pack-write.c: extract 'write_rev_file_order'

Existing callers provide the reverse index code with an array of 'struct
pack_idx_entry *'s, which is then sorted by pack order (comparing the
offsets of each object within the pack).

Prepare for the multi-pack index to write a .rev file by providing a way
to write the reverse index without an array of pack_idx_entry (which the
MIDX code does not have).

Instead, callers can invoke 'write_rev_index_positions()', which takes
an array of uint32_t's. The ith entry in this array specifies the ith
object's (in index order) position within the pack (in pack order).

Expose this new function for use in a later patch, and rewrite the
existing write_rev_file() in terms of this new function.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau 2021-03-30 11:04:29 -04:00 committed by Junio C Hamano
parent f894081dea
commit a587b5a786
2 changed files with 26 additions and 11 deletions

View File

@ -201,21 +201,12 @@ static void write_rev_header(struct hashfile *f)
}
static void write_rev_index_positions(struct hashfile *f,
struct pack_idx_entry **objects,
uint32_t *pack_order,
uint32_t nr_objects)
{
uint32_t *pack_order;
uint32_t i;
ALLOC_ARRAY(pack_order, nr_objects);
for (i = 0; i < nr_objects; i++)
pack_order[i] = i;
QSORT_S(pack_order, nr_objects, pack_order_cmp, objects);
for (i = 0; i < nr_objects; i++)
hashwrite_be32(f, pack_order[i]);
free(pack_order);
}
static void write_rev_trailer(struct hashfile *f, const unsigned char *hash)
@ -228,6 +219,29 @@ const char *write_rev_file(const char *rev_name,
uint32_t nr_objects,
const unsigned char *hash,
unsigned flags)
{
uint32_t *pack_order;
uint32_t i;
const char *ret;
ALLOC_ARRAY(pack_order, nr_objects);
for (i = 0; i < nr_objects; i++)
pack_order[i] = i;
QSORT_S(pack_order, nr_objects, pack_order_cmp, objects);
ret = write_rev_file_order(rev_name, pack_order, nr_objects, hash,
flags);
free(pack_order);
return ret;
}
const char *write_rev_file_order(const char *rev_name,
uint32_t *pack_order,
uint32_t nr_objects,
const unsigned char *hash,
unsigned flags)
{
struct hashfile *f;
int fd;
@ -262,7 +276,7 @@ const char *write_rev_file(const char *rev_name,
write_rev_header(f);
write_rev_index_positions(f, objects, nr_objects);
write_rev_index_positions(f, pack_order, nr_objects);
write_rev_trailer(f, hash);
if (rev_name && adjust_shared_perm(rev_name) < 0)

1
pack.h
View File

@ -94,6 +94,7 @@ struct ref;
void write_promisor_file(const char *promisor_name, struct ref **sought, int nr_sought);
const char *write_rev_file(const char *rev_name, struct pack_idx_entry **objects, uint32_t nr_objects, const unsigned char *hash, unsigned flags);
const char *write_rev_file_order(const char *rev_name, uint32_t *pack_order, uint32_t nr_objects, const unsigned char *hash, unsigned flags);
/*
* The "hdr" output buffer should be at least this big, which will handle sizes