[v2,6/6] scalar: teach `diagnose` to gather loose objects information

Commit Message

Matthew John Cheetham Feb. 6, 2022, 10:39 p.m. UTC

From: Matthew John Cheetham <[e-mail]>

When operating at the scale that Scalar wants to support, certain data
shapes are more likely to cause undesirable performance issues, such as
large numbers of loose objects.

By including statistics about this, `scalar diagnose` now makes it
easier to identify such scenarios.

Signed-off-by: Matthew John Cheetham <[e-mail]>
Signed-off-by: Johannes Schindelin <[e-mail]>
---
 contrib/scalar/scalar.c          | 59 ++++++++++++++++++++++++++++++++
 contrib/scalar/t/t9099-scalar.sh |  5 ++-
 2 files changed, 63 insertions(+), 1 deletion(-)

Patch

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index 331d48b2a80..537b97ae734 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -616,6 +616,60 @@  static int dir_file_stats(struct object_directory *object_dir, void *data)
 	return 0;
 }
 
+static int count_files(char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count = 0;
+
+	if (!dir)
+		return 0;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) && e->d_type == DT_REG)
+			count++;
+
+	closedir(dir);
+	return count;
+}
+
+static void loose_objs_stats(struct strbuf *buf, const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *e;
+	int count;
+	int total = 0;
+	unsigned char c;
+	struct strbuf count_path = STRBUF_INIT;
+	size_t base_path_len;
+
+	if (!dir)
+		return;
+
+	strbuf_addstr(buf, "Object directory stats for ");
+	strbuf_add_absolute_path(buf, path);
+	strbuf_addstr(buf, ":\n");
+
+	strbuf_add_absolute_path(&count_path, path);
+	strbuf_addch(&count_path, '/');
+	base_path_len = count_path.len;
+
+	while ((e = readdir(dir)) != NULL)
+		if (!is_dot_or_dotdot(e->d_name) &&
+		    e->d_type == DT_DIR && strlen(e->d_name) == 2 &&
+		    !hex_to_bytes(&c, e->d_name, 1)) {
+			strbuf_setlen(&count_path, base_path_len);
+			strbuf_addstr(&count_path, e->d_name);
+			total += (count = count_files(count_path.buf));
+			strbuf_addf(buf, "%s : %7d files\n", e->d_name, count);
+		}
+
+	strbuf_addf(buf, "Total: %d loose objects", total);
+
+	strbuf_release(&count_path);
+	closedir(dir);
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -686,6 +740,11 @@  static int cmd_diagnose(int argc, const char **argv)
 	foreach_alt_odb(dir_file_stats, &buf);
 	strvec_push(&archiver_args, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-file-with-content=objects-local.txt:");
+	loose_objs_stats(&buf, ".git/objects");
+	strvec_push(&archiver_args, buf.buf);
+
 	if ((res = add_directory_to_archiver(&archiver_args, ".git", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/hooks", 0)) ||
 	    (res = add_directory_to_archiver(&archiver_args, ".git/info", 0)) ||
diff --git a/contrib/scalar/t/t9099-scalar.sh b/contrib/scalar/t/t9099-scalar.sh
index e049221609d..9b4eedbb0aa 100755
--- a/contrib/scalar/t/t9099-scalar.sh
+++ b/contrib/scalar/t/t9099-scalar.sh
@@ -95,6 +95,7 @@  test_expect_success UNZIP 'scalar diagnose' '
 	scalar clone "file://$(pwd)" cloned --single-branch &&
 	git repack &&
 	echo "$(pwd)/.git/objects/" >>cloned/src/.git/objects/info/alternates &&
+	test_commit -C cloned/src loose &&
 	scalar diagnose cloned >out &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <out >zip_path &&
@@ -106,7 +107,9 @@  test_expect_success UNZIP 'scalar diagnose' '
 	unzip -p "$zip_path" diagnostics.log >out &&
 	test_file_not_empty out &&
 	unzip -p "$zip_path" packs-local.txt >out &&
-	grep "$(pwd)/.git/objects" out
+	grep "$(pwd)/.git/objects" out &&
+	unzip -p "$zip_path" objects-local.txt >out &&
+	grep "^Total: [1-9]" out
 '
 
 test_done