A new command "git last-modified" has been added to show the closest
ancestor commit that touched each path.
* tc/last-modified:
last-modified: use Bloom filters when available
t/perf: add last-modified perf script
last-modified: new subcommand to show when files were last modified
Our 'git last-modified' performs a revision walk, and computes a diff at
each point in the walk to figure out whether a given revision changed
any of the paths it considers interesting.
When changed-path Bloom filters are available, we can avoid computing
many such diffs. Before computing a diff, we first check if any of the
remaining paths of interest were possibly changed at a given commit by
consulting its Bloom filter. If any of them are, we are resigned to
compute the diff.
If none of those queries returned "maybe", we know that the given commit
doesn't contain any changed paths which are interesting to us. So, we
can avoid computing it in this case.
Comparing the perf test results on git.git:
Test HEAD~ HEAD
------------------------------------------------------------------------------------
8020.1: top-level last-modified 4.49(4.34+0.11) 2.22(2.05+0.09) -50.6%
8020.2: top-level recursive last-modified 5.64(5.45+0.11) 5.62(5.30+0.11) -0.4%
8020.3: subdir last-modified 0.11(0.06+0.04) 0.07(0.03+0.04) -36.4%
Based-on-patch-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Toon Claes <toon@iotcl.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to git-blame(1), introduce a new subcommand
git-last-modified(1). This command shows the most recent modification to
paths in a tree. It does so by expanding the tree at a given commit,
taking note of the current state of each path, and then walking
backwards through history looking for commits where each path changed
into its final commit ID.
Based-on-patch-by: Jeff King <peff@peff.net>
Improved-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Toon Claes <toon@iotcl.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>