diff options
author | Derrick Stolee <stolee@gmail.com> | 2018-07-12 22:39:31 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2018-07-20 21:27:28 +0300 |
commit | d7cacf29ccfcb2a33bcd8468f83daf822430f19a (patch) | |
tree | 2a554bd2a30108604d533686b430034f74f41286 /midx.c | |
parent | 0d5b3a5ef72383f3b6fe93793be3bbd107a88eaa (diff) |
midx: write object id fanout chunk
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'midx.c')
-rw-r--r-- | midx.c | 53 |
1 files changed, 50 insertions, 3 deletions
@@ -18,11 +18,13 @@ #define MIDX_HASH_LEN 20 #define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN) -#define MIDX_MAX_CHUNKS 2 +#define MIDX_MAX_CHUNKS 3 #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_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t)) +#define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256) static char *get_midx_filename(const char *object_dir) { @@ -102,6 +104,10 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir) m->chunk_pack_names = m->data + chunk_offset; break; + case MIDX_CHUNKID_OIDFANOUT: + m->chunk_oid_fanout = (uint32_t *)(m->data + chunk_offset); + break; + case MIDX_CHUNKID_OIDLOOKUP: m->chunk_oid_lookup = m->data + chunk_offset; break; @@ -121,9 +127,13 @@ 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_fanout) + die(_("multi-pack-index missing required OID fanout chunk")); if (!m->chunk_oid_lookup) die(_("multi-pack-index missing required OID lookup chunk")); + m->num_objects = ntohl(m->chunk_oid_fanout[255]); + m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names)); cur_pack_name = (const char *)m->chunk_pack_names; @@ -389,6 +399,35 @@ static size_t write_midx_pack_names(struct hashfile *f, return written; } +static size_t write_midx_oid_fanout(struct hashfile *f, + struct pack_midx_entry *objects, + uint32_t nr_objects) +{ + struct pack_midx_entry *list = objects; + struct pack_midx_entry *last = objects + nr_objects; + 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 MIDX_CHUNK_FANOUT_SIZE; +} + static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len, struct pack_midx_entry *objects, uint32_t nr_objects) @@ -461,7 +500,7 @@ int write_midx_file(const char *object_dir) FREE_AND_NULL(midx_name); cur_chunk = 0; - num_chunks = 2; + num_chunks = 3; written = write_midx_header(f, num_chunks, packs.nr); @@ -469,10 +508,14 @@ 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] = MIDX_CHUNKID_OIDLOOKUP; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDFANOUT; chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + packs.pack_name_concat_len; cur_chunk++; + chunk_ids[cur_chunk] = MIDX_CHUNKID_OIDLOOKUP; + chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + MIDX_CHUNK_FANOUT_SIZE; + + cur_chunk++; chunk_ids[cur_chunk] = 0; chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + nr_entries * MIDX_HASH_LEN; @@ -505,6 +548,10 @@ int write_midx_file(const char *object_dir) written += write_midx_pack_names(f, packs.names, packs.nr); break; + case MIDX_CHUNKID_OIDFANOUT: + written += write_midx_oid_fanout(f, entries, nr_entries); + break; + case MIDX_CHUNKID_OIDLOOKUP: written += write_midx_oid_lookup(f, MIDX_HASH_LEN, entries, nr_entries); break; |