midx: write object ids in a chunk

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt
index 6c5a77475f4a65fc6d177e6430696dde3e244edf..78ee0489c60cf38cf5fff104364cf9532a60e139 100644 (file)
--- 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.
 
            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:
        (This section intentionally left incomplete.)
 
 TRAILER:

diff --git a/midx.c b/midx.c
index 29f8de5ee6461e1a8f7cd3ba7a3089c408fed30d..3f113e1bebbf74e639290d525c34b208e1bfc57f 100644 (file)
--- 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_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_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)
 #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;
 
                                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;
                        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_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));
 
 
        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;
 }
 
        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;
 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;
        FREE_AND_NULL(midx_name);
 
        cur_chunk = 0;

-       num_chunks = 1;
+       num_chunks = 2;

 
        written = write_midx_header(f, num_chunks, packs.nr);
 
 
        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_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;
 
        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,
        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;
 
                                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]);
                        default:
                                BUG("trying to write unknown chunk id %"PRIx32,
                                    chunk_ids[i]);

diff --git a/midx.h b/midx.h
index 17b56172e3cc4c075d74e0814a45e9517284550c..4d3bceafc5805850f067bf4c82cf0c3900e5e9b3 100644 (file)
--- a/midx.h
+++ b/midx.h
@@ -15,6 +15,7 @@ struct multi_pack_index {
        uint32_t num_objects;
 
        const unsigned char *chunk_pack_names;
        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];
 
        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 76a60d78828307b20040ebeedb97fb4b642f2c81..de6d452a7ced7d5b7a1b02d8ebf26d267ae2cc05 100644 (file)
--- 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_pack_names)
                printf(" pack-names");

+       if (m->chunk_oid_lookup)
+               printf(" oid-lookup");

 
        printf("\n");
 
 
        printf("\n");
 

diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index e8da082c64fa496728e62a32b0e24d37fc145488..4813610115783fb5938cc2335a78b95af36350f9 100755 (executable)
--- 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 &&
        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
                packs:
                EOF
                if test $NUM_PACKS -ge 1