[PATCH] Expose packed_git and alt_odb.

The commands git-fsck-cache and probably git-*-pull needs to have a way
to enumerate objects contained in packed GIT archives and alternate
object pools.  This commit exposes the data structure used to keep track
of them from sha1_file.c, and adds a couple of accessor interface
functions for use by the enhanced git-fsck-cache command.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/cache.h b/cache.h
index 383fc866416e68d68e91255de8c5ab600e667d5a..9bfcdb641a934da3accef7846540d40a6016c8c7 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -233,4 +233,23 @@ struct checkout {
 
 extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
 
+extern struct alternate_object_database {
+       char *base;
+       char *name;
+} *alt_odb;
+extern void prepare_alt_odb(void);
+
+extern struct packed_git {
+       struct packed_git *next;
+       unsigned long index_size;
+       unsigned long pack_size;
+       unsigned int *index_base;
+       void *pack_base;
+       unsigned int pack_last_used;
+       char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
+} *packed_git;
+extern void prepare_packed_git(void);
+extern int num_packed_objects(const struct packed_git *p);
+extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
+
 #endif /* CACHE_H */

diff --git a/sha1_file.c b/sha1_file.c
index e27affb2885717974b5612d4a41a91ed390d7ff7..17546061c15175275b6dce2949e73281d8d9d7ce 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -184,10 +184,7 @@ char *sha1_file_name(const unsigned char *sha1)
        return base;
 }
 
-static struct alternate_object_database {
-       char *base;
-       char *name;
-} *alt_odb;
+struct alternate_object_database *alt_odb;
 
 /*
  * Prepare alternate object database registry.
@@ -205,13 +202,15 @@ static struct alternate_object_database {
  * pointed by base fields of the array elements with one xmalloc();
  * the string pool immediately follows the array.
  */
-static void prepare_alt_odb(void)
+void prepare_alt_odb(void)
 {
        int pass, totlen, i;
        const char *cp, *last;
        char *op = NULL;
        const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
 
+       if (alt_odb)
+               return;
        /* The first pass counts how large an area to allocate to
         * hold the entire alt_odb structure, including array of
         * structs and path buffers for them.  The second pass fills
@@ -258,8 +257,7 @@ static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 
        if (!stat(name, st))
                return name;
-       if (!alt_odb)
-               prepare_alt_odb();
+       prepare_alt_odb();
        for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
                fill_sha1_path(name, sha1);
                if (!stat(alt_odb[i].base, st))
@@ -271,15 +269,7 @@ static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 #define PACK_MAX_SZ (1<<26)
 static int pack_used_ctr;
 static unsigned long pack_mapped;
-static struct packed_git {
-       struct packed_git *next;
-       unsigned long index_size;
-       unsigned long pack_size;
-       unsigned int *index_base;
-       void *pack_base;
-       unsigned int pack_last_used;
-       char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
-} *packed_git;
+struct packed_git *packed_git;
 
 struct pack_entry {
        unsigned int offset;
@@ -429,7 +419,7 @@ static void prepare_packed_git_one(char *objdir)
        }
 }
 
-static void prepare_packed_git(void)
+void prepare_packed_git(void)
 {
        int i;
        static int run_once = 0;
@@ -438,8 +428,7 @@ static void prepare_packed_git(void)
                return;
 
        prepare_packed_git_one(get_object_directory());
-       if (!alt_odb)
-               prepare_alt_odb();
+       prepare_alt_odb();
        for (i = 0; alt_odb[i].base != NULL; i++) {
                alt_odb[i].name[0] = 0;
                prepare_packed_git_one(alt_odb[i].base);
@@ -820,6 +809,22 @@ static void *unpack_entry(struct pack_entry *entry,
        return unpack_non_delta_entry(pack+5, size, left);
 }
 
+int num_packed_objects(const struct packed_git *p)
+{
+       /* See check_packed_git_idx and pack-objects.c */
+       return (p->index_size - 20 - 20 - 4*256) / 24;
+}
+
+int nth_packed_object_sha1(const struct packed_git *p, int n,
+                          unsigned char* sha1)
+{
+       void *index = p->index_base + 256;
+       if (n < 0 || num_packed_objects(p) <= n)
+               return -1;
+       memcpy(sha1, (index + 24 * n + 4), 20);
+       return 0;
+}
+
 static int find_pack_entry_1(const unsigned char *sha1,
                             struct pack_entry *e, struct packed_git *p)
 {