git/log-tree.c, branch v2.0.2

reuse cached commit buffer when parsing signatures

2014-06-13T19:10:13Z

When we call show_signature or show_mergetag, we read the commit object fresh via read_sha1_file and reparse its headers. However, in most cases we already have the object data available, attached to the "struct commit". This is partially laziness in dealing with the memory allocation issues, but partially defensive programming, in that we would always want to verify a clean version of the buffer (not one that might have been munged by other users of the commit). However, we do not currently ever munge the commit buffer, and not using the already-available buffer carries a fairly big performance penalty when we are looking at a large number of commits. Here are timings on linux.git: [baseline, no signatures] $ time git log >/dev/null real 0m4.902s user 0m4.784s sys 0m0.120s [before] $ time git log --show-signature >/dev/null real 0m14.735s user 0m9.964s sys 0m0.944s [after] $ time git log --show-signature >/dev/null real 0m9.981s user 0m5.260s sys 0m0.936s Note that our user CPU time drops almost in half, close to the non-signature case, but we do still spend more wall-clock and system time, presumably from dealing with gpg. An alternative to this is to note that most commits do not have signatures (less than 1% in this repo), yet we pay the re-parsing cost for every commit just to find out if it has a mergetag or signature. If we checked that when parsing the commit initially, we could avoid re-examining most commits later on. Even if we did pursue that direction, however, this would still speed up the cases where we _do_ have signatures. So it's probably worth doing either way. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

commit: record buffer length in cache

2014-06-13T19:09:38Z

Most callsites which use the commit buffer try to use the cached version attached to the commit, rather than re-reading from disk. Unfortunately, that interface provides only a pointer to the NUL-terminated buffer, with no indication of the original length. For the most part, this doesn't matter. People do not put NULs in their commit messages, and the log code is happy to treat it all as a NUL-terminated string. However, some code paths do care. For example, when checking signatures, we want to be very careful that we verify all the bytes to avoid malicious trickery. This patch just adds an optional "size" out-pointer to get_commit_buffer and friends. The existing callers all pass NULL (there did not seem to be any obvious sites where we could avoid an immediate strlen() call, though perhaps with some further refactoring we could). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

use get_cached_commit_buffer where appropriate

2014-06-13T19:08:17Z

Some call sites check commit->buffer to see whether we have a cached buffer, and if so, do some work with it. In the long run we may want to switch these code paths to make their decision on a different boolean flag (because checking the cache may get a little more expensive in the future). But for now, we can easily support them by converting the calls to use get_cached_commit_buffer. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'nd/log-show-linear-break'

2014-04-03T19:38:11Z

Attempts to show where a single-strand-of-pearls break in "git log" output. * nd/log-show-linear-break: log: add --show-linear-break to help see non-linear history object.h: centralize object flag allocation

log: add --show-linear-break to help see non-linear history

2014-03-25T22:09:49Z

Option explanation is in rev-list-options.txt. The interaction with -z is left undecided. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

rename read_replace_refs to check_replace_refs

2014-02-20T22:16:55Z

The semantics of this flag was changed in commit e1111cef23 inline lookup_replace_object() calls but wasn't renamed at the time to minimize code churn. Rename it now, and add a comment explaining its use. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

Merge branch 'bc/log-decoration'

2014-01-10T18:32:39Z

"git log --decorate" did not handle a tag pointed by another tag nicely. * bc/log-decoration: log: properly handle decorations with chained tags

log: properly handle decorations with chained tags

2013-12-20T22:37:03Z

git log did not correctly handle decorations when a tag object referenced another tag object that was no longer a ref, such as when the second tag was deleted. The commit would not be decorated correctly because parse_object had not been called on the second tag and therefore its tagged field had not been filled in, resulting in none of the tags being associated with the relevant commit. Call parse_object to fill in this field if it is absent so that the chain of tags can be dereferenced and the commit can be properly decorated. Include tests as well to prevent future regressions. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano

Merge branch 'cc/starts-n-ends-with'

2013-12-17T20:02:44Z

Remove a few duplicate implementations of prefix/suffix comparison functions, and rename them to starts_with and ends_with. * cc/starts-n-ends-with: replace {pre,suf}fixcmp() with {starts,ends}_with() strbuf: introduce starts_with() and ends_with() builtin/remote: remove postfixcmp() and use suffixcmp() instead environment: normalize use of prefixcmp() by removing " != 0"

replace {pre,suf}fixcmp() with {starts,ends}_with()

2013-12-05T22:13:21Z