test-tool: use 'read-graph' helper

The 'git commit-graph read' subcommand is used in test scripts to check
that the commit-graph contents match the expected data. Mostly, this
helps check the header information and the list of chunks. Users do not
need this information, so move the functionality to a test helper.

Reported-by: Bryan Turner <bturner@atlassian.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

8 files changed, 58 insertions, 82 deletions

diff --git a/Documentation/git-commit-graph.txt b/Documentation/git-commit-graph.txt
index 8c708a7a16..bcd85c1976 100644
--- a/Documentation/git-commit-graph.txt
+++ b/Documentation/git-commit-graph.txt
@@ -9,7 +9,6 @@ git-commit-graph - Write and verify Git commit-graph files
 SYNOPSIS
 --------
 [verse]
-'git commit-graph read' [--object-dir <dir>]
 'git commit-graph verify' [--object-dir <dir>] [--shallow] [--[no-]progress]
 'git commit-graph write' <options> [--object-dir <dir>] [--[no-]progress]
 
@@ -74,11 +73,6 @@ Finally, if `--expire-time=<datetime>` is not specified, let `datetime`
 be the current time. After writing the split commit-graph, delete all
 unused commit-graph whose modified times are older than `datetime`.
 
-'read'::
-
-Read the commit-graph file and output basic details about it.
-Used for debugging purposes.
-
 'verify'::
 
 Read the commit-graph file and verify its contents against the object
@@ -118,12 +112,6 @@ $ git show-ref -s | git commit-graph write --stdin-commits
 $ git rev-parse HEAD | git commit-graph write --stdin-commits --append
 ------------------------------------------------
 
-* Read basic information from the commit-graph file.
-+
-------------------------------------------------
-$ git commit-graph read
-------------------------------------------------
-
 
 GIT
 ---
diff --git a/Makefile b/Makefile
index 58b92af54b..44997f6f57 100644
--- a/Makefile
+++ b/Makefile
@@ -727,6 +727,7 @@ TEST_BUILTINS_OBJS += test-prio-queue.o
 TEST_BUILTINS_OBJS += test-progress.o
 TEST_BUILTINS_OBJS += test-reach.o
 TEST_BUILTINS_OBJS += test-read-cache.o
+TEST_BUILTINS_OBJS += test-read-graph.o
 TEST_BUILTINS_OBJS += test-read-midx.o
 TEST_BUILTINS_OBJS += test-ref-store.o
 TEST_BUILTINS_OBJS += test-regex.o
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index ec0fc93d39..e0c6fc4bbf 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -8,7 +8,6 @@
 #include "object-store.h"
 
 static char const * const builtin_commit_graph_usage[] = {
-	N_("git commit-graph read [--object-dir <objdir>]"),
 	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
 	N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--[no-]progress] <split options>"),
 	NULL
@@ -19,11 +18,6 @@ static const char * const builtin_commit_graph_verify_usage[] = {
 	NULL
 };
 
-static const char * const builtin_commit_graph_read_usage[] = {
-	N_("git commit-graph read [--object-dir <objdir>]"),
-	NULL
-};
-
 static const char * const builtin_commit_graph_write_usage[] = {
 	N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--[no-]progress] <split options>"),
 	NULL
@@ -93,66 +87,6 @@ static int graph_verify(int argc, const char **argv)
 	return verify_commit_graph(the_repository, graph, flags);
 }
 
-static int graph_read(int argc, const char **argv)
-{
-	struct commit_graph *graph = NULL;
-	char *graph_name;
-	int open_ok;
-	int fd;
-	struct stat st;
-
-	static struct option builtin_commit_graph_read_options[] = {
-		OPT_STRING(0, "object-dir", &opts.obj_dir,
-			N_("dir"),
-			N_("The object directory to store the graph")),
-		OPT_END(),
-	};
-
-	trace2_cmd_mode("read");
-
-	argc = parse_options(argc, argv, NULL,
-			     builtin_commit_graph_read_options,
-			     builtin_commit_graph_read_usage, 0);
-
-	if (!opts.obj_dir)
-		opts.obj_dir = get_object_directory();
-
-	graph_name = get_commit_graph_filename(opts.obj_dir);
-
-	open_ok = open_commit_graph(graph_name, &fd, &st);
-	if (!open_ok)
-		die_errno(_("Could not open commit-graph '%s'"), graph_name);
-
-	graph = load_commit_graph_one_fd_st(fd, &st);
-	if (!graph)
-		return 1;
-
-	FREE_AND_NULL(graph_name);
-
-	printf("header: %08x %d %d %d %d\n",
-		ntohl(*(uint32_t*)graph->data),
-		*(unsigned char*)(graph->data + 4),
-		*(unsigned char*)(graph->data + 5),
-		*(unsigned char*)(graph->data + 6),
-		*(unsigned char*)(graph->data + 7));
-	printf("num_commits: %u\n", graph->num_commits);
-	printf("chunks:");
-
-	if (graph->chunk_oid_fanout)
-		printf(" oid_fanout");
-	if (graph->chunk_oid_lookup)
-		printf(" oid_lookup");
-	if (graph->chunk_commit_data)
-		printf(" commit_metadata");
-	if (graph->chunk_extra_edges)
-		printf(" extra_edges");
-	printf("\n");
-
-	UNLEAK(graph);
-
-	return 0;
-}
-
 extern int read_replace_refs;
 static struct split_commit_graph_opts split_opts;
 
@@ -268,8 +202,6 @@ int cmd_commit_graph(int argc, const char **argv, const char *prefix)
 	save_commit_buffer = 0;
 
 	if (argc > 0) {
-		if (!strcmp(argv[0], "read"))
-			return graph_read(argc, argv);
 		if (!strcmp(argv[0], "verify"))
 			return graph_verify(argc, argv);
 		if (!strcmp(argv[0], "write"))
diff --git a/t/helper/test-read-graph.c b/t/helper/test-read-graph.c
new file mode 100644
index 0000000000..d2884efe0a
--- /dev/null
+++ b/t/helper/test-read-graph.c
@@ -0,0 +1,53 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "commit-graph.h"
+#include "repository.h"
+#include "object-store.h"
+
+int cmd__read_graph(int argc, const char **argv)
+{
+	struct commit_graph *graph = NULL;
+	char *graph_name;
+	int open_ok;
+	int fd;
+	struct stat st;
+	const char *object_dir;
+
+	setup_git_directory();
+	object_dir = get_object_directory();
+
+	graph_name = get_commit_graph_filename(object_dir);
+
+	open_ok = open_commit_graph(graph_name, &fd, &st);
+	if (!open_ok)
+		die_errno(_("Could not open commit-graph '%s'"), graph_name);
+
+	graph = load_commit_graph_one_fd_st(fd, &st);
+	if (!graph)
+		return 1;
+
+	FREE_AND_NULL(graph_name);
+
+	printf("header: %08x %d %d %d %d\n",
+		ntohl(*(uint32_t*)graph->data),
+		*(unsigned char*)(graph->data + 4),
+		*(unsigned char*)(graph->data + 5),
+		*(unsigned char*)(graph->data + 6),
+		*(unsigned char*)(graph->data + 7));
+	printf("num_commits: %u\n", graph->num_commits);
+	printf("chunks:");
+
+	if (graph->chunk_oid_fanout)
+		printf(" oid_fanout");
+	if (graph->chunk_oid_lookup)
+		printf(" oid_lookup");
+	if (graph->chunk_commit_data)
+		printf(" commit_metadata");
+	if (graph->chunk_extra_edges)
+		printf(" extra_edges");
+	printf("\n");
+
+	UNLEAK(graph);
+
+	return 0;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 19ee26d931..f20989d449 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -45,6 +45,7 @@ static struct test_cmd cmds[] = {
 	{ "progress", cmd__progress },
 	{ "reach", cmd__reach },
 	{ "read-cache", cmd__read_cache },
+	{ "read-graph", cmd__read_graph },
 	{ "read-midx", cmd__read_midx },
 	{ "ref-store", cmd__ref_store },
 	{ "regex", cmd__regex },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index c2aa56ef50..8ed2af71d1 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -35,6 +35,7 @@ int cmd__prio_queue(int argc, const char **argv);
 int cmd__progress(int argc, const char **argv);
 int cmd__reach(int argc, const char **argv);
 int cmd__read_cache(int argc, const char **argv);
+int cmd__read_graph(int argc, const char **argv);
 int cmd__read_midx(int argc, const char **argv);
 int cmd__ref_store(int argc, const char **argv);
 int cmd__regex(int argc, const char **argv);
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index d42b3efe39..798968374f 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -85,7 +85,7 @@ graph_read_expect() {
 	num_commits: $1
 	chunks: oid_fanout oid_lookup commit_metadata$OPTIONAL
 	EOF
-	git commit-graph read >output &&
+	test-tool read-graph >output &&
 	test_cmp expect output
 }
 
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 115aabd141..c24823431f 100755
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -25,7 +25,7 @@ graph_read_expect() {
 	num_commits: $1
 	chunks: oid_fanout oid_lookup commit_metadata
 	EOF
-	git commit-graph read >output &&
+	test-tool read-graph >output &&
 	test_cmp expect output
 }