From 0d5b3a5ef72383f3b6fe93793be3bbd107a88eaa Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Thu, 12 Jul 2018 15:39:30 -0400 Subject: [PATCH] midx: write object ids in a chunk Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano --- Documentation/technical/pack-format.txt | 4 +++ midx.c | 47 +++++++++++++++++++++++-- midx.h | 1 + t/helper/test-read-midx.c | 2 ++ t/t5319-multi-pack-index.sh | 4 +-- 5 files changed, 53 insertions(+), 5 deletions(-) diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index 6c5a77475f..78ee0489c6 100644 --- a/Documentation/technical/pack-format.txt +++ b/Documentation/technical/pack-format.txt @@ -302,6 +302,10 @@ CHUNK DATA: name. This is the only chunk not guaranteed to be a multiple of four bytes in length, so should be the last chunk for alignment reasons. + OID Lookup (ID: {'O', 'I', 'D', 'L'}) + The OIDs for all objects in the MIDX are stored in lexicographic + order in this chunk. + (This section intentionally left incomplete.) TRAILER: diff --git a/midx.c b/midx.c index 29f8de5ee6..3f113e1beb 100644 --- a/midx.c +++ b/midx.c @@ -18,9 +18,10 @@ #define MIDX_HASH_LEN 20 #define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN) -#define MIDX_MAX_CHUNKS 1 +#define MIDX_MAX_CHUNKS 2 #define MIDX_CHUNK_ALIGNMENT 4 #define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */ +#define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */ #define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t)) static char *get_midx_filename(const char *object_dir) @@ -101,6 +102,10 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir) m->chunk_pack_names = m->data + chunk_offset; break; + case MIDX_CHUNKID_OIDLOOKUP: + m->chunk_oid_lookup = m->data + chunk_offset; + break; + case 0: die(_("terminating multi-pack-index chunk id appears earlier than expected")); break; @@ -116,6 +121,8 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir) if (!m->chunk_pack_names) die(_("multi-pack-index missing required pack-name chunk")); + if (!m->chunk_oid_lookup) + die(_("multi-pack-index missing required OID lookup chunk")); m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names)); @@ -382,6 +389,32 @@ static size_t write_midx_pack_names(struct hashfile *f, return written; } +static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len, + struct pack_midx_entry *objects, + uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects; + uint32_t i; + size_t written = 0; + + for (i = 0; i < nr_objects; i++) { + struct pack_midx_entry *obj = list++; + + if (i < nr_objects - 1) { + struct pack_midx_entry *next = list; + if (oidcmp(&obj->oid, &next->oid) >= 0) + BUG("OIDs not in order: %s >= %s", + oid_to_hex(&obj->oid), + oid_to_hex(&next->oid)); + } + + hashwrite(f, obj->oid.hash, (int)hash_len); + written += hash_len; + } + + return written; +} + int write_midx_file(const char *object_dir) { unsigned char cur_chunk, num_chunks = 0; @@ -428,7 +461,7 @@ int write_midx_file(const char *object_dir) FREE_AND_NULL(midx_name); cur_chunk = 0; - num_chunks = 1; + num_chunks = 2; written = write_midx_header(f, num_chunks, packs.nr); @@ -436,9 +469,13 @@ int write_midx_file(const char *object_dir) chunk_offsets[cur_chunk] = written + (num_chunks + 1) * MIDX_CHUNKLOOKUP_WIDTH; cur_chunk++; - chunk_ids[cur_chunk] = 0; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDLOOKUP; chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + packs.pack_name_concat_len; + cur_chunk++; + chunk_ids[cur_chunk] = 0; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * MIDX_HASH_LEN; + for (i = 0; i <= num_chunks; i++) { if (i && chunk_offsets[i] < chunk_offsets[i - 1]) BUG("incorrect chunk offsets: %"PRIu64" before %"PRIu64, @@ -468,6 +505,10 @@ int write_midx_file(const char *object_dir) written += write_midx_pack_names(f, packs.names, packs.nr); break; + case MIDX_CHUNKID_OIDLOOKUP: + written += write_midx_oid_lookup(f, MIDX_HASH_LEN, entries, nr_entries); + break; + default: BUG("trying to write unknown chunk id %"PRIx32, chunk_ids[i]); diff --git a/midx.h b/midx.h index 17b56172e3..4d3bceafc5 100644 --- a/midx.h +++ b/midx.h @@ -15,6 +15,7 @@ struct multi_pack_index { uint32_t num_objects; const unsigned char *chunk_pack_names; + const unsigned char *chunk_oid_lookup; const char **pack_names; char object_dir[FLEX_ARRAY]; diff --git a/t/helper/test-read-midx.c b/t/helper/test-read-midx.c index 76a60d7882..de6d452a7c 100644 --- a/t/helper/test-read-midx.c +++ b/t/helper/test-read-midx.c @@ -22,6 +22,8 @@ static int read_midx_file(const char *object_dir) if (m->chunk_pack_names) printf(" pack-names"); + if (m->chunk_oid_lookup) + printf(" oid-lookup"); printf("\n"); diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh index e8da082c64..4813610115 100755 --- a/t/t5319-multi-pack-index.sh +++ b/t/t5319-multi-pack-index.sh @@ -7,8 +7,8 @@ midx_read_expect () { NUM_PACKS=$1 { cat <<-EOF && - header: 4d494458 1 1 $NUM_PACKS - chunks: pack-names + header: 4d494458 1 2 $NUM_PACKS + chunks: pack-names oid-lookup packs: EOF if test $NUM_PACKS -ge 1