On Mon, Jan 25, 2021 at 06:37:51PM -0500, Taylor Blau wrote:
> 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. Unfortuantely, explicit existing coverage is
> rather sparse, so only a basic test is added.
>
> The new test is parameterized over whether or not the .rev file should
> be written, and is run in both modes by t5325 (without having to touch
> GIT_TEST_WRITE_REV_INDEX).
Thanks, I think this is worth having.
> +revindex_tests () {
> + on_disk="$1"
> +
> + test_expect_success "setup revindex tests (on_disk=$on_disk)" "
> + test_oid_cache <<-EOF &&
> + disklen sha1:47
> + disklen sha256:59
> + EOF
These sizes aren't really guaranteed to be stable. I think you've
eliminated most variables by not having the opportunity for deltas,
though we're still subject to the whims of zlib, for example.
I think what we care about most is just that the on-disk and fallback
cases generate the same results. If they do, we can assume those results
are probably sane. If they're not, then a lot of _other_ stuff is going
to be broken (like, say, pack-objects, which is writing out N bytes
based on the sizes claimed by the revindex).
What do you think about just doing this:
...setup some commits... &&
git rev-list --objects --no-object-names --all >objects &&
git -c pack.writeReverseIndex=false repack -ad &&
test_path_is_missing .git/objects/pack/*.rev &&
git cat-file --batch-check="%(objectsize:disk) %(objectname)" \
<objects >in-core &&
git -c pack.writeReverseIndex=true repack -ad &&
test_path_is_file .git/objects/pack/*.rev &&
git cat-file --batch-check="%(objectsize:disk) %(objectname)" \
<objects >on-disk &&
test_cmp on-disk in-core
> + if test ztrue = \"z$on_disk\"
> + then
> + git config pack.writeReverseIndex true
> + fi &&
Are we autotools now? :) I think we can assume that on_disk contains
something sensible. Perhaps even:
git config pack.writeReverseIndex $on_disk
though if you take my advice above, all of this goes away.
-Peff
