Commit Graph

4 Commits

Author SHA1 Message Date
7af607c58d reftable/record: store "val1" hashes as static arrays
When reading ref records of type "val1", we store its object ID in an
allocated array. This results in an additional allocation for every
single ref record we read, which is rather inefficient especially when
iterating over refs.

Refactor the code to instead use an embedded array of `GIT_MAX_RAWSZ`
bytes. While this means that `struct ref_record` is bigger now, we
typically do not store all refs in an array anyway and instead only
handle a limited number of records at the same point in time.

Using `git show-ref --quiet` in a repository with ~350k refs this leads
to a significant drop in allocations. Before:

    HEAP SUMMARY:
        in use at exit: 21,098 bytes in 192 blocks
      total heap usage: 2,116,683 allocs, 2,116,491 frees, 76,098,060 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 21,098 bytes in 192 blocks
      total heap usage: 1,419,031 allocs, 1,418,839 frees, 62,145,036 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-03 09:54:20 -08:00
22d2f70e85 reftable tests: avoid "int" overflow, use "uint64_t"
Change code added in 1ae2b8cda8 (reftable: add merged table view,
2021-10-07) to consistently use the "uint64_t" type. These "min" and
"max" variables get passed in the body of this function to a function
whose prototype is:

    [...] reftable_writer_set_limits([...], uint64_t min, uint64_t max

This avoids the following warning on SunCC 12.5 on
gcc211.fsffrance.org:

    "reftable/merged_test.c", line 27: warning: initializer does not fit or is out of range: 0xffffffff

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-13 13:39:09 -08:00
f2b255141b reftable: avoid initializing structs from structs
Apparently, the IBM xlc compiler doesn't like this.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-13 13:36:34 -08:00
1ae2b8cda8 reftable: add merged table view
This adds an abstract, read-only interface to the ref database.

This primitive is used to construct the read view of the ref database
(the read view is constructed by merging several *.ref files). It also
provides the mechanism to provide a unified view of the refs in the main
repository and the per-worktree refs.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00