[PATCH 13/22] pack-bitmap: write multi-pack bitmaps
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Apr 9, 2021, 18:11 UTC
- Message-ID
- <fd320c5ed48c7431b64b898f49101b0f53655a95.1617991824.git.me@ttaylorr.com>
- In-Reply-To
- <cover.1617991824.git.me@ttaylorr.com>
Write multi-pack bitmaps in the format described by Documentation/technical/bitmap-format.txt, inferring their presence with the absence of '--bitmap'.
To write a multi-pack bitmap, this patch attempts to reuse as much of the existing machinery from pack-objects as possible. Specifically, the MIDX code prepares a packing_data struct that pretends as if a single packfile has been generated containing all of the objects contained within the MIDX.
Signed-off-by: Taylor Blau <me@ttaylorr.com> --- Documentation/git-multi-pack-index.txt | 12 +- builtin/multi-pack-index.c | 2 + midx.c | 195 ++++++++++++++++++++++++- midx.h | 1 + 4 files changed, 202 insertions(+), 8 deletions(-)
diff --git a/Documentation/git-multi-pack-index.txt b/Documentation/git-multi-pack-index.txt index ffd601bc17..ada14deb2c 100644 --- a/Documentation/git-multi-pack-index.txt +++ b/Documentation/git-multi-pack-index.txt @@ -10,7 +10,7 @@ SYNOPSIS -------- [verse] 'git multi-pack-index' [--object-dir=<dir>] [--[no-]progress] - [--preferred-pack=<pack>] <subcommand> + [--preferred-pack=<pack>] [--[no-]bitmap] <subcommand> DESCRIPTION ----------- @@ -40,6 +40,9 @@ write:: multiple packs contain the same object. If not given, ties are broken in favor of the pack with the lowest mtime. + + --[no-]bitmap:: + Control whether or not a multi-pack bitmap is written. -- verify:: @@ -81,6 +84,13 @@ EXAMPLES $ git multi-pack-index write ----------------------------------------------- +* Write a MIDX file for the packfiles in the current .git folder with a +corresponding bitmap. ++ +------------------------------------------------------------- +$ git multi-pack-index write --preferred-pack <pack> --bitmap +------------------------------------------------------------- + * Write a MIDX file for the packfiles in an alternate object store. + ----------------------------------------------- diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c index 5d3ea445fd..bf6fa982e3 100644 --- a/builtin/multi-pack-index.c +++ b/builtin/multi-pack-index.c @@ -68,6 +68,8 @@ static int cmd_multi_pack_index_write(int argc, const char **argv) OPT_STRING(0, "preferred-pack", &opts.preferred_pack, N_("preferred-pack"), N_("pack for reuse when computing a multi-pack bitmap")), + OPT_BIT(0, "bitmap", &opts.flags, N_("write multi-pack bitmap"), + MIDX_WRITE_BITMAP | MIDX_WRITE_REV_INDEX), OPT_END(), }; diff --git a/midx.c b/midx.c index 567cdf0fcf..32d7d184c0 100644 --- a/midx.c +++ b/midx.c @@ -13,6 +13,10 @@ #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 @@ -885,6 +889,145 @@ static void write_midx_reverse_index(char *midx_name, unsigned char *midx_hash, static void clear_midx_files_ext(struct repository *r, const char *ext, unsigned char *keep_hash); +static void prepare_midx_packing_data(struct packing_data *pdata, + struct write_midx_context *ctx) +{ + uint32_t i; + + 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); + } +} + +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 *object; + + if ((flag & REF_ISSYMREF) && (flag & REF_ISBROKEN)) { + warning("symbolic ref is dangling: %s", refname); + return 0; + } + + 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; + if (oid_pos(&commit->object.oid, data->ctx->entries, + data->ctx->entries_nr, + bitmap_oid_access) > -1) { + ALLOC_GROW(data->commits, data->commits_nr + 1, + data->commits_alloc); + data->commits[data->commits_nr++] = commit; + } +} + +static struct commit **find_commits_for_midx_bitmap(uint32_t *indexed_commits_nr_p, + struct write_midx_context *ctx) +{ + struct rev_info revs; + struct bitmap_commit_cb cb; + + memset(&cb, 0, sizeof(struct bitmap_commit_cb)); + cb.ctx = ctx; + + repo_init_revisions(the_repository, &revs, NULL); + for_each_ref(add_ref_to_pending, &revs); + + 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; + + return cb.commits; +} + +static int write_midx_bitmap(char *midx_name, unsigned char *midx_hash, + struct write_midx_context *ctx, + unsigned flags) +{ + struct packing_data pdata; + struct pack_idx_entry **index; + struct commit **commits = NULL; + uint32_t i, commits_nr; + char *bitmap_name = xstrfmt("%s-%s.bitmap", midx_name, hash_to_hex(midx_hash)); + int ret; + + prepare_midx_packing_data(&pdata, ctx); + + commits = find_commits_for_midx_bitmap(&commits_nr, ctx); + + /* + * 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] = (struct pack_idx_entry *)&pdata.objects[i]; + + bitmap_writer_show_progress(flags & MIDX_PROGRESS); + bitmap_writer_build_type_index(&pdata, index, pdata.nr_objects); + + /* + * bitmap_writer_select_commits expects objects in lex order, but + * pack_order gives us exactly that. use it directly instead of + * re-sorting the array + */ + for (i = 0; i < pdata.nr_objects; i++) + index[ctx->pack_order[i]] = (struct pack_idx_entry *)&pdata.objects[i]; + + bitmap_writer_select_commits(commits, commits_nr, -1); + ret = bitmap_writer_build(&pdata); + if (!ret) + goto cleanup; + + bitmap_writer_set_checksum(midx_hash); + bitmap_writer_finish(index, pdata.nr_objects, bitmap_name, 0); + +cleanup: + free(index); + free(bitmap_name); + return ret; +} + static int write_midx_internal(const char *object_dir, struct multi_pack_index *m, struct string_list *packs_to_drop, const char *preferred_pack_name, @@ -930,9 +1073,16 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * for (i = 0; i < ctx.m->num_packs; i++) { ALLOC_GROW(ctx.info, ctx.nr + 1, ctx.alloc); + if (prepare_midx_pack(the_repository, ctx.m, i)) { + error(_("could not load pack %s"), + ctx.m->pack_names[i]); + result = 1; + goto cleanup; + } + 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 = NULL; + ctx.info[ctx.nr].p = ctx.m->packs[i]; ctx.info[ctx.nr].expired = 0; ctx.nr++; } @@ -947,8 +1097,26 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * 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_drop) - goto cleanup; + if (ctx.m && ctx.nr == ctx.m->num_packs && !packs_to_drop) { + struct bitmap_index *bitmap_git; + int bitmap_exists; + int want_bitmap = flags & MIDX_WRITE_BITMAP; + + bitmap_git = prepare_bitmap_git(the_repository); + 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(the_repository, ".bitmap", + NULL); + goto cleanup; + } + } ctx.preferred_pack_idx = -1; if (preferred_pack_name) { @@ -1048,9 +1216,6 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR); f = hashfd(get_lock_file_fd(&lk), get_lock_file_path(&lk)); - if (ctx.m) - close_midx(ctx.m); - if (ctx.nr - dropped_packs == 0) { error(_("no pack files to index.")); result = 1; @@ -1081,14 +1246,17 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * finalize_hashfile(f, midx_hash, CSUM_FSYNC | CSUM_HASH_IN_STREAM); free_chunkfile(cf); - if (flags & MIDX_WRITE_REV_INDEX) + if (flags & (MIDX_WRITE_REV_INDEX | MIDX_WRITE_BITMAP)) ctx.pack_order = midx_pack_order(&ctx); if (flags & MIDX_WRITE_REV_INDEX) write_midx_reverse_index(midx_name, midx_hash, &ctx); + if (flags & MIDX_WRITE_BITMAP) + write_midx_bitmap(midx_name, midx_hash, &ctx, flags); commit_lock_file(&lk); + clear_midx_files_ext(the_repository, ".bitmap", midx_hash); clear_midx_files_ext(the_repository, ".rev", midx_hash); cleanup: @@ -1096,6 +1264,15 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * if (ctx.info[i].p) { close_pack(ctx.info[i].p); free(ctx.info[i].p); + if (ctx.m) { + /* + * Destroy a stale reference to the pack in + * 'ctx.m'. + */ + uint32_t orig = ctx.info[i].orig_pack_int_id; + if (orig < ctx.m->num_packs) + ctx.m->packs[orig] = NULL; + } } free(ctx.info[i].pack_name); } @@ -1105,6 +1282,9 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * free(ctx.pack_perm); free(ctx.pack_order); free(midx_name); + if (ctx.m) + close_midx(ctx.m); + return result; } @@ -1166,6 +1346,7 @@ void clear_midx_file(struct repository *r) if (remove_path(midx)) die(_("failed to clear multi-pack-index at %s"), midx); + clear_midx_files_ext(r, ".bitmap", NULL); clear_midx_files_ext(r, ".rev", NULL); free(midx); diff --git a/midx.h b/midx.h index 1172df1a71..350f4d0a7b 100644 --- a/midx.h +++ b/midx.h @@ -41,6 +41,7 @@ struct multi_pack_index { #define MIDX_PROGRESS (1 << 0) #define MIDX_WRITE_REV_INDEX (1 << 1) +#define MIDX_WRITE_BITMAP (1 << 2) const unsigned char *get_midx_checksum(struct multi_pack_index *m); char *get_midx_filename(const char *object_dir);
-- 2.31.1.163.ga65ce7f831