fsck: use for_each_loose_file_in_objdir

Since 27e1e22 (prune: factor out loose-object directory
traversal, 2014-10-15), we now have a generic callback
system for iterating over the loose object directories. This
is used by prune, count-objects, etc.

We did not convert git-fsck at the time because it
implemented an inode-sorting scheme that was not part of the
generic code. Now that the inode-sorting code is gone, we
can reuse the generic code.  The result is shorter,
hopefully more readable, and drops some unchecked sprintf
calls.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fsck.c

@@ -365,45 +365,6 @@ static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
 	return fsck_obj(obj);
 }
 
-static inline int is_loose_object_file(struct dirent *de,
-				       char *name, unsigned char *sha1)
-{
-	if (strlen(de->d_name) != 38)
-		return 0;
-	memcpy(name + 2, de->d_name, 39);
-	return !get_sha1_hex(name, sha1);
-}
-
-static void fsck_dir(int i, char *path)
-{
-	DIR *dir = opendir(path);
-	struct dirent *de;
-	char name[100];
-
-	if (!dir)
-		return;
-
-	if (verbose)
-		fprintf(stderr, "Checking directory %s\n", path);
-
-	sprintf(name, "%02x", i);
-	while ((de = readdir(dir)) != NULL) {
-		unsigned char sha1[20];
-
-		if (is_dot_or_dotdot(de->d_name))
-			continue;
-		if (is_loose_object_file(de, name, sha1)) {
-			if (fsck_sha1(sha1))
-				errors_found |= ERROR_OBJECT;
-			continue;
-		}
-		if (starts_with(de->d_name, "tmp_obj_"))
-			continue;
-		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
-	}
-	closedir(dir);
-}
-
 static int default_refs;
 
 static void fsck_handle_reflog_sha1(const char *refname, unsigned char *sha1)
@@ -491,22 +452,39 @@ static void get_default_heads(void)
 	}
 }
 
+static int fsck_loose(const unsigned char *sha1, const char *path, void *data)
+{
+	if (fsck_sha1(sha1))
+		errors_found |= ERROR_OBJECT;
+	return 0;
+}
+
+static int fsck_cruft(const char *basename, const char *path, void *data)
+{
+	if (!starts_with(basename, "tmp_obj_"))
+		fprintf(stderr, "bad sha1 file: %s\n", path);
+	return 0;
+}
+
+static int fsck_subdir(int nr, const char *path, void *progress)
+{
+	display_progress(progress, nr + 1);
+	return 0;
+}
+
 static void fsck_object_dir(const char *path)
 {
-	int i;
 	struct progress *progress = NULL;
 
 	if (verbose)
 		fprintf(stderr, "Checking object directory\n");
 
 	if (show_progress)
 		progress = start_progress(_("Checking object directories"), 256);
-	for (i = 0; i < 256; i++) {
-		static char dir[4096];
-		sprintf(dir, "%s/%02x", path, i);
-		fsck_dir(i, dir);
-		display_progress(progress, i+1);
-	}
+
+	for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
+				      progress);
+	display_progress(progress, 256);
 	stop_progress(&progress);
 }