@matheusbsbs / matheus-bagliano / commits / d22d941ac0

refs/packed-backend.c: refactor `find_reference_location()`

The function `find_reference_location()` is used to perform a binary search-like function over the contents of a repository's `$GIT_DIR/packed-refs` file. The search it implements is unlike a standard binary search in that the records it searches over are not of a fixed width, so the comparison must locate the end of a record before comparing it. Extract the core routine of `find_reference_location()` in order to implement a function in the following patch which will find the first location in the `packed-refs` file that *doesn't* match the given pattern. The behavior of `find_reference_location()` is unchanged. Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Taylor Blau committed Jul 10, 2023 at 17:12 UTC d22d941ac08aa31266bb0b38d78c79c3ffdc4f86

1 file changed +22 -16

refs/packed-backend.c

+22 -16

@@ -527,22 +527,8 @@ static int load_contents(struct snapshot *snapshot)

527 return 1;

528 }

529

530 -/*

531 - * Find the place in `snapshot->buf` where the start of the record for

532 - * `refname` starts. If `mustexist` is true and the reference doesn't

533 - * exist, then return NULL. If `mustexist` is false and the reference

534 - * doesn't exist, then return the point where that reference would be

535 - * inserted, or `snapshot->eof` (which might be NULL) if it would be

536 - * inserted at the end of the file. In the latter mode, `refname`

537 - * doesn't have to be a proper reference name; for example, one could

538 - * search for "refs/replace/" to find the start of any replace

539 - * references.

540 - *

541 - * The record is sought using a binary search, so `snapshot->buf` must

542 - * be sorted.

543 - */

544 -static const char *find_reference_location(struct snapshot *snapshot,

545 - const char *refname, int mustexist)

530 +static const char *find_reference_location_1(struct snapshot *snapshot,

531 + const char *refname, int mustexist)

532 {

533 /*

534 * This is not *quite* a garden-variety binary search, because

@@ -588,6 +574,26 @@ static const char *find_reference_location(struct snapshot *snapshot,

574 return lo;

575 }

576

577 +/*

578 + * Find the place in `snapshot->buf` where the start of the record for

579 + * `refname` starts. If `mustexist` is true and the reference doesn't

580 + * exist, then return NULL. If `mustexist` is false and the reference

581 + * doesn't exist, then return the point where that reference would be

582 + * inserted, or `snapshot->eof` (which might be NULL) if it would be

583 + * inserted at the end of the file. In the latter mode, `refname`

584 + * doesn't have to be a proper reference name; for example, one could

585 + * search for "refs/replace/" to find the start of any replace

586 + * references.

587 + *

588 + * The record is sought using a binary search, so `snapshot->buf` must

589 + * be sorted.

590 + */

591 +static const char *find_reference_location(struct snapshot *snapshot,

592 + const char *refname, int mustexist)

593 +{

594 + return find_reference_location_1(snapshot, refname, mustexist);

595 +}

596 +

597 /*

598 * Create a newly-allocated `snapshot` of the `packed-refs` file in

599 * its current state and return it. The return value will already have