#!/bin/sh
test_description='performance with large numbers of packs'
. ./perf-lib.sh
test_perf_large_repo
# A real many-pack situation would probably come from having a lot of pushes
# over time. We don't know how big each push would be, but we can fake it by
# just walking the first-parent chain and having every 5 commits be their own
# "push". This isn't _entirely_ accurate, as real pushes would have some
# duplicate objects due to thin-pack fixing, but it's a reasonable
# approximation.
#
# And then all of the rest of the objects can go in a single packfile that
# represents the state before any of those pushes (actually, we'll generate
# that first because in such a setup it would be the oldest pack, and we sort
# the packs by reverse mtime inside git).
repack_into_n () {
rm -rf staging &&
mkdir staging &&
git rev-list --first-parent HEAD |
perl -e '
my $n = shift;
while (<>) {
last unless @commits < $n;
push @commits, $_ if $. % 5 == 1;
}
print reverse @commits;
' "$1" >pushes &&
# create base packfile
base_pack=$(
head -n 1 pushes |
git pack-objects --delta-base-offset --revs staging/pack
) &&
test_export base_pack &&
# create an empty packfile
empty_pack=$(git pack-objects staging/pack </dev/null) &&
test_export empty_pack &&
# and then incrementals between each pair of commits
last= &&
while read rev
do
if test -n "$last"; then
{
echo "$rev" &&
echo "^$last"
} |
git pack-objects --delta-base-offset --revs \
staging/pack || return 1
fi
last=$rev
done <pushes &&
(
find staging -type f -name 'pack-*.pack' |
xargs -n 1 basename | grep -v "$base_pack" &&
printf "^pack-%s.pack\n" $base_pack
) >stdin.packs
# and install the whole thing
rm -f .git/objects/pack/* &&
mv staging/* .git/objects/pack/
}
# Pretend we just have a single branch and no reflogs, and that everything is
# in objects/pack; that makes our fake pack-building via repack_into_n()
# much simpler.
test_expect_success 'simplify reachability' '
tip=$(git rev-parse --verify HEAD) &&
git for-each-ref --format="option no-deref%0adelete %(refname)" |
git update-ref --stdin &&
rm -rf .git/logs &&
git update-ref refs/heads/master $tip &&
git symbolic-ref HEAD refs/heads/master &&
git repack -ad
'
for nr_packs in 1 50 1000
do
test_expect_success "create $nr_packs-pack scenario" '
repack_into_n $nr_packs
'
test_perf "rev-list ($nr_packs)" '
git rev-list --objects --all >/dev/null
'
test_perf "abbrev-commit ($nr_packs)" '
git rev-list --abbrev-commit HEAD >/dev/null
'
# This simulates the interesting part of the repack, which is the
# actual pack generation, without smudging the on-disk setup
# between trials.
test_perf "repack ($nr_packs)" '
GIT_TEST_FULL_IN_PACK_ARRAY=1 \
git pack-objects --keep-true-parents \
--honor-pack-keep --non-empty --all \
--reflog --indexed-objects --delta-base-offset \
--stdout </dev/null >/dev/null
'
test_perf "repack with kept ($nr_packs)" '
git pack-objects --keep-true-parents \
--keep-pack=pack-$empty_pack.pack \
--honor-pack-keep --non-empty --all \
--reflog --indexed-objects --delta-base-offset \
--stdout </dev/null >/dev/null
'
test_perf "repack with --stdin-packs ($nr_packs)" '
git pack-objects \
--keep-true-parents \
--stdin-packs \
--non-empty \
--delta-base-offset \
--stdout <stdin.packs >/dev/null
'
done
# Measure pack loading with 10,000 packs.
test_expect_success 'generate lots of packs' '
for i in $(test_seq 10000); do
echo "blob" &&
echo "data <<EOF" &&
echo "blob $i" &&
echo "EOF" &&
echo "checkpoint" || return 1
done |
git -c fastimport.unpackLimit=0 fast-import
'
# The purpose of this test is to evaluate load time for a large number
# of packs while doing as little other work as possible.
test_perf "load 10,000 packs" '
git rev-parse --verify "HEAD^{commit}"
'
test_done
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