[PATCH v3 03/13] pack-bitmap.c: open and store incremental bitmap layers
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Nov 19, 2024, 22:07 UTC
- Message-ID
- <5b5d625cbe02560a20c12b7dd20aeda4979017bb.1732054032.git.me@ttaylorr.com>
- In-Reply-To
- <cover.1732054032.git.me@ttaylorr.com>
Prepare the pack-bitmap machinery to work with incremental MIDXs by adding a new "base" field to keep track of the bitmap index associated with the previous MIDX layer.
The changes in this commit are mostly boilerplate to open the correct bitmap(s), add them to the chain bitmap layers along the "base" pointer, ensures that the correct packs and their reverse indexes are loaded across MIDX layers, etc.
While we're at it, keep track of a base_nr field to indicate how many bitmap layers (including the current bitmap) exist. This will be used in a future commit to allocate an array of 'struct ewah_bitmap' pointers to collect all of the respective type bitmaps among all layers to initialize a multi-EWAH iterator.
Subsequent commits will teach the functions within the pack-bitmap machinery how to interact with these new fields.
Signed-off-by: Taylor Blau <me@ttaylorr.com> --- pack-bitmap.c | 64 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 51 insertions(+), 13 deletions(-)
diff --git a/pack-bitmap.c b/pack-bitmap.c index bba9c6a905a..41675a69f68 100644 --- a/pack-bitmap.c +++ b/pack-bitmap.c @@ -54,6 +54,13 @@ struct bitmap_index { struct packed_git *pack; struct multi_pack_index *midx; + /* + * If using a multi-pack index chain, 'base' points to the + * bitmap index corresponding to this bitmap's midx->base_midx. + */ + struct bitmap_index *base; + uint32_t base_nr; + /* mmapped buffer of the whole bitmap index */ unsigned char *map; size_t map_size; /* size of the mmaped buffer */ @@ -377,8 +384,13 @@ static int load_bitmap_entries_v1(struct bitmap_index *index) char *midx_bitmap_filename(struct multi_pack_index *midx) { struct strbuf buf = STRBUF_INIT; - get_midx_filename_ext(&buf, midx->object_dir, get_midx_checksum(midx), - MIDX_EXT_BITMAP); + if (midx->has_chain) + get_split_midx_filename_ext(&buf, midx->object_dir, + get_midx_checksum(midx), + MIDX_EXT_BITMAP); + else + get_midx_filename_ext(&buf, midx->object_dir, + get_midx_checksum(midx), MIDX_EXT_BITMAP); return strbuf_detach(&buf, NULL); } @@ -397,10 +409,17 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git, { struct stat st; char *bitmap_name = midx_bitmap_filename(midx); - int fd = git_open(bitmap_name); + int fd; uint32_t i, preferred_pack; struct packed_git *preferred; + fd = git_open(bitmap_name); + if (fd < 0 && errno == ENOENT) { + FREE_AND_NULL(bitmap_name); + bitmap_name = midx_bitmap_filename(midx); + fd = git_open(bitmap_name); + } + if (fd < 0) { if (errno != ENOENT) warning_errno("cannot open '%s'", bitmap_name); @@ -446,7 +465,7 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git, goto cleanup; } - for (i = 0; i < bitmap_git->midx->num_packs; i++) { + for (i = 0; i < bitmap_git->midx->num_packs + bitmap_git->midx->num_packs_in_base; i++) { if (prepare_midx_pack(the_repository, bitmap_git->midx, i)) { warning(_("could not open pack %s"), bitmap_git->midx->pack_names[i]); @@ -459,13 +478,20 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git, goto cleanup; } - preferred = bitmap_git->midx->packs[preferred_pack]; + preferred = nth_midxed_pack(bitmap_git->midx, preferred_pack); if (!is_pack_valid(preferred)) { warning(_("preferred pack (%s) is invalid"), preferred->pack_name); goto cleanup; } + if (midx->base_midx) { + bitmap_git->base = prepare_midx_bitmap_git(midx->base_midx); + bitmap_git->base_nr = bitmap_git->base->base_nr + 1; + } else { + bitmap_git->base_nr = 1; + } + return 0; cleanup: @@ -516,6 +542,7 @@ static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git bitmap_git->map_size = xsize_t(st.st_size); bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0); bitmap_git->map_pos = 0; + bitmap_git->base_nr = 1; close(fd); if (load_bitmap_header(bitmap_git) < 0) { @@ -535,8 +562,7 @@ static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git static int load_reverse_index(struct repository *r, struct bitmap_index *bitmap_git) { if (bitmap_is_midx(bitmap_git)) { - uint32_t i; - int ret; + struct multi_pack_index *m; /* * The multi-pack-index's .rev file is already loaded via @@ -545,10 +571,15 @@ static int load_reverse_index(struct repository *r, struct bitmap_index *bitmap_ * But we still need to open the individual pack .rev files, * since we will need to make use of them in pack-objects. */ - for (i = 0; i < bitmap_git->midx->num_packs; i++) { - ret = load_pack_revindex(r, bitmap_git->midx->packs[i]); - if (ret) - return ret; + for (m = bitmap_git->midx; m; m = m->base_midx) { + uint32_t i; + int ret; + + for (i = 0; i < m->num_packs; i++) { + ret = load_pack_revindex(r, m->packs[i]); + if (ret) + return ret; + } } return 0; } @@ -574,6 +605,13 @@ static int load_bitmap(struct repository *r, struct bitmap_index *bitmap_git) if (!bitmap_git->table_lookup && load_bitmap_entries_v1(bitmap_git) < 0) goto failed; + if (bitmap_git->base) { + if (!bitmap_is_midx(bitmap_git)) + BUG("non-MIDX bitmap has non-NULL base bitmap index"); + if (load_bitmap(r, bitmap_git->base) < 0) + goto failed; + } + return 0; failed: @@ -658,10 +696,9 @@ struct bitmap_index *prepare_bitmap_git(struct repository *r) struct bitmap_index *prepare_midx_bitmap_git(struct multi_pack_index *midx) { - struct repository *r = the_repository; struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git)); - if (!open_midx_bitmap_1(bitmap_git, midx) && !load_bitmap(r, bitmap_git)) + if (!open_midx_bitmap_1(bitmap_git, midx)) return bitmap_git; free_bitmap_index(bitmap_git); @@ -2875,6 +2912,7 @@ void free_bitmap_index(struct bitmap_index *b) close_midx_revindex(b->midx); } free_pseudo_merge_map(&b->pseudo_merges); + free_bitmap_index(b->base); free(b); }
-- 2.47.0.301.g77ddd1170f9