[GSoC][PATCH v10 06/10] builtin/refs: add verify subcommand and verbose_refs for "fsck_options"

[shejialuo <shejialuo@gmail.com>]

Introduce a new subcommand "verify" in git-refs(1) to allow the user to
check the reference database consistency and also this subcommand will
be used as the entry point of checking refs for "git-fsck(1)". Last, add
"verbose_refs" field into "fsck_options" to indicate whether we should
print verbose messages when checking refs consistency.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: shejialuo <shejialuo@gmail.com>
---
 Documentation/git-refs.txt | 13 +++++++++++
 builtin/refs.c             | 44 ++++++++++++++++++++++++++++++++++++++
 fsck.h                     |  1 +
 3 files changed, 58 insertions(+)

diff --git a/Documentation/git-refs.txt b/Documentation/git-refs.txt
index 5b99e04385..1244a85b64 100644
--- a/Documentation/git-refs.txt
+++ b/Documentation/git-refs.txt
@@ -10,6 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git refs migrate' --ref-format=<format> [--dry-run]
+'git refs verify' [--strict] [--verbose]
 
 DESCRIPTION
 -----------
@@ -22,6 +23,9 @@ COMMANDS
 migrate::
 	Migrate ref store between different formats.
 
+verify::
+	Verify reference database consistency.
+
 OPTIONS
 -------
 
@@ -39,6 +43,15 @@ include::ref-storage-format.txt[]
 	can be used to double check that the migration works as expected before
 	performing the actual migration.
 
+The following options are specific to 'git refs verify':
+
+--strict::
+	Enable more strict checking, every WARN severity for the `Fsck Messages`
+	be seen as ERROR. See linkgit:git-fsck[1].
+
+--verbose::
+	When verifying the reference database consistency, be chatty.
+
 KNOWN LIMITATIONS
 -----------------
 
diff --git a/builtin/refs.c b/builtin/refs.c
index 46dcd150d4..599b526786 100644
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -1,4 +1,6 @@
 #include "builtin.h"
+#include "config.h"
+#include "fsck.h"
 #include "parse-options.h"
 #include "refs.h"
 #include "repository.h"
@@ -7,6 +9,9 @@
 #define REFS_MIGRATE_USAGE \
 	N_("git refs migrate --ref-format=<format> [--dry-run]")
 
+#define REFS_VERIFY_USAGE \
+	N_("git refs verify [--strict] [--verbose]")
+
 static int cmd_refs_migrate(int argc, const char **argv, const char *prefix)
 {
 	const char * const migrate_usage[] = {
@@ -58,15 +63,54 @@ static int cmd_refs_migrate(int argc, const char **argv, const char *prefix)
 	return err;
 }
 
+static int cmd_refs_verify(int argc, const char **argv, const char *prefix)
+{
+	struct fsck_options fsck_refs_options = FSCK_REFS_OPTIONS_DEFAULT;
+	const char * const verify_usage[] = {
+		REFS_VERIFY_USAGE,
+		NULL,
+	};
+	unsigned int verbose = 0, strict = 0;
+	struct option options[] = {
+		OPT__VERBOSE(&verbose, N_("be verbose")),
+		OPT_BOOL(0, "strict", &strict, N_("enable strict checking")),
+		OPT_END(),
+	};
+	int ret;
+
+	argc = parse_options(argc, argv, prefix, options, verify_usage, 0);
+	if (argc)
+		usage(_("too many arguments"));
+
+	if (verbose)
+		fsck_refs_options.verbose_refs = 1;
+	if (strict)
+		fsck_refs_options.strict = 1;
+
+	git_config(git_fsck_config, &fsck_refs_options);
+	prepare_repo_settings(the_repository);
+
+	ret = refs_fsck(get_main_ref_store(the_repository), &fsck_refs_options);
+
+	/*
+	 * Explicitly free the allocated array and "skip_oids" set
+	 */
+	free(fsck_refs_options.msg_type);
+	oidset_clear(&fsck_refs_options.skip_oids);
+	return ret;
+}
+
 int cmd_refs(int argc, const char **argv, const char *prefix)
 {
 	const char * const refs_usage[] = {
 		REFS_MIGRATE_USAGE,
+		REFS_VERIFY_USAGE,
 		NULL,
 	};
 	parse_opt_subcommand_fn *fn = NULL;
 	struct option opts[] = {
 		OPT_SUBCOMMAND("migrate", &fn, cmd_refs_migrate),
+		OPT_SUBCOMMAND("verify", &fn, cmd_refs_verify),
 		OPT_END(),
 	};
 
diff --git a/fsck.h b/fsck.h
index fe5d4d2ad9..ef1f1ed15e 100644
--- a/fsck.h
+++ b/fsck.h
@@ -147,6 +147,7 @@ struct fsck_options {
 	fsck_walk_func walk;
 	fsck_error error_func;
 	unsigned strict:1;
+	unsigned verbose_refs:1;
 	enum fsck_msg_type *msg_type;
 	struct oidset skip_oids;
 	struct oidset gitmodules_found;
-- 
2.45.2