git-commit-vandalism/t/t7700-repack.sh
Taylor Blau 1d89d88d37 builtin/repack.c: support writing a MIDX while repacking
Teach `git repack` a new `--write-midx` option for callers that wish to
persist a multi-pack index in their repository while repacking.

There are two existing alternatives to this new flag, but they don't
cover our particular use-case. These alternatives are:

  - Call 'git multi-pack-index write' after running 'git repack', or

  - Set 'GIT_TEST_MULTI_PACK_INDEX=1' in your environment when running
    'git repack'.

The former works, but introduces a gap in bitmap coverage between
repacking and writing a new MIDX (since the repack may have deleted a
pack included in the existing MIDX, invalidating it altogether).

Setting the 'GIT_TEST_' environment variable is obviously unsupported.
In fact, even if it were supported officially, it still wouldn't work,
because it generates the MIDX *after* redundant packs have been dropped,
leading to the same issue as above.

Introduce a new option which eliminates this race by teaching `git
repack` to generate the MIDX at the critical point: after the new packs
have been written and moved into place, but before the redundant packs
have been removed.

This option is compatible with `git repack`'s '--bitmap' option (it
changes the interpretation to be: "write a bitmap corresponding to the
MIDX after one has been generated").

There is a little bit of additional noise in the patch below to avoid
repeating ourselves when selecting which packs to delete. Instead of a
single loop as before (where we iterate over 'existing_packs', decide if
a pack is worth deleting, and if so, delete it), we have two loops (the
first where we decide which ones are worth deleting, and the second
where we actually do the deleting). This makes it so we have a single
check we can make consistently when (1) telling the MIDX which packs we
want to exclude, and (2) actually unlinking the redundant packs.

There is also a tiny change to short-circuit the body of
write_midx_included_packs() when no packs remain in the case of an empty
repository. The MIDX code does not handle this, so avoid trying to
generate a MIDX covering zero packs in the first place.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-28 21:20:56 -07:00

334 lines
9.5 KiB
Bash
Executable File

#!/bin/sh
test_description='git repack works correctly'
. ./test-lib.sh
. "${TEST_DIRECTORY}/lib-bitmap.sh"
. "${TEST_DIRECTORY}/lib-midx.sh"
commit_and_pack () {
test_commit "$@" 1>&2 &&
incrpackid=$(git pack-objects --all --unpacked --incremental .git/objects/pack/pack </dev/null) &&
echo pack-${incrpackid}.pack
}
test_no_missing_in_packs () {
myidx=$(ls -1 .git/objects/pack/*.idx) &&
test_path_is_file "$myidx" &&
git verify-pack -v alt_objects/pack/*.idx >orig.raw &&
sed -n -e "s/^\($OID_REGEX\).*/\1/p" orig.raw | sort >orig &&
git verify-pack -v $myidx >dest.raw &&
cut -d" " -f1 dest.raw | sort >dest &&
comm -23 orig dest >missing &&
test_must_be_empty missing
}
# we expect $packid and $oid to be defined
test_has_duplicate_object () {
want_duplicate_object="$1"
found_duplicate_object=false
for p in .git/objects/pack/*.idx
do
idx=$(basename $p)
test "pack-$packid.idx" = "$idx" && continue
git verify-pack -v $p >packlist || return $?
if grep "^$oid" packlist
then
found_duplicate_object=true
echo "DUPLICATE OBJECT FOUND"
break
fi
done &&
test "$want_duplicate_object" = "$found_duplicate_object"
}
test_expect_success 'objects in packs marked .keep are not repacked' '
echo content1 >file1 &&
echo content2 >file2 &&
git add . &&
test_tick &&
git commit -m initial_commit &&
# Create two packs
# The first pack will contain all of the objects except one
git rev-list --objects --all >objs &&
grep -v file2 objs | git pack-objects pack &&
# The second pack will contain the excluded object
packid=$(grep file2 objs | git pack-objects pack) &&
>pack-$packid.keep &&
git verify-pack -v pack-$packid.idx >packlist &&
oid=$(head -n 1 packlist | sed -e "s/^\($OID_REGEX\).*/\1/") &&
mv pack-* .git/objects/pack/ &&
git repack -A -d -l &&
git prune-packed &&
test_has_duplicate_object false
'
test_expect_success 'writing bitmaps via command-line can duplicate .keep objects' '
# build on $oid, $packid, and .keep state from previous
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 git repack -Adbl &&
test_has_duplicate_object true
'
test_expect_success 'writing bitmaps via config can duplicate .keep objects' '
# build on $oid, $packid, and .keep state from previous
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -c repack.writebitmaps=true repack -Adl &&
test_has_duplicate_object true
'
test_expect_success 'loose objects in alternate ODB are not repacked' '
mkdir alt_objects &&
echo $(pwd)/alt_objects >.git/objects/info/alternates &&
echo content3 >file3 &&
oid=$(GIT_OBJECT_DIRECTORY=alt_objects git hash-object -w file3) &&
git add file3 &&
test_tick &&
git commit -m commit_file3 &&
git repack -a -d -l &&
git prune-packed &&
test_has_duplicate_object false
'
test_expect_success 'packed obs in alt ODB are repacked even when local repo is packless' '
mkdir alt_objects/pack &&
mv .git/objects/pack/* alt_objects/pack &&
git repack -a &&
test_no_missing_in_packs
'
test_expect_success 'packed obs in alt ODB are repacked when local repo has packs' '
rm -f .git/objects/pack/* &&
echo new_content >>file1 &&
git add file1 &&
test_tick &&
git commit -m more_content &&
git repack &&
git repack -a -d &&
test_no_missing_in_packs
'
test_expect_success 'packed obs in alternate ODB kept pack are repacked' '
# swap the .keep so the commit object is in the pack with .keep
for p in alt_objects/pack/*.pack
do
base_name=$(basename $p .pack) &&
if test_path_is_file alt_objects/pack/$base_name.keep
then
rm alt_objects/pack/$base_name.keep
else
touch alt_objects/pack/$base_name.keep
fi
done &&
git repack -a -d &&
test_no_missing_in_packs
'
test_expect_success 'packed unreachable obs in alternate ODB are not loosened' '
rm -f alt_objects/pack/*.keep &&
mv .git/objects/pack/* alt_objects/pack/ &&
coid=$(git rev-parse HEAD^{commit}) &&
git reset --hard HEAD^ &&
test_tick &&
git reflog expire --expire=$test_tick --expire-unreachable=$test_tick --all &&
# The pack-objects call on the next line is equivalent to
# git repack -A -d without the call to prune-packed
git pack-objects --honor-pack-keep --non-empty --all --reflog \
--unpack-unreachable </dev/null pack &&
rm -f .git/objects/pack/* &&
mv pack-* .git/objects/pack/ &&
git verify-pack -v -- .git/objects/pack/*.idx >packlist &&
! grep "^$coid " packlist &&
echo >.git/objects/info/alternates &&
test_must_fail git show $coid
'
test_expect_success 'local packed unreachable obs that exist in alternate ODB are not loosened' '
echo $(pwd)/alt_objects >.git/objects/info/alternates &&
echo "$coid" | git pack-objects --non-empty --all --reflog pack &&
rm -f .git/objects/pack/* &&
mv pack-* .git/objects/pack/ &&
# The pack-objects call on the next line is equivalent to
# git repack -A -d without the call to prune-packed
git pack-objects --honor-pack-keep --non-empty --all --reflog \
--unpack-unreachable </dev/null pack &&
rm -f .git/objects/pack/* &&
mv pack-* .git/objects/pack/ &&
git verify-pack -v -- .git/objects/pack/*.idx >packlist &&
! grep "^$coid " &&
echo >.git/objects/info/alternates &&
test_must_fail git show $coid
'
test_expect_success 'objects made unreachable by grafts only are kept' '
test_tick &&
git commit --allow-empty -m "commit 4" &&
H0=$(git rev-parse HEAD) &&
H1=$(git rev-parse HEAD^) &&
H2=$(git rev-parse HEAD^^) &&
echo "$H0 $H2" >.git/info/grafts &&
git reflog expire --expire=$test_tick --expire-unreachable=$test_tick --all &&
git repack -a -d &&
git cat-file -t $H1
'
test_expect_success 'repack --keep-pack' '
test_create_repo keep-pack &&
(
cd keep-pack &&
P1=$(commit_and_pack 1) &&
P2=$(commit_and_pack 2) &&
P3=$(commit_and_pack 3) &&
P4=$(commit_and_pack 4) &&
ls .git/objects/pack/*.pack >old-counts &&
test_line_count = 4 old-counts &&
git repack -a -d --keep-pack $P1 --keep-pack $P4 &&
ls .git/objects/pack/*.pack >new-counts &&
grep -q $P1 new-counts &&
grep -q $P4 new-counts &&
test_line_count = 3 new-counts &&
git fsck
)
'
test_expect_success 'bitmaps are created by default in bare repos' '
git clone --bare .git bare.git &&
rm -f bare.git/objects/pack/*.bitmap &&
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -C bare.git repack -ad &&
bitmap=$(ls bare.git/objects/pack/*.bitmap) &&
test_path_is_file "$bitmap"
'
test_expect_success 'incremental repack does not complain' '
git -C bare.git repack -q 2>repack.err &&
test_must_be_empty repack.err
'
test_expect_success 'bitmaps can be disabled on bare repos' '
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -c repack.writeBitmaps=false -C bare.git repack -ad &&
bitmap=$(ls bare.git/objects/pack/*.bitmap || :) &&
test -z "$bitmap"
'
test_expect_success 'no bitmaps created if .keep files present' '
pack=$(ls bare.git/objects/pack/*.pack) &&
test_path_is_file "$pack" &&
keep=${pack%.pack}.keep &&
test_when_finished "rm -f \"\$keep\"" &&
>"$keep" &&
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -C bare.git repack -ad 2>stderr &&
test_must_be_empty stderr &&
find bare.git/objects/pack/ -type f -name "*.bitmap" >actual &&
test_must_be_empty actual
'
test_expect_success 'auto-bitmaps do not complain if unavailable' '
test_config -C bare.git pack.packSizeLimit 1M &&
blob=$(test-tool genrandom big $((1024*1024)) |
git -C bare.git hash-object -w --stdin) &&
git -C bare.git update-ref refs/tags/big $blob &&
GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -C bare.git repack -ad 2>stderr &&
test_must_be_empty stderr &&
find bare.git/objects/pack -type f -name "*.bitmap" >actual &&
test_must_be_empty actual
'
objdir=.git/objects
midx=$objdir/pack/multi-pack-index
test_expect_success 'setup for --write-midx tests' '
git init midx &&
(
cd midx &&
git config core.multiPackIndex true &&
test_commit base
)
'
test_expect_success '--write-midx unchanged' '
(
cd midx &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack &&
test_path_is_missing $midx &&
test_path_is_missing $midx-*.bitmap &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack --write-midx &&
test_path_is_file $midx &&
test_path_is_missing $midx-*.bitmap &&
test_midx_consistent $objdir
)
'
test_expect_success '--write-midx with a new pack' '
(
cd midx &&
test_commit loose &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack --write-midx &&
test_path_is_file $midx &&
test_path_is_missing $midx-*.bitmap &&
test_midx_consistent $objdir
)
'
test_expect_success '--write-midx with -b' '
(
cd midx &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack -mb &&
test_path_is_file $midx &&
test_path_is_file $midx-*.bitmap &&
test_midx_consistent $objdir
)
'
test_expect_success '--write-midx with -d' '
(
cd midx &&
test_commit repack &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack -Ad --write-midx &&
test_path_is_file $midx &&
test_path_is_missing $midx-*.bitmap &&
test_midx_consistent $objdir
)
'
test_expect_success 'cleans up MIDX when appropriate' '
(
cd midx &&
test_commit repack-2 &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack -Adb --write-midx &&
checksum=$(midx_checksum $objdir) &&
test_path_is_file $midx &&
test_path_is_file $midx-$checksum.bitmap &&
test_path_is_file $midx-$checksum.rev &&
test_commit repack-3 &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack -Adb --write-midx &&
test_path_is_file $midx &&
test_path_is_missing $midx-$checksum.bitmap &&
test_path_is_missing $midx-$checksum.rev &&
test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
test_path_is_file $midx-$(midx_checksum $objdir).rev &&
test_commit repack-4 &&
GIT_TEST_MULTI_PACK_INDEX=0 git repack -Adb &&
find $objdir/pack -type f -name "multi-pack-index*" >files &&
test_must_be_empty files
)
'
test_done