diff options
Diffstat (limited to 'midx.c')
| -rw-r--r-- | midx.c | 2090 |
1 files changed, 2090 insertions, 0 deletions
@@ -0,0 +1,2090 @@ +#include "cache.h" +#include "config.h" +#include "csum-file.h" +#include "dir.h" +#include "lockfile.h" +#include "packfile.h" +#include "object-store.h" +#include "hash-lookup.h" +#include "midx.h" +#include "progress.h" +#include "trace2.h" +#include "run-command.h" +#include "repository.h" +#include "chunk-format.h" +#include "pack.h" +#include "pack-bitmap.h" +#include "refs.h" +#include "revision.h" +#include "list-objects.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_HEADER_SIZE 12 +#define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + the_hash_algo->rawsz) + +#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_CHUNKID_REVINDEX 0x52494458 /* "RIDX" */ +#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 + +const unsigned char *get_midx_checksum(struct multi_pack_index *m) +{ + return m->data + m->data_len - the_hash_algo->rawsz; +} + +void get_midx_filename(struct strbuf *out, const char *object_dir) +{ + strbuf_addf(out, "%s/pack/multi-pack-index", object_dir); +} + +void get_midx_rev_filename(struct strbuf *out, struct multi_pack_index *m) +{ + get_midx_filename(out, m->object_dir); + strbuf_addf(out, "-%s.rev", hash_to_hex(get_midx_checksum(m))); +} + +static int midx_read_oid_fanout(const unsigned char *chunk_start, + size_t chunk_size, void *data) +{ + struct multi_pack_index *m = data; + m->chunk_oid_fanout = (uint32_t *)chunk_start; + + if (chunk_size != 4 * 256) { + error(_("multi-pack-index OID fanout is of the wrong size")); + return 1; + } + return 0; +} + +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; + struct strbuf midx_name = STRBUF_INIT; + uint32_t i; + const char *cur_pack_name; + struct chunkfile *cf = NULL; + + get_midx_filename(&midx_name, object_dir); + + fd = git_open(midx_name.buf); + + if (fd < 0) + goto cleanup_fail; + if (fstat(fd, &st)) { + error_errno(_("failed to read %s"), midx_name.buf); + 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.buf); + goto cleanup_fail; + } + + strbuf_release(&midx_name); + + midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0); + close(fd); + + FLEX_ALLOC_STR(m, object_dir, object_dir); + 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 != oid_version(the_hash_algo)) { + error(_("multi-pack-index hash version %u does not match version %u"), + hash_version, oid_version(the_hash_algo)); + goto cleanup_fail; + } + m->hash_len = the_hash_algo->rawsz; + + m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS]; + + m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS); + + cf = init_chunkfile(NULL); + + if (read_table_of_contents(cf, m->data, midx_size, + MIDX_HEADER_SIZE, m->num_chunks)) + goto cleanup_fail; + + if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names) == CHUNK_NOT_FOUND) + die(_("multi-pack-index missing required pack-name chunk")); + if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND) + die(_("multi-pack-index missing required OID fanout chunk")); + if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, &m->chunk_oid_lookup) == CHUNK_NOT_FOUND) + die(_("multi-pack-index missing required OID lookup chunk")); + if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, &m->chunk_object_offsets) == CHUNK_NOT_FOUND) + die(_("multi-pack-index missing required object offsets chunk")); + + pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets); + + if (git_env_bool("GIT_TEST_MIDX_READ_RIDX", 1)) + pair_chunk(cf, MIDX_CHUNKID_REVINDEX, &m->chunk_revindex); + + m->num_objects = ntohl(m->chunk_oid_fanout[255]); + + CALLOC_ARRAY(m->pack_names, m->num_packs); + CALLOC_ARRAY(m->packs, m->num_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); + + free_chunkfile(cf); + return m; + +cleanup_fail: + free(m); + strbuf_release(&midx_name); + free_chunkfile(cf); + 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; + + close_midx(m->next); + + munmap((unsigned char *)m->data, m->data_len); + + 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); + free(m); +} + +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, + the_hash_algo->rawsz, 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; + + oidread(oid, m->chunk_oid_lookup + m->hash_len * n); + return oid; +} + +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 + (off_t)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; +} + +uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos) +{ + return get_be32(m->chunk_object_offsets + + (off_t)pos * MIDX_CHUNK_OFFSET_WIDTH); +} + +int fill_midx_entry(struct repository *r, + const struct object_id *oid, + struct pack_entry *e, + struct multi_pack_index *m) +{ + uint32_t pos; + uint32_t pack_int_id; + struct packed_git *p; + + if (!bsearch_midx(oid, m, &pos)) + return 0; + + 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)) + return 0; + 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 (oidset_size(&p->bad_objects) && + oidset_contains(&p->bad_objects, oid)) + return 0; + + e->offset = nth_midxed_offset(m, pos); + e->p = p; + + return 1; +} + +/* 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; + + prepare_repo_settings(r); + if (!r->settings.core_multi_pack_index) + 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) { + struct multi_pack_index *mp = r->objects->multi_pack_index; + if (mp) { + m->next = mp->next; + mp->next = m; + } else + 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) +{ + hashwrite_be32(f, MIDX_SIGNATURE); + hashwrite_u8(f, MIDX_VERSION); + hashwrite_u8(f, oid_version(the_hash_algo)); + hashwrite_u8(f, num_chunks); + hashwrite_u8(f, 0); /* unused */ + 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); +} + +static int idx_or_pack_name_cmp(const void *_va, const void *_vb) +{ + const char *pack_name = _va; + const struct pack_info *compar = _vb; + + return cmp_idx_or_pack_name(pack_name, compar->pack_name); +} + +struct write_midx_context { + struct pack_info *info; + uint32_t nr; + uint32_t alloc; + struct multi_pack_index *m; + struct progress *progress; + unsigned pack_paths_checked; + + struct pack_midx_entry *entries; + uint32_t entries_nr; + + uint32_t *pack_perm; + uint32_t *pack_order; + unsigned large_offsets_needed:1; + uint32_t num_large_offsets; + + int preferred_pack_idx; + + struct string_list *to_include; +}; + +static void add_pack_to_midx(const char *full_path, size_t full_path_len, + const char *file_name, void *data) +{ + struct write_midx_context *ctx = data; + + if (ends_with(file_name, ".idx")) { + display_progress(ctx->progress, ++ctx->pack_paths_checked); + /* + * Note that at most one of ctx->m and ctx->to_include are set, + * so we are testing midx_contains_pack() and + * string_list_has_string() independently (guarded by the + * appropriate NULL checks). + * + * We could support passing to_include while reusing an existing + * MIDX, but don't currently since the reuse process drags + * forward all packs from an existing MIDX (without checking + * whether or not they appear in the to_include list). + * + * If we added support for that, these next two conditional + * should be performed independently (likely checking + * to_include before the existing MIDX). + */ + if (ctx->m && midx_contains_pack(ctx->m, file_name)) + return; + else if (ctx->to_include && + !string_list_has_string(ctx->to_include, file_name)) + return; + + ALLOC_GROW(ctx->info, ctx->nr + 1, ctx->alloc); + + ctx->info[ctx->nr].p = add_packed_git(full_path, + full_path_len, + 0); + + if (!ctx->info[ctx->nr].p) { + warning(_("failed to add packfile '%s'"), + full_path); + return; + } + + if (open_pack_index(ctx->info[ctx->nr].p)) { + warning(_("failed to open pack-index '%s'"), + full_path); + close_pack(ctx->info[ctx->nr].p); + FREE_AND_NULL(ctx->info[ctx->nr].p); + return; + } + + ctx->info[ctx->nr].pack_name = xstrdup(file_name); + ctx->info[ctx->nr].orig_pack_int_id = ctx->nr; + ctx->info[ctx->nr].expired = 0; + ctx->nr++; + } +} + +struct pack_midx_entry { + struct object_id oid; + uint32_t pack_int_id; + time_t pack_mtime; + uint64_t offset; + unsigned preferred : 1; +}; + +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; + + /* Sort objects in a preferred pack first when multiple copies exist. */ + if (a->preferred > b->preferred) + return -1; + if (a->preferred < b->preferred) + return 1; + + 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, + int preferred) +{ + if (nth_packed_object_id(&entry->oid, p, cur_object) < 0) + 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); + entry->preferred = !!preferred; +} + +struct midx_fanout { + struct pack_midx_entry *entries; + uint32_t nr; + uint32_t alloc; +}; + +static void midx_fanout_grow(struct midx_fanout *fanout, uint32_t nr) +{ + ALLOC_GROW(fanout->entries, nr, fanout->alloc); +} + +static void midx_fanout_sort(struct midx_fanout *fanout) +{ + QSORT(fanout->entries, fanout->nr, midx_oid_compare); +} + +static void midx_fanout_add_midx_fanout(struct midx_fanout *fanout, + struct multi_pack_index *m, + uint32_t cur_fanout, + int preferred_pack) +{ + uint32_t start = 0, end; + uint32_t cur_object; + + 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++) { + if ((preferred_pack > -1) && + (preferred_pack == nth_midxed_pack_int_id(m, cur_object))) { + /* + * Objects from preferred packs are added + * separately. + */ + continue; + } + + midx_fanout_grow(fanout, fanout->nr + 1); + nth_midxed_pack_midx_entry(m, + &fanout->entries[fanout->nr], + cur_object); + fanout->entries[fanout->nr].preferred = 0; + fanout->nr++; + } +} + +static void midx_fanout_add_pack_fanout(struct midx_fanout *fanout, + struct pack_info *info, + uint32_t cur_pack, + int preferred, + uint32_t cur_fanout) +{ + struct packed_git *pack = info[cur_pack].p; + uint32_t start = 0, end; + uint32_t cur_object; + + if (cur_fanout) + start = get_pack_fanout(pack, cur_fanout - 1); + end = get_pack_fanout(pack, cur_fanout); + + for (cur_object = start; cur_object < end; cur_object++) { + midx_fanout_grow(fanout, fanout->nr + 1); + fill_pack_entry(cur_pack, + info[cur_pack].p, + cur_object, + &fanout->entries[fanout->nr], + preferred); + fanout->nr++; + } +} + +/* + * 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, + int preferred_pack) +{ + uint32_t cur_fanout, cur_pack, cur_object; + uint32_t alloc_objects, total_objects = 0; + struct midx_fanout fanout = { 0 }; + 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 = fanout.alloc = total_objects > 3200 ? total_objects / 200 : 16; + + ALLOC_ARRAY(fanout.entries, fanout.alloc); + ALLOC_ARRAY(deduplicated_entries, alloc_objects); + *nr_objects = 0; + + for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) { + fanout.nr = 0; + + if (m) + midx_fanout_add_midx_fanout(&fanout, m, cur_fanout, + preferred_pack); + + for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) { + int preferred = cur_pack == preferred_pack; + midx_fanout_add_pack_fanout(&fanout, + info, cur_pack, + preferred, cur_fanout); + } + + if (-1 < preferred_pack && preferred_pack < start_pack) + midx_fanout_add_pack_fanout(&fanout, info, + preferred_pack, 1, + cur_fanout); + + midx_fanout_sort(&fanout); + + /* + * The batch is now sorted by OID and then mtime (descending). + * Take only the first duplicate. + */ + for (cur_object = 0; cur_object < fanout.nr; cur_object++) { + if (cur_object && oideq(&fanout.entries[cur_object - 1].oid, + &fanout.entries[cur_object].oid)) + continue; + + ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects); + memcpy(&deduplicated_entries[*nr_objects], + &fanout.entries[cur_object], + sizeof(struct pack_midx_entry)); + (*nr_objects)++; + } + } + + free(fanout.entries); + return deduplicated_entries; +} + +static int write_midx_pack_names(struct hashfile *f, void *data) +{ + struct write_midx_context *ctx = data; + uint32_t i; + unsigned char padding[MIDX_CHUNK_ALIGNMENT]; + size_t written = 0; + + for (i = 0; i < ctx->nr; i++) { + size_t writelen; + + if (ctx->info[i].expired) + continue; + + if (i && strcmp(ctx->info[i].pack_name, ctx->info[i - 1].pack_name) <= 0) + BUG("incorrect pack-file order: %s before %s", + ctx->info[i - 1].pack_name, + ctx->info[i].pack_name); + + writelen = strlen(ctx->info[i].pack_name) + 1; + hashwrite(f, ctx->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); + } + + return 0; +} + +static int write_midx_oid_fanout(struct hashfile *f, + void *data) +{ + struct write_midx_context *ctx = data; + struct pack_midx_entry *list = ctx->entries; + struct pack_midx_entry *last = ctx->entries + ctx->entries_nr; + 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 0; +} + +static int write_midx_oid_lookup(struct hashfile *f, + void *data) +{ + struct write_midx_context *ctx = data; + unsigned char hash_len = the_hash_algo->rawsz; + struct pack_midx_entry *list = ctx->entries; + uint32_t i; + + for (i = 0; i < ctx->entries_nr; i++) { + struct pack_midx_entry *obj = list++; + + if (i < ctx->entries_nr - 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); + } + + return 0; +} + +static int write_midx_object_offsets(struct hashfile *f, + void *data) +{ + struct write_midx_context *ctx = data; + struct pack_midx_entry *list = ctx->entries; + uint32_t i, nr_large_offset = 0; + + for (i = 0; i < ctx->entries_nr; i++) { + struct pack_midx_entry *obj = list++; + + if (ctx->pack_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, ctx->pack_perm[obj->pack_int_id]); + + if (ctx->large_offsets_needed && obj->offset >> 31) + hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++); + else if (!ctx->large_offsets_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); + } + + return 0; +} + +static int write_midx_large_offsets(struct hashfile *f, + void *data) +{ + struct write_midx_context *ctx = data; + struct pack_midx_entry *list = ctx->entries; + struct pack_midx_entry *end = ctx->entries + ctx->entries_nr; + uint32_t nr_large_offset = ctx->num_large_offsets; + + 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_be64(f, offset); + + nr_large_offset--; + } + + return 0; +} + +static int write_midx_revindex(struct hashfile *f, + void *data) +{ + struct write_midx_context *ctx = data; + uint32_t i; + + for (i = 0; i < ctx->entries_nr; i++) + hashwrite_be32(f, ctx->pack_order[i]); + + return 0; +} + +struct midx_pack_order_data { + uint32_t nr; + uint32_t pack; + off_t offset; +}; + +static int midx_pack_order_cmp(const void *va, const void *vb) +{ + const struct midx_pack_order_data *a = va, *b = vb; + if (a->pack < b->pack) + return -1; + else if (a->pack > b->pack) + return 1; + else if (a->offset < b->offset) + return -1; + else if (a->offset > b->offset) + return 1; + else + return 0; +} + +static uint32_t *midx_pack_order(struct write_midx_context *ctx) +{ + struct midx_pack_order_data *data; + uint32_t *pack_order; + uint32_t i; + + trace2_region_enter("midx", "midx_pack_order", the_repository); + + ALLOC_ARRAY(data, ctx->entries_nr); + for (i = 0; i < ctx->entries_nr; i++) { + struct pack_midx_entry *e = &ctx->entries[i]; + data[i].nr = i; + data[i].pack = ctx->pack_perm[e->pack_int_id]; + if (!e->preferred) + data[i].pack |= (1U << 31); + data[i].offset = e->offset; + } + + QSORT(data, ctx->entries_nr, midx_pack_order_cmp); + + ALLOC_ARRAY(pack_order, ctx->entries_nr); + for (i = 0; i < ctx->entries_nr; i++) + pack_order[i] = data[i].nr; + free(data); + + trace2_region_leave("midx", "midx_pack_order", the_repository); + + return pack_order; +} + +static void write_midx_reverse_index(char *midx_name, unsigned char *midx_hash, + struct write_midx_context *ctx) +{ + struct strbuf buf = STRBUF_INIT; + const char *tmp_file; + + trace2_region_enter("midx", "write_midx_reverse_index", the_repository); + + strbuf_addf(&buf, "%s-%s.rev", midx_name, hash_to_hex(midx_hash)); + + tmp_file = write_rev_file_order(NULL, ctx->pack_order, ctx->entries_nr, + midx_hash, WRITE_REV); + + if (finalize_object_file(tmp_file, buf.buf)) + die(_("cannot store reverse index file")); + + strbuf_release(&buf); + + trace2_region_leave("midx", "write_midx_reverse_index", the_repository); +} + +static void clear_midx_files_ext(const char *object_dir, const char *ext, + unsigned char *keep_hash); + +static int midx_checksum_valid(struct multi_pack_index *m) +{ + return hashfile_checksum_valid(m->data, m->data_len); +} + +static void prepare_midx_packing_data(struct packing_data *pdata, + struct write_midx_context *ctx) +{ + uint32_t i; + + trace2_region_enter("midx", "prepare_midx_packing_data", the_repository); + + memset(pdata, 0, sizeof(struct packing_data)); + prepare_packing_data(the_repository, pdata); + + for (i = 0; i < ctx->entries_nr; i++) { + struct pack_midx_entry *from = &ctx->entries[ctx->pack_order[i]]; + struct object_entry *to = packlist_alloc(pdata, &from->oid); + + oe_set_in_pack(pdata, to, + ctx->info[ctx->pack_perm[from->pack_int_id]].p); + } + + trace2_region_leave("midx", "prepare_midx_packing_data", the_repository); +} + +static int add_ref_to_pending(const char *refname, + const struct object_id *oid, + int flag, void *cb_data) +{ + struct rev_info *revs = (struct rev_info*)cb_data; + struct object_id peeled; + struct object *object; + + if ((flag & REF_ISSYMREF) && (flag & REF_ISBROKEN)) { + warning("symbolic ref is dangling: %s", refname); + return 0; + } + + if (!peel_iterated_oid(oid, &peeled)) + oid = &peeled; + + object = parse_object_or_die(oid, refname); + if (object->type != OBJ_COMMIT) + return 0; + + add_pending_object(revs, object, ""); + if (bitmap_is_preferred_refname(revs->repo, refname)) + object->flags |= NEEDS_BITMAP; + return 0; +} + +struct bitmap_commit_cb { + struct commit **commits; + size_t commits_nr, commits_alloc; + + struct write_midx_context *ctx; +}; + +static const struct object_id *bitmap_oid_access(size_t index, + const void *_entries) +{ + const struct pack_midx_entry *entries = _entries; + return &entries[index].oid; +} + +static void bitmap_show_commit(struct commit *commit, void *_data) +{ + struct bitmap_commit_cb *data = _data; + int pos = oid_pos(&commit->object.oid, data->ctx->entries, + data->ctx->entries_nr, + bitmap_oid_access); + if (pos < 0) + return; + + ALLOC_GROW(data->commits, data->commits_nr + 1, data->commits_alloc); + data->commits[data->commits_nr++] = commit; +} + +static int read_refs_snapshot(const char *refs_snapshot, + struct rev_info *revs) +{ + struct strbuf buf = STRBUF_INIT; + struct object_id oid; + FILE *f = xfopen(refs_snapshot, "r"); + + while (strbuf_getline(&buf, f) != EOF) { + struct object *object; + int preferred = 0; + char *hex = buf.buf; + const char *end = NULL; + + if (buf.len && *buf.buf == '+') { + preferred = 1; + hex = &buf.buf[1]; + } + + if (parse_oid_hex(hex, &oid, &end) < 0) + die(_("could not parse line: %s"), buf.buf); + if (*end) + die(_("malformed line: %s"), buf.buf); + + object = parse_object_or_die(&oid, NULL); + if (preferred) + object->flags |= NEEDS_BITMAP; + + add_pending_object(revs, object, ""); + } + + fclose(f); + strbuf_release(&buf); + return 0; +} + +static struct commit **find_commits_for_midx_bitmap(uint32_t *indexed_commits_nr_p, + const char *refs_snapshot, + struct write_midx_context *ctx) +{ + struct rev_info revs; + struct bitmap_commit_cb cb = {0}; + + trace2_region_enter("midx", "find_commits_for_midx_bitmap", + the_repository); + + cb.ctx = ctx; + + repo_init_revisions(the_repository, &revs, NULL); + if (refs_snapshot) { + read_refs_snapshot(refs_snapshot, &revs); + } else { + setup_revisions(0, NULL, &revs, NULL); + for_each_ref(add_ref_to_pending, &revs); + } + + /* + * Skipping promisor objects here is intentional, since it only excludes + * them from the list of reachable commits that we want to select from + * when computing the selection of MIDX'd commits to receive bitmaps. + * + * Reachability bitmaps do require that their objects be closed under + * reachability, but fetching any objects missing from promisors at this + * point is too late. But, if one of those objects can be reached from + * an another object that is included in the bitmap, then we will + * complain later that we don't have reachability closure (and fail + * appropriately). + */ + fetch_if_missing = 0; + revs.exclude_promisor_objects = 1; + + if (prepare_revision_walk(&revs)) + die(_("revision walk setup failed")); + + traverse_commit_list(&revs, bitmap_show_commit, NULL, &cb); + if (indexed_commits_nr_p) + *indexed_commits_nr_p = cb.commits_nr; + + release_revisions(&revs); + + trace2_region_leave("midx", "find_commits_for_midx_bitmap", + the_repository); + + return cb.commits; +} + +static int write_midx_bitmap(const char *midx_name, + const unsigned char *midx_hash, + struct packing_data *pdata, + struct commit **commits, + uint32_t commits_nr, + uint32_t *pack_order, + unsigned flags) +{ + int ret, i; + uint16_t options = 0; + struct pack_idx_entry **index; + char *bitmap_name = xstrfmt("%s-%s.bitmap", midx_name, + hash_to_hex(midx_hash)); + + trace2_region_enter("midx", "write_midx_bitmap", the_repository); + + if (flags & MIDX_WRITE_BITMAP_HASH_CACHE) + options |= BITMAP_OPT_HASH_CACHE; + + if (flags & MIDX_WRITE_BITMAP_LOOKUP_TABLE) + options |= BITMAP_OPT_LOOKUP_TABLE; + + /* + * Build the MIDX-order index based on pdata.objects (which is already + * in MIDX order; c.f., 'midx_pack_order_cmp()' for the definition of + * this order). + */ + ALLOC_ARRAY(index, pdata->nr_objects); + for (i = 0; i < pdata->nr_objects; i++) + index[i] = &pdata->objects[i].idx; + + bitmap_writer_show_progress(flags & MIDX_PROGRESS); + bitmap_writer_build_type_index(pdata, index, pdata->nr_objects); + + /* + * bitmap_writer_finish expects objects in lex order, but pack_order + * gives us exactly that. use it directly instead of re-sorting the + * array. + * + * This changes the order of objects in 'index' between + * bitmap_writer_build_type_index and bitmap_writer_finish. + * + * The same re-ordering takes place in the single-pack bitmap code via + * write_idx_file(), which is called by finish_tmp_packfile(), which + * happens between bitmap_writer_build_type_index() and + * bitmap_writer_finish(). + */ + for (i = 0; i < pdata->nr_objects; i++) + index[pack_order[i]] = &pdata->objects[i].idx; + + bitmap_writer_select_commits(commits, commits_nr, -1); + ret = bitmap_writer_build(pdata); + if (ret < 0) + goto cleanup; + + bitmap_writer_set_checksum(midx_hash); + bitmap_writer_finish(index, pdata->nr_objects, bitmap_name, options); + +cleanup: + free(index); + free(bitmap_name); + + trace2_region_leave("midx", "write_midx_bitmap", the_repository); + + return ret; +} + +static struct multi_pack_index *lookup_multi_pack_index(struct repository *r, + const char *object_dir) +{ + struct multi_pack_index *result = NULL; + struct multi_pack_index *cur; + char *obj_dir_real = real_pathdup(object_dir, 1); + struct strbuf cur_path_real = STRBUF_INIT; + + /* Ensure the given object_dir is local, or a known alternate. */ + find_odb(r, obj_dir_real); + + for (cur = get_multi_pack_index(r); cur; cur = cur->next) { + strbuf_realpath(&cur_path_real, cur->object_dir, 1); + if (!strcmp(obj_dir_real, cur_path_real.buf)) { + result = cur; + goto cleanup; + } + } + +cleanup: + free(obj_dir_real); + strbuf_release(&cur_path_real); + return result; +} + +static int write_midx_internal(const char *object_dir, + struct string_list *packs_to_include, + struct string_list *packs_to_drop, + const char *preferred_pack_name, + const char *refs_snapshot, + unsigned flags) +{ + struct strbuf midx_name = STRBUF_INIT; + unsigned char midx_hash[GIT_MAX_RAWSZ]; + uint32_t i; + struct hashfile *f = NULL; + struct lock_file lk; + struct write_midx_context ctx = { 0 }; + int pack_name_concat_len = 0; + int dropped_packs = 0; + int result = 0; + struct chunkfile *cf; + + trace2_region_enter("midx", "write_midx_internal", the_repository); + + get_midx_filename(&midx_name, object_dir); + if (safe_create_leading_directories(midx_name.buf)) + die_errno(_("unable to create leading directories of %s"), + midx_name.buf); + + if (!packs_to_include) { + /* + * Only reference an existing MIDX when not filtering which + * packs to include, since all packs and objects are copied + * blindly from an existing MIDX if one is present. + */ + ctx.m = lookup_multi_pack_index(the_repository, object_dir); + } + + if (ctx.m && !midx_checksum_valid(ctx.m)) { + warning(_("ignoring existing multi-pack-index; checksum mismatch")); + ctx.m = NULL; + } + + ctx.nr = 0; + ctx.alloc = ctx.m ? ctx.m->num_packs : 16; + ctx.info = NULL; + ALLOC_ARRAY(ctx.info, ctx.alloc); + + if (ctx.m) { + for (i = 0; i < ctx.m->num_packs; i++) { + ALLOC_GROW(ctx.info, ctx.nr + 1, ctx.alloc); + + ctx.info[ctx.nr].orig_pack_int_id = i; + ctx.info[ctx.nr].pack_name = xstrdup(ctx.m->pack_names[i]); + ctx.info[ctx.nr].p = ctx.m->packs[i]; + ctx.info[ctx.nr].expired = 0; + + if (flags & MIDX_WRITE_REV_INDEX) { + /* + * If generating a reverse index, need to have + * packed_git's loaded to compare their + * mtimes and object count. + */ + if (prepare_midx_pack(the_repository, ctx.m, i)) { + error(_("could not load pack")); + result = 1; + goto cleanup; + } + + if (open_pack_index(ctx.m->packs[i])) + die(_("could not open index for %s"), + ctx.m->packs[i]->pack_name); + ctx.info[ctx.nr].p = ctx.m->packs[i]; + } + + ctx.nr++; + } + } + + ctx.pack_paths_checked = 0; + if (flags & MIDX_PROGRESS) + ctx.progress = start_delayed_progress(_("Adding packfiles to multi-pack-index"), 0); + else + ctx.progress = NULL; + + ctx.to_include = packs_to_include; + + for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &ctx); + stop_progress(&ctx.progress); + + if ((ctx.m && ctx.nr == ctx.m->num_packs) && + !(packs_to_include || packs_to_drop)) { + struct bitmap_index *bitmap_git; + int bitmap_exists; + int want_bitmap = flags & MIDX_WRITE_BITMAP; + + bitmap_git = prepare_midx_bitmap_git(ctx.m); + bitmap_exists = bitmap_git && bitmap_is_midx(bitmap_git); + free_bitmap_index(bitmap_git); + + if (bitmap_exists || !want_bitmap) { + /* + * The correct MIDX already exists, and so does a + * corresponding bitmap (or one wasn't requested). + */ + if (!want_bitmap) + clear_midx_files_ext(object_dir, ".bitmap", + NULL); + goto cleanup; + } + } + + if (preferred_pack_name) { + int found = 0; + for (i = 0; i < ctx.nr; i++) { + if (!cmp_idx_or_pack_name(preferred_pack_name, + ctx.info[i].pack_name)) { + ctx.preferred_pack_idx = i; + found = 1; + break; + } + } + + if (!found) + warning(_("unknown preferred pack: '%s'"), + preferred_pack_name); + } else if (ctx.nr && + (flags & (MIDX_WRITE_REV_INDEX | MIDX_WRITE_BITMAP))) { + struct packed_git *oldest = ctx.info[ctx.preferred_pack_idx].p; + ctx.preferred_pack_idx = 0; + + if (packs_to_drop && packs_to_drop->nr) + BUG("cannot write a MIDX bitmap during expiration"); + + /* + * set a preferred pack when writing a bitmap to ensure that + * the pack from which the first object is selected in pseudo + * pack-order has all of its objects selected from that pack + * (and not another pack containing a duplicate) + */ + for (i = 1; i < ctx.nr; i++) { + struct packed_git *p = ctx.info[i].p; + + if (!oldest->num_objects || p->mtime < oldest->mtime) { + oldest = p; + ctx.preferred_pack_idx = i; + } + } + + if (!oldest->num_objects) { + /* + * If all packs are empty; unset the preferred index. + * This is acceptable since there will be no duplicate + * objects to resolve, so the preferred value doesn't + * matter. + */ + ctx.preferred_pack_idx = -1; + } + } else { + /* + * otherwise don't mark any pack as preferred to avoid + * interfering with expiration logic below + */ + ctx.preferred_pack_idx = -1; + } + + if (ctx.preferred_pack_idx > -1) { + struct packed_git *preferred = ctx.info[ctx.preferred_pack_idx].p; + if (!preferred->num_objects) { + error(_("cannot select preferred pack %s with no objects"), + preferred->pack_name); + result = 1; + goto cleanup; + } + } + + ctx.entries = get_sorted_entries(ctx.m, ctx.info, ctx.nr, &ctx.entries_nr, + ctx.preferred_pack_idx); + + ctx.large_offsets_needed = 0; + for (i = 0; i < ctx.entries_nr; i++) { + if (ctx.entries[i].offset > 0x7fffffff) + ctx.num_large_offsets++; + if (ctx.entries[i].offset > 0xffffffff) + ctx.large_offsets_needed = 1; + } + + QSORT(ctx.info, ctx.nr, pack_info_compare); + + if (packs_to_drop && packs_to_drop->nr) { + int drop_index = 0; + int missing_drops = 0; + + for (i = 0; i < ctx.nr && drop_index < packs_to_drop->nr; i++) { + int cmp = strcmp(ctx.info[i].pack_name, + packs_to_drop->items[drop_index].string); + + if (!cmp) { + drop_index++; + ctx.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 { + ctx.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(ctx.pack_perm, ctx.nr); + for (i = 0; i < ctx.nr; i++) { + if (ctx.info[i].expired) { + dropped_packs++; + ctx.pack_perm[ctx.info[i].orig_pack_int_id] = PACK_EXPIRED; + } else { + ctx.pack_perm[ctx.info[i].orig_pack_int_id] = i - dropped_packs; + } + } + + for (i = 0; i < ctx.nr; i++) { + if (!ctx.info[i].expired) + pack_name_concat_len += strlen(ctx.info[i].pack_name) + 1; + } + + /* Check that the preferred pack wasn't expired (if given). */ + if (preferred_pack_name) { + struct pack_info *preferred = bsearch(preferred_pack_name, + ctx.info, ctx.nr, + sizeof(*ctx.info), + idx_or_pack_name_cmp); + if (preferred) { + uint32_t perm = ctx.pack_perm[preferred->orig_pack_int_id]; + if (perm == PACK_EXPIRED) + warning(_("preferred pack '%s' is expired"), + preferred_pack_name); + } + } + + 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.buf, LOCK_DIE_ON_ERROR); + f = hashfd(get_lock_file_fd(&lk), get_lock_file_path(&lk)); + + if (ctx.nr - dropped_packs == 0) { + error(_("no pack files to index.")); + result = 1; + goto cleanup; + } + + if (!ctx.entries_nr) { + if (flags & MIDX_WRITE_BITMAP) + warning(_("refusing to write multi-pack .bitmap without any objects")); + flags &= ~(MIDX_WRITE_REV_INDEX | MIDX_WRITE_BITMAP); + } + + cf = init_chunkfile(f); + + add_chunk(cf, MIDX_CHUNKID_PACKNAMES, pack_name_concat_len, + write_midx_pack_names); + add_chunk(cf, MIDX_CHUNKID_OIDFANOUT, MIDX_CHUNK_FANOUT_SIZE, + write_midx_oid_fanout); + add_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, + (size_t)ctx.entries_nr * the_hash_algo->rawsz, + write_midx_oid_lookup); + add_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, + (size_t)ctx.entries_nr * MIDX_CHUNK_OFFSET_WIDTH, + write_midx_object_offsets); + + if (ctx.large_offsets_needed) + add_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, + (size_t)ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH, + write_midx_large_offsets); + + if (flags & (MIDX_WRITE_REV_INDEX | MIDX_WRITE_BITMAP)) { + ctx.pack_order = midx_pack_order(&ctx); + add_chunk(cf, MIDX_CHUNKID_REVINDEX, + ctx.entries_nr * sizeof(uint32_t), + write_midx_revindex); + } + + write_midx_header(f, get_num_chunks(cf), ctx.nr - dropped_packs); + write_chunkfile(cf, &ctx); + + finalize_hashfile(f, midx_hash, FSYNC_COMPONENT_PACK_METADATA, + CSUM_FSYNC | CSUM_HASH_IN_STREAM); + free_chunkfile(cf); + + if (flags & MIDX_WRITE_REV_INDEX && + git_env_bool("GIT_TEST_MIDX_WRITE_REV", 0)) + write_midx_reverse_index(midx_name.buf, midx_hash, &ctx); + + if (flags & MIDX_WRITE_BITMAP) { + struct packing_data pdata; + struct commit **commits; + uint32_t commits_nr; + + if (!ctx.entries_nr) + BUG("cannot write a bitmap without any objects"); + + prepare_midx_packing_data(&pdata, &ctx); + + commits = find_commits_for_midx_bitmap(&commits_nr, refs_snapshot, &ctx); + + /* + * The previous steps translated the information from + * 'entries' into information suitable for constructing + * bitmaps. We no longer need that array, so clear it to + * reduce memory pressure. + */ + FREE_AND_NULL(ctx.entries); + ctx.entries_nr = 0; + + if (write_midx_bitmap(midx_name.buf, midx_hash, &pdata, + commits, commits_nr, ctx.pack_order, + flags) < 0) { + error(_("could not write multi-pack bitmap")); + result = 1; + goto cleanup; + } + } + /* + * NOTE: Do not use ctx.entries beyond this point, since it might + * have been freed in the previous if block. + */ + + if (ctx.m) + close_object_store(the_repository->objects); + + if (commit_lock_file(&lk) < 0) + die_errno(_("could not write multi-pack-index")); + + clear_midx_files_ext(object_dir, ".bitmap", midx_hash); + clear_midx_files_ext(object_dir, ".rev", midx_hash); + +cleanup: + for (i = 0; i < ctx.nr; i++) { + if (ctx.info[i].p) { + close_pack(ctx.info[i].p); + free(ctx.info[i].p); + } + free(ctx.info[i].pack_name); + } + + free(ctx.info); + free(ctx.entries); + free(ctx.pack_perm); + free(ctx.pack_order); + strbuf_release(&midx_name); + + trace2_region_leave("midx", "write_midx_internal", the_repository); + + return result; +} + +int write_midx_file(const char *object_dir, + const char *preferred_pack_name, + const char *refs_snapshot, + unsigned flags) +{ + return write_midx_internal(object_dir, NULL, NULL, preferred_pack_name, + refs_snapshot, flags); +} + +int write_midx_file_only(const char *object_dir, + struct string_list *packs_to_include, + const char *preferred_pack_name, + const char *refs_snapshot, + unsigned flags) +{ + return write_midx_internal(object_dir, packs_to_include, NULL, + preferred_pack_name, refs_snapshot, flags); +} + +struct clear_midx_data { + char *keep; + const char *ext; +}; + +static void clear_midx_file_ext(const char *full_path, size_t full_path_len, + const char *file_name, void *_data) +{ + struct clear_midx_data *data = _data; + + if (!(starts_with(file_name, "multi-pack-index-") && + ends_with(file_name, data->ext))) + return; + if (data->keep && !strcmp(data->keep, file_name)) + return; + + if (unlink(full_path)) + die_errno(_("failed to remove %s"), full_path); +} + +static void clear_midx_files_ext(const char *object_dir, const char *ext, + unsigned char *keep_hash) +{ + struct clear_midx_data data; + memset(&data, 0, sizeof(struct clear_midx_data)); + + if (keep_hash) + data.keep = xstrfmt("multi-pack-index-%s%s", + hash_to_hex(keep_hash), ext); + data.ext = ext; + + for_each_file_in_pack_dir(object_dir, + clear_midx_file_ext, + &data); + + free(data.keep); +} + +void clear_midx_file(struct repository *r) +{ + struct strbuf midx = STRBUF_INIT; + + get_midx_filename(&midx, 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.buf)) + die(_("failed to clear multi-pack-index at %s"), midx.buf); + + clear_midx_files_ext(r->objects->odb->path, ".bitmap", NULL); + clear_midx_files_ext(r->objects->odb->path, ".rev", NULL); + + strbuf_release(&midx); +} + +static int verify_midx_error; + +__attribute__((format (printf, 1, 2))) +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, unsigned flags) +{ + struct pair_pos_vs_id *pairs = NULL; + uint32_t i; + struct progress *progress = NULL; + struct multi_pack_index *m = load_multi_pack_index(object_dir, 1); + verify_midx_error = 0; + + if (!m) { + int result = 0; + struct stat sb; + struct strbuf filename = STRBUF_INIT; + + get_midx_filename(&filename, object_dir); + + if (!stat(filename.buf, &sb)) { + error(_("multi-pack-index file exists, but failed to parse")); + result = 1; + } + strbuf_release(&filename); + return result; + } + + if (!midx_checksum_valid(m)) + midx_report(_("incorrect checksum")); + + if (flags & MIDX_PROGRESS) + progress = start_delayed_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); + } + + if (m->num_objects == 0) { + midx_report(_("the midx contains no oid")); + /* + * Remaining tests assume that we have objects, so we can + * return here. + */ + goto cleanup; + } + + if (flags & MIDX_PROGRESS) + progress = start_sparse_progress(_("Verifying OID order in multi-pack-index"), + 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); + } + + if (flags & MIDX_PROGRESS) + 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); + + if (flags & MIDX_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); + +cleanup: + free(pairs); + close_midx(m); + + return verify_midx_error; +} + +int expire_midx_packs(struct repository *r, const char *object_dir, unsigned flags) +{ + uint32_t i, *count, result = 0; + struct string_list packs_to_drop = STRING_LIST_INIT_DUP; + struct multi_pack_index *m = lookup_multi_pack_index(r, object_dir); + struct progress *progress = NULL; + + if (!m) + return 0; + + CALLOC_ARRAY(count, m->num_packs); + + if (flags & MIDX_PROGRESS) + progress = start_delayed_progress(_("Counting referenced objects"), + m->num_objects); + for (i = 0; i < m->num_objects; i++) { + int pack_int_id = nth_midxed_pack_int_id(m, i); + count[pack_int_id]++; + display_progress(progress, i + 1); + } + stop_progress(&progress); + + if (flags & MIDX_PROGRESS) + progress = start_delayed_progress(_("Finding and deleting unreferenced packfiles"), + m->num_packs); + for (i = 0; i < m->num_packs; i++) { + char *pack_name; + display_progress(progress, i + 1); + + if (count[i]) + continue; + + if (prepare_midx_pack(r, m, i)) + continue; + + if (m->packs[i]->pack_keep || m->packs[i]->is_cruft) + 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); + } + stop_progress(&progress); + + free(count); + + if (packs_to_drop.nr) + result = write_midx_internal(object_dir, NULL, &packs_to_drop, NULL, NULL, flags); + + 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 repository *r, + struct multi_pack_index *m, + unsigned char *include_pack) +{ + uint32_t i, count = 0; + int pack_kept_objects = 0; + + repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects); + + for (i = 0; i < m->num_packs; i++) { + if (prepare_midx_pack(r, m, i)) + continue; + if (!pack_kept_objects && m->packs[i]->pack_keep) + continue; + if (m->packs[i]->is_cruft) + continue; + + include_pack[i] = 1; + count++; + } + + return count < 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; + int pack_kept_objects = 0; + + CALLOC_ARRAY(pack_info, m->num_packs); + + repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects); + + 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; 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 (!pack_kept_objects && p->pack_keep) + continue; + if (p->is_cruft) + 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 (packs_to_repack < 2) + return 1; + + return 0; +} + +int midx_repack(struct repository *r, const char *object_dir, size_t batch_size, unsigned flags) +{ + int result = 0; + uint32_t i; + unsigned char *include_pack; + struct child_process cmd = CHILD_PROCESS_INIT; + FILE *cmd_in; + struct strbuf base_name = STRBUF_INIT; + struct multi_pack_index *m = lookup_multi_pack_index(r, object_dir); + + /* + * When updating the default for these configuration + * variables in builtin/repack.c, these must be adjusted + * to match. + */ + int delta_base_offset = 1; + int use_delta_islands = 0; + + if (!m) + return 0; + + CALLOC_ARRAY(include_pack, m->num_packs); + + if (batch_size) { + if (fill_included_packs_batch(r, m, include_pack, batch_size)) + goto cleanup; + } else if (fill_included_packs_all(r, m, include_pack)) + goto cleanup; + + repo_config_get_bool(r, "repack.usedeltabaseoffset", &delta_base_offset); + repo_config_get_bool(r, "repack.usedeltaislands", &use_delta_islands); + + strvec_push(&cmd.args, "pack-objects"); + + strbuf_addstr(&base_name, object_dir); + strbuf_addstr(&base_name, "/pack/pack"); + strvec_push(&cmd.args, base_name.buf); + + if (delta_base_offset) + strvec_push(&cmd.args, "--delta-base-offset"); + if (use_delta_islands) + strvec_push(&cmd.args, "--delta-islands"); + + if (flags & MIDX_PROGRESS) + strvec_push(&cmd.args, "--progress"); + else + strvec_push(&cmd.args, "-q"); + + 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; + } + + cmd_in = xfdopen(cmd.in, "w"); + + 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); + fprintf(cmd_in, "%s\n", oid_to_hex(&oid)); + } + fclose(cmd_in); + + if (finish_command(&cmd)) { + error(_("could not finish pack-objects")); + result = 1; + goto cleanup; + } + + result = write_midx_internal(object_dir, NULL, NULL, NULL, NULL, flags); + +cleanup: + free(include_pack); + return result; +} |