mode in the index, regardless of the status of the file, make sure the option behaves the same way in git add. Signed-off-by: Thomas Gummerer Signed-off-by: Junio C Hamano

read-cache: introduce chmod_index_entry

2016-09-15T19:13:54Z

As there are chmod options for both add and update-index, introduce a new chmod_index_entry function to do the work. Use it in update-index, while it will be used in add in the next patch. Signed-off-by: Thomas Gummerer Signed-off-by: Junio C Hamano

Merge branch 'jk/reflog-date' into maint

2016-09-09T04:35:52Z

The reflog output format is documented better, and a new format --date=unix to report the seconds-since-epoch (without timezone) has been added. * jk/reflog-date: date: clarify --date=raw description date: add "unix" format date: document and test "raw-local" mode doc/pretty-formats: explain shortening of %gd doc/pretty-formats: describe index/time formats for %gd doc/rev-list-options: explain "-g" output formats doc/rev-list-options: clarify "commit@{Nth}" for "-g" option

Merge branch 'jc/renormalize-merge-kill-safer-crlf' into maint

2016-09-09T04:35:52Z

"git merge" with renormalization did not work well with merge-recursive, due to "safer crlf" conversion kicking in when it shouldn't. * jc/renormalize-merge-kill-safer-crlf: merge: avoid "safer crlf" during recording of merge results convert: unify the "auto" handling of CRLF

introduce hex2chr() for converting two hexadecimal digits to a character

2016-09-07T17:42:46Z

Add and use a helper function that decodes the char value of two hexadecimal digits. It returns a negative number on error, avoids running over the end of the given string and doesn't shift negative values. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Merge branch 'jk/trace-fixup'

2016-08-12T16:47:36Z

Various small fixups to the "GIT_TRACE" facility. * jk/trace-fixup: trace: do not fall back to stderr write_or_die: drop write_or_whine_pipe() trace: disable key after write error trace: correct variable name in write() error message trace: cosmetic fixes for error messages trace: use warning() for printing trace errors trace: stop using write_or_whine_pipe() trace: handle NULL argument in trace_disable()