git-commit-vandalism/pack-objects.c
Jeff King e3ff0683e2 convert "hashcmp() == 0" to hasheq()
This is the partner patch to the previous one, but covering
the "hash" variants instead of "oid".  Note that our
coccinelle rule is slightly more complex to avoid triggering
the call in hasheq().

I didn't bother to add a new rule to convert:

  - hasheq(E1->hash, E2->hash)
  + oideq(E1, E2)

Since these are new functions, there won't be any such
existing callers. And since most of the code is already
using oideq, we're not likely to introduce new ones.

We might still see "!hashcmp(E1->hash, E2->hash)" from topics
in flight. But because our new rule comes after the existing
ones, that should first get converted to "!oidcmp(E1, E2)"
and then to "oideq(E1, E2)".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00

184 lines
4.0 KiB
C

#include "cache.h"
#include "object.h"
#include "pack.h"
#include "pack-objects.h"
#include "packfile.h"
#include "config.h"
static uint32_t locate_object_entry_hash(struct packing_data *pdata,
const unsigned char *sha1,
int *found)
{
uint32_t i, mask = (pdata->index_size - 1);
i = sha1hash(sha1) & mask;
while (pdata->index[i] > 0) {
uint32_t pos = pdata->index[i] - 1;
if (hasheq(sha1, pdata->objects[pos].idx.oid.hash)) {
*found = 1;
return i;
}
i = (i + 1) & mask;
}
*found = 0;
return i;
}
static inline uint32_t closest_pow2(uint32_t v)
{
v = v - 1;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
return v + 1;
}
static void rehash_objects(struct packing_data *pdata)
{
uint32_t i;
struct object_entry *entry;
pdata->index_size = closest_pow2(pdata->nr_objects * 3);
if (pdata->index_size < 1024)
pdata->index_size = 1024;
free(pdata->index);
pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
entry = pdata->objects;
for (i = 0; i < pdata->nr_objects; i++) {
int found;
uint32_t ix = locate_object_entry_hash(pdata,
entry->idx.oid.hash,
&found);
if (found)
BUG("Duplicate object in hash");
pdata->index[ix] = i + 1;
entry++;
}
}
struct object_entry *packlist_find(struct packing_data *pdata,
const unsigned char *sha1,
uint32_t *index_pos)
{
uint32_t i;
int found;
if (!pdata->index_size)
return NULL;
i = locate_object_entry_hash(pdata, sha1, &found);
if (index_pos)
*index_pos = i;
if (!found)
return NULL;
return &pdata->objects[pdata->index[i] - 1];
}
static void prepare_in_pack_by_idx(struct packing_data *pdata)
{
struct packed_git **mapping, *p;
int cnt = 0, nr = 1U << OE_IN_PACK_BITS;
ALLOC_ARRAY(mapping, nr);
/*
* oe_in_pack() on an all-zero'd object_entry
* (i.e. in_pack_idx also zero) should return NULL.
*/
mapping[cnt++] = NULL;
for (p = get_packed_git(the_repository); p; p = p->next, cnt++) {
if (cnt == nr) {
free(mapping);
return;
}
p->index = cnt;
mapping[cnt] = p;
}
pdata->in_pack_by_idx = mapping;
}
/*
* A new pack appears after prepare_in_pack_by_idx() has been
* run. This is likely a race.
*
* We could map this new pack to in_pack_by_idx[] array, but then we
* have to deal with full array anyway. And since it's hard to test
* this fall back code, just stay simple and fall back to using
* in_pack[] array.
*/
void oe_map_new_pack(struct packing_data *pack,
struct packed_git *p)
{
uint32_t i;
REALLOC_ARRAY(pack->in_pack, pack->nr_alloc);
for (i = 0; i < pack->nr_objects; i++)
pack->in_pack[i] = oe_in_pack(pack, pack->objects + i);
FREE_AND_NULL(pack->in_pack_by_idx);
}
/* assume pdata is already zero'd by caller */
void prepare_packing_data(struct packing_data *pdata)
{
if (git_env_bool("GIT_TEST_FULL_IN_PACK_ARRAY", 0)) {
/*
* do not initialize in_pack_by_idx[] to force the
* slow path in oe_in_pack()
*/
} else {
prepare_in_pack_by_idx(pdata);
}
pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE",
1U << OE_SIZE_BITS);
pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
1UL << OE_DELTA_SIZE_BITS);
}
struct object_entry *packlist_alloc(struct packing_data *pdata,
const unsigned char *sha1,
uint32_t index_pos)
{
struct object_entry *new_entry;
if (pdata->nr_objects >= pdata->nr_alloc) {
pdata->nr_alloc = (pdata->nr_alloc + 1024) * 3 / 2;
REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
if (!pdata->in_pack_by_idx)
REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc);
if (pdata->delta_size)
REALLOC_ARRAY(pdata->delta_size, pdata->nr_alloc);
}
new_entry = pdata->objects + pdata->nr_objects++;
memset(new_entry, 0, sizeof(*new_entry));
hashcpy(new_entry->idx.oid.hash, sha1);
if (pdata->index_size * 3 <= pdata->nr_objects * 4)
rehash_objects(pdata);
else
pdata->index[index_pos] = pdata->nr_objects;
if (pdata->in_pack)
pdata->in_pack[pdata->nr_objects - 1] = NULL;
return new_entry;
}