[PATCH v4 11/23] midx: read pack names into array

[Derrick Stolee]

Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
 midx.c                      | 17 +++++++++++++++++
 midx.h                      |  1 +
 t/helper/test-read-midx.c   |  5 +++++
 t/t5319-multi-pack-index.sh | 17 ++++++++++++-----
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/midx.c b/midx.c
index ca7a32bf95..fcdf6553ce 100644
--- a/midx.c
+++ b/midx.c
@@ -37,6 +37,7 @@ struct multi_pack_index *load_multi_pack_index(const char 
*object_dir)
        uint32_t hash_version;
        char *midx_name = get_midx_filename(object_dir);
        uint32_t i;
+       const char *cur_pack_name;
 
        fd = git_open(midx_name);
 
@@ -115,6 +116,22 @@ 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"));
 
+       m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names));
+
+       cur_pack_name = (const char *)m->chunk_pack_names;
+       for (i = 0; i < m->num_packs; i++) {
+               m->pack_names[i] = cur_pack_name;
+
+               cur_pack_name += strlen(cur_pack_name) + 1;
+
+               if (i && strcmp(m->pack_names[i], m->pack_names[i - 1]) <= 0) {
+                       error(_("multi-pack-index pack names out of order: '%s' 
before '%s'"),
+                             m->pack_names[i - 1],
+                             m->pack_names[i]);
+                       goto cleanup_fail;
+               }
+       }
+
        return m;
 
 cleanup_fail:
diff --git a/midx.h b/midx.h
index 38af01fa3b..17b56172e3 100644
--- a/midx.h
+++ b/midx.h
@@ -16,6 +16,7 @@ struct multi_pack_index {
 
        const unsigned char *chunk_pack_names;
 
+       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 3f2d2cfa78..76a60d7882 100644
--- a/t/helper/test-read-midx.c
+++ b/t/helper/test-read-midx.c
@@ -6,6 +6,7 @@
 
 static int read_midx_file(const char *object_dir)
 {
+       uint32_t i;
        struct multi_pack_index *m = load_multi_pack_index(object_dir);
 
        if (!m)
@@ -24,6 +25,10 @@ static int read_midx_file(const char *object_dir)
 
        printf("\n");
 
+       printf("packs:\n");
+       for (i = 0; i < m->num_packs; i++)
+               printf("%s\n", m->pack_names[i]);
+
        printf("object-dir: %s\n", m->object_dir);
 
        return 0;
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 7512d55c92..e8da082c64 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -5,11 +5,18 @@ test_description='multi-pack-indexes'
 
 midx_read_expect () {
        NUM_PACKS=$1
-       cat >expect <<-EOF
-       header: 4d494458 1 1 $NUM_PACKS
-       chunks: pack-names
-       object-dir: .
-       EOF
+       {
+               cat <<-EOF &&
+               header: 4d494458 1 1 $NUM_PACKS
+               chunks: pack-names
+               packs:
+               EOF
+               if test $NUM_PACKS -ge 1
+               then
+                       ls pack/ | grep idx | sort
+               fi &&
+               printf "object-dir: .\n"
+       } >expect &&
        test-tool read-midx . >actual &&
        test_cmp expect actual
 }
-- 
2.18.0.118.gd4f65b8d14