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>
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>
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>
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>
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>
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>
