[PATCH 02/26] 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 +++-
 cache.h        |  4 ++--
 object-store.h |  7 ++++++-
 packfile.c     |  3 ++-
 sha1_file.c    | 25 ++++++++++++-------------
 sha1_name.c    |  3 ++-
 6 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 04846d46f9..1048255da1 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"
@@ -694,7 +695,8 @@ 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/cache.h b/cache.h
index d8b975a571..918c2f15b4 100644
--- a/cache.h
+++ b/cache.h
@@ -1573,7 +1573,7 @@ extern int has_dirs_only_path(const char *name, int len, int prefix_len);
 extern void schedule_dir_for_removal(const char *name, int len);
 extern void remove_scheduled_dirs(void);
 
-extern struct alternate_object_database {
+struct alternate_object_database {
 	struct alternate_object_database *next;
 
 	/* see alt_scratch_buf() */
@@ -1591,7 +1591,7 @@ extern struct alternate_object_database {
 	struct oid_array loose_objects_cache;
 
 	char path[FLEX_ARRAY];
-} *alt_odb_list;
+};
 extern void prepare_alt_odb(void);
 extern char *compute_alternate_path(const char *path, struct strbuf *err);
 typedef int alt_odb_fn(struct alternate_object_database *, void *);
diff --git a/object-store.h b/object-store.h
index cf35760ceb..44b8f84753 100644
--- a/object-store.h
+++ b/object-store.h
@@ -1,14 +1,19 @@
 #ifndef OBJECT_STORE_H
 #define OBJECT_STORE_H
 
+#include "cache.h"
+
 struct raw_object_store {
 	/*
 	 * Path to the repository's 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 4a5fe7ab18..d61076faaf 100644
--- a/packfile.c
+++ b/packfile.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "mru.h"
 #include "pack.h"
+#include "repository.h"
 #include "dir.h"
 #include "mergesort.h"
 #include "packfile.h"
@@ -880,7 +881,7 @@ 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 3da70ac650..2826d5d6ed 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 "mru.h"
@@ -346,9 +347,6 @@ 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.
  */
@@ -368,7 +366,7 @@ 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;
 	}
@@ -428,8 +426,8 @@ 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 */
@@ -563,7 +561,7 @@ 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);
@@ -661,7 +659,7 @@ 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;
@@ -673,12 +671,13 @@ 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);
@@ -717,7 +716,7 @@ 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;
@@ -873,7 +872,7 @@ 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;
@@ -899,7 +898,7 @@ 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 611c7d24dd..957ce25680 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;
-- 
2.16.1.73.ga2c3e9663f.dirty