[PATCHv4 03/27] object-store: move alt_odb_list and alt_odb_tail to object store

[Stefan Beller <sbeller@google.com>]

In a process with multiple repositories open, alternates should be
associated to a single repository and not shared globally. Move
alt_odb_list and alt_odb_tail into the_repository and adjust callers
to reflect this.

Now that the alternative object data base is per repository, we're
leaking its memory upon freeing a repository. The next patch plugs
this hole.

No functional change intended.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 builtin/fsck.c |  4 +++-
 object-store.h |  9 ++++++---
 packfile.c     |  3 ++-
 sha1_file.c    | 25 ++++++++++++-------------
 sha1_name.c    |  3 ++-
 5 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 9981db22637..78edcb75c45 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "cache.h"
+#include "repository.h"
 #include "config.h"
 #include "commit.h"
 #include "tree.h"
@@ -722,7 +723,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 		fsck_object_dir(get_object_directory());
 
 		prepare_alt_odb();
-		for (alt = alt_odb_list; alt; alt = alt->next)
+		for (alt = the_repository->objects.alt_odb_list;
+		     alt; alt = alt->next)
 			fsck_object_dir(alt->path);
 
 		if (check_full) {
diff --git a/object-store.h b/object-store.h
index 5678aa1136c..e78eea1dde3 100644
--- a/object-store.h
+++ b/object-store.h
@@ -1,7 +1,7 @@
 #ifndef OBJECT_STORE_H
 #define OBJECT_STORE_H
 
-extern struct alternate_object_database {
+struct alternate_object_database {
 	struct alternate_object_database *next;
 
 	/* see alt_scratch_buf() */
@@ -19,7 +19,7 @@ extern struct alternate_object_database {
 	struct oid_array loose_objects_cache;
 
 	char path[FLEX_ARRAY];
-} *alt_odb_list;
+};
 void prepare_alt_odb(void);
 char *compute_alternate_path(const char *path, struct strbuf *err);
 typedef int alt_odb_fn(struct alternate_object_database *, void *);
@@ -58,8 +58,11 @@ struct raw_object_store {
 	 * Cannot be NULL after initialization.
 	 */
 	char *objectdir;
+
+	struct alternate_object_database *alt_odb_list;
+	struct alternate_object_database **alt_odb_tail;
 };
-#define RAW_OBJECT_STORE_INIT { NULL }
+#define RAW_OBJECT_STORE_INIT { NULL, NULL, NULL }
 
 void raw_object_store_clear(struct raw_object_store *o);
 
diff --git a/packfile.c b/packfile.c
index 7dbe8739d17..216ea836ee3 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "list.h"
 #include "pack.h"
+#include "repository.h"
 #include "dir.h"
 #include "mergesort.h"
 #include "packfile.h"
@@ -891,7 +892,7 @@ void prepare_packed_git(void)
 		return;
 	prepare_packed_git_one(get_object_directory(), 1);
 	prepare_alt_odb();
-	for (alt = alt_odb_list; alt; alt = alt->next)
+	for (alt = the_repository->objects.alt_odb_list; alt; alt = alt->next)
 		prepare_packed_git_one(alt->path, 0);
 	rearrange_packed_git();
 	prepare_packed_git_mru();
diff --git a/sha1_file.c b/sha1_file.c
index 826d7a0ae37..ac25146076e 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -22,6 +22,7 @@
 #include "pack-revindex.h"
 #include "sha1-lookup.h"
 #include "bulk-checkin.h"
+#include "repository.h"
 #include "streaming.h"
 #include "dir.h"
 #include "list.h"
@@ -340,9 +341,6 @@ static const char *alt_sha1_path(struct alternate_object_database *alt,
 	return buf->buf;
 }
 
-struct alternate_object_database *alt_odb_list;
-static struct alternate_object_database **alt_odb_tail;
-
 /*
  * Return non-zero iff the path is usable as an alternate object database.
  */
@@ -362,7 +360,7 @@ static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
 	 * Prevent the common mistake of listing the same
 	 * thing twice, or object directory itself.
 	 */
-	for (alt = alt_odb_list; alt; alt = alt->next) {
+	for (alt = the_repository->objects.alt_odb_list; alt; alt = alt->next) {
 		if (!fspathcmp(path->buf, alt->path))
 			return 0;
 	}
@@ -422,8 +420,8 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base,
 	ent = alloc_alt_odb(pathbuf.buf);
 
 	/* add the alternate entry */
-	*alt_odb_tail = ent;
-	alt_odb_tail = &(ent->next);
+	*the_repository->objects.alt_odb_tail = ent;
+	the_repository->objects.alt_odb_tail = &(ent->next);
 	ent->next = NULL;
 
 	/* recursively add alternates */
@@ -557,7 +555,7 @@ void add_to_alternates_file(const char *reference)
 		fprintf_or_die(out, "%s\n", reference);
 		if (commit_lock_file(&lock))
 			die_errno("unable to move new alternates file into place");
-		if (alt_odb_tail)
+		if (the_repository->objects.alt_odb_tail)
 			link_alt_odb_entries(reference, '\n', NULL, 0);
 	}
 	free(alts);
@@ -655,7 +653,7 @@ int foreach_alt_odb(alt_odb_fn fn, void *cb)
 	int r = 0;
 
 	prepare_alt_odb();
-	for (ent = alt_odb_list; ent; ent = ent->next) {
+	for (ent = the_repository->objects.alt_odb_list; ent; ent = ent->next) {
 		r = fn(ent, cb);
 		if (r)
 			break;
@@ -667,12 +665,13 @@ void prepare_alt_odb(void)
 {
 	const char *alt;
 
-	if (alt_odb_tail)
+	if (the_repository->objects.alt_odb_tail)
 		return;
 
 	alt = getenv(ALTERNATE_DB_ENVIRONMENT);
 
-	alt_odb_tail = &alt_odb_list;
+	the_repository->objects.alt_odb_tail =
+			&the_repository->objects.alt_odb_list;
 	link_alt_odb_entries(alt, PATH_SEP, NULL, 0);
 
 	read_info_alternates(get_object_directory(), 0);
@@ -716,7 +715,7 @@ static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
 {
 	struct alternate_object_database *alt;
 	prepare_alt_odb();
-	for (alt = alt_odb_list; alt; alt = alt->next) {
+	for (alt = the_repository->objects.alt_odb_list; alt; alt = alt->next) {
 		const char *path = alt_sha1_path(alt, sha1);
 		if (check_and_freshen_file(path, freshen))
 			return 1;
@@ -876,7 +875,7 @@ static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
 
 	prepare_alt_odb();
 	errno = ENOENT;
-	for (alt = alt_odb_list; alt; alt = alt->next) {
+	for (alt = the_repository->objects.alt_odb_list; alt; alt = alt->next) {
 		*path = alt_sha1_path(alt, sha1);
 		if (!lstat(*path, st))
 			return 0;
@@ -906,7 +905,7 @@ static int open_sha1_file(const unsigned char *sha1, const char **path)
 	most_interesting_errno = errno;
 
 	prepare_alt_odb();
-	for (alt = alt_odb_list; alt; alt = alt->next) {
+	for (alt = the_repository->objects.alt_odb_list; alt; alt = alt->next) {
 		*path = alt_sha1_path(alt, sha1);
 		fd = git_open(*path);
 		if (fd >= 0)
diff --git a/sha1_name.c b/sha1_name.c
index 611c7d24dde..957ce25680b 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -10,6 +10,7 @@
 #include "dir.h"
 #include "sha1-array.h"
 #include "packfile.h"
+#include "repository.h"
 
 static int get_oid_oneline(const char *, struct object_id *, struct commit_list *);
 
@@ -104,7 +105,7 @@ static void find_short_object_filename(struct disambiguate_state *ds)
 		 */
 		fakeent = alloc_alt_odb(get_object_directory());
 	}
-	fakeent->next = alt_odb_list;
+	fakeent->next = the_repository->objects.alt_odb_list;
 
 	for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
 		int pos;
-- 
2.16.1.291.g4437f3f132-goog