| #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 (!hashcmp(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); |
| } |
| |
| 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); |
| } |
| |
| 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; |
| } |