mirror of
https://github.com/git/git.git
synced 2026-09-29 17:49:58 +02:00
Henrique Ferreiro
716766765c
Diffing the working tree against a commit with a pathspec can take time quadratic in the size of the index when the pathspec matches a subtree whose entries are the first entries of the index. Fix it by having next_cache_entry() record how far it scanned in cache_bottom, so repeated calls no longer rescan the growing prefix of already-unpacked entries. On a Chromium checkout (~500k index entries), git diff HEAD -- .agents/OWNERS took about 8 minutes before this change and 0.07 seconds after it. The same diff without the commit, without the pathspec, or with --cached was already instant. Add p0009-diff-pathspec.sh, which builds a 10,000-entry index whose first path lives in a subtree (100,000 entries under --long-tests), to guard against the regression. Comparing v2.55.0 with this change using GIT_TEST_LONG=t: Test v2.55.0 HEAD ------------------------------------------------------------------------ 0009.2: diff pathspec subtree 7.16(7.12+0.01) 0.02(0.01+0.00) -99.7% Signed-off-by: Henrique Ferreiro <hferreiro@igalia.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
33 lines
645 B
Bash
Executable File
33 lines
645 B
Bash
Executable File
#!/bin/sh
|
|
|
|
test_description='Tests performance of diffing the working tree with a pathspec'
|
|
|
|
. ./perf-lib.sh
|
|
|
|
test_perf_fresh_repo
|
|
|
|
count=10000
|
|
if test_have_prereq EXPENSIVE
|
|
then
|
|
count=100000
|
|
fi
|
|
|
|
# The entries exist only in the index, which is enough to
|
|
# exercise the index scan.
|
|
test_expect_success 'setup' '
|
|
blob=$(echo content | git hash-object -w --stdin) &&
|
|
{
|
|
printf "100644 $blob\taaa/file\n" &&
|
|
printf "100644 $blob\tf%s\n" $(test_seq $count)
|
|
} | git update-index --index-info &&
|
|
git commit -q -m initial &&
|
|
mkdir -p aaa &&
|
|
echo content >aaa/file
|
|
'
|
|
|
|
test_perf 'diff pathspec subtree' '
|
|
git diff HEAD -- aaa/file
|
|
'
|
|
|
|
test_done
|