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7 commits

Author SHA1 Message Date
Patrick Steinhardt bbd6106967 t: mark tests regarding git-pack-refs(1) to be backend specific
Both t1409 and t3210 exercise parts of git-pack-refs(1). Given that we
must check the on-disk files to verify whether the backend has indeed
packed refs as expected those test suites are deeply tied to the actual
backend that is in use.

Mark the test suites to depend on the REFFILES backend.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-29 13:54:33 -08:00
Ævar Arnfjörð Bjarmason 03267e8656 commit: discard partial cache before (re-)reading it
The read_cache() in prepare_to_commit() would end up clobbering the
pointer we had for a previously populated "the_index.cache_tree" in
the very common case of "git commit" stressed by e.g. the tests being
changed here.

We'd populate "the_index.cache_tree" by calling
"update_main_cache_tree" in prepare_index(), but would not end up with
a "fully prepared" index. What constitutes an existing index is
clearly overly fuzzy, here we'll check "active_nr" (aka
"the_index.cache_nr"), but our "the_index.cache_tree" might have been
malloc()'d already.

Thus the code added in 11c8a74a64 (commit: write cache-tree data when
writing index anyway, 2011-12-06) would end up allocating the
"cache_tree", and would interact here with code added in
7168624c35 (Do not generate full commit log message if it is not
going to be used, 2007-11-28). The result was a very common memory
leak.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-21 12:32:48 +09:00
Denton Liu 62d58cda69 t1409: use test_path_is_missing()
The test_must_fail() function should only be used for git commands since
we should assume that external commands work sanely. Replace
`test_must_fail test -f` with `test_path_is_missing` since we expect
these paths to not exist.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-20 11:30:45 -08:00
Denton Liu b87b02cfe6 t1409: let sed open its own input file
In one case, we were using a redirection operator to feed input into
sed. However, since sed is capable of opening its own input file, make
sed do that instead of redirecting input into it.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-20 11:30:45 -08:00
Denton Liu f511bc02ed t0020: use ! check_packed_refs_marked
The test_must_fail function should only be used for git commands since
we should assume that external commands work sanely. Since
check_packed_refs_marked() just wraps a grep invocation, replace
`test_must_fail check_packed_refs_marked` with
`! check_packed_refs_marked`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-20 11:30:44 -08:00
Michael Haggerty 7c6bd25c7d files-backend: don't rewrite the packed-refs file unnecessarily
Even when we are deleting references, we needn't overwrite the
`packed-refs` file if the references that we are deleting only exist
as loose references. Implement this optimization as follows:

* Add a function `is_packed_transaction_needed()`, which checks
  whether a given packed-refs transaction actually needs to be carried
  out (i.e., it returns false if the transaction obviously wouldn't
  have any effect). This function must be called while holding the
  `packed-refs` lock to avoid races.

* Change `files_transaction_prepare()` to check whether the
  packed-refs transaction is actually needed. If not, squelch it, but
  continue holding the `packed-refs` lock until the end of the
  transaction to avoid races.

This fixes a mild regression caused by dc39e09942 (files_ref_store:
use a transaction to update packed refs, 2017-09-08). Before that
commit, unnecessary rewrites of `packed-refs` were suppressed by
`repack_without_refs()`. But the transaction-based writing introduced
by that commit didn't perform that optimization.

Note that the pre-dc39e09942 code still had to *read* the whole
`packed-refs` file to determine that the rewrite could be skipped, so
the performance for the cases that the write could be elided was
`O(N)` in the number of packed references both before and after
dc39e09942. But after that commit the constant factor increased.

This commit reimplements the optimization of eliding unnecessary
`packed-refs` rewrites. That, plus the fact that since
cfa2e29c34 (packed_ref_store: get rid of the `ref_cache` entirely,
2017-03-17) we don't necessarily have to read the whole `packed-refs`
file at all, means that deletes of one or a few loose references can
now be done with `O(n lg N)` effort, where `n` is the number of loose
references being deleted and `N` is the total number of packed
references.

This commit fixes two tests in t1409.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-30 09:45:15 +09:00
Michael Haggerty cf79bd9f4c t1409: check that packed-refs is not rewritten unnecessarily
There is no need to rewrite the `packed-refs` file except for the case
that we are deleting a reference that has a packed version. Verify
that `packed-refs` is not rewritten when it shouldn't be.

In fact, two of these tests fail:

* A new (empty) `packed-refs` file is created when deleting any loose
  reference and no `packed-refs` file previously existed.

* The `packed-refs` file is rewritten unnecessarily when deleting a
  loose reference that has no packed counterpart.

Both problems will be fixed in the next commit.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-27 10:12:42 +09:00