odb/source-loose: wire up `count_objects()` callback

Move `odb_source_loose_count_objects()` and its associated helpers from
"object-file.c" into "odb/source-loose.c" and wire it up as the
`count_objects()` callback of the loose source.

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

builtin/gc.c

@@ -466,6 +466,7 @@ out:
 
 static int too_many_loose_objects(int limit)
 {
+	struct odb_source_files *files = odb_source_files_downcast(the_repository->objects->sources);
 	/*
 	 * This is weird, but stems from legacy behaviour: the GC auto
 	 * threshold was always essentially interpreted as if it was rounded up
@@ -474,9 +475,8 @@ static int too_many_loose_objects(int limit)
 	int auto_threshold = DIV_ROUND_UP(limit, 256) * 256;
 	unsigned long loose_count;
 
-	if (odb_source_loose_count_objects(the_repository->objects->sources,
-					   ODB_COUNT_OBJECTS_APPROXIMATE,
-					   &loose_count) < 0)
+	if (odb_source_count_objects(&files->loose->base, ODB_COUNT_OBJECTS_APPROXIMATE,
+				     &loose_count) < 0)
 		return 0;
 
 	return loose_count > auto_threshold;

object-file.c

@@ -1602,66 +1602,6 @@ int for_each_loose_file_in_source(struct odb_source *source,
 	return r;
 }
 
-static int count_loose_object(const struct object_id *oid UNUSED,
-			      struct object_info *oi UNUSED,
-			      void *payload)
-{
-	unsigned long *count = payload;
-	(*count)++;
-	return 0;
-}
-
-int odb_source_loose_count_objects(struct odb_source *source,
-				   enum odb_count_objects_flags flags,
-				   unsigned long *out)
-{
-	struct odb_source_files *files = odb_source_files_downcast(source);
-	const unsigned hexsz = source->odb->repo->hash_algo->hexsz - 2;
-	char *path = NULL;
-	DIR *dir = NULL;
-	int ret;
-
-	if (flags & ODB_COUNT_OBJECTS_APPROXIMATE) {
-		unsigned long count = 0;
-		struct dirent *ent;
-
-		path = xstrfmt("%s/17", source->path);
-
-		dir = opendir(path);
-		if (!dir) {
-			if (errno == ENOENT) {
-				*out = 0;
-				ret = 0;
-				goto out;
-			}
-
-			ret = error_errno("cannot open object shard '%s'", path);
-			goto out;
-		}
-
-		while ((ent = readdir(dir)) != NULL) {
-			if (strspn(ent->d_name, "0123456789abcdef") != hexsz ||
-			    ent->d_name[hexsz] != '\0')
-				continue;
-			count++;
-		}
-
-		*out = count * 256;
-		ret = 0;
-	} else {
-		struct odb_for_each_object_options opts = { 0 };
-		*out = 0;
-		ret = odb_source_for_each_object(&files->loose->base, NULL, count_loose_object,
-						 out, &opts);
-	}
-
-out:
-	if (dir)
-		closedir(dir);
-	free(path);
-	return ret;
-}
-
 static int check_stream_oid(git_zstream *stream,
 			    const char *hdr,
 			    unsigned long size,

object-file.h

@@ -96,20 +96,6 @@ int for_each_file_in_obj_subdir(unsigned int subdir_nr,
 				each_loose_subdir_fn subdir_cb,
 				void *data);
 
-/*
- * Count the number of loose objects in this source.
- *
- * The object count is approximated by opening a single sharding directory for
- * loose objects and scanning its contents. The result is then extrapolated by
- * 256. This should generally work as a reasonable estimate given that the
- * object hash is supposed to be indistinguishable from random.
- *
- * Returns 0 on success, a negative error code otherwise.
- */
-int odb_source_loose_count_objects(struct odb_source *source,
-				   enum odb_count_objects_flags flags,
-				   unsigned long *out);
-
 /**
  * format_object_header() is a thin wrapper around s xsnprintf() that
  * writes the initial "<type> <obj-len>" part of the loose object

odb/source-files.c

@@ -109,7 +109,7 @@ static int odb_source_files_count_objects(struct odb_source *source,
 	if (!(flags & ODB_COUNT_OBJECTS_APPROXIMATE)) {
 		unsigned long loose_count;
 
-		ret = odb_source_loose_count_objects(source, flags, &loose_count);
+		ret = odb_source_count_objects(&files->loose->base, flags, &loose_count);
 		if (ret < 0)
 			goto out;
 

odb/source-loose.c

@@ -520,6 +520,66 @@ static int odb_source_loose_find_abbrev_len(struct odb_source *source,
 	return ret;
 }
 
+static int count_loose_object(const struct object_id *oid UNUSED,
+			      struct object_info *oi UNUSED,
+			      void *payload)
+{
+	unsigned long *count = payload;
+	(*count)++;
+	return 0;
+}
+
+static int odb_source_loose_count_objects(struct odb_source *source,
+					  enum odb_count_objects_flags flags,
+					  unsigned long *out)
+{
+	struct odb_source_loose *loose = odb_source_loose_downcast(source);
+	const unsigned hexsz = source->odb->repo->hash_algo->hexsz - 2;
+	char *path = NULL;
+	DIR *dir = NULL;
+	int ret;
+
+	if (flags & ODB_COUNT_OBJECTS_APPROXIMATE) {
+		unsigned long count = 0;
+		struct dirent *ent;
+
+		path = xstrfmt("%s/17", source->path);
+
+		dir = opendir(path);
+		if (!dir) {
+			if (errno == ENOENT) {
+				*out = 0;
+				ret = 0;
+				goto out;
+			}
+
+			ret = error_errno("cannot open object shard '%s'", path);
+			goto out;
+		}
+
+		while ((ent = readdir(dir)) != NULL) {
+			if (strspn(ent->d_name, "0123456789abcdef") != hexsz ||
+			    ent->d_name[hexsz] != '\0')
+				continue;
+			count++;
+		}
+
+		*out = count * 256;
+		ret = 0;
+	} else {
+		struct odb_for_each_object_options opts = { 0 };
+		*out = 0;
+		ret = odb_source_for_each_object(&loose->base, NULL, count_loose_object,
+						 out, &opts);
+	}
+
+out:
+	if (dir)
+		closedir(dir);
+	free(path);
+	return ret;
+}
+
 static void odb_source_loose_clear_cache(struct odb_source_loose *loose)
 {
 	oidtree_clear(loose->cache);
@@ -577,6 +637,7 @@ struct odb_source_loose *odb_source_loose_new(struct odb_source_files *files)
 	loose->base.read_object_stream = odb_source_loose_read_object_stream;
 	loose->base.for_each_object = odb_source_loose_for_each_object;
 	loose->base.find_abbrev_len = odb_source_loose_find_abbrev_len;
+	loose->base.count_objects = odb_source_loose_count_objects;
 
 	if (!is_absolute_path(loose->base.path))
 		chdir_notify_register(NULL, odb_source_loose_reparent, loose);