Re: Git is not scalable with too many refs/*

@@ -12,11 +12,14 @@ check_not_detached () {
 }
 
 ORPHAN_WARNING='you are leaving .* commit.*behind'
+PREV_HEAD_DESC='Previous HEAD position was'
 check_orphan_warning() {
-	test_i18ngrep "$ORPHAN_WARNING" "$1"
+	test_i18ngrep "$ORPHAN_WARNING" "$1" &&
+	test_i18ngrep ! "$PREV_HEAD_DESC" "$1"
 }
 check_no_orphan_warning() {
-	test_i18ngrep ! "$ORPHAN_WARNING" "$1"
+	test_i18ngrep ! "$ORPHAN_WARNING" "$1" &&
+	test_i18ngrep "$PREV_HEAD_DESC" "$1"
 }
 
 reset () {

@@ -185,6 +185,13 @@ static struct object *get_reference(struct rev_info *revs, const char *name, con
 	return object;
 }
 
+void add_pending_sha1(struct rev_info *revs, const char *name,
+		      const unsigned char *sha1, unsigned int flags)
+{
+	struct object *object = get_reference(revs, name, sha1, flags);
+	add_pending_object(revs, object, name);
+}
+
 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 {
 	unsigned long flags = object->flags;

@@ -832,9 +839,7 @@ struct all_refs_cb {
 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct all_refs_cb *cb = cb_data;
-	struct object *object = get_reference(cb->all_revs, path, sha1,
-					      cb->all_flags);
-	add_pending_object(cb->all_revs, object, path);
+	add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 	return 0;
 }
 

@@ -191,6 +191,7 @@ extern void add_object(struct object *obj,
 		       const char *name);
 
 extern void add_pending_object(struct rev_info *revs, struct object *obj, const char *name);
+extern void add_pending_sha1(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags);
 
 extern void add_head_to_pending(struct rev_info *);
 

@@ -588,24 +588,11 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 		report_tracking(new);
 }
 
-struct rev_list_args {
-	int argc;
-	int alloc;
-	const char **argv;
-};
-
-static void add_one_rev_list_arg(struct rev_list_args *args, const char *s)
-{
-	ALLOC_GROW(args->argv, args->argc + 1, args->alloc);
-	args->argv[args->argc++] = s;
-}
-
-static int add_one_ref_to_rev_list_arg(const char *refname,
-				       const unsigned char *sha1,
-				       int flags,
-				       void *cb_data)
+static int add_pending_uninteresting_ref(const char *refname,
+					 const unsigned char *sha1,
+					 int flags, void *cb_data)
 {
-	add_one_rev_list_arg(cb_data, refname);
+	add_pending_sha1(cb_data, refname, sha1, flags | UNINTERESTING);
 	return 0;
 }
 

@@ -685,19 +672,17 @@ static void suggest_reattach(struct commit *commit, struct rev_info *revs)
  */
 static void orphaned_commit_warning(struct commit *commit)
 {
-	struct rev_list_args args = { 0, 0, NULL };
 	struct rev_info revs;
-
-	add_one_rev_list_arg(&args, "(internal)");
-	add_one_rev_list_arg(&args, sha1_to_hex(commit->object.sha1));
-	add_one_rev_list_arg(&args, "--not");
-	for_each_ref(add_one_ref_to_rev_list_arg, &args);
-	add_one_rev_list_arg(&args, "--");
-	add_one_rev_list_arg(&args, NULL);
+	struct object *object = &commit->object;
 
 	init_revisions(&revs, NULL);
-	if (setup_revisions(args.argc - 1, args.argv, &revs, NULL) != 1)
-		die(_("internal error: only -- alone should have been left"));
+	setup_revisions(0, NULL, &revs, NULL);
+
+	object->flags &= ~UNINTERESTING;
+	add_pending_object(&revs, object, sha1_to_hex(object->sha1));
+
+	for_each_ref(add_pending_uninteresting_ref, &revs);
+
 	if (prepare_revision_walk(&revs))
 		die(_("internal error in revision walk"));
 	if (!(commit->object.flags & UNINTERESTING))

@@ -1974,7 +1974,8 @@ int prepare_revision_walk(struct rev_info *revs)
 		}
 		e++;
 	}
-	free(list);
+	if (!revs->leak_pending)
+		free(list);
 
 	if (revs->no_walk)
 		return 0;

@@ -97,6 +97,7 @@ struct rev_info {
 			date_mode_explicit:1,
 			preserve_subject:1;
 	unsigned int	disable_stdin:1;
+	unsigned int	leak_pending:1;
 
 	enum date_mode date_mode;
 

@@ -831,12 +831,14 @@ static int check_ancestors(const char *prefix)
 	bisect_rev_setup(&revs, prefix, "^%s", "%s", 0);
 
 	/* Save pending objects, so they can be cleaned up later. */
-	memset(&pending_copy, 0, sizeof(pending_copy));
-	for (i = 0; i < revs.pending.nr; i++)
-		add_object_array(revs.pending.objects[i].item,
-				 revs.pending.objects[i].name,
-				 &pending_copy);
+	pending_copy = revs.pending;
+	revs.leak_pending = 1;
 
+	/*
+	 * bisect_common calls prepare_revision_walk right away, which
+	 * (together with .leak_pending = 1) makes us the sole owner of
+	 * the list of pending objects.
+	 */
 	bisect_common(&revs);
 	res = (revs.commits != NULL);
 

@@ -845,6 +847,7 @@ static int check_ancestors(const char *prefix)
 		struct object *o = pending_copy.objects[i].item;
 		clear_commit_marks((struct commit *)o, ALL_REV_FLAGS);
 	}
+	free(pending_copy.objects);
 
 	return res;
 }

@@ -122,11 +122,8 @@ int verify_bundle(struct bundle_header *header, int verbose)
 	req_nr = revs.pending.nr;
 	setup_revisions(2, argv, &revs, NULL);
 
-	memset(&refs, 0, sizeof(struct object_array));
-	for (i = 0; i < revs.pending.nr; i++) {
-		struct object_array_entry *e = revs.pending.objects + i;
-		add_object_array(e->item, e->name, &refs);
-	}
+	refs = revs.pending;
+	revs.leak_pending = 1;
 
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");

@@ -146,6 +143,7 @@ int verify_bundle(struct bundle_header *header, int verbose)
 
 	for (i = 0; i < refs.nr; i++)
 		clear_commit_marks((struct commit *)refs.objects[i].item, -1);
+	free(refs.objects);
 
 	if (verbose) {
 		struct ref_list *r;

@@ -596,17 +596,6 @@ static int add_pending_uninteresting_ref(const char *refname,
 	return 0;
 }
 
-static int clear_commit_marks_from_one_ref(const char *refname,
-				      const unsigned char *sha1,
-				      int flags,
-				      void *cb_data)
-{
-	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
-	if (commit)
-		clear_commit_marks(commit, -1);
-	return 0;
-}
-
 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
 {
 	parse_commit(commit);

@@ -674,6 +663,8 @@ static void orphaned_commit_warning(struct commit *commit)
 {
 	struct rev_info revs;
 	struct object *object = &commit->object;
+	struct object_array refs;
+	unsigned int i;
 
 	init_revisions(&revs, NULL);
 	setup_revisions(0, NULL, &revs, NULL);

@@ -683,6 +674,9 @@ static void orphaned_commit_warning(struct commit *commit)
 
 	for_each_ref(add_pending_uninteresting_ref, &revs);
 
+	refs = revs.pending;
+	revs.leak_pending = 1;
+
 	if (prepare_revision_walk(&revs))
 		die(_("internal error in revision walk"));
 	if (!(commit->object.flags & UNINTERESTING))

@@ -690,8 +684,13 @@ static void orphaned_commit_warning(struct commit *commit)
 	else
 		describe_detached_head(_("Previous HEAD position was"), commit);
 
-	clear_commit_marks(commit, -1);
-	for_each_ref(clear_commit_marks_from_one_ref, NULL);
+	for (i = 0; i < refs.nr; i++) {
+		struct object *o = refs.objects[i].item;
+		struct commit *c = lookup_commit_reference_gently(o->sha1, 1);
+		if (c)
+			clear_commit_marks(c, ALL_REV_FLAGS);
+	}
+	free(refs.objects);
 }
 
 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)

@@ -826,7 +826,7 @@ static int check_ancestors(const char *prefix)
 {
 	struct rev_info revs;
 	struct object_array pending_copy;
-	int i, res;
+	int res;
 
 	bisect_rev_setup(&revs, prefix, "^%s", "%s", 0);
 

@@ -843,10 +843,7 @@ static int check_ancestors(const char *prefix)
 	res = (revs.commits != NULL);
 
 	/* Clean up objects used, as they will be reused. */
-	for (i = 0; i < pending_copy.nr; i++) {
-		struct object *o = pending_copy.objects[i].item;
-		clear_commit_marks((struct commit *)o, ALL_REV_FLAGS);
-	}
+	clear_commit_marks_for_object_array(&pending_copy, ALL_REV_FLAGS);
 	free(pending_copy.objects);
 
 	return res;

@@ -664,7 +664,6 @@ static void orphaned_commit_warning(struct commit *commit)
 	struct rev_info revs;
 	struct object *object = &commit->object;
 	struct object_array refs;
-	unsigned int i;
 
 	init_revisions(&revs, NULL);
 	setup_revisions(0, NULL, &revs, NULL);

@@ -684,12 +683,7 @@ static void orphaned_commit_warning(struct commit *commit)
 	else
 		describe_detached_head(_("Previous HEAD position was"), commit);
 
-	for (i = 0; i < refs.nr; i++) {
-		struct object *o = refs.objects[i].item;
-		struct commit *c = lookup_commit_reference_gently(o->sha1, 1);
-		if (c)
-			clear_commit_marks(c, ALL_REV_FLAGS);
-	}
+	clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
 	free(refs.objects);
 }
 

@@ -141,8 +141,7 @@ int verify_bundle(struct bundle_header *header, int verbose)
 				refs.objects[i].name);
 		}
 
-	for (i = 0; i < refs.nr; i++)
-		clear_commit_marks((struct commit *)refs.objects[i].item, -1);
+	clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
 	free(refs.objects);
 
 	if (verbose) {

@@ -430,6 +430,20 @@ void clear_commit_marks(struct commit *commit, unsigned int mark)
 	}
 }
 
+void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
+{
+	struct object *object;
+	struct commit *commit;
+	unsigned int i;
+
+	for (i = 0; i < a->nr; i++) {
+		object = a->objects[i].item;
+		commit = lookup_commit_reference_gently(object->sha1, 1);
+		if (commit)
+			clear_commit_marks(commit, mark);
+	}
+}
+
 struct commit *pop_commit(struct commit_list **stack)
 {
 	struct commit_list *top = *stack;

@@ -126,6 +126,7 @@ struct commit *pop_most_recent_commit(struct commit_list **list,
 struct commit *pop_commit(struct commit_list **stack);
 
 void clear_commit_marks(struct commit *commit, unsigned int mark);
+void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark);
 
 /*
  * Performs an in-place topological sort of list supplied.