Commit Graph

5 Commits

Author SHA1 Message Date
Taylor Blau
6885cd7dc5 t5325: check both on-disk and in-memory reverse index
Right now, the test suite can be run with 'GIT_TEST_WRITE_REV_INDEX=1'
in the environment, which causes all operations which write a pack to
also write a .rev file.

To prepare for when that eventually becomes the default, we should
continue to test the in-memory reverse index, too, in order to avoid
losing existing coverage. Unfortunately, explicit existing coverage is
rather sparse, so only a basic test is added that compares the result of

    git rev-list --objects --no-object-names --all |
    git cat-file --batch-check='%(objectsize:disk) %(objectname)'

with and without an on-disk reverse index.

Suggested-by: Jeff King <peff@peff.net>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-28 22:51:51 -08:00
Taylor Blau
ec8e7760ac pack-revindex: ensure that on-disk reverse indexes are given precedence
When an on-disk reverse index exists, there is no need to generate one
in memory. In fact, doing so can be slow, and require large amounts of
the heap.

Let's make sure that we treat the on-disk reverse index with precedence
(i.e., that when it exists, we don't bother trying to generate an
equivalent one in memory) by teaching Git how to conditionally die()
when generating a reverse index in memory.

Then, add a test to ensure that when (a) an on-disk reverse index
exists, and (b) when setting GIT_TEST_REV_INDEX_DIE_IN_MEMORY, that we
do not die, implying that we read from the on-disk one.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:44 -08:00
Taylor Blau
35a8a3547a t: prepare for GIT_TEST_WRITE_REV_INDEX
In the next patch, we'll add support for unconditionally enabling the
'pack.writeReverseIndex' setting with a new GIT_TEST_WRITE_REV_INDEX
environment variable.

This causes a little bit of fallout with tests that, for example,
compare the list of files in the pack directory being unprepared to see
.rev files in its output.

Those locations can be cleaned up to look for specific file extensions,
rather than take everything in the pack directory (for instance) and
then grep out unwanted items.

Once the pack.writeReverseIndex option has been thoroughly
tested, we will default it to 'true', removing GIT_TEST_WRITE_REV_INDEX,
and making it possible to revert this patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:44 -08:00
Taylor Blau
c97733435a builtin/pack-objects.c: respect 'pack.writeReverseIndex'
Now that we have an implementation that can write the new reverse index
format, enable writing a .rev file in 'git pack-objects' by consulting
the pack.writeReverseIndex configuration variable.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:43 -08:00
Taylor Blau
e37d0b8730 builtin/index-pack.c: write reverse indexes
Teach 'git index-pack' to optionally write and verify reverse index with
'--[no-]rev-index', as well as respecting the 'pack.writeReverseIndex'
configuration option.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:43 -08:00