diff options
Diffstat (limited to 'midx-write.c')
| -rw-r--r-- | midx-write.c | 1801 |
1 files changed, 1801 insertions, 0 deletions
diff --git a/midx-write.c b/midx-write.c new file mode 100644 index 0000000000..a0aceab5e0 --- /dev/null +++ b/midx-write.c @@ -0,0 +1,1801 @@ +#define DISABLE_SIGN_COMPARE_WARNINGS + +#include "git-compat-util.h" +#include "abspath.h" +#include "config.h" +#include "hex.h" +#include "lockfile.h" +#include "packfile.h" +#include "object-file.h" +#include "hash-lookup.h" +#include "midx.h" +#include "progress.h" +#include "trace2.h" +#include "run-command.h" +#include "chunk-format.h" +#include "pack-bitmap.h" +#include "refs.h" +#include "revision.h" +#include "list-objects.h" +#include "path.h" +#include "pack-revindex.h" + +#define PACK_EXPIRED UINT_MAX +#define BITMAP_POS_UNKNOWN (~((uint32_t)0)) +#define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256) +#define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t)) + +extern int midx_checksum_valid(struct multi_pack_index *m); +extern void clear_midx_files_ext(const char *object_dir, const char *ext, + const char *keep_hash); +extern void clear_incremental_midx_files_ext(const char *object_dir, + const char *ext, + const char **keep_hashes, + uint32_t hashes_nr); +extern int cmp_idx_or_pack_name(const char *idx_or_pack_name, + const char *idx_name); + +static size_t write_midx_header(const struct git_hash_algo *hash_algo, + 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(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; + + uint32_t bitmap_pos; + uint32_t bitmap_nr; + + unsigned expired : 1; +}; + +static void fill_pack_info(struct pack_info *info, + struct packed_git *p, const char *pack_name, + uint32_t orig_pack_int_id) +{ + memset(info, 0, sizeof(struct pack_info)); + + info->orig_pack_int_id = orig_pack_int_id; + info->pack_name = xstrdup(pack_name); + info->p = p; + info->bitmap_pos = BITMAP_POS_UNKNOWN; +} + +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; + size_t nr; + size_t alloc; + struct multi_pack_index *m; + struct multi_pack_index *base_midx; + struct progress *progress; + unsigned pack_paths_checked; + + struct pack_midx_entry *entries; + size_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; + + int incremental; + uint32_t num_multi_pack_indexes_before; + + struct string_list *to_include; + + struct repository *repo; +}; + +static int should_include_pack(const struct write_midx_context *ctx, + const char *file_name) +{ + /* + * 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 0; + else if (ctx->base_midx && midx_contains_pack(ctx->base_midx, + file_name)) + return 0; + else if (ctx->to_include && + !string_list_has_string(ctx->to_include, file_name)) + return 0; + return 1; +} + +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; + struct packed_git *p; + + if (ends_with(file_name, ".idx")) { + display_progress(ctx->progress, ++ctx->pack_paths_checked); + + if (!should_include_pack(ctx, file_name)) + return; + + ALLOC_GROW(ctx->info, ctx->nr + 1, ctx->alloc); + p = add_packed_git(ctx->repo, full_path, full_path_len, 0); + if (!p) { + warning(_("failed to add packfile '%s'"), + full_path); + return; + } + + if (open_pack_index(p)) { + warning(_("failed to open pack-index '%s'"), + full_path); + close_pack(p); + free(p); + return; + } + + fill_pack_info(&ctx->info[ctx->nr], p, file_name, ctx->nr); + 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 + m->num_objects_in_base) + 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; + size_t nr, alloc; +}; + +static void midx_fanout_grow(struct midx_fanout *fanout, size_t nr) +{ + if (nr < fanout->nr) + BUG("negative growth in midx_fanout_grow() (%"PRIuMAX" < %"PRIuMAX")", + (uintmax_t)nr, (uintmax_t)fanout->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 = m->num_objects_in_base, end; + uint32_t cur_object; + + if (m->base_midx) + midx_fanout_add_midx_fanout(fanout, m->base_midx, cur_fanout, + preferred_pack); + + if (cur_fanout) + start += ntohl(m->chunk_oid_fanout[cur_fanout - 1]); + end = m->num_objects_in_base + 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 void compute_sorted_entries(struct write_midx_context *ctx, + uint32_t start_pack) +{ + uint32_t cur_fanout, cur_pack, cur_object; + size_t alloc_objects, total_objects = 0; + struct midx_fanout fanout = { 0 }; + + for (cur_pack = start_pack; cur_pack < ctx->nr; cur_pack++) + total_objects = st_add(total_objects, + ctx->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(ctx->entries, alloc_objects); + ctx->entries_nr = 0; + + for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) { + fanout.nr = 0; + + if (ctx->m && !ctx->incremental) + midx_fanout_add_midx_fanout(&fanout, ctx->m, cur_fanout, + ctx->preferred_pack_idx); + + for (cur_pack = start_pack; cur_pack < ctx->nr; cur_pack++) { + int preferred = cur_pack == ctx->preferred_pack_idx; + midx_fanout_add_pack_fanout(&fanout, + ctx->info, cur_pack, + preferred, cur_fanout); + } + + if (-1 < ctx->preferred_pack_idx && ctx->preferred_pack_idx < start_pack) + midx_fanout_add_pack_fanout(&fanout, ctx->info, + ctx->preferred_pack_idx, 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; + if (ctx->incremental && ctx->base_midx && + midx_has_oid(ctx->base_midx, + &fanout.entries[cur_object].oid)) + continue; + + ALLOC_GROW(ctx->entries, st_add(ctx->entries_nr, 1), + alloc_objects); + memcpy(&ctx->entries[ctx->entries_nr], + &fanout.entries[cur_object], + sizeof(struct pack_midx_entry)); + ctx->entries_nr++; + } + } + + free(fanout.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_bitmapped_packs(struct hashfile *f, void *data) +{ + struct write_midx_context *ctx = data; + size_t i; + + for (i = 0; i < ctx->nr; i++) { + struct pack_info *pack = &ctx->info[i]; + if (pack->expired) + continue; + + if (pack->bitmap_pos == BITMAP_POS_UNKNOWN && pack->bitmap_nr) + BUG("pack '%s' has no bitmap position, but has %d bitmapped object(s)", + pack->pack_name, pack->bitmap_nr); + + hashwrite_be32(f, pack->bitmap_pos); + hashwrite_be32(f, pack->bitmap_nr); + } + 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 = ctx->repo->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, nr_base; + + if (ctx->incremental && ctx->base_midx) + nr_base = ctx->base_midx->num_objects + + ctx->base_midx->num_objects_in_base; + else + nr_base = 0; + + for (i = 0; i < ctx->entries_nr; i++) + hashwrite_be32(f, ctx->pack_order[i] + nr_base); + + 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, base_objects = 0; + uint32_t i; + + trace2_region_enter("midx", "midx_pack_order", ctx->repo); + + if (ctx->incremental && ctx->base_midx) + base_objects = ctx->base_midx->num_objects + + ctx->base_midx->num_objects_in_base; + + ALLOC_ARRAY(pack_order, ctx->entries_nr); + 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); + + for (i = 0; i < ctx->entries_nr; i++) { + struct pack_midx_entry *e = &ctx->entries[data[i].nr]; + struct pack_info *pack = &ctx->info[ctx->pack_perm[e->pack_int_id]]; + if (pack->bitmap_pos == BITMAP_POS_UNKNOWN) + pack->bitmap_pos = i + base_objects; + pack->bitmap_nr++; + pack_order[i] = data[i].nr; + } + for (i = 0; i < ctx->nr; i++) { + struct pack_info *pack = &ctx->info[ctx->pack_perm[i]]; + if (pack->bitmap_pos == BITMAP_POS_UNKNOWN) + pack->bitmap_pos = 0; + } + free(data); + + trace2_region_leave("midx", "midx_pack_order", ctx->repo); + + return pack_order; +} + +static void write_midx_reverse_index(struct write_midx_context *ctx, + const char *object_dir, + unsigned char *midx_hash) +{ + struct strbuf buf = STRBUF_INIT; + char *tmp_file; + + trace2_region_enter("midx", "write_midx_reverse_index", ctx->repo); + + if (ctx->incremental) + get_split_midx_filename_ext(ctx->repo->hash_algo, &buf, + object_dir, midx_hash, + MIDX_EXT_REV); + else + get_midx_filename_ext(ctx->repo->hash_algo, &buf, object_dir, + midx_hash, MIDX_EXT_REV); + + tmp_file = write_rev_file_order(ctx->repo, NULL, ctx->pack_order, + ctx->entries_nr, midx_hash, WRITE_REV); + + if (finalize_object_file(ctx->repo, tmp_file, buf.buf)) + die(_("cannot store reverse index file")); + + strbuf_release(&buf); + free(tmp_file); + + trace2_region_leave("midx", "write_midx_reverse_index", ctx->repo); +} + +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", ctx->repo); + + memset(pdata, 0, sizeof(struct packing_data)); + prepare_packing_data(ctx->repo, pdata); + + for (i = 0; i < ctx->entries_nr; i++) { + uint32_t pos = ctx->pack_order[i]; + struct pack_midx_entry *from = &ctx->entries[pos]; + 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", ctx->repo); +} + +static int add_ref_to_pending(const char *refname, const char *referent UNUSED, + 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(revs->repo, oid, &peeled)) + oid = &peeled; + + object = parse_object_or_die(revs->repo, 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_algop(hex, &oid, &end, revs->repo->hash_algo) < 0) + die(_("could not parse line: %s"), buf.buf); + if (*end) + die(_("malformed line: %s"), buf.buf); + + object = parse_object_or_die(revs->repo, &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", ctx->repo); + + cb.ctx = ctx; + + repo_init_revisions(ctx->repo, &revs, NULL); + if (refs_snapshot) { + read_refs_snapshot(refs_snapshot, &revs); + } else { + setup_revisions(0, NULL, &revs, NULL); + refs_for_each_ref(get_main_ref_store(ctx->repo), + 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", ctx->repo); + + return cb.commits; +} + +static int write_midx_bitmap(struct write_midx_context *ctx, + const char *object_dir, + const unsigned char *midx_hash, + struct packing_data *pdata, + struct commit **commits, + uint32_t commits_nr, + unsigned flags) +{ + int ret, i; + uint16_t options = 0; + struct bitmap_writer writer; + struct pack_idx_entry **index; + struct strbuf bitmap_name = STRBUF_INIT; + + trace2_region_enter("midx", "write_midx_bitmap", ctx->repo); + + if (ctx->incremental) + get_split_midx_filename_ext(ctx->repo->hash_algo, &bitmap_name, + object_dir, midx_hash, + MIDX_EXT_BITMAP); + else + get_midx_filename_ext(ctx->repo->hash_algo, &bitmap_name, + object_dir, midx_hash, MIDX_EXT_BITMAP); + + 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_init(&writer, ctx->repo, pdata, + ctx->incremental ? ctx->base_midx : NULL); + bitmap_writer_show_progress(&writer, flags & MIDX_PROGRESS); + bitmap_writer_build_type_index(&writer, index); + + /* + * 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[ctx->pack_order[i]] = &pdata->objects[i].idx; + + bitmap_writer_select_commits(&writer, commits, commits_nr); + ret = bitmap_writer_build(&writer); + if (ret < 0) + goto cleanup; + + bitmap_writer_set_checksum(&writer, midx_hash); + bitmap_writer_finish(&writer, index, bitmap_name.buf, options); + +cleanup: + free(index); + strbuf_release(&bitmap_name); + bitmap_writer_free(&writer); + + trace2_region_leave("midx", "write_midx_bitmap", ctx->repo); + + return ret; +} + +static struct multi_pack_index *lookup_multi_pack_index(struct repository *r, + const char *object_dir) +{ + struct odb_source *source = odb_find_source(r->objects, object_dir); + return get_multi_pack_index(source); +} + +static int fill_packs_from_midx(struct write_midx_context *ctx, + const char *preferred_pack_name, uint32_t flags) +{ + struct multi_pack_index *m; + + for (m = ctx->m; m; m = m->base_midx) { + uint32_t i; + + for (i = 0; i < m->num_packs; i++) { + ALLOC_GROW(ctx->info, ctx->nr + 1, ctx->alloc); + + /* + * If generating a reverse index, need to have + * packed_git's loaded to compare their + * mtimes and object count. + * + * If a preferred pack is specified, need to + * have packed_git's loaded to ensure the chosen + * preferred pack has a non-zero object count. + */ + if (flags & MIDX_WRITE_REV_INDEX || + preferred_pack_name) { + if (prepare_midx_pack(ctx->repo, m, + m->num_packs_in_base + i)) { + error(_("could not load pack")); + return 1; + } + + if (open_pack_index(m->packs[i])) + die(_("could not open index for %s"), + m->packs[i]->pack_name); + } + + fill_pack_info(&ctx->info[ctx->nr++], m->packs[i], + m->pack_names[i], + m->num_packs_in_base + i); + } + } + return 0; +} + +static struct { + const char *non_split; + const char *split; +} midx_exts[] = { + {NULL, MIDX_EXT_MIDX}, + {MIDX_EXT_BITMAP, MIDX_EXT_BITMAP}, + {MIDX_EXT_REV, MIDX_EXT_REV}, +}; + +static int link_midx_to_chain(struct multi_pack_index *m) +{ + struct strbuf from = STRBUF_INIT; + struct strbuf to = STRBUF_INIT; + int ret = 0; + size_t i; + + if (!m || m->has_chain) { + /* + * Either no MIDX previously existed, or it was already + * part of a MIDX chain. In both cases, we have nothing + * to link, so return early. + */ + goto done; + } + + for (i = 0; i < ARRAY_SIZE(midx_exts); i++) { + const unsigned char *hash = get_midx_checksum(m); + + get_midx_filename_ext(m->repo->hash_algo, &from, m->object_dir, + hash, midx_exts[i].non_split); + get_split_midx_filename_ext(m->repo->hash_algo, &to, + m->object_dir, hash, + midx_exts[i].split); + + if (link(from.buf, to.buf) < 0 && errno != ENOENT) { + ret = error_errno(_("unable to link '%s' to '%s'"), + from.buf, to.buf); + goto done; + } + + strbuf_reset(&from); + strbuf_reset(&to); + } + +done: + strbuf_release(&from); + strbuf_release(&to); + return ret; +} + +static void clear_midx_files(struct repository *r, const char *object_dir, + const char **hashes, uint32_t hashes_nr, + unsigned incremental) +{ + /* + * if incremental: + * - remove all non-incremental MIDX files + * - remove any incremental MIDX files not in the current one + * + * if non-incremental: + * - remove all incremental MIDX files + * - remove any non-incremental MIDX files not matching the current + * hash + */ + struct strbuf buf = STRBUF_INIT; + const char *exts[] = { MIDX_EXT_BITMAP, MIDX_EXT_REV, MIDX_EXT_MIDX }; + uint32_t i, j; + + for (i = 0; i < ARRAY_SIZE(exts); i++) { + clear_incremental_midx_files_ext(object_dir, exts[i], + hashes, hashes_nr); + for (j = 0; j < hashes_nr; j++) + clear_midx_files_ext(object_dir, exts[i], hashes[j]); + } + + if (incremental) + get_midx_filename(r->hash_algo, &buf, object_dir); + else + get_midx_chain_filename(&buf, object_dir); + + if (unlink(buf.buf) && errno != ENOENT) + die_errno(_("failed to clear multi-pack-index at %s"), buf.buf); + + strbuf_release(&buf); +} + +static int write_midx_internal(struct repository *r, 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, start_pack; + struct hashfile *f = NULL; + struct lock_file lk; + struct tempfile *incr; + struct write_midx_context ctx = { 0 }; + int bitmapped_packs_concat_len = 0; + int pack_name_concat_len = 0; + int dropped_packs = 0; + int result = 0; + const char **keep_hashes = NULL; + struct chunkfile *cf; + + trace2_region_enter("midx", "write_midx_internal", r); + + ctx.repo = r; + + ctx.incremental = !!(flags & MIDX_WRITE_INCREMENTAL); + + if (ctx.incremental) + strbuf_addf(&midx_name, + "%s/pack/multi-pack-index.d/tmp_midx_XXXXXX", + object_dir); + else + get_midx_filename(r->hash_algo, &midx_name, object_dir); + if (safe_create_leading_directories(r, midx_name.buf)) + die_errno(_("unable to create leading directories of %s"), + midx_name.buf); + + if (!packs_to_include || ctx.incremental) { + struct multi_pack_index *m = lookup_multi_pack_index(r, object_dir); + if (m && !midx_checksum_valid(m)) { + warning(_("ignoring existing multi-pack-index; checksum mismatch")); + m = NULL; + } + + if (m) { + /* + * 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. + */ + if (ctx.incremental) + ctx.base_midx = m; + else if (!packs_to_include) + ctx.m = m; + } + } + + ctx.nr = 0; + ctx.alloc = ctx.m ? ctx.m->num_packs + ctx.m->num_packs_in_base : 16; + ctx.info = NULL; + ALLOC_ARRAY(ctx.info, ctx.alloc); + + if (ctx.incremental) { + struct multi_pack_index *m = ctx.base_midx; + while (m) { + if (flags & MIDX_WRITE_BITMAP && load_midx_revindex(m)) { + error(_("could not load reverse index for MIDX %s"), + hash_to_hex_algop(get_midx_checksum(m), + m->repo->hash_algo)); + result = 1; + goto cleanup; + } + ctx.num_multi_pack_indexes_before++; + m = m->base_midx; + } + } else if (ctx.m && fill_packs_from_midx(&ctx, preferred_pack_name, + flags) < 0) { + goto cleanup; + } + + start_pack = ctx.nr; + + ctx.pack_paths_checked = 0; + if (flags & MIDX_PROGRESS) + ctx.progress = start_delayed_progress(r, + _("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 + ctx.m->num_packs_in_base) && + !ctx.incremental && + !(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 (ctx.incremental && !ctx.nr) + goto cleanup; /* nothing to do */ + + if (preferred_pack_name) { + ctx.preferred_pack_idx = -1; + + 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; + break; + } + } + + if (ctx.preferred_pack_idx == -1) + 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; + } + } + + compute_sorted_entries(&ctx, start_pack); + + 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) + continue; + pack_name_concat_len += strlen(ctx.info[i].pack_name) + 1; + bitmapped_packs_concat_len += 2 * sizeof(uint32_t); + } + + /* 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); + + 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); + } + + if (ctx.incremental) { + struct strbuf lock_name = STRBUF_INIT; + + get_midx_chain_filename(&lock_name, object_dir); + hold_lock_file_for_update(&lk, lock_name.buf, LOCK_DIE_ON_ERROR); + strbuf_release(&lock_name); + + incr = mks_tempfile_m(midx_name.buf, 0444); + if (!incr) { + error(_("unable to create temporary MIDX layer")); + return -1; + } + + if (adjust_shared_perm(r, get_tempfile_path(incr))) { + error(_("unable to adjust shared permissions for '%s'"), + get_tempfile_path(incr)); + return -1; + } + + f = hashfd(r->hash_algo, get_tempfile_fd(incr), + get_tempfile_path(incr)); + } else { + hold_lock_file_for_update(&lk, midx_name.buf, LOCK_DIE_ON_ERROR); + f = hashfd(r->hash_algo, get_lock_file_fd(&lk), + get_lock_file_path(&lk)); + } + + 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, + st_mult(ctx.entries_nr, r->hash_algo->rawsz), + write_midx_oid_lookup); + add_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, + st_mult(ctx.entries_nr, MIDX_CHUNK_OFFSET_WIDTH), + write_midx_object_offsets); + + if (ctx.large_offsets_needed) + add_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, + st_mult(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, + st_mult(ctx.entries_nr, sizeof(uint32_t)), + write_midx_revindex); + add_chunk(cf, MIDX_CHUNKID_BITMAPPEDPACKS, + bitmapped_packs_concat_len, + write_midx_bitmapped_packs); + } + + write_midx_header(r->hash_algo, 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(&ctx, object_dir, midx_hash); + + 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(&ctx, object_dir, + midx_hash, &pdata, commits, commits_nr, + flags) < 0) { + error(_("could not write multi-pack bitmap")); + result = 1; + clear_packing_data(&pdata); + free(commits); + goto cleanup; + } + + clear_packing_data(&pdata); + free(commits); + } + /* + * NOTE: Do not use ctx.entries beyond this point, since it might + * have been freed in the previous if block. + */ + + CALLOC_ARRAY(keep_hashes, ctx.num_multi_pack_indexes_before + 1); + + if (ctx.incremental) { + FILE *chainf = fdopen_lock_file(&lk, "w"); + struct strbuf final_midx_name = STRBUF_INIT; + struct multi_pack_index *m = ctx.base_midx; + + if (!chainf) { + error_errno(_("unable to open multi-pack-index chain file")); + return -1; + } + + if (link_midx_to_chain(ctx.base_midx) < 0) + return -1; + + get_split_midx_filename_ext(r->hash_algo, &final_midx_name, + object_dir, midx_hash, MIDX_EXT_MIDX); + + if (rename_tempfile(&incr, final_midx_name.buf) < 0) { + error_errno(_("unable to rename new multi-pack-index layer")); + return -1; + } + + strbuf_release(&final_midx_name); + + keep_hashes[ctx.num_multi_pack_indexes_before] = + xstrdup(hash_to_hex_algop(midx_hash, r->hash_algo)); + + for (i = 0; i < ctx.num_multi_pack_indexes_before; i++) { + uint32_t j = ctx.num_multi_pack_indexes_before - i - 1; + + keep_hashes[j] = xstrdup(hash_to_hex_algop(get_midx_checksum(m), + r->hash_algo)); + m = m->base_midx; + } + + for (i = 0; i < ctx.num_multi_pack_indexes_before + 1; i++) + fprintf(get_lock_file_fp(&lk), "%s\n", keep_hashes[i]); + } else { + keep_hashes[ctx.num_multi_pack_indexes_before] = + xstrdup(hash_to_hex_algop(midx_hash, r->hash_algo)); + } + + if (ctx.m || ctx.base_midx) + close_object_store(ctx.repo->objects); + + if (commit_lock_file(&lk) < 0) + die_errno(_("could not write multi-pack-index")); + + clear_midx_files(r, object_dir, keep_hashes, + ctx.num_multi_pack_indexes_before + 1, + ctx.incremental); + +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); + if (keep_hashes) { + for (i = 0; i < ctx.num_multi_pack_indexes_before + 1; i++) + free((char *)keep_hashes[i]); + free(keep_hashes); + } + strbuf_release(&midx_name); + + trace2_region_leave("midx", "write_midx_internal", r); + + return result; +} + +int write_midx_file(struct repository *r, const char *object_dir, + const char *preferred_pack_name, + const char *refs_snapshot, unsigned flags) +{ + return write_midx_internal(r, object_dir, NULL, NULL, + preferred_pack_name, refs_snapshot, + flags); +} + +int write_midx_file_only(struct repository *r, 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(r, object_dir, packs_to_include, NULL, + preferred_pack_name, refs_snapshot, flags); +} + +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; + + if (m->base_midx) + die(_("cannot expire packs from an incremental multi-pack-index")); + + CALLOC_ARRAY(count, m->num_packs); + + if (flags & MIDX_PROGRESS) + progress = start_delayed_progress( + r, + _("Counting referenced objects"), + m->num_objects); + for (i = 0; i < m->num_objects; i++) { + uint32_t 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( + r, + _("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(r, 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 want_included_pack(struct repository *r, + struct multi_pack_index *m, + int pack_kept_objects, + uint32_t pack_int_id) +{ + struct packed_git *p; + if (prepare_midx_pack(r, m, pack_int_id)) + return 0; + p = m->packs[pack_int_id]; + if (!pack_kept_objects && p->pack_keep) + return 0; + if (p->is_cruft) + return 0; + if (open_pack_index(p) || !p->num_objects) + return 0; + return 1; +} + +static void fill_included_packs_all(struct repository *r, + struct multi_pack_index *m, + unsigned char *include_pack) +{ + uint32_t i; + int pack_kept_objects = 0; + + repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects); + + for (i = 0; i < m->num_packs; i++) { + if (!want_included_pack(r, m, pack_kept_objects, i)) + continue; + + include_pack[i] = 1; + } +} + +static void fill_included_packs_batch(struct repository *r, + struct multi_pack_index *m, + unsigned char *include_pack, + size_t batch_size) +{ + uint32_t i; + 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; + for (i = 0; total_size < batch_size && i < m->num_packs; i++) { + uint32_t pack_int_id = pack_info[i].pack_int_id; + struct packed_git *p = m->packs[pack_int_id]; + uint64_t expected_size; + + if (!want_included_pack(r, m, pack_kept_objects, pack_int_id)) + continue; + + /* + * Use shifted integer arithmetic to calculate the + * expected pack size to ~4 significant digits without + * overflow for packsizes less that 1PB. + */ + expected_size = (uint64_t)pack_info[i].referenced_objects << 14; + expected_size /= p->num_objects; + expected_size = u64_mult(expected_size, p->pack_size); + expected_size = u64_add(expected_size, 1u << 13) >> 14; + + if (expected_size >= batch_size) + continue; + + if (unsigned_add_overflows(total_size, (size_t)expected_size)) + total_size = SIZE_MAX; + else + total_size += expected_size; + + include_pack[pack_int_id] = 1; + } + + free(pack_info); +} + +int midx_repack(struct repository *r, const char *object_dir, size_t batch_size, unsigned flags) +{ + int result = 0; + uint32_t i, packs_to_repack = 0; + unsigned char *include_pack; + struct child_process cmd = CHILD_PROCESS_INIT; + FILE *cmd_in; + 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; + if (m->base_midx) + die(_("cannot repack an incremental multi-pack-index")); + + CALLOC_ARRAY(include_pack, m->num_packs); + + if (batch_size) + fill_included_packs_batch(r, m, include_pack, batch_size); + else + fill_included_packs_all(r, m, include_pack); + + for (i = 0; i < m->num_packs; i++) { + if (include_pack[i]) + packs_to_repack++; + } + if (packs_to_repack <= 1) + 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"); + + strvec_pushf(&cmd.args, "%s/pack/pack", object_dir); + + 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"); + + 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(r, object_dir, NULL, NULL, NULL, NULL, + flags); + +cleanup: + free(include_pack); + return result; +} |