scalar: teach `diagnose` to gather packfile info

It's helpful to see if there are other crud files in the pack
directory. Let's teach the `scalar diagnose` command to gather
file size information about pack files.

While at it, also enumerate the pack files in the alternate
object directories, if any are registered.

Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/scalar/scalar.c

@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "help.h"
 #include "archive.h"
+#include "object-store.h"
 
 /*
  * Remove the deepest subdirectory in the provided path string. Path must not
@@ -594,6 +595,29 @@ cleanup:
 	return res;
 }
 
+static void dir_file_stats_objects(const char *full_path, size_t full_path_len,
+				   const char *file_name, void *data)
+{
+	struct strbuf *buf = data;
+	struct stat st;
+
+	if (!stat(full_path, &st))
+		strbuf_addf(buf, "%-70s %16" PRIuMAX "\n", file_name,
+			    (uintmax_t)st.st_size);
+}
+
+static int dir_file_stats(struct object_directory *object_dir, void *data)
+{
+	struct strbuf *buf = data;
+
+	strbuf_addf(buf, "Contents of %s:\n", object_dir->path);
+
+	for_each_file_in_pack_dir(object_dir->path, dir_file_stats_objects,
+				  data);
+
+	return 0;
+}
+
 static int cmd_diagnose(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -656,6 +680,12 @@ static int cmd_diagnose(int argc, const char **argv)
 		     "--add-virtual-file=diagnostics.log:%.*s",
 		     (int)buf.len, buf.buf);
 
+	strbuf_reset(&buf);
+	strbuf_addstr(&buf, "--add-virtual-file=packs-local.txt:");
+	dir_file_stats(the_repository->objects->odb, &buf);
+	foreach_alt_odb(dir_file_stats, &buf);
+	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)) ||

contrib/scalar/t/t9099-scalar.sh

@@ -101,6 +101,8 @@ test_expect_success '`scalar [...] <dir>` errors out when dir is missing' '
 SQ="'"
 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 &&
 	scalar diagnose cloned >out 2>err &&
 	grep "Available space" out &&
 	sed -n "s/.*$SQ\\(.*\\.zip\\)$SQ.*/\\1/p" <err >zip_path &&
@@ -110,7 +112,9 @@ test_expect_success UNZIP 'scalar diagnose' '
 	folder=${zip_path%.zip} &&
 	test_path_is_missing "$folder" &&
 	unzip -p "$zip_path" diagnostics.log >out &&
-	test_file_not_empty out
+	test_file_not_empty out &&
+	unzip -p "$zip_path" packs-local.txt >out &&
+	grep "$(pwd)/.git/objects" out
 '
 
 test_done