git/t/t4216-log-bloom.sh

195 строки
5.9 KiB
Bash
Исходник Обычный вид История

#!/bin/sh
test_description='git log for a path with Bloom filters'
. ./test-lib.sh
GIT_TEST_COMMIT_GRAPH=0
GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
test_expect_success 'setup test - repo, commits, commit graph, log outputs' '
git init &&
mkdir A A/B A/B/C &&
test_commit c1 A/file1 &&
test_commit c2 A/B/file2 &&
test_commit c3 A/B/C/file3 &&
test_commit c4 A/file1 &&
test_commit c5 A/B/file2 &&
test_commit c6 A/B/C/file3 &&
test_commit c7 A/file1 &&
test_commit c8 A/B/file2 &&
test_commit c9 A/B/C/file3 &&
test_commit c10 file_to_be_deleted &&
git checkout -b side HEAD~4 &&
test_commit side-1 file4 &&
git checkout master &&
git merge side &&
test_commit c11 file5 &&
mv file5 file5_renamed &&
git add file5_renamed &&
git commit -m "rename" &&
rm file_to_be_deleted &&
git add . &&
git commit -m "file removed" &&
git commit-graph write --reachable --changed-paths
'
graph_read_expect () {
NUM_CHUNKS=5
cat >expect <<- EOF
header: 43475048 1 1 $NUM_CHUNKS 0
num_commits: $1
chunks: oid_fanout oid_lookup commit_metadata bloom_indexes bloom_data
EOF
test-tool read-graph >actual &&
test_cmp expect actual
}
test_expect_success 'commit-graph write wrote out the bloom chunks' '
graph_read_expect 15
'
# Turn off any inherited trace2 settings for this test.
sane_unset GIT_TRACE2 GIT_TRACE2_PERF GIT_TRACE2_EVENT
sane_unset GIT_TRACE2_PERF_BRIEF
sane_unset GIT_TRACE2_CONFIG_PARAMS
setup () {
rm "$TRASH_DIRECTORY/trace.perf"
git -c core.commitGraph=false log --pretty="format:%s" $1 >log_wo_bloom &&
GIT_TRACE2_PERF="$TRASH_DIRECTORY/trace.perf" git -c core.commitGraph=true log --pretty="format:%s" $1 >log_w_bloom
}
test_bloom_filters_used () {
log_args=$1
bloom_trace_prefix="statistics:{\"filter_not_present\":0,\"maybe\""
setup "$log_args" &&
grep -q "$bloom_trace_prefix" "$TRASH_DIRECTORY/trace.perf" &&
test_cmp log_wo_bloom log_w_bloom &&
test_path_is_file "$TRASH_DIRECTORY/trace.perf"
}
test_bloom_filters_not_used () {
log_args=$1
setup "$log_args" &&
! grep -q "statistics:{\"filter_not_present\":" "$TRASH_DIRECTORY/trace.perf" &&
test_cmp log_wo_bloom log_w_bloom
}
for path in A A/B A/B/C A/file1 A/B/file2 A/B/C/file3 file4 file5 file5_renamed file_to_be_deleted
do
for option in "" \
"--all" \
"--full-history" \
"--full-history --simplify-merges" \
"--simplify-merges" \
"--simplify-by-decoration" \
"--follow" \
"--first-parent" \
"--topo-order" \
"--date-order" \
"--author-date-order" \
"--ancestry-path side..master"
do
test_expect_success "git log option: $option for path: $path" '
test_bloom_filters_used "$option -- $path"
'
done
done
test_expect_success 'git log -- folder works with and without the trailing slash' '
test_bloom_filters_used "-- A" &&
test_bloom_filters_used "-- A/"
'
test_expect_success 'git log for path that does not exist. ' '
test_bloom_filters_used "-- path_does_not_exist"
'
test_expect_success 'git log with --walk-reflogs does not use Bloom filters' '
test_bloom_filters_not_used "--walk-reflogs -- A"
'
test_expect_success 'git log -- multiple path specs does not use Bloom filters' '
test_bloom_filters_not_used "-- file4 A/file1"
'
test_expect_success 'git log -- "." pathspec at root does not use Bloom filters' '
test_bloom_filters_not_used "-- ."
'
test_expect_success 'git log with wildcard that resolves to a single path uses Bloom filters' '
test_bloom_filters_used "-- *4" &&
test_bloom_filters_used "-- *renamed"
'
test_expect_success 'git log with wildcard that resolves to a multiple paths does not uses Bloom filters' '
test_bloom_filters_not_used "-- *" &&
test_bloom_filters_not_used "-- file*"
'
test_expect_success 'setup - add commit-graph to the chain without Bloom filters' '
test_commit c14 A/anotherFile2 &&
test_commit c15 A/B/anotherFile2 &&
test_commit c16 A/B/C/anotherFile2 &&
git commit-graph write --reachable --split --no-changed-paths &&
test_line_count = 2 .git/objects/info/commit-graphs/commit-graph-chain
'
test_expect_success 'Do not use Bloom filters if the latest graph does not have Bloom filters.' '
test_bloom_filters_not_used "-- A/B"
'
test_expect_success 'setup - add commit-graph to the chain with Bloom filters' '
test_commit c17 A/anotherFile3 &&
git commit-graph write --reachable --changed-paths --split &&
test_line_count = 3 .git/objects/info/commit-graphs/commit-graph-chain
'
test_bloom_filters_used_when_some_filters_are_missing () {
log_args=$1
commit-graph: check all leading directories in changed path Bloom filters The file 'dir/subdir/file' can only be modified if its leading directories 'dir' and 'dir/subdir' are modified as well. So when checking modified path Bloom filters looking for commits modifying a path with multiple path components, then check not only the full path in the Bloom filters, but all its leading directories as well. Take care to check these paths in "deepest first" order, because it's the full path that is least likely to be modified, and the Bloom filter queries can short circuit sooner. This can significantly reduce the average false positive rate, by about an order of magnitude or three(!), and can further speed up pathspec-limited revision walks. The table below compares the average false positive rate and runtime of git rev-list HEAD -- "$path" before and after this change for 5000+ randomly* selected paths from each repository: Average false Average Average positive rate runtime runtime before after before after difference ------------------------------------------------------------------ git 3.220% 0.7853% 0.0558s 0.0387s -30.6% linux 2.453% 0.0296% 0.1046s 0.0766s -26.8% tensorflow 2.536% 0.6977% 0.0594s 0.0420s -29.2% *Path selection was done with the following pipeline: git ls-tree -r --name-only HEAD | sort -R | head -n 5000 The improvements in runtime are much smaller than the improvements in average false positive rate, as we are clearly reaching diminishing returns here. However, all these timings depend on that accessing tree objects is reasonably fast (warm caches). If we had a partial clone and the tree objects had to be fetched from a promisor remote, e.g.: $ git clone --filter=tree:0 --bare file://.../webkit.git webkit.notrees.git $ git -C webkit.git -c core.modifiedPathBloomFilters=1 \ commit-graph write --reachable $ cp webkit.git/objects/info/commit-graph webkit.notrees.git/objects/info/ $ git -C webkit.notrees.git -c core.modifiedPathBloomFilters=1 \ rev-list HEAD -- "$path" then checking all leading path component can reduce the runtime from over an hour to a few seconds (and this is with the clone and the promisor on the same machine). This adjusts the tracing values in t4216-log-bloom.sh, which provides a concrete way to notice the improvement. Helped-by: Taylor Blau <me@ttaylorr.com> Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-01 16:27:30 +03:00
bloom_trace_prefix="statistics:{\"filter_not_present\":3,\"maybe\":6,\"definitely_not\":8"
setup "$log_args" &&
grep -q "$bloom_trace_prefix" "$TRASH_DIRECTORY/trace.perf" &&
test_cmp log_wo_bloom log_w_bloom
}
test_expect_success 'Use Bloom filters if they exist in the latest but not all commit graphs in the chain.' '
test_bloom_filters_used_when_some_filters_are_missing "-- A/B"
'
test_expect_success 'persist filter settings' '
test_when_finished rm -rf .git/objects/info/commit-graph* &&
rm -rf .git/objects/info/commit-graph* &&
GIT_TRACE2_EVENT="$(pwd)/trace2.txt" \
GIT_TRACE2_EVENT_NESTING=5 \
GIT_TEST_BLOOM_SETTINGS_NUM_HASHES=9 \
GIT_TEST_BLOOM_SETTINGS_BITS_PER_ENTRY=15 \
git commit-graph write --reachable --changed-paths &&
grep "{\"hash_version\":1,\"num_hashes\":9,\"bits_per_entry\":15}" trace2.txt &&
GIT_TRACE2_EVENT="$(pwd)/trace2-auto.txt" \
GIT_TRACE2_EVENT_NESTING=5 \
git commit-graph write --reachable --changed-paths &&
grep "{\"hash_version\":1,\"num_hashes\":9,\"bits_per_entry\":15}" trace2-auto.txt
'
test_expect_success 'correctly report changes over limit' '
git init 513changes &&
(
cd 513changes &&
for i in $(test_seq 1 513)
do
echo $i >file$i.txt || return 1
done &&
git add . &&
git commit -m "files" &&
git commit-graph write --reachable --changed-paths &&
for i in $(test_seq 1 513)
do
git -c core.commitGraph=false log -- file$i.txt >expect &&
git log -- file$i.txt >actual &&
test_cmp expect actual || return 1
done
)
'
test_done