diff options
Diffstat (limited to 'third_party/git/midx.c')
| -rw-r--r-- | third_party/git/midx.c | 1382 |
1 files changed, 1382 insertions, 0 deletions
diff --git a/third_party/git/midx.c b/third_party/git/midx.c new file mode 100644 index 000000000000..d6496444206a --- /dev/null +++ b/third_party/git/midx.c @@ -0,0 +1,1382 @@ +#include "cache.h" +#include "config.h" +#include "csum-file.h" +#include "dir.h" +#include "lockfile.h" +#include "packfile.h" +#include "object-store.h" +#include "sha1-lookup.h" +#include "midx.h" +#include "progress.h" +#include "trace2.h" +#include "run-command.h" + +#define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */ +#define MIDX_VERSION 1 +#define MIDX_BYTE_FILE_VERSION 4 +#define MIDX_BYTE_HASH_VERSION 5 +#define MIDX_BYTE_NUM_CHUNKS 6 +#define MIDX_BYTE_NUM_PACKS 8 +#define MIDX_HASH_VERSION 1 +#define MIDX_HEADER_SIZE 12 +#define MIDX_HASH_LEN 20 +#define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN) + +#define MIDX_MAX_CHUNKS 5 +#define MIDX_CHUNK_ALIGNMENT 4 +#define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */ +#define MIDX_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */ +#define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */ +#define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */ +#define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */ +#define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t)) +#define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256) +#define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t)) +#define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t)) +#define MIDX_LARGE_OFFSET_NEEDED 0x80000000 + +#define PACK_EXPIRED UINT_MAX + +static char *get_midx_filename(const char *object_dir) +{ + return xstrfmt("%s/pack/multi-pack-index", object_dir); +} + +struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local) +{ + struct multi_pack_index *m = NULL; + int fd; + struct stat st; + size_t midx_size; + void *midx_map = NULL; + uint32_t hash_version; + char *midx_name = get_midx_filename(object_dir); + uint32_t i; + const char *cur_pack_name; + + fd = git_open(midx_name); + + if (fd < 0) + goto cleanup_fail; + if (fstat(fd, &st)) { + error_errno(_("failed to read %s"), midx_name); + goto cleanup_fail; + } + + midx_size = xsize_t(st.st_size); + + if (midx_size < MIDX_MIN_SIZE) { + error(_("multi-pack-index file %s is too small"), midx_name); + goto cleanup_fail; + } + + FREE_AND_NULL(midx_name); + + midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0); + + FLEX_ALLOC_STR(m, object_dir, object_dir); + m->fd = fd; + m->data = midx_map; + m->data_len = midx_size; + m->local = local; + + m->signature = get_be32(m->data); + if (m->signature != MIDX_SIGNATURE) + die(_("multi-pack-index signature 0x%08x does not match signature 0x%08x"), + m->signature, MIDX_SIGNATURE); + + m->version = m->data[MIDX_BYTE_FILE_VERSION]; + if (m->version != MIDX_VERSION) + die(_("multi-pack-index version %d not recognized"), + m->version); + + hash_version = m->data[MIDX_BYTE_HASH_VERSION]; + if (hash_version != MIDX_HASH_VERSION) + die(_("hash version %u does not match"), hash_version); + m->hash_len = MIDX_HASH_LEN; + + m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS]; + + m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS); + + for (i = 0; i < m->num_chunks; i++) { + uint32_t chunk_id = get_be32(m->data + MIDX_HEADER_SIZE + + MIDX_CHUNKLOOKUP_WIDTH * i); + uint64_t chunk_offset = get_be64(m->data + MIDX_HEADER_SIZE + 4 + + MIDX_CHUNKLOOKUP_WIDTH * i); + + if (chunk_offset >= m->data_len) + die(_("invalid chunk offset (too large)")); + + switch (chunk_id) { + case MIDX_CHUNKID_PACKNAMES: + m->chunk_pack_names = m->data + chunk_offset; + break; + + case MIDX_CHUNKID_OIDFANOUT: + m->chunk_oid_fanout = (uint32_t *)(m->data + chunk_offset); + break; + + case MIDX_CHUNKID_OIDLOOKUP: + m->chunk_oid_lookup = m->data + chunk_offset; + break; + + case MIDX_CHUNKID_OBJECTOFFSETS: + m->chunk_object_offsets = m->data + chunk_offset; + break; + + case MIDX_CHUNKID_LARGEOFFSETS: + m->chunk_large_offsets = m->data + chunk_offset; + break; + + case 0: + die(_("terminating multi-pack-index chunk id appears earlier than expected")); + break; + + default: + /* + * Do nothing on unrecognized chunks, allowing future + * extensions to add optional chunks. + */ + break; + } + } + + if (!m->chunk_pack_names) + die(_("multi-pack-index missing required pack-name chunk")); + if (!m->chunk_oid_fanout) + die(_("multi-pack-index missing required OID fanout chunk")); + if (!m->chunk_oid_lookup) + die(_("multi-pack-index missing required OID lookup chunk")); + if (!m->chunk_object_offsets) + die(_("multi-pack-index missing required object offsets chunk")); + + m->num_objects = ntohl(m->chunk_oid_fanout[255]); + + m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names)); + m->packs = xcalloc(m->num_packs, sizeof(*m->packs)); + + cur_pack_name = (const char *)m->chunk_pack_names; + for (i = 0; i < m->num_packs; i++) { + m->pack_names[i] = cur_pack_name; + + cur_pack_name += strlen(cur_pack_name) + 1; + + if (i && strcmp(m->pack_names[i], m->pack_names[i - 1]) <= 0) + die(_("multi-pack-index pack names out of order: '%s' before '%s'"), + m->pack_names[i - 1], + m->pack_names[i]); + } + + trace2_data_intmax("midx", the_repository, "load/num_packs", m->num_packs); + trace2_data_intmax("midx", the_repository, "load/num_objects", m->num_objects); + + return m; + +cleanup_fail: + free(m); + free(midx_name); + if (midx_map) + munmap(midx_map, midx_size); + if (0 <= fd) + close(fd); + return NULL; +} + +void close_midx(struct multi_pack_index *m) +{ + uint32_t i; + + if (!m) + return; + + munmap((unsigned char *)m->data, m->data_len); + close(m->fd); + m->fd = -1; + + for (i = 0; i < m->num_packs; i++) { + if (m->packs[i]) + m->packs[i]->multi_pack_index = 0; + } + FREE_AND_NULL(m->packs); + FREE_AND_NULL(m->pack_names); +} + +int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id) +{ + struct strbuf pack_name = STRBUF_INIT; + struct packed_git *p; + + if (pack_int_id >= m->num_packs) + die(_("bad pack-int-id: %u (%u total packs)"), + pack_int_id, m->num_packs); + + if (m->packs[pack_int_id]) + return 0; + + strbuf_addf(&pack_name, "%s/pack/%s", m->object_dir, + m->pack_names[pack_int_id]); + + p = add_packed_git(pack_name.buf, pack_name.len, m->local); + strbuf_release(&pack_name); + + if (!p) + return 1; + + p->multi_pack_index = 1; + m->packs[pack_int_id] = p; + install_packed_git(r, p); + list_add_tail(&p->mru, &r->objects->packed_git_mru); + + return 0; +} + +int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result) +{ + return bsearch_hash(oid->hash, m->chunk_oid_fanout, m->chunk_oid_lookup, + MIDX_HASH_LEN, result); +} + +struct object_id *nth_midxed_object_oid(struct object_id *oid, + struct multi_pack_index *m, + uint32_t n) +{ + if (n >= m->num_objects) + return NULL; + + hashcpy(oid->hash, m->chunk_oid_lookup + m->hash_len * n); + return oid; +} + +static off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos) +{ + const unsigned char *offset_data; + uint32_t offset32; + + offset_data = m->chunk_object_offsets + pos * MIDX_CHUNK_OFFSET_WIDTH; + offset32 = get_be32(offset_data + sizeof(uint32_t)); + + if (m->chunk_large_offsets && offset32 & MIDX_LARGE_OFFSET_NEEDED) { + if (sizeof(off_t) < sizeof(uint64_t)) + die(_("multi-pack-index stores a 64-bit offset, but off_t is too small")); + + offset32 ^= MIDX_LARGE_OFFSET_NEEDED; + return get_be64(m->chunk_large_offsets + sizeof(uint64_t) * offset32); + } + + return offset32; +} + +static uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos) +{ + return get_be32(m->chunk_object_offsets + pos * MIDX_CHUNK_OFFSET_WIDTH); +} + +static int nth_midxed_pack_entry(struct repository *r, + struct multi_pack_index *m, + struct pack_entry *e, + uint32_t pos) +{ + uint32_t pack_int_id; + struct packed_git *p; + + if (pos >= m->num_objects) + return 0; + + pack_int_id = nth_midxed_pack_int_id(m, pos); + + if (prepare_midx_pack(r, m, pack_int_id)) + die(_("error preparing packfile from multi-pack-index")); + p = m->packs[pack_int_id]; + + /* + * We are about to tell the caller where they can locate the + * requested object. We better make sure the packfile is + * still here and can be accessed before supplying that + * answer, as it may have been deleted since the MIDX was + * loaded! + */ + if (!is_pack_valid(p)) + return 0; + + if (p->num_bad_objects) { + uint32_t i; + struct object_id oid; + nth_midxed_object_oid(&oid, m, pos); + for (i = 0; i < p->num_bad_objects; i++) + if (hasheq(oid.hash, + p->bad_object_sha1 + the_hash_algo->rawsz * i)) + return 0; + } + + e->offset = nth_midxed_offset(m, pos); + e->p = p; + + return 1; +} + +int fill_midx_entry(struct repository * r, + const struct object_id *oid, + struct pack_entry *e, + struct multi_pack_index *m) +{ + uint32_t pos; + + if (!bsearch_midx(oid, m, &pos)) + return 0; + + return nth_midxed_pack_entry(r, m, e, pos); +} + +/* Match "foo.idx" against either "foo.pack" _or_ "foo.idx". */ +static int cmp_idx_or_pack_name(const char *idx_or_pack_name, + const char *idx_name) +{ + /* Skip past any initial matching prefix. */ + while (*idx_name && *idx_name == *idx_or_pack_name) { + idx_name++; + idx_or_pack_name++; + } + + /* + * If we didn't match completely, we may have matched "pack-1234." and + * be left with "idx" and "pack" respectively, which is also OK. We do + * not have to check for "idx" and "idx", because that would have been + * a complete match (and in that case these strcmps will be false, but + * we'll correctly return 0 from the final strcmp() below. + * + * Technically this matches "fooidx" and "foopack", but we'd never have + * such names in the first place. + */ + if (!strcmp(idx_name, "idx") && !strcmp(idx_or_pack_name, "pack")) + return 0; + + /* + * This not only checks for a complete match, but also orders based on + * the first non-identical character, which means our ordering will + * match a raw strcmp(). That makes it OK to use this to binary search + * a naively-sorted list. + */ + return strcmp(idx_or_pack_name, idx_name); +} + +int midx_contains_pack(struct multi_pack_index *m, const char *idx_or_pack_name) +{ + uint32_t first = 0, last = m->num_packs; + + while (first < last) { + uint32_t mid = first + (last - first) / 2; + const char *current; + int cmp; + + current = m->pack_names[mid]; + cmp = cmp_idx_or_pack_name(idx_or_pack_name, current); + if (!cmp) + return 1; + if (cmp > 0) { + first = mid + 1; + continue; + } + last = mid; + } + + return 0; +} + +int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local) +{ + struct multi_pack_index *m; + struct multi_pack_index *m_search; + int config_value; + static int env_value = -1; + + if (env_value < 0) + env_value = git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0); + + if (!env_value && + (repo_config_get_bool(r, "core.multipackindex", &config_value) || + !config_value)) + return 0; + + for (m_search = r->objects->multi_pack_index; m_search; m_search = m_search->next) + if (!strcmp(object_dir, m_search->object_dir)) + return 1; + + m = load_multi_pack_index(object_dir, local); + + if (m) { + m->next = r->objects->multi_pack_index; + r->objects->multi_pack_index = m; + return 1; + } + + return 0; +} + +static size_t write_midx_header(struct hashfile *f, + unsigned char num_chunks, + uint32_t num_packs) +{ + unsigned char byte_values[4]; + + hashwrite_be32(f, MIDX_SIGNATURE); + byte_values[0] = MIDX_VERSION; + byte_values[1] = MIDX_HASH_VERSION; + byte_values[2] = num_chunks; + byte_values[3] = 0; /* unused */ + hashwrite(f, byte_values, sizeof(byte_values)); + hashwrite_be32(f, num_packs); + + return MIDX_HEADER_SIZE; +} + +struct pack_info { + uint32_t orig_pack_int_id; + char *pack_name; + struct packed_git *p; + unsigned expired : 1; +}; + +static int pack_info_compare(const void *_a, const void *_b) +{ + struct pack_info *a = (struct pack_info *)_a; + struct pack_info *b = (struct pack_info *)_b; + return strcmp(a->pack_name, b->pack_name); +} + +struct pack_list { + struct pack_info *info; + uint32_t nr; + uint32_t alloc; + struct multi_pack_index *m; +}; + +static void add_pack_to_midx(const char *full_path, size_t full_path_len, + const char *file_name, void *data) +{ + struct pack_list *packs = (struct pack_list *)data; + + if (ends_with(file_name, ".idx")) { + if (packs->m && midx_contains_pack(packs->m, file_name)) + return; + + ALLOC_GROW(packs->info, packs->nr + 1, packs->alloc); + + packs->info[packs->nr].p = add_packed_git(full_path, + full_path_len, + 0); + + if (!packs->info[packs->nr].p) { + warning(_("failed to add packfile '%s'"), + full_path); + return; + } + + if (open_pack_index(packs->info[packs->nr].p)) { + warning(_("failed to open pack-index '%s'"), + full_path); + close_pack(packs->info[packs->nr].p); + FREE_AND_NULL(packs->info[packs->nr].p); + return; + } + + packs->info[packs->nr].pack_name = xstrdup(file_name); + packs->info[packs->nr].orig_pack_int_id = packs->nr; + packs->info[packs->nr].expired = 0; + packs->nr++; + } +} + +struct pack_midx_entry { + struct object_id oid; + uint32_t pack_int_id; + time_t pack_mtime; + uint64_t offset; +}; + +static int midx_oid_compare(const void *_a, const void *_b) +{ + const struct pack_midx_entry *a = (const struct pack_midx_entry *)_a; + const struct pack_midx_entry *b = (const struct pack_midx_entry *)_b; + int cmp = oidcmp(&a->oid, &b->oid); + + if (cmp) + return cmp; + + if (a->pack_mtime > b->pack_mtime) + return -1; + else if (a->pack_mtime < b->pack_mtime) + return 1; + + return a->pack_int_id - b->pack_int_id; +} + +static int nth_midxed_pack_midx_entry(struct multi_pack_index *m, + struct pack_midx_entry *e, + uint32_t pos) +{ + if (pos >= m->num_objects) + return 1; + + nth_midxed_object_oid(&e->oid, m, pos); + e->pack_int_id = nth_midxed_pack_int_id(m, pos); + e->offset = nth_midxed_offset(m, pos); + + /* consider objects in midx to be from "old" packs */ + e->pack_mtime = 0; + return 0; +} + +static void fill_pack_entry(uint32_t pack_int_id, + struct packed_git *p, + uint32_t cur_object, + struct pack_midx_entry *entry) +{ + if (!nth_packed_object_oid(&entry->oid, p, cur_object)) + die(_("failed to locate object %d in packfile"), cur_object); + + entry->pack_int_id = pack_int_id; + entry->pack_mtime = p->mtime; + + entry->offset = nth_packed_object_offset(p, cur_object); +} + +/* + * It is possible to artificially get into a state where there are many + * duplicate copies of objects. That can create high memory pressure if + * we are to create a list of all objects before de-duplication. To reduce + * this memory pressure without a significant performance drop, automatically + * group objects by the first byte of their object id. Use the IDX fanout + * tables to group the data, copy to a local array, then sort. + * + * Copy only the de-duplicated entries (selected by most-recent modified time + * of a packfile containing the object). + */ +static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m, + struct pack_info *info, + uint32_t nr_packs, + uint32_t *nr_objects) +{ + uint32_t cur_fanout, cur_pack, cur_object; + uint32_t alloc_fanout, alloc_objects, total_objects = 0; + struct pack_midx_entry *entries_by_fanout = NULL; + struct pack_midx_entry *deduplicated_entries = NULL; + uint32_t start_pack = m ? m->num_packs : 0; + + for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) + total_objects += info[cur_pack].p->num_objects; + + /* + * As we de-duplicate by fanout value, we expect the fanout + * slices to be evenly distributed, with some noise. Hence, + * allocate slightly more than one 256th. + */ + alloc_objects = alloc_fanout = total_objects > 3200 ? total_objects / 200 : 16; + + ALLOC_ARRAY(entries_by_fanout, alloc_fanout); + ALLOC_ARRAY(deduplicated_entries, alloc_objects); + *nr_objects = 0; + + for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) { + uint32_t nr_fanout = 0; + + if (m) { + uint32_t start = 0, end; + + if (cur_fanout) + start = ntohl(m->chunk_oid_fanout[cur_fanout - 1]); + end = ntohl(m->chunk_oid_fanout[cur_fanout]); + + for (cur_object = start; cur_object < end; cur_object++) { + ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout); + nth_midxed_pack_midx_entry(m, + &entries_by_fanout[nr_fanout], + cur_object); + nr_fanout++; + } + } + + for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) { + uint32_t start = 0, end; + + if (cur_fanout) + start = get_pack_fanout(info[cur_pack].p, cur_fanout - 1); + end = get_pack_fanout(info[cur_pack].p, cur_fanout); + + for (cur_object = start; cur_object < end; cur_object++) { + ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout); + fill_pack_entry(cur_pack, info[cur_pack].p, cur_object, &entries_by_fanout[nr_fanout]); + nr_fanout++; + } + } + + QSORT(entries_by_fanout, nr_fanout, midx_oid_compare); + + /* + * The batch is now sorted by OID and then mtime (descending). + * Take only the first duplicate. + */ + for (cur_object = 0; cur_object < nr_fanout; cur_object++) { + if (cur_object && oideq(&entries_by_fanout[cur_object - 1].oid, + &entries_by_fanout[cur_object].oid)) + continue; + + ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects); + memcpy(&deduplicated_entries[*nr_objects], + &entries_by_fanout[cur_object], + sizeof(struct pack_midx_entry)); + (*nr_objects)++; + } + } + + free(entries_by_fanout); + return deduplicated_entries; +} + +static size_t write_midx_pack_names(struct hashfile *f, + struct pack_info *info, + uint32_t num_packs) +{ + uint32_t i; + unsigned char padding[MIDX_CHUNK_ALIGNMENT]; + size_t written = 0; + + for (i = 0; i < num_packs; i++) { + size_t writelen; + + if (info[i].expired) + continue; + + if (i && strcmp(info[i].pack_name, info[i - 1].pack_name) <= 0) + BUG("incorrect pack-file order: %s before %s", + info[i - 1].pack_name, + info[i].pack_name); + + writelen = strlen(info[i].pack_name) + 1; + hashwrite(f, info[i].pack_name, writelen); + written += writelen; + } + + /* add padding to be aligned */ + i = MIDX_CHUNK_ALIGNMENT - (written % MIDX_CHUNK_ALIGNMENT); + if (i < MIDX_CHUNK_ALIGNMENT) { + memset(padding, 0, sizeof(padding)); + hashwrite(f, padding, i); + written += i; + } + + return written; +} + +static size_t write_midx_oid_fanout(struct hashfile *f, + struct pack_midx_entry *objects, + uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects; + struct pack_midx_entry *last = objects + nr_objects; + uint32_t count = 0; + uint32_t i; + + /* + * Write the first-level table (the list is sorted, + * but we use a 256-entry lookup to be able to avoid + * having to do eight extra binary search iterations). + */ + for (i = 0; i < 256; i++) { + struct pack_midx_entry *next = list; + + while (next < last && next->oid.hash[0] == i) { + count++; + next++; + } + + hashwrite_be32(f, count); + list = next; + } + + return MIDX_CHUNK_FANOUT_SIZE; +} + +static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len, + struct pack_midx_entry *objects, + uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects; + uint32_t i; + size_t written = 0; + + for (i = 0; i < nr_objects; i++) { + struct pack_midx_entry *obj = list++; + + if (i < nr_objects - 1) { + struct pack_midx_entry *next = list; + if (oidcmp(&obj->oid, &next->oid) >= 0) + BUG("OIDs not in order: %s >= %s", + oid_to_hex(&obj->oid), + oid_to_hex(&next->oid)); + } + + hashwrite(f, obj->oid.hash, (int)hash_len); + written += hash_len; + } + + return written; +} + +static size_t write_midx_object_offsets(struct hashfile *f, int large_offset_needed, + uint32_t *perm, + struct pack_midx_entry *objects, uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects; + uint32_t i, nr_large_offset = 0; + size_t written = 0; + + for (i = 0; i < nr_objects; i++) { + struct pack_midx_entry *obj = list++; + + if (perm[obj->pack_int_id] == PACK_EXPIRED) + BUG("object %s is in an expired pack with int-id %d", + oid_to_hex(&obj->oid), + obj->pack_int_id); + + hashwrite_be32(f, perm[obj->pack_int_id]); + + if (large_offset_needed && obj->offset >> 31) + hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++); + else if (!large_offset_needed && obj->offset >> 32) + BUG("object %s requires a large offset (%"PRIx64") but the MIDX is not writing large offsets!", + oid_to_hex(&obj->oid), + obj->offset); + else + hashwrite_be32(f, (uint32_t)obj->offset); + + written += MIDX_CHUNK_OFFSET_WIDTH; + } + + return written; +} + +static size_t write_midx_large_offsets(struct hashfile *f, uint32_t nr_large_offset, + struct pack_midx_entry *objects, uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects, *end = objects + nr_objects; + size_t written = 0; + + while (nr_large_offset) { + struct pack_midx_entry *obj; + uint64_t offset; + + if (list >= end) + BUG("too many large-offset objects"); + + obj = list++; + offset = obj->offset; + + if (!(offset >> 31)) + continue; + + hashwrite_be32(f, offset >> 32); + hashwrite_be32(f, offset & 0xffffffffUL); + written += 2 * sizeof(uint32_t); + + nr_large_offset--; + } + + return written; +} + +static int write_midx_internal(const char *object_dir, struct multi_pack_index *m, + struct string_list *packs_to_drop) +{ + unsigned char cur_chunk, num_chunks = 0; + char *midx_name; + uint32_t i; + struct hashfile *f = NULL; + struct lock_file lk; + struct pack_list packs; + uint32_t *pack_perm = NULL; + uint64_t written = 0; + uint32_t chunk_ids[MIDX_MAX_CHUNKS + 1]; + uint64_t chunk_offsets[MIDX_MAX_CHUNKS + 1]; + uint32_t nr_entries, num_large_offsets = 0; + struct pack_midx_entry *entries = NULL; + int large_offsets_needed = 0; + int pack_name_concat_len = 0; + int dropped_packs = 0; + int result = 0; + + midx_name = get_midx_filename(object_dir); + if (safe_create_leading_directories(midx_name)) { + UNLEAK(midx_name); + die_errno(_("unable to create leading directories of %s"), + midx_name); + } + + if (m) + packs.m = m; + else + packs.m = load_multi_pack_index(object_dir, 1); + + packs.nr = 0; + packs.alloc = packs.m ? packs.m->num_packs : 16; + packs.info = NULL; + ALLOC_ARRAY(packs.info, packs.alloc); + + if (packs.m) { + for (i = 0; i < packs.m->num_packs; i++) { + ALLOC_GROW(packs.info, packs.nr + 1, packs.alloc); + + packs.info[packs.nr].orig_pack_int_id = i; + packs.info[packs.nr].pack_name = xstrdup(packs.m->pack_names[i]); + packs.info[packs.nr].p = NULL; + packs.info[packs.nr].expired = 0; + packs.nr++; + } + } + + for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &packs); + + if (packs.m && packs.nr == packs.m->num_packs && !packs_to_drop) + goto cleanup; + + entries = get_sorted_entries(packs.m, packs.info, packs.nr, &nr_entries); + + for (i = 0; i < nr_entries; i++) { + if (entries[i].offset > 0x7fffffff) + num_large_offsets++; + if (entries[i].offset > 0xffffffff) + large_offsets_needed = 1; + } + + QSORT(packs.info, packs.nr, pack_info_compare); + + if (packs_to_drop && packs_to_drop->nr) { + int drop_index = 0; + int missing_drops = 0; + + for (i = 0; i < packs.nr && drop_index < packs_to_drop->nr; i++) { + int cmp = strcmp(packs.info[i].pack_name, + packs_to_drop->items[drop_index].string); + + if (!cmp) { + drop_index++; + packs.info[i].expired = 1; + } else if (cmp > 0) { + error(_("did not see pack-file %s to drop"), + packs_to_drop->items[drop_index].string); + drop_index++; + missing_drops++; + i--; + } else { + packs.info[i].expired = 0; + } + } + + if (missing_drops) { + result = 1; + goto cleanup; + } + } + + /* + * pack_perm stores a permutation between pack-int-ids from the + * previous multi-pack-index to the new one we are writing: + * + * pack_perm[old_id] = new_id + */ + ALLOC_ARRAY(pack_perm, packs.nr); + for (i = 0; i < packs.nr; i++) { + if (packs.info[i].expired) { + dropped_packs++; + pack_perm[packs.info[i].orig_pack_int_id] = PACK_EXPIRED; + } else { + pack_perm[packs.info[i].orig_pack_int_id] = i - dropped_packs; + } + } + + for (i = 0; i < packs.nr; i++) { + if (!packs.info[i].expired) + pack_name_concat_len += strlen(packs.info[i].pack_name) + 1; + } + + if (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT) + pack_name_concat_len += MIDX_CHUNK_ALIGNMENT - + (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT); + + hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR); + f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf); + FREE_AND_NULL(midx_name); + + if (packs.m) + close_midx(packs.m); + + cur_chunk = 0; + num_chunks = large_offsets_needed ? 5 : 4; + + written = write_midx_header(f, num_chunks, packs.nr - dropped_packs); + + chunk_ids[cur_chunk] = MIDX_CHUNKID_PACKNAMES; + chunk_offsets[cur_chunk] = written + (num_chunks + 1) * MIDX_CHUNKLOOKUP_WIDTH; + + cur_chunk++; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDFANOUT; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + pack_name_concat_len; + + cur_chunk++; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDLOOKUP; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + MIDX_CHUNK_FANOUT_SIZE; + + cur_chunk++; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OBJECTOFFSETS; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * MIDX_HASH_LEN; + + cur_chunk++; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * MIDX_CHUNK_OFFSET_WIDTH; + if (large_offsets_needed) { + chunk_ids[cur_chunk] = MIDX_CHUNKID_LARGEOFFSETS; + + cur_chunk++; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + + num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH; + } + + chunk_ids[cur_chunk] = 0; + + for (i = 0; i <= num_chunks; i++) { + if (i && chunk_offsets[i] < chunk_offsets[i - 1]) + BUG("incorrect chunk offsets: %"PRIu64" before %"PRIu64, + chunk_offsets[i - 1], + chunk_offsets[i]); + + if (chunk_offsets[i] % MIDX_CHUNK_ALIGNMENT) + BUG("chunk offset %"PRIu64" is not properly aligned", + chunk_offsets[i]); + + hashwrite_be32(f, chunk_ids[i]); + hashwrite_be32(f, chunk_offsets[i] >> 32); + hashwrite_be32(f, chunk_offsets[i]); + + written += MIDX_CHUNKLOOKUP_WIDTH; + } + + for (i = 0; i < num_chunks; i++) { + if (written != chunk_offsets[i]) + BUG("incorrect chunk offset (%"PRIu64" != %"PRIu64") for chunk id %"PRIx32, + chunk_offsets[i], + written, + chunk_ids[i]); + + switch (chunk_ids[i]) { + case MIDX_CHUNKID_PACKNAMES: + written += write_midx_pack_names(f, packs.info, packs.nr); + break; + + case MIDX_CHUNKID_OIDFANOUT: + written += write_midx_oid_fanout(f, entries, nr_entries); + break; + + case MIDX_CHUNKID_OIDLOOKUP: + written += write_midx_oid_lookup(f, MIDX_HASH_LEN, entries, nr_entries); + break; + + case MIDX_CHUNKID_OBJECTOFFSETS: + written += write_midx_object_offsets(f, large_offsets_needed, pack_perm, entries, nr_entries); + break; + + case MIDX_CHUNKID_LARGEOFFSETS: + written += write_midx_large_offsets(f, num_large_offsets, entries, nr_entries); + break; + + default: + BUG("trying to write unknown chunk id %"PRIx32, + chunk_ids[i]); + } + } + + if (written != chunk_offsets[num_chunks]) + BUG("incorrect final offset %"PRIu64" != %"PRIu64, + written, + chunk_offsets[num_chunks]); + + finalize_hashfile(f, NULL, CSUM_FSYNC | CSUM_HASH_IN_STREAM); + commit_lock_file(&lk); + +cleanup: + for (i = 0; i < packs.nr; i++) { + if (packs.info[i].p) { + close_pack(packs.info[i].p); + free(packs.info[i].p); + } + free(packs.info[i].pack_name); + } + + free(packs.info); + free(entries); + free(pack_perm); + free(midx_name); + return result; +} + +int write_midx_file(const char *object_dir) +{ + return write_midx_internal(object_dir, NULL, NULL); +} + +void clear_midx_file(struct repository *r) +{ + char *midx = get_midx_filename(r->objects->odb->path); + + if (r->objects && r->objects->multi_pack_index) { + close_midx(r->objects->multi_pack_index); + r->objects->multi_pack_index = NULL; + } + + if (remove_path(midx)) { + UNLEAK(midx); + die(_("failed to clear multi-pack-index at %s"), midx); + } + + free(midx); +} + +static int verify_midx_error; + +static void midx_report(const char *fmt, ...) +{ + va_list ap; + verify_midx_error = 1; + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + fprintf(stderr, "\n"); + va_end(ap); +} + +struct pair_pos_vs_id +{ + uint32_t pos; + uint32_t pack_int_id; +}; + +static int compare_pair_pos_vs_id(const void *_a, const void *_b) +{ + struct pair_pos_vs_id *a = (struct pair_pos_vs_id *)_a; + struct pair_pos_vs_id *b = (struct pair_pos_vs_id *)_b; + + return b->pack_int_id - a->pack_int_id; +} + +/* + * Limit calls to display_progress() for performance reasons. + * The interval here was arbitrarily chosen. + */ +#define SPARSE_PROGRESS_INTERVAL (1 << 12) +#define midx_display_sparse_progress(progress, n) \ + do { \ + uint64_t _n = (n); \ + if ((_n & (SPARSE_PROGRESS_INTERVAL - 1)) == 0) \ + display_progress(progress, _n); \ + } while (0) + +int verify_midx_file(struct repository *r, const char *object_dir) +{ + struct pair_pos_vs_id *pairs = NULL; + uint32_t i; + struct progress *progress; + struct multi_pack_index *m = load_multi_pack_index(object_dir, 1); + verify_midx_error = 0; + + if (!m) + return 0; + + progress = start_progress(_("Looking for referenced packfiles"), + m->num_packs); + for (i = 0; i < m->num_packs; i++) { + if (prepare_midx_pack(r, m, i)) + midx_report("failed to load pack in position %d", i); + + display_progress(progress, i + 1); + } + stop_progress(&progress); + + for (i = 0; i < 255; i++) { + uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]); + uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i + 1]); + + if (oid_fanout1 > oid_fanout2) + midx_report(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"), + i, oid_fanout1, oid_fanout2, i + 1); + } + + progress = start_sparse_progress(_("Verifying OID order in MIDX"), + m->num_objects - 1); + for (i = 0; i < m->num_objects - 1; i++) { + struct object_id oid1, oid2; + + nth_midxed_object_oid(&oid1, m, i); + nth_midxed_object_oid(&oid2, m, i + 1); + + if (oidcmp(&oid1, &oid2) >= 0) + midx_report(_("oid lookup out of order: oid[%d] = %s >= %s = oid[%d]"), + i, oid_to_hex(&oid1), oid_to_hex(&oid2), i + 1); + + midx_display_sparse_progress(progress, i + 1); + } + stop_progress(&progress); + + /* + * Create an array mapping each object to its packfile id. Sort it + * to group the objects by packfile. Use this permutation to visit + * each of the objects and only require 1 packfile to be open at a + * time. + */ + ALLOC_ARRAY(pairs, m->num_objects); + for (i = 0; i < m->num_objects; i++) { + pairs[i].pos = i; + pairs[i].pack_int_id = nth_midxed_pack_int_id(m, i); + } + + progress = start_sparse_progress(_("Sorting objects by packfile"), + m->num_objects); + display_progress(progress, 0); /* TODO: Measure QSORT() progress */ + QSORT(pairs, m->num_objects, compare_pair_pos_vs_id); + stop_progress(&progress); + + progress = start_sparse_progress(_("Verifying object offsets"), m->num_objects); + for (i = 0; i < m->num_objects; i++) { + struct object_id oid; + struct pack_entry e; + off_t m_offset, p_offset; + + if (i > 0 && pairs[i-1].pack_int_id != pairs[i].pack_int_id && + m->packs[pairs[i-1].pack_int_id]) + { + close_pack_fd(m->packs[pairs[i-1].pack_int_id]); + close_pack_index(m->packs[pairs[i-1].pack_int_id]); + } + + nth_midxed_object_oid(&oid, m, pairs[i].pos); + + if (!fill_midx_entry(r, &oid, &e, m)) { + midx_report(_("failed to load pack entry for oid[%d] = %s"), + pairs[i].pos, oid_to_hex(&oid)); + continue; + } + + if (open_pack_index(e.p)) { + midx_report(_("failed to load pack-index for packfile %s"), + e.p->pack_name); + break; + } + + m_offset = e.offset; + p_offset = find_pack_entry_one(oid.hash, e.p); + + if (m_offset != p_offset) + midx_report(_("incorrect object offset for oid[%d] = %s: %"PRIx64" != %"PRIx64), + pairs[i].pos, oid_to_hex(&oid), m_offset, p_offset); + + midx_display_sparse_progress(progress, i + 1); + } + stop_progress(&progress); + + free(pairs); + + return verify_midx_error; +} + +int expire_midx_packs(struct repository *r, const char *object_dir) +{ + uint32_t i, *count, result = 0; + struct string_list packs_to_drop = STRING_LIST_INIT_DUP; + struct multi_pack_index *m = load_multi_pack_index(object_dir, 1); + + if (!m) + return 0; + + count = xcalloc(m->num_packs, sizeof(uint32_t)); + for (i = 0; i < m->num_objects; i++) { + int pack_int_id = nth_midxed_pack_int_id(m, i); + count[pack_int_id]++; + } + + for (i = 0; i < m->num_packs; i++) { + char *pack_name; + + if (count[i]) + continue; + + if (prepare_midx_pack(r, m, i)) + continue; + + if (m->packs[i]->pack_keep) + continue; + + pack_name = xstrdup(m->packs[i]->pack_name); + close_pack(m->packs[i]); + + string_list_insert(&packs_to_drop, m->pack_names[i]); + unlink_pack_path(pack_name, 0); + free(pack_name); + } + + free(count); + + if (packs_to_drop.nr) + result = write_midx_internal(object_dir, m, &packs_to_drop); + + string_list_clear(&packs_to_drop, 0); + return result; +} + +struct repack_info { + timestamp_t mtime; + uint32_t referenced_objects; + uint32_t pack_int_id; +}; + +static int compare_by_mtime(const void *a_, const void *b_) +{ + const struct repack_info *a, *b; + + a = (const struct repack_info *)a_; + b = (const struct repack_info *)b_; + + if (a->mtime < b->mtime) + return -1; + if (a->mtime > b->mtime) + return 1; + return 0; +} + +static int fill_included_packs_all(struct multi_pack_index *m, + unsigned char *include_pack) +{ + uint32_t i; + + for (i = 0; i < m->num_packs; i++) + include_pack[i] = 1; + + return m->num_packs < 2; +} + +static int fill_included_packs_batch(struct repository *r, + struct multi_pack_index *m, + unsigned char *include_pack, + size_t batch_size) +{ + uint32_t i, packs_to_repack; + size_t total_size; + struct repack_info *pack_info = xcalloc(m->num_packs, sizeof(struct repack_info)); + + for (i = 0; i < m->num_packs; i++) { + pack_info[i].pack_int_id = i; + + if (prepare_midx_pack(r, m, i)) + continue; + + pack_info[i].mtime = m->packs[i]->mtime; + } + + for (i = 0; batch_size && i < m->num_objects; i++) { + uint32_t pack_int_id = nth_midxed_pack_int_id(m, i); + pack_info[pack_int_id].referenced_objects++; + } + + QSORT(pack_info, m->num_packs, compare_by_mtime); + + total_size = 0; + packs_to_repack = 0; + for (i = 0; total_size < batch_size && i < m->num_packs; i++) { + int pack_int_id = pack_info[i].pack_int_id; + struct packed_git *p = m->packs[pack_int_id]; + size_t expected_size; + + if (!p) + continue; + if (open_pack_index(p) || !p->num_objects) + continue; + + expected_size = (size_t)(p->pack_size + * pack_info[i].referenced_objects); + expected_size /= p->num_objects; + + if (expected_size >= batch_size) + continue; + + packs_to_repack++; + total_size += expected_size; + include_pack[pack_int_id] = 1; + } + + free(pack_info); + + if (total_size < batch_size || packs_to_repack < 2) + return 1; + + return 0; +} + +int midx_repack(struct repository *r, const char *object_dir, size_t batch_size) +{ + int result = 0; + uint32_t i; + unsigned char *include_pack; + struct child_process cmd = CHILD_PROCESS_INIT; + struct strbuf base_name = STRBUF_INIT; + struct multi_pack_index *m = load_multi_pack_index(object_dir, 1); + + if (!m) + return 0; + + include_pack = xcalloc(m->num_packs, sizeof(unsigned char)); + + if (batch_size) { + if (fill_included_packs_batch(r, m, include_pack, batch_size)) + goto cleanup; + } else if (fill_included_packs_all(m, include_pack)) + goto cleanup; + + argv_array_push(&cmd.args, "pack-objects"); + + strbuf_addstr(&base_name, object_dir); + strbuf_addstr(&base_name, "/pack/pack"); + argv_array_push(&cmd.args, base_name.buf); + strbuf_release(&base_name); + + cmd.git_cmd = 1; + cmd.in = cmd.out = -1; + + if (start_command(&cmd)) { + error(_("could not start pack-objects")); + result = 1; + goto cleanup; + } + + for (i = 0; i < m->num_objects; i++) { + struct object_id oid; + uint32_t pack_int_id = nth_midxed_pack_int_id(m, i); + + if (!include_pack[pack_int_id]) + continue; + + nth_midxed_object_oid(&oid, m, i); + xwrite(cmd.in, oid_to_hex(&oid), the_hash_algo->hexsz); + xwrite(cmd.in, "\n", 1); + } + close(cmd.in); + + if (finish_command(&cmd)) { + error(_("could not finish pack-objects")); + result = 1; + goto cleanup; + } + + result = write_midx_internal(object_dir, m, NULL); + m = NULL; + +cleanup: + if (m) + close_midx(m); + free(include_pack); + return result; +} |