repack: respect kept objects with '--write-midx -b'

Historically, we needed a single packfile in order to have reachability
bitmaps. This introduced logic that when 'git repack' had a '-b' option
that we should stop sending the '--honor-pack-keep' option to the 'git
pack-objects' child process, ensuring that we create a packfile
containing all reachable objects.

In the world of multi-pack-index bitmaps, we no longer need to repack
all objects into a single pack to have valid bitmaps. Thus, we should
continue sending the '--honor-pack-keep' flag to 'git pack-objects'.

The fix is very simple: only disable the flag when writing bitmaps but
also _not_ writing the multi-pack-index.

This opens the door to new repacking strategies that might want to keep
some historical set of objects in a stable pack-file while only
repacking more recent objects.

To test, create a new 'test_subcommand_inexact' helper that is more
flexible than 'test_subcommand'. This allows us to look for the
--honor-pack-keep flag without over-indexing on the exact set of
arguments.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Derrick Stolee 2021-12-20 14:48:10 +00:00 коммит произвёл Junio C Hamano
Родитель e9d7761bb9
Коммит e4d0c11c04
3 изменённых файлов: 41 добавлений и 1 удалений

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@ -691,7 +691,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
write_bitmaps = 0; write_bitmaps = 0;
} }
if (pack_kept_objects < 0) if (pack_kept_objects < 0)
pack_kept_objects = write_bitmaps > 0; pack_kept_objects = write_bitmaps > 0 && !write_midx;
if (write_bitmaps && !(pack_everything & ALL_INTO_ONE) && !write_midx) if (write_bitmaps && !(pack_everything & ALL_INTO_ONE) && !write_midx)
die(_(incremental_bitmap_conflict_error)); die(_(incremental_bitmap_conflict_error));

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@ -372,4 +372,10 @@ test_expect_success '--write-midx with preferred bitmap tips' '
) )
' '
test_expect_success '--write-midx -b packs non-kept objects' '
GIT_TRACE2_EVENT="$(pwd)/trace.txt" \
git repack --write-midx -a -b &&
test_subcommand_inexact git pack-objects --honor-pack-keep <trace.txt
'
test_done test_done

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@ -1748,6 +1748,40 @@ test_subcommand () {
fi fi
} }
# Check that the given command was invoked as part of the
# trace2-format trace on stdin, but without an exact set of
# arguments.
#
# test_subcommand [!] <command> <args>... < <trace>
#
# For example, to look for an invocation of "git pack-objects"
# with the "--honor-pack-keep" argument, use
#
# GIT_TRACE2_EVENT=event.log git repack ... &&
# test_subcommand git pack-objects --honor-pack-keep <event.log
#
# If the first parameter passed is !, this instead checks that
# the given command was not called.
#
test_subcommand_inexact () {
local negate=
if test "$1" = "!"
then
negate=t
shift
fi
local expr=$(printf '"%s".*' "$@")
expr="${expr%,}"
if test -n "$negate"
then
! grep "\"event\":\"child_start\".*\[$expr\]"
else
grep "\"event\":\"child_start\".*\[$expr\]"
fi
}
# Check that the given command was invoked as part of the # Check that the given command was invoked as part of the
# trace2-format trace on stdin. # trace2-format trace on stdin.
# #