Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
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
--
2.18.0.118.gd4f65b8d14
