odb: get rid of `the_repository` in `for_each()` functions

There are a couple of iterator-style functions that execute a callback
for each instance of a given set, all of which currently depend on
`the_repository`. Refactor them to instead take an object database as
parameter so that we can get rid of this dependency.

Rename the functions accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/count-objects.c

@@ -159,7 +159,7 @@ int cmd_count_objects(int argc,
 		printf("prune-packable: %lu\n", packed_loose);
 		printf("garbage: %lu\n", garbage);
 		printf("size-garbage: %s\n", garbage_buf.buf);
-		foreach_alt_odb(print_alternate, NULL);
+		odb_for_each_alternate(the_repository->objects, print_alternate, NULL);
 		strbuf_release(&loose_buf);
 		strbuf_release(&pack_buf);
 		strbuf_release(&garbage_buf);

builtin/receive-pack.c

@@ -359,7 +359,8 @@ static void write_head_info(void)
 
 	refs_for_each_fullref_in(get_main_ref_store(the_repository), "",
 				 exclude_patterns, show_ref_cb, &seen);
-	for_each_alternate_ref(show_one_alternate_ref, &seen);
+	odb_for_each_alternate_ref(the_repository->objects,
+				   show_one_alternate_ref, &seen);
 
 	oidset_clear(&seen);
 	strvec_clear(&excludes_vector);

builtin/submodule--helper.c

@@ -1668,7 +1668,8 @@ static void prepare_possible_alternates(const char *sm_name,
 		die(_("Value '%s' for submodule.alternateErrorStrategy is not recognized"), error_strategy);
 
 	if (!strcmp(sm_alternate, "superproject"))
-		foreach_alt_odb(add_possible_reference_from_superproject, &sas);
+		odb_for_each_alternate(the_repository->objects,
+				       add_possible_reference_from_superproject, &sas);
 	else if (!strcmp(sm_alternate, "no"))
 		; /* do nothing */
 	else

diagnose.c

@@ -229,7 +229,7 @@ int create_diagnostics_archive(struct repository *r,
 	strbuf_reset(&buf);
 	strbuf_addstr(&buf, "--add-virtual-file=packs-local.txt:");
 	dir_file_stats(r->objects->sources, &buf);
-	foreach_alt_odb(dir_file_stats, &buf);
+	odb_for_each_alternate(r->objects, dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
 	strbuf_reset(&buf);

fetch-pack.c

@@ -115,7 +115,8 @@ static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
 	size_t i;
 
 	if (!initialized) {
-		for_each_alternate_ref(cache_one_alternate, &cache);
+		odb_for_each_alternate_ref(the_repository->objects,
+					   cache_one_alternate, &cache);
 		initialized = 1;
 	}
 

odb.c

@@ -494,8 +494,8 @@ static void fill_alternate_refs_command(struct child_process *cmd,
 }
 
 static void read_alternate_refs(const char *path,
-				alternate_ref_fn *cb,
-				void *data)
+				odb_for_each_alternate_ref_fn *cb,
+				void *payload)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct strbuf line = STRBUF_INIT;
@@ -517,7 +517,7 @@ static void read_alternate_refs(const char *path,
 			break;
 		}
 
-		cb(&oid, data);
+		cb(&oid, payload);
 	}
 
 	fclose(fh);
@@ -526,16 +526,16 @@ static void read_alternate_refs(const char *path,
 }
 
 struct alternate_refs_data {
-	alternate_ref_fn *fn;
-	void *data;
+	odb_for_each_alternate_ref_fn *fn;
+	void *payload;
 };
 
 static int refs_from_alternate_cb(struct odb_source *alternate,
-				  void *data)
+				  void *payload)
 {
 	struct strbuf path = STRBUF_INIT;
 	size_t base_len;
-	struct alternate_refs_data *cb = data;
+	struct alternate_refs_data *cb = payload;
 
 	if (!strbuf_realpath(&path, alternate->path, 0))
 		goto out;
@@ -549,29 +549,31 @@ static int refs_from_alternate_cb(struct odb_source *alternate,
 		goto out;
 	strbuf_setlen(&path, base_len);
 
-	read_alternate_refs(path.buf, cb->fn, cb->data);
+	read_alternate_refs(path.buf, cb->fn, cb->payload);
 
 out:
 	strbuf_release(&path);
 	return 0;
 }
 
-void for_each_alternate_ref(alternate_ref_fn fn, void *data)
+void odb_for_each_alternate_ref(struct object_database *odb,
+				odb_for_each_alternate_ref_fn cb, void *payload)
 {
-	struct alternate_refs_data cb;
-	cb.fn = fn;
-	cb.data = data;
-	foreach_alt_odb(refs_from_alternate_cb, &cb);
+	struct alternate_refs_data data;
+	data.fn = cb;
+	data.payload = payload;
+	odb_for_each_alternate(odb, refs_from_alternate_cb, &data);
 }
 
-int foreach_alt_odb(alt_odb_fn fn, void *cb)
+int odb_for_each_alternate(struct object_database *odb,
+			 odb_for_each_alternate_fn cb, void *payload)
 {
 	struct odb_source *alternate;
 	int r = 0;
 
-	odb_prepare_alternates(the_repository->objects);
-	for (alternate = the_repository->objects->sources->next; alternate; alternate = alternate->next) {
-		r = fn(alternate, cb);
+	odb_prepare_alternates(odb);
+	for (alternate = odb->sources->next; alternate; alternate = alternate->next) {
+		r = cb(alternate, payload);
 		if (r)
 			break;
 	}

odb.h

@@ -73,11 +73,6 @@ struct odb_source {
 	char *path;
 };
 
-typedef int alt_odb_fn(struct odb_source *, void *);
-int foreach_alt_odb(alt_odb_fn, void*);
-typedef void alternate_ref_fn(const struct object_id *oid, void *);
-void for_each_alternate_ref(alternate_ref_fn, void *);
-
 /*
  * Replace the current writable object directory with the specified temporary
  * object directory; returns the former primary object directory.
@@ -192,6 +187,24 @@ void odb_clear(struct object_database *o);
  */
 struct odb_source *odb_find_source(struct object_database *odb, const char *obj_dir);
 
+/*
+ * Iterate through all alternates of the database and execute the provided
+ * callback function for each of them. Stop iterating once the callback
+ * function returns a non-zero value, in which case the value is bubbled up
+ * from the callback.
+ */
+typedef int odb_for_each_alternate_fn(struct odb_source *, void *);
+int odb_for_each_alternate(struct object_database *odb,
+			   odb_for_each_alternate_fn cb, void *payload);
+
+/*
+ * Iterate through all alternates of the database and yield their respective
+ * references.
+ */
+typedef void odb_for_each_alternate_ref_fn(const struct object_id *oid, void *);
+void odb_for_each_alternate_ref(struct object_database *odb,
+				odb_for_each_alternate_ref_fn cb, void *payload);
+
 /*
  * Create a temporary file rooted in the primary alternate's directory, or die
  * on failure. The filename is taken from "pattern", which should have the

revision.c

@@ -1907,7 +1907,8 @@ static void add_alternate_refs_to_pending(struct rev_info *revs,
 	struct add_alternate_refs_data data;
 	data.revs = revs;
 	data.flags = flags;
-	for_each_alternate_ref(add_one_alternate_ref, &data);
+	odb_for_each_alternate_ref(the_repository->objects,
+				   add_one_alternate_ref, &data);
 }
 
 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,