git-commit-vandalism/t/t5319-multi-pack-index.sh

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#!/bin/sh
test_description='multi-pack-indexes'
. ./test-lib.sh
maintenance: add incremental-repack task The previous change cleaned up loose objects using the 'loose-objects' that can be run safely in the background. Add a similar job that performs similar cleanups for pack-files. One issue with running 'git repack' is that it is designed to repack all pack-files into a single pack-file. While this is the most space-efficient way to store object data, it is not time or memory efficient. This becomes extremely important if the repo is so large that a user struggles to store two copies of the pack on their disk. Instead, perform an "incremental" repack by collecting a few small pack-files into a new pack-file. The multi-pack-index facilitates this process ever since 'git multi-pack-index expire' was added in 19575c7 (multi-pack-index: implement 'expire' subcommand, 2019-06-10) and 'git multi-pack-index repack' was added in ce1e4a1 (midx: implement midx_repack(), 2019-06-10). The 'incremental-repack' task runs the following steps: 1. 'git multi-pack-index write' creates a multi-pack-index file if one did not exist, and otherwise will update the multi-pack-index with any new pack-files that appeared since the last write. This is particularly relevant with the background fetch job. When the multi-pack-index sees two copies of the same object, it stores the offset data into the newer pack-file. This means that some old pack-files could become "unreferenced" which I will use to mean "a pack-file that is in the pack-file list of the multi-pack-index but none of the objects in the multi-pack-index reference a location inside that pack-file." 2. 'git multi-pack-index expire' deletes any unreferenced pack-files and updaes the multi-pack-index to drop those pack-files from the list. This is safe to do as concurrent Git processes will see the multi-pack-index and not open those packs when looking for object contents. (Similar to the 'loose-objects' job, there are some Git commands that open pack-files regardless of the multi-pack-index, but they are rarely used. Further, a user that self-selects to use background operations would likely refrain from using those commands.) 3. 'git multi-pack-index repack --bacth-size=<size>' collects a set of pack-files that are listed in the multi-pack-index and creates a new pack-file containing the objects whose offsets are listed by the multi-pack-index to be in those objects. The set of pack- files is selected greedily by sorting the pack-files by modified time and adding a pack-file to the set if its "expected size" is smaller than the batch size until the total expected size of the selected pack-files is at least the batch size. The "expected size" is calculated by taking the size of the pack-file divided by the number of objects in the pack-file and multiplied by the number of objects from the multi-pack-index with offset in that pack-file. The expected size approximates how much data from that pack-file will contribute to the resulting pack-file size. The intention is that the resulting pack-file will be close in size to the provided batch size. The next run of the incremental-repack task will delete these repacked pack-files during the 'expire' step. In this version, the batch size is set to "0" which ignores the size restrictions when selecting the pack-files. It instead selects all pack-files and repacks all packed objects into a single pack-file. This will be updated in the next change, but it requires doing some calculations that are better isolated to a separate change. These steps are based on a similar background maintenance step in Scalar (and VFS for Git) [1]. This was incredibly effective for users of the Windows OS repository. After using the same VFS for Git repository for over a year, some users had _thousands_ of pack-files that combined to up to 250 GB of data. We noticed a few users were running into the open file descriptor limits (due in part to a bug in the multi-pack-index fixed by af96fe3 (midx: add packs to packed_git linked list, 2019-04-29). These pack-files were mostly small since they contained the commits and trees that were pushed to the origin in a given hour. The GVFS protocol includes a "prefetch" step that asks for pre-computed pack- files containing commits and trees by timestamp. These pack-files were grouped into "daily" pack-files once a day for up to 30 days. If a user did not request prefetch packs for over 30 days, then they would get the entire history of commits and trees in a new, large pack-file. This led to a large number of pack-files that had poor delta compression. By running this pack-file maintenance step once per day, these repos with thousands of packs spanning 200+ GB dropped to dozens of pack- files spanning 30-50 GB. This was done all without removing objects from the system and using a constant batch size of two gigabytes. Once the work was done to reduce the pack-files to small sizes, the batch size of two gigabytes means that not every run triggers a repack operation, so the following run will not expire a pack-file. This has kept these repos in a "clean" state. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/PackfileMaintenanceStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 14:33:36 +02:00
GIT_TEST_MULTI_PACK_INDEX=0
objdir=.git/objects
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
HASH_LEN=$(test_oid rawsz)
midx_read_expect () {
NUM_PACKS=$1
NUM_OBJECTS=$2
NUM_CHUNKS=$3
OBJECT_DIR=$4
EXTRA_CHUNKS="$5"
{
cat <<-EOF &&
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
header: 4d494458 1 $HASH_LEN $NUM_CHUNKS $NUM_PACKS
chunks: pack-names oid-fanout oid-lookup object-offsets$EXTRA_CHUNKS
num_objects: $NUM_OBJECTS
packs:
EOF
if test $NUM_PACKS -ge 1
then
ls $OBJECT_DIR/pack/ | grep idx | sort
fi &&
printf "object-dir: $OBJECT_DIR\n"
} >expect &&
test-tool read-midx $OBJECT_DIR >actual &&
test_cmp expect actual
}
test_expect_success 'setup' '
test_oid_cache <<-EOF
idxoff sha1:2999
idxoff sha256:3739
packnameoff sha1:652
packnameoff sha256:940
fanoutoff sha1:1
fanoutoff sha256:3
EOF
'
test_expect_success "don't write midx with no packs" '
test_must_fail git multi-pack-index --object-dir=. write &&
test_path_is_missing pack/multi-pack-index
'
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
test_expect_success SHA1 'warn if a midx contains no oid' '
cp "$TEST_DIRECTORY"/t5319/no-objects.midx $objdir/pack/multi-pack-index &&
test_must_fail git multi-pack-index verify &&
rm $objdir/pack/multi-pack-index
'
generate_objects () {
i=$1
iii=$(printf '%03i' $i)
{
test-tool genrandom "bar" 200 &&
test-tool genrandom "baz $iii" 50
} >wide_delta_$iii &&
{
test-tool genrandom "foo"$i 100 &&
test-tool genrandom "foo"$(( $i + 1 )) 100 &&
test-tool genrandom "foo"$(( $i + 2 )) 100
} >deep_delta_$iii &&
{
echo $iii &&
test-tool genrandom "$iii" 8192
} >file_$iii &&
git update-index --add file_$iii deep_delta_$iii wide_delta_$iii
}
commit_and_list_objects () {
{
echo 101 &&
test-tool genrandom 100 8192;
} >file_101 &&
git update-index --add file_101 &&
tree=$(git write-tree) &&
commit=$(git commit-tree $tree -p HEAD</dev/null) &&
{
echo $tree &&
git ls-tree $tree | sed -e "s/.* \\([0-9a-f]*\\) .*/\\1/"
} >obj-list &&
git reset --hard $commit
}
test_expect_success 'create objects' '
test_commit initial &&
for i in $(test_seq 1 5)
do
generate_objects $i
done &&
commit_and_list_objects
'
test_expect_success 'write midx with one v1 pack' '
pack=$(git pack-objects --index-version=1 $objdir/pack/test <obj-list) &&
test_when_finished rm $objdir/pack/test-$pack.pack \
$objdir/pack/test-$pack.idx $objdir/pack/multi-pack-index &&
git multi-pack-index --object-dir=$objdir write &&
midx_read_expect 1 18 4 $objdir
'
midx_git_two_modes () {
git -c core.multiPackIndex=false $1 >expect &&
git -c core.multiPackIndex=true $1 >actual &&
if [ "$2" = "sorted" ]
then
sort <expect >expect.sorted &&
mv expect.sorted expect &&
sort <actual >actual.sorted &&
mv actual.sorted actual
fi &&
test_cmp expect actual
}
compare_results_with_midx () {
MSG=$1
test_expect_success "check normal git operations: $MSG" '
midx_git_two_modes "rev-list --objects --all" &&
midx_git_two_modes "log --raw" &&
midx_git_two_modes "count-objects --verbose" &&
midx_git_two_modes "cat-file --batch-all-objects --batch-check" &&
midx_git_two_modes "cat-file --batch-all-objects --batch-check --unordered" sorted
'
}
test_expect_success 'write midx with one v2 pack' '
git pack-objects --index-version=2,0x40 $objdir/pack/test <obj-list &&
git multi-pack-index --object-dir=$objdir write &&
midx_read_expect 1 18 4 $objdir
'
compare_results_with_midx "one v2 pack"
packfile.c: protect against disappearing indexes In 17c35c8969 (packfile: skip loading index if in multi-pack-index, 2018-07-12) we stopped loading the .idx file for packs that are contained within a multi-pack index. This saves us the effort of loading an .idx and doing some lightweight validity checks by way of 'packfile.c:load_idx()', but introduces a race between processes that need to load the index (e.g., to generate a reverse index) and processes that can delete the index. For example, running the following in your shell: $ git init repo && cd repo $ git commit --allow-empty -m 'base' $ git repack -ad && git multi-pack-index write followed by: $ rm -f .git/objects/pack/pack-*.idx $ git rev-parse HEAD | git cat-file --batch-check='%(objectsize:disk)' will result in a segfault prior to this patch. What's happening here is that we notice that the pack is in the multi-pack index, and so don't check that it still has a .idx. When we then try and load that index to generate a reverse index, we don't have it, so the call to 'find_pack_revindex()' in 'packfile.c:packed_object_info()' returns NULL, and then dereferencing it causes a segfault. Of course, we don't ever expect someone to remove the index file by hand, or to be in a state where we never wrote it to begin with (yet find that pack in the multi-pack-index). But, this can happen in a timing race with 'git repack -ad', which removes all existing packs after writing a new pack containing all of their objects. Avoid this by reverting the hunk of 17c35c8969 which stops loading the index when the pack is contained in a MIDX. This makes the latter half of 17c35c8969 useless, since we'll always have a non-NULL 'p->index_data', in which case that if statement isn't guarding anything. These two together effectively revert 17c35c8969, and avoid the race explained above. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:28 +01:00
test_expect_success 'corrupt idx reports errors' '
idx=$(test-tool read-midx $objdir | grep "\.idx\$") &&
mv $objdir/pack/$idx backup-$idx &&
test_when_finished "mv backup-\$idx \$objdir/pack/\$idx" &&
# This is the minimum size for a sha-1 based .idx; this lets
# us pass perfunctory tests, but anything that actually opens and reads
# the idx file will complain.
test_copy_bytes 1064 <backup-$idx >$objdir/pack/$idx &&
git -c core.multiPackIndex=true rev-list --objects --all 2>err &&
packfile.c: protect against disappearing indexes In 17c35c8969 (packfile: skip loading index if in multi-pack-index, 2018-07-12) we stopped loading the .idx file for packs that are contained within a multi-pack index. This saves us the effort of loading an .idx and doing some lightweight validity checks by way of 'packfile.c:load_idx()', but introduces a race between processes that need to load the index (e.g., to generate a reverse index) and processes that can delete the index. For example, running the following in your shell: $ git init repo && cd repo $ git commit --allow-empty -m 'base' $ git repack -ad && git multi-pack-index write followed by: $ rm -f .git/objects/pack/pack-*.idx $ git rev-parse HEAD | git cat-file --batch-check='%(objectsize:disk)' will result in a segfault prior to this patch. What's happening here is that we notice that the pack is in the multi-pack index, and so don't check that it still has a .idx. When we then try and load that index to generate a reverse index, we don't have it, so the call to 'find_pack_revindex()' in 'packfile.c:packed_object_info()' returns NULL, and then dereferencing it causes a segfault. Of course, we don't ever expect someone to remove the index file by hand, or to be in a state where we never wrote it to begin with (yet find that pack in the multi-pack-index). But, this can happen in a timing race with 'git repack -ad', which removes all existing packs after writing a new pack containing all of their objects. Avoid this by reverting the hunk of 17c35c8969 which stops loading the index when the pack is contained in a MIDX. This makes the latter half of 17c35c8969 useless, since we'll always have a non-NULL 'p->index_data', in which case that if statement isn't guarding anything. These two together effectively revert 17c35c8969, and avoid the race explained above. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:28 +01:00
grep "index unavailable" err
'
test_expect_success 'add more objects' '
for i in $(test_seq 6 10)
do
generate_objects $i
done &&
commit_and_list_objects
'
test_expect_success 'write midx with two packs' '
git pack-objects --index-version=1 $objdir/pack/test-2 <obj-list &&
git multi-pack-index --object-dir=$objdir write &&
midx_read_expect 2 34 4 $objdir
'
compare_results_with_midx "two packs"
test_expect_success 'write progress off for redirected stderr' '
git multi-pack-index --object-dir=$objdir write 2>err &&
test_line_count = 0 err
'
test_expect_success 'write force progress on for stderr' '
GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --progress write 2>err &&
test_file_not_empty err
'
test_expect_success 'write with the --no-progress option' '
GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --no-progress write 2>err &&
test_line_count = 0 err
'
test_expect_success 'add more packs' '
for j in $(test_seq 11 20)
do
generate_objects $j &&
commit_and_list_objects &&
git pack-objects --index-version=2 $objdir/pack/test-pack <obj-list
done
'
compare_results_with_midx "mixed mode (two packs + extra)"
test_expect_success 'write midx with twelve packs' '
git multi-pack-index --object-dir=$objdir write &&
midx_read_expect 12 74 4 $objdir
'
compare_results_with_midx "twelve packs"
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
test_expect_success 'warn on improper hash version' '
git init --object-format=sha1 sha1 &&
(
cd sha1 &&
git config core.multiPackIndex true &&
test_commit 1 &&
git repack -a &&
git multi-pack-index write &&
mv .git/objects/pack/multi-pack-index ../mpi-sha1
) &&
git init --object-format=sha256 sha256 &&
(
cd sha256 &&
git config core.multiPackIndex true &&
test_commit 1 &&
git repack -a &&
git multi-pack-index write &&
mv .git/objects/pack/multi-pack-index ../mpi-sha256
) &&
(
cd sha1 &&
mv ../mpi-sha256 .git/objects/pack/multi-pack-index &&
git log -1 2>err &&
test_i18ngrep "multi-pack-index hash version 2 does not match version 1" err
) &&
(
cd sha256 &&
mv ../mpi-sha1 .git/objects/pack/multi-pack-index &&
git log -1 2>err &&
test_i18ngrep "multi-pack-index hash version 1 does not match version 2" err
)
'
test_expect_success 'midx picks objects from preferred pack' '
test_when_finished rm -rf preferred.git &&
git init --bare preferred.git &&
(
cd preferred.git &&
a=$(echo "a" | git hash-object -w --stdin) &&
b=$(echo "b" | git hash-object -w --stdin) &&
c=$(echo "c" | git hash-object -w --stdin) &&
# Set up two packs, duplicating the object "B" at different
# offsets.
#
# Note that the "BC" pack (the one we choose as preferred) sorts
# lexically after the "AB" pack, meaning that omitting the
# --preferred-pack argument would cause this test to fail (since
# the MIDX code would select the copy of "b" in the "AB" pack).
git pack-objects objects/pack/test-AB <<-EOF &&
$a
$b
EOF
bc=$(git pack-objects objects/pack/test-BC <<-EOF
$b
$c
EOF
) &&
git multi-pack-index --object-dir=objects \
write --preferred-pack=test-BC-$bc.idx 2>err &&
test_must_be_empty err &&
test-tool read-midx --show-objects objects >out &&
ofs=$(git show-index <objects/pack/test-BC-$bc.idx | grep $b |
cut -d" " -f1) &&
printf "%s %s\tobjects/pack/test-BC-%s.pack\n" \
"$b" "$ofs" "$bc" >expect &&
grep ^$b out >actual &&
test_cmp expect actual
)
'
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
test_expect_success 'verify multi-pack-index success' '
git multi-pack-index verify --object-dir=$objdir
'
test_expect_success 'verify progress off for redirected stderr' '
git multi-pack-index verify --object-dir=$objdir 2>err &&
test_line_count = 0 err
'
test_expect_success 'verify force progress on for stderr' '
git multi-pack-index verify --object-dir=$objdir --progress 2>err &&
test_file_not_empty err
'
test_expect_success 'verify with the --no-progress option' '
git multi-pack-index verify --object-dir=$objdir --no-progress 2>err &&
test_line_count = 0 err
'
# usage: corrupt_midx_and_verify <pos> <data> <objdir> <string>
corrupt_midx_and_verify() {
POS=$1 &&
DATA="${2:-\0}" &&
OBJDIR=$3 &&
GREPSTR="$4" &&
COMMAND="$5" &&
if test -z "$COMMAND"
then
COMMAND="git multi-pack-index verify --object-dir=$OBJDIR"
fi &&
FILE=$OBJDIR/pack/multi-pack-index &&
chmod a+w $FILE &&
test_when_finished mv midx-backup $FILE &&
cp $FILE midx-backup &&
printf "$DATA" | dd of="$FILE" bs=1 seek="$POS" conv=notrunc &&
test_must_fail $COMMAND 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "$GREPSTR" err
}
test_expect_success 'verify bad signature' '
corrupt_midx_and_verify 0 "\00" $objdir \
"multi-pack-index signature"
'
NUM_OBJECTS=74
MIDX_BYTE_VERSION=4
MIDX_BYTE_OID_VERSION=5
MIDX_BYTE_CHUNK_COUNT=6
MIDX_HEADER_SIZE=12
MIDX_BYTE_CHUNK_ID=$MIDX_HEADER_SIZE
MIDX_BYTE_CHUNK_OFFSET=$(($MIDX_HEADER_SIZE + 4))
MIDX_NUM_CHUNKS=5
MIDX_CHUNK_LOOKUP_WIDTH=12
MIDX_OFFSET_PACKNAMES=$(($MIDX_HEADER_SIZE + \
$MIDX_NUM_CHUNKS * $MIDX_CHUNK_LOOKUP_WIDTH))
MIDX_BYTE_PACKNAME_ORDER=$(($MIDX_OFFSET_PACKNAMES + 2))
MIDX_OFFSET_OID_FANOUT=$(($MIDX_OFFSET_PACKNAMES + $(test_oid packnameoff)))
MIDX_OID_FANOUT_WIDTH=4
MIDX_BYTE_OID_FANOUT_ORDER=$((MIDX_OFFSET_OID_FANOUT + 250 * $MIDX_OID_FANOUT_WIDTH + $(test_oid fanoutoff)))
MIDX_OFFSET_OID_LOOKUP=$(($MIDX_OFFSET_OID_FANOUT + 256 * $MIDX_OID_FANOUT_WIDTH))
MIDX_BYTE_OID_LOOKUP=$(($MIDX_OFFSET_OID_LOOKUP + 16 * $HASH_LEN))
MIDX_OFFSET_OBJECT_OFFSETS=$(($MIDX_OFFSET_OID_LOOKUP + $NUM_OBJECTS * $HASH_LEN))
MIDX_OFFSET_WIDTH=8
MIDX_BYTE_PACK_INT_ID=$(($MIDX_OFFSET_OBJECT_OFFSETS + 16 * $MIDX_OFFSET_WIDTH + 2))
MIDX_BYTE_OFFSET=$(($MIDX_OFFSET_OBJECT_OFFSETS + 16 * $MIDX_OFFSET_WIDTH + 6))
test_expect_success 'verify bad version' '
corrupt_midx_and_verify $MIDX_BYTE_VERSION "\00" $objdir \
"multi-pack-index version"
'
test_expect_success 'verify bad OID version' '
multi-pack-index: use hash version byte Similar to the commit-graph format, the multi-pack-index format has a byte in the header intended to track the hash version used to write the file. This allows one to interpret the hash length without having the context of the repository config specifying the hash length. This was not modified as part of the SHA-256 work because the hash length was automatically up-shifted due to that config. Since we have this byte available, we can make the file formats more obviously incompatible instead of relying on other context from the repository. Add a new oid_version() method in midx.c similar to the one in commit-graph.c. This is specifically made separate from that implementation to avoid artificially linking the formats. The test impact requires a few more things than the corresponding change in the commit-graph format. Specifically, 'test-tool read-midx' was not writing anything about this header value to output. Since the value available in 'struct multi_pack_index' is hash_len instead of a version value, we output "20" or "32" instead of "1" or "2". Since we want a user to not have their Git commands fail if their multi-pack-index has the incorrect hash version compared to the repository's hash version, we relax the die() to an error() in load_multi_pack_index(). This has some effect on 'git multi-pack-index verify' as we need to check that a failed parse of a file that exists is actually a verify error. For that test that checks the hash version matches, we change the corrupted byte from "2" to "3" to ensure the test fails for both hash algorithms. Helped-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 16:04:48 +02:00
corrupt_midx_and_verify $MIDX_BYTE_OID_VERSION "\03" $objdir \
"hash version"
'
test_expect_success 'verify truncated chunk count' '
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\01" $objdir \
"final chunk has non-zero id"
'
test_expect_success 'verify extended chunk count' '
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\07" $objdir \
"terminating chunk id appears earlier than expected"
'
test_expect_success 'verify missing required chunk' '
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_ID "\01" $objdir \
"missing required"
'
test_expect_success 'verify invalid chunk offset' '
corrupt_midx_and_verify $MIDX_BYTE_CHUNK_OFFSET "\01" $objdir \
"improper chunk offset(s)"
'
test_expect_success 'verify packnames out of order' '
corrupt_midx_and_verify $MIDX_BYTE_PACKNAME_ORDER "z" $objdir \
"pack names out of order"
'
test_expect_success 'verify packnames out of order' '
corrupt_midx_and_verify $MIDX_BYTE_PACKNAME_ORDER "a" $objdir \
"failed to load pack"
'
test_expect_success 'verify oid fanout out of order' '
corrupt_midx_and_verify $MIDX_BYTE_OID_FANOUT_ORDER "\01" $objdir \
"oid fanout out of order"
'
test_expect_success 'verify oid lookup out of order' '
corrupt_midx_and_verify $MIDX_BYTE_OID_LOOKUP "\00" $objdir \
"oid lookup out of order"
'
test_expect_success 'verify incorrect pack-int-id' '
corrupt_midx_and_verify $MIDX_BYTE_PACK_INT_ID "\07" $objdir \
"bad pack-int-id"
'
test_expect_success 'verify incorrect offset' '
corrupt_midx_and_verify $MIDX_BYTE_OFFSET "\377" $objdir \
"incorrect object offset"
'
test_expect_success 'git-fsck incorrect offset' '
corrupt_midx_and_verify $MIDX_BYTE_OFFSET "\377" $objdir \
"incorrect object offset" \
"git -c core.multipackindex=true fsck"
'
test_expect_success 'repack progress off for redirected stderr' '
GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir repack 2>err &&
test_line_count = 0 err
'
test_expect_success 'repack force progress on for stderr' '
GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --progress repack 2>err &&
test_file_not_empty err
'
test_expect_success 'repack with the --no-progress option' '
GIT_PROGRESS_DELAY=0 git multi-pack-index --object-dir=$objdir --no-progress repack 2>err &&
test_line_count = 0 err
'
test_expect_success 'repack removes multi-pack-index when deleting packs' '
test_path_is_file $objdir/pack/multi-pack-index &&
# Set GIT_TEST_MULTI_PACK_INDEX to 0 to avoid writing a new
# multi-pack-index after repacking, but set "core.multiPackIndex" to
# true so that "git repack" can read the existing MIDX.
GIT_TEST_MULTI_PACK_INDEX=0 git -c core.multiPackIndex repack -adf &&
test_path_is_missing $objdir/pack/multi-pack-index
'
test_expect_success 'repack preserves multi-pack-index when creating packs' '
git init preserve &&
test_when_finished "rm -fr preserve" &&
(
cd preserve &&
packdir=.git/objects/pack &&
midx=$packdir/multi-pack-index &&
test_commit 1 &&
pack1=$(git pack-objects --all $packdir/pack) &&
touch $packdir/pack-$pack1.keep &&
test_commit 2 &&
pack2=$(git pack-objects --revs $packdir/pack) &&
touch $packdir/pack-$pack2.keep &&
git multi-pack-index write &&
cp $midx $midx.bak &&
cat >pack-input <<-EOF &&
HEAD
^HEAD~1
EOF
test_commit 3 &&
pack3=$(git pack-objects --revs $packdir/pack <pack-input) &&
test_commit 4 &&
pack4=$(git pack-objects --revs $packdir/pack <pack-input) &&
GIT_TEST_MULTI_PACK_INDEX=0 git -c core.multiPackIndex repack -ad &&
ls -la $packdir &&
test_path_is_file $packdir/pack-$pack1.pack &&
test_path_is_file $packdir/pack-$pack2.pack &&
test_path_is_missing $packdir/pack-$pack3.pack &&
test_path_is_missing $packdir/pack-$pack4.pack &&
test_cmp_bin $midx.bak $midx
)
'
compare_results_with_midx "after repack"
test_expect_success 'multi-pack-index and pack-bitmap' '
git -c repack.writeBitmaps=true repack -ad &&
git multi-pack-index write &&
git rev-list --test-bitmap HEAD
'
test_expect_success 'multi-pack-index and alternates' '
git init --bare alt.git &&
echo $(pwd)/alt.git/objects >.git/objects/info/alternates &&
echo content1 >file1 &&
altblob=$(GIT_DIR=alt.git git hash-object -w file1) &&
git cat-file blob $altblob &&
git rev-list --all
'
compare_results_with_midx "with alternate (local midx)"
test_expect_success 'multi-pack-index in an alternate' '
mv .git/objects/pack/* alt.git/objects/pack &&
test_commit add_local_objects &&
git repack --local &&
git multi-pack-index write &&
midx_read_expect 1 3 4 $objdir &&
git reset --hard HEAD~1 &&
rm -f .git/objects/pack/*
'
compare_results_with_midx "with alternate (remote midx)"
# usage: corrupt_data <file> <pos> [<data>]
corrupt_data () {
file=$1
pos=$2
data="${3:-\0}"
printf "$data" | dd of="$file" bs=1 seek="$pos" conv=notrunc
}
# Force 64-bit offsets by manipulating the idx file.
# This makes the IDX file _incorrect_ so be careful to clean up after!
test_expect_success 'force some 64-bit offsets with pack-objects' '
mkdir objects64 &&
mkdir objects64/pack &&
for i in $(test_seq 1 11)
do
generate_objects 11
done &&
commit_and_list_objects &&
pack64=$(git pack-objects --index-version=2,0x40 objects64/pack/test-64 <obj-list) &&
idx64=objects64/pack/test-64-$pack64.idx &&
chmod u+w $idx64 &&
corrupt_data $idx64 $(test_oid idxoff) "\02" &&
midx64=$(git multi-pack-index --object-dir=objects64 write) &&
midx_read_expect 1 63 5 objects64 " large-offsets"
'
test_expect_success 'verify multi-pack-index with 64-bit offsets' '
git multi-pack-index verify --object-dir=objects64
'
NUM_OBJECTS=63
MIDX_OFFSET_OID_FANOUT=$((MIDX_OFFSET_PACKNAMES + 54))
MIDX_OFFSET_OID_LOOKUP=$((MIDX_OFFSET_OID_FANOUT + 256 * $MIDX_OID_FANOUT_WIDTH))
MIDX_OFFSET_OBJECT_OFFSETS=$(($MIDX_OFFSET_OID_LOOKUP + $NUM_OBJECTS * $HASH_LEN))
MIDX_OFFSET_LARGE_OFFSETS=$(($MIDX_OFFSET_OBJECT_OFFSETS + $NUM_OBJECTS * $MIDX_OFFSET_WIDTH))
MIDX_BYTE_LARGE_OFFSET=$(($MIDX_OFFSET_LARGE_OFFSETS + 3))
test_expect_success 'verify incorrect 64-bit offset' '
corrupt_midx_and_verify $MIDX_BYTE_LARGE_OFFSET "\07" objects64 \
"incorrect object offset"
'
test_expect_success 'setup expire tests' '
mkdir dup &&
(
cd dup &&
git init &&
test-tool genrandom "data" 4096 >large_file.txt &&
git update-index --add large_file.txt &&
for i in $(test_seq 1 20)
do
test_commit $i
done &&
git branch A HEAD &&
git branch B HEAD~8 &&
git branch C HEAD~13 &&
git branch D HEAD~16 &&
git branch E HEAD~18 &&
git pack-objects --revs .git/objects/pack/pack-A <<-EOF &&
refs/heads/A
^refs/heads/B
EOF
git pack-objects --revs .git/objects/pack/pack-B <<-EOF &&
refs/heads/B
^refs/heads/C
EOF
git pack-objects --revs .git/objects/pack/pack-C <<-EOF &&
refs/heads/C
^refs/heads/D
EOF
git pack-objects --revs .git/objects/pack/pack-D <<-EOF &&
refs/heads/D
^refs/heads/E
EOF
git pack-objects --revs .git/objects/pack/pack-E <<-EOF &&
refs/heads/E
EOF
multi-pack-index: prepare 'repack' subcommand In an environment where the multi-pack-index is useful, it is due to many pack-files and an inability to repack the object store into a single pack-file. However, it is likely that many of these pack-files are rather small, and could be repacked into a slightly larger pack-file without too much effort. It may also be important to ensure the object store is highly available and the repack operation does not interrupt concurrent git commands. Introduce a 'repack' subcommand to 'git multi-pack-index' that takes a '--batch-size' option. The subcommand will inspect the multi-pack-index for referenced pack-files whose size is smaller than the batch size, until collecting a list of pack-files whose sizes sum to larger than the batch size. Then, a new pack-file will be created containing the objects from those pack-files that are referenced by the multi-pack-index. The resulting pack is likely to actually be smaller than the batch size due to compression and the fact that there may be objects in the pack- files that have duplicate copies in other pack-files. The current change introduces the command-line arguments, and we add a test that ensures we parse these options properly. Since we specify a small batch size, we will guarantee that future implementations do not change the list of pack-files. In addition, we hard-code the modified times of the packs in the pack directory to ensure the list of packs sorted by modified time matches the order if sorted by size (ascending). This will be important in a future test. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:26 +02:00
git multi-pack-index write &&
cp -r .git/objects/pack .git/objects/pack-backup
)
'
test_expect_success 'expire does not remove any packs' '
(
cd dup &&
ls .git/objects/pack >expect &&
git multi-pack-index expire &&
ls .git/objects/pack >actual &&
test_cmp expect actual
)
'
test_expect_success 'expire progress off for redirected stderr' '
(
cd dup &&
git multi-pack-index expire 2>err &&
test_line_count = 0 err
)
'
test_expect_success 'expire force progress on for stderr' '
(
cd dup &&
GIT_PROGRESS_DELAY=0 git multi-pack-index --progress expire 2>err &&
test_file_not_empty err
)
'
test_expect_success 'expire with the --no-progress option' '
(
cd dup &&
GIT_PROGRESS_DELAY=0 git multi-pack-index --no-progress expire 2>err &&
test_line_count = 0 err
)
'
test_expect_success 'expire removes unreferenced packs' '
(
cd dup &&
git pack-objects --revs .git/objects/pack/pack-combined <<-EOF &&
refs/heads/A
^refs/heads/C
EOF
git multi-pack-index write &&
ls .git/objects/pack | grep -v -e pack-[AB] >expect &&
git multi-pack-index expire &&
ls .git/objects/pack >actual &&
test_cmp expect actual &&
ls .git/objects/pack/ | grep idx >expect-idx &&
test-tool read-midx .git/objects | grep idx >actual-midx &&
test_cmp expect-idx actual-midx &&
git multi-pack-index verify &&
git fsck
)
'
multi-pack-index: prepare 'repack' subcommand In an environment where the multi-pack-index is useful, it is due to many pack-files and an inability to repack the object store into a single pack-file. However, it is likely that many of these pack-files are rather small, and could be repacked into a slightly larger pack-file without too much effort. It may also be important to ensure the object store is highly available and the repack operation does not interrupt concurrent git commands. Introduce a 'repack' subcommand to 'git multi-pack-index' that takes a '--batch-size' option. The subcommand will inspect the multi-pack-index for referenced pack-files whose size is smaller than the batch size, until collecting a list of pack-files whose sizes sum to larger than the batch size. Then, a new pack-file will be created containing the objects from those pack-files that are referenced by the multi-pack-index. The resulting pack is likely to actually be smaller than the batch size due to compression and the fact that there may be objects in the pack- files that have duplicate copies in other pack-files. The current change introduces the command-line arguments, and we add a test that ensures we parse these options properly. Since we specify a small batch size, we will guarantee that future implementations do not change the list of pack-files. In addition, we hard-code the modified times of the packs in the pack directory to ensure the list of packs sorted by modified time matches the order if sorted by size (ascending). This will be important in a future test. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:26 +02:00
test_expect_success 'repack with minimum size does not alter existing packs' '
(
cd dup &&
rm -rf .git/objects/pack &&
mv .git/objects/pack-backup .git/objects/pack &&
test-tool chmtime =-5 .git/objects/pack/pack-D* &&
test-tool chmtime =-4 .git/objects/pack/pack-C* &&
test-tool chmtime =-3 .git/objects/pack/pack-B* &&
test-tool chmtime =-2 .git/objects/pack/pack-A* &&
multi-pack-index: prepare 'repack' subcommand In an environment where the multi-pack-index is useful, it is due to many pack-files and an inability to repack the object store into a single pack-file. However, it is likely that many of these pack-files are rather small, and could be repacked into a slightly larger pack-file without too much effort. It may also be important to ensure the object store is highly available and the repack operation does not interrupt concurrent git commands. Introduce a 'repack' subcommand to 'git multi-pack-index' that takes a '--batch-size' option. The subcommand will inspect the multi-pack-index for referenced pack-files whose size is smaller than the batch size, until collecting a list of pack-files whose sizes sum to larger than the batch size. Then, a new pack-file will be created containing the objects from those pack-files that are referenced by the multi-pack-index. The resulting pack is likely to actually be smaller than the batch size due to compression and the fact that there may be objects in the pack- files that have duplicate copies in other pack-files. The current change introduces the command-line arguments, and we add a test that ensures we parse these options properly. Since we specify a small batch size, we will guarantee that future implementations do not change the list of pack-files. In addition, we hard-code the modified times of the packs in the pack directory to ensure the list of packs sorted by modified time matches the order if sorted by size (ascending). This will be important in a future test. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:26 +02:00
ls .git/objects/pack >expect &&
MINSIZE=$(test-tool path-utils file-size .git/objects/pack/*pack | sort -n | head -n 1) &&
multi-pack-index: prepare 'repack' subcommand In an environment where the multi-pack-index is useful, it is due to many pack-files and an inability to repack the object store into a single pack-file. However, it is likely that many of these pack-files are rather small, and could be repacked into a slightly larger pack-file without too much effort. It may also be important to ensure the object store is highly available and the repack operation does not interrupt concurrent git commands. Introduce a 'repack' subcommand to 'git multi-pack-index' that takes a '--batch-size' option. The subcommand will inspect the multi-pack-index for referenced pack-files whose size is smaller than the batch size, until collecting a list of pack-files whose sizes sum to larger than the batch size. Then, a new pack-file will be created containing the objects from those pack-files that are referenced by the multi-pack-index. The resulting pack is likely to actually be smaller than the batch size due to compression and the fact that there may be objects in the pack- files that have duplicate copies in other pack-files. The current change introduces the command-line arguments, and we add a test that ensures we parse these options properly. Since we specify a small batch size, we will guarantee that future implementations do not change the list of pack-files. In addition, we hard-code the modified times of the packs in the pack directory to ensure the list of packs sorted by modified time matches the order if sorted by size (ascending). This will be important in a future test. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:26 +02:00
git multi-pack-index repack --batch-size=$MINSIZE &&
ls .git/objects/pack >actual &&
test_cmp expect actual
)
'
test_expect_success 'repack respects repack.packKeptObjects=false' '
test_when_finished rm -f dup/.git/objects/pack/*keep &&
(
cd dup &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 5 idx-list &&
ls .git/objects/pack/*.pack | sed "s/\.pack/.keep/" >keep-list &&
test_line_count = 5 keep-list &&
for keep in $(cat keep-list)
do
touch $keep || return 1
done &&
git multi-pack-index repack --batch-size=0 &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 5 idx-list &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 5 midx-list &&
THIRD_SMALLEST_SIZE=$(test-tool path-utils file-size .git/objects/pack/*pack | sort -n | sed -n 3p) &&
BATCH_SIZE=$((THIRD_SMALLEST_SIZE + 1)) &&
git multi-pack-index repack --batch-size=$BATCH_SIZE &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 5 idx-list &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 5 midx-list
)
'
midx: implement midx_repack() To repack with a non-zero batch-size, first sort all pack-files by their modified time. Second, walk those pack-files from oldest to newest, compute their expected size, and add the packs to a list if they are smaller than the given batch-size. Stop when the total expected size is at least the batch size. If the batch size is zero, select all packs in the multi-pack-index. Finally, collect the objects from the multi-pack-index that are in the selected packs and send them to 'git pack-objects'. Write a new multi-pack-index that includes the new pack. Using a batch size of zero is very similar to a standard 'git repack' command, except that we do not delete the old packs and instead rely on the new multi-pack-index to prevent new processes from reading the old packs. This does not disrupt other Git processes that are currently reading the old packs based on the old multi-pack-index. While first designing a 'git multi-pack-index repack' operation, I started by collecting the batches based on the actual size of the objects instead of the size of the pack-files. This allows repacking a large pack-file that has very few referencd objects. However, this came at a significant cost of parsing pack-files instead of simply reading the multi-pack-index and getting the file information for the pack-files. The "expected size" version provides similar behavior, but could skip a pack-file if the average object size is much larger than the actual size of the referenced objects, or can create a large pack if the actual size of the referenced objects is larger than the expected size. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:27 +02:00
test_expect_success 'repack creates a new pack' '
(
cd dup &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 5 idx-list &&
THIRD_SMALLEST_SIZE=$(test-tool path-utils file-size .git/objects/pack/*pack | sort -n | head -n 3 | tail -n 1) &&
midx: implement midx_repack() To repack with a non-zero batch-size, first sort all pack-files by their modified time. Second, walk those pack-files from oldest to newest, compute their expected size, and add the packs to a list if they are smaller than the given batch-size. Stop when the total expected size is at least the batch size. If the batch size is zero, select all packs in the multi-pack-index. Finally, collect the objects from the multi-pack-index that are in the selected packs and send them to 'git pack-objects'. Write a new multi-pack-index that includes the new pack. Using a batch size of zero is very similar to a standard 'git repack' command, except that we do not delete the old packs and instead rely on the new multi-pack-index to prevent new processes from reading the old packs. This does not disrupt other Git processes that are currently reading the old packs based on the old multi-pack-index. While first designing a 'git multi-pack-index repack' operation, I started by collecting the batches based on the actual size of the objects instead of the size of the pack-files. This allows repacking a large pack-file that has very few referencd objects. However, this came at a significant cost of parsing pack-files instead of simply reading the multi-pack-index and getting the file information for the pack-files. The "expected size" version provides similar behavior, but could skip a pack-file if the average object size is much larger than the actual size of the referenced objects, or can create a large pack if the actual size of the referenced objects is larger than the expected size. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-11 01:35:27 +02:00
BATCH_SIZE=$(($THIRD_SMALLEST_SIZE + 1)) &&
git multi-pack-index repack --batch-size=$BATCH_SIZE &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 6 idx-list &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 6 midx-list
)
'
test_expect_success 'expire removes repacked packs' '
(
cd dup &&
ls -al .git/objects/pack/*pack &&
ls -S .git/objects/pack/*pack | head -n 4 >expect &&
git multi-pack-index expire &&
ls -S .git/objects/pack/*pack >actual &&
test_cmp expect actual &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 4 midx-list
)
'
test_expect_success 'expire works when adding new packs' '
(
cd dup &&
git pack-objects --revs .git/objects/pack/pack-combined <<-EOF &&
refs/heads/A
^refs/heads/B
EOF
git pack-objects --revs .git/objects/pack/pack-combined <<-EOF &&
refs/heads/B
^refs/heads/C
EOF
git pack-objects --revs .git/objects/pack/pack-combined <<-EOF &&
refs/heads/C
^refs/heads/D
EOF
git multi-pack-index write &&
git pack-objects --revs .git/objects/pack/a-pack <<-EOF &&
refs/heads/D
^refs/heads/E
EOF
git multi-pack-index write &&
git pack-objects --revs .git/objects/pack/z-pack <<-EOF &&
refs/heads/E
EOF
git multi-pack-index expire &&
ls .git/objects/pack/ | grep idx >expect &&
test-tool read-midx .git/objects | grep idx >actual &&
test_cmp expect actual &&
git multi-pack-index verify
)
'
test_expect_success 'expire respects .keep files' '
(
cd dup &&
git pack-objects --revs .git/objects/pack/pack-all <<-EOF &&
refs/heads/A
EOF
git multi-pack-index write &&
PACKA=$(ls .git/objects/pack/a-pack*\.pack | sed s/\.pack\$//) &&
touch $PACKA.keep &&
git multi-pack-index expire &&
test_path_is_file $PACKA.idx &&
test_path_is_file $PACKA.keep &&
test_path_is_file $PACKA.pack &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 2 midx-list
)
'
test_expect_success 'repack --batch-size=0 repacks everything' '
multi-pack-index: repack batches below --batch-size The --batch-size=<size> option of 'git multi-pack-index repack' is intended to limit the amount of work done by the repack. In the case of a large repository, this command should repack a number of small pack-files but leave the large pack-files alone. Most often, the repository has one large pack-file from a 'git clone' operation and number of smaller pack-files from incremental 'git fetch' operations. The issue with '--batch-size' is that it also _prevents_ the repack from happening if the expected size of the resulting pack-file is too small. This was intended as a way to avoid frequent churn of small pack-files, but it has mostly caused confusion when a repository is of "medium" size. That is, not enormous like the Windows OS repository, but also not so small that this incremental repack isn't valuable. The solution presented here is to collect pack-files for repack if their expected size is smaller than the batch-size parameter until either the total expected size exceeds the batch-size or all pack-files are considered. If there are at least two pack-files, then these are combined to a new pack-file whose size should not be too much larger than the batch-size. This new strategy should succeed in keeping the number of pack-files small in these "medium" size repositories. The concern about churn is likely not interesting, as the real control over that is the frequency in which the repack command is run. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-11 17:30:18 +02:00
cp -r dup dup2 &&
(
cd dup &&
rm .git/objects/pack/*.keep &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 2 idx-list &&
git multi-pack-index repack --batch-size=0 &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 3 idx-list &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 3 midx-list &&
git multi-pack-index expire &&
ls -al .git/objects/pack/*idx >idx-list &&
test_line_count = 1 idx-list &&
git multi-pack-index repack --batch-size=0 &&
ls -al .git/objects/pack/*idx >new-idx-list &&
test_cmp idx-list new-idx-list
)
'
multi-pack-index: repack batches below --batch-size The --batch-size=<size> option of 'git multi-pack-index repack' is intended to limit the amount of work done by the repack. In the case of a large repository, this command should repack a number of small pack-files but leave the large pack-files alone. Most often, the repository has one large pack-file from a 'git clone' operation and number of smaller pack-files from incremental 'git fetch' operations. The issue with '--batch-size' is that it also _prevents_ the repack from happening if the expected size of the resulting pack-file is too small. This was intended as a way to avoid frequent churn of small pack-files, but it has mostly caused confusion when a repository is of "medium" size. That is, not enormous like the Windows OS repository, but also not so small that this incremental repack isn't valuable. The solution presented here is to collect pack-files for repack if their expected size is smaller than the batch-size parameter until either the total expected size exceeds the batch-size or all pack-files are considered. If there are at least two pack-files, then these are combined to a new pack-file whose size should not be too much larger than the batch-size. This new strategy should succeed in keeping the number of pack-files small in these "medium" size repositories. The concern about churn is likely not interesting, as the real control over that is the frequency in which the repack command is run. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-11 17:30:18 +02:00
test_expect_success 'repack --batch-size=<large> repacks everything' '
(
cd dup2 &&
rm .git/objects/pack/*.keep &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 2 idx-list &&
git multi-pack-index repack --batch-size=2000000 &&
ls .git/objects/pack/*idx >idx-list &&
test_line_count = 3 idx-list &&
test-tool read-midx .git/objects | grep idx >midx-list &&
test_line_count = 3 midx-list &&
git multi-pack-index expire &&
ls -al .git/objects/pack/*idx >idx-list &&
test_line_count = 1 idx-list
)
'
midx.c: protect against disappearing packs When a packed object is stored in a multi-pack index, but that pack has racily gone away, the MIDX code simply calls die(), when it could be returning an error to the caller, which would in turn lead to re-scanning the pack directory. A pack can racily disappear, for example, due to a simultaneous 'git repack -ad', You can also reproduce this with two terminals, where one is running: git init while true; do git commit -q --allow-empty -m foo git repack -ad git multi-pack-index write done (in effect, constantly writing new MIDXs), and the other is running: obj=$(git rev-parse HEAD) while true; do echo $obj | git cat-file --batch-check='%(objectsize:disk)' || break done That will sometimes hit the error preparing packfile from multi-pack-index message, which this patch fixes. Right now, that path to discovering a missing pack looks something like 'find_pack_entry()' calling 'fill_midx_entry()' and eventually making its way to call 'nth_midxed_pack_entry()'. 'nth_midxed_pack_entry()' already checks 'is_pack_valid()' and propagates an error if the pack is invalid. So, this works if the pack has gone away between calling 'prepare_midx_pack()' and before calling 'is_pack_valid()', but not if it disappears before then. Catch the case where the pack has already disappeared before 'prepare_midx_pack()' by returning an error in that case, too. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:33 +01:00
test_expect_success 'load reverse index when missing .idx, .pack' '
packfile.c: protect against disappearing indexes In 17c35c8969 (packfile: skip loading index if in multi-pack-index, 2018-07-12) we stopped loading the .idx file for packs that are contained within a multi-pack index. This saves us the effort of loading an .idx and doing some lightweight validity checks by way of 'packfile.c:load_idx()', but introduces a race between processes that need to load the index (e.g., to generate a reverse index) and processes that can delete the index. For example, running the following in your shell: $ git init repo && cd repo $ git commit --allow-empty -m 'base' $ git repack -ad && git multi-pack-index write followed by: $ rm -f .git/objects/pack/pack-*.idx $ git rev-parse HEAD | git cat-file --batch-check='%(objectsize:disk)' will result in a segfault prior to this patch. What's happening here is that we notice that the pack is in the multi-pack index, and so don't check that it still has a .idx. When we then try and load that index to generate a reverse index, we don't have it, so the call to 'find_pack_revindex()' in 'packfile.c:packed_object_info()' returns NULL, and then dereferencing it causes a segfault. Of course, we don't ever expect someone to remove the index file by hand, or to be in a state where we never wrote it to begin with (yet find that pack in the multi-pack-index). But, this can happen in a timing race with 'git repack -ad', which removes all existing packs after writing a new pack containing all of their objects. Avoid this by reverting the hunk of 17c35c8969 which stops loading the index when the pack is contained in a MIDX. This makes the latter half of 17c35c8969 useless, since we'll always have a non-NULL 'p->index_data', in which case that if statement isn't guarding anything. These two together effectively revert 17c35c8969, and avoid the race explained above. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:28 +01:00
git init repo &&
test_when_finished "rm -fr repo" &&
(
cd repo &&
git config core.multiPackIndex true &&
test_commit base &&
git repack -ad &&
git multi-pack-index write &&
git rev-parse HEAD >tip &&
midx.c: protect against disappearing packs When a packed object is stored in a multi-pack index, but that pack has racily gone away, the MIDX code simply calls die(), when it could be returning an error to the caller, which would in turn lead to re-scanning the pack directory. A pack can racily disappear, for example, due to a simultaneous 'git repack -ad', You can also reproduce this with two terminals, where one is running: git init while true; do git commit -q --allow-empty -m foo git repack -ad git multi-pack-index write done (in effect, constantly writing new MIDXs), and the other is running: obj=$(git rev-parse HEAD) while true; do echo $obj | git cat-file --batch-check='%(objectsize:disk)' || break done That will sometimes hit the error preparing packfile from multi-pack-index message, which this patch fixes. Right now, that path to discovering a missing pack looks something like 'find_pack_entry()' calling 'fill_midx_entry()' and eventually making its way to call 'nth_midxed_pack_entry()'. 'nth_midxed_pack_entry()' already checks 'is_pack_valid()' and propagates an error if the pack is invalid. So, this works if the pack has gone away between calling 'prepare_midx_pack()' and before calling 'is_pack_valid()', but not if it disappears before then. Catch the case where the pack has already disappeared before 'prepare_midx_pack()' by returning an error in that case, too. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:33 +01:00
pack=$(ls .git/objects/pack/pack-*.pack) &&
packfile.c: protect against disappearing indexes In 17c35c8969 (packfile: skip loading index if in multi-pack-index, 2018-07-12) we stopped loading the .idx file for packs that are contained within a multi-pack index. This saves us the effort of loading an .idx and doing some lightweight validity checks by way of 'packfile.c:load_idx()', but introduces a race between processes that need to load the index (e.g., to generate a reverse index) and processes that can delete the index. For example, running the following in your shell: $ git init repo && cd repo $ git commit --allow-empty -m 'base' $ git repack -ad && git multi-pack-index write followed by: $ rm -f .git/objects/pack/pack-*.idx $ git rev-parse HEAD | git cat-file --batch-check='%(objectsize:disk)' will result in a segfault prior to this patch. What's happening here is that we notice that the pack is in the multi-pack index, and so don't check that it still has a .idx. When we then try and load that index to generate a reverse index, we don't have it, so the call to 'find_pack_revindex()' in 'packfile.c:packed_object_info()' returns NULL, and then dereferencing it causes a segfault. Of course, we don't ever expect someone to remove the index file by hand, or to be in a state where we never wrote it to begin with (yet find that pack in the multi-pack-index). But, this can happen in a timing race with 'git repack -ad', which removes all existing packs after writing a new pack containing all of their objects. Avoid this by reverting the hunk of 17c35c8969 which stops loading the index when the pack is contained in a MIDX. This makes the latter half of 17c35c8969 useless, since we'll always have a non-NULL 'p->index_data', in which case that if statement isn't guarding anything. These two together effectively revert 17c35c8969, and avoid the race explained above. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:28 +01:00
idx=$(ls .git/objects/pack/pack-*.idx) &&
mv $idx $idx.bak &&
midx.c: protect against disappearing packs When a packed object is stored in a multi-pack index, but that pack has racily gone away, the MIDX code simply calls die(), when it could be returning an error to the caller, which would in turn lead to re-scanning the pack directory. A pack can racily disappear, for example, due to a simultaneous 'git repack -ad', You can also reproduce this with two terminals, where one is running: git init while true; do git commit -q --allow-empty -m foo git repack -ad git multi-pack-index write done (in effect, constantly writing new MIDXs), and the other is running: obj=$(git rev-parse HEAD) while true; do echo $obj | git cat-file --batch-check='%(objectsize:disk)' || break done That will sometimes hit the error preparing packfile from multi-pack-index message, which this patch fixes. Right now, that path to discovering a missing pack looks something like 'find_pack_entry()' calling 'fill_midx_entry()' and eventually making its way to call 'nth_midxed_pack_entry()'. 'nth_midxed_pack_entry()' already checks 'is_pack_valid()' and propagates an error if the pack is invalid. So, this works if the pack has gone away between calling 'prepare_midx_pack()' and before calling 'is_pack_valid()', but not if it disappears before then. Catch the case where the pack has already disappeared before 'prepare_midx_pack()' by returning an error in that case, too. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:33 +01:00
git cat-file --batch-check="%(objectsize:disk)" <tip &&
mv $idx.bak $idx &&
mv $pack $pack.bak &&
packfile.c: protect against disappearing indexes In 17c35c8969 (packfile: skip loading index if in multi-pack-index, 2018-07-12) we stopped loading the .idx file for packs that are contained within a multi-pack index. This saves us the effort of loading an .idx and doing some lightweight validity checks by way of 'packfile.c:load_idx()', but introduces a race between processes that need to load the index (e.g., to generate a reverse index) and processes that can delete the index. For example, running the following in your shell: $ git init repo && cd repo $ git commit --allow-empty -m 'base' $ git repack -ad && git multi-pack-index write followed by: $ rm -f .git/objects/pack/pack-*.idx $ git rev-parse HEAD | git cat-file --batch-check='%(objectsize:disk)' will result in a segfault prior to this patch. What's happening here is that we notice that the pack is in the multi-pack index, and so don't check that it still has a .idx. When we then try and load that index to generate a reverse index, we don't have it, so the call to 'find_pack_revindex()' in 'packfile.c:packed_object_info()' returns NULL, and then dereferencing it causes a segfault. Of course, we don't ever expect someone to remove the index file by hand, or to be in a state where we never wrote it to begin with (yet find that pack in the multi-pack-index). But, this can happen in a timing race with 'git repack -ad', which removes all existing packs after writing a new pack containing all of their objects. Avoid this by reverting the hunk of 17c35c8969 which stops loading the index when the pack is contained in a MIDX. This makes the latter half of 17c35c8969 useless, since we'll always have a non-NULL 'p->index_data', in which case that if statement isn't guarding anything. These two together effectively revert 17c35c8969, and avoid the race explained above. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25 18:17:28 +01:00
git cat-file --batch-check="%(objectsize:disk)" <tip
)
'
test_done