[PATCH 04/10] fetch: new option to set preferred pack version for transfer

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/fetch-options.txt |  5 +++++
 builtin/fetch.c                 | 10 ++++++++++
 fetch-pack.c                    |  3 +++
 fetch-pack.h                    |  1 +
 t/t5510-fetch.sh                | 13 +++++++++++++
 transport.c                     |  4 ++++
 transport.h                     |  5 +++++
 7 files changed, 41 insertions(+)

diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
index ba1fe49..47d55e5 100644
--- a/Documentation/fetch-options.txt
+++ b/Documentation/fetch-options.txt
@@ -17,6 +17,11 @@
 	Convert a shallow repository to a complete one, removing all
 	the limitations imposed by shallow repositories.
 
+--pack-version=<n>::
+	Define the preferred pack format version for data transfer.
+	Valid values are 2 and 4. Default value is specified by
+	core.preferredPackVersion setting. See linkgit:git-config[1].
+
 ifndef::git-pull[]
 --dry-run::
 	Show what would be done, without making any changes.
diff --git a/builtin/fetch.c b/builtin/fetch.c
index d784b2e..695fbf1 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -31,6 +31,7 @@ enum {
 };
 
 static int all, append, dry_run, force, keep, multiple, prune, update_head_ok, verbosity;
+static int pack_version;
 static int progress = -1, recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 static int tags = TAGS_DEFAULT, unshallow;
 static const char *depth;
@@ -90,6 +91,8 @@ static struct option builtin_fetch_options[] = {
 	{ OPTION_STRING, 0, "recurse-submodules-default",
 		   &recurse_submodules_default, NULL,
 		   N_("default mode for recursion"), PARSE_OPT_HIDDEN },
+	OPT_INTEGER(0, "pack-version", &pack_version,
+		    N_("preferred pack version for transfer")),
 	OPT_END()
 };
 
@@ -957,6 +960,8 @@ static int fetch_one(struct remote *remote, int argc, const char **argv)
 		set_option(TRANS_OPT_KEEP, "yes");
 	if (depth)
 		set_option(TRANS_OPT_DEPTH, depth);
+	if (pack_version == 4)
+		set_option(TRANS_OPT_PACKV4, "yes");
 
 	if (argc > 0) {
 		int j = 0;
@@ -1010,6 +1015,11 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix,
 			     builtin_fetch_options, builtin_fetch_usage, 0);
 
+	if (!pack_version)
+		pack_version = core_default_pack_version;
+	if (pack_version != 2 && pack_version != 4)
+		die(_("invalid pack version %d"), pack_version);
+
 	if (unshallow) {
 		if (depth)
 			die(_("--depth and --unshallow cannot be used together"));
diff --git a/fetch-pack.c b/fetch-pack.c
index 6684348..16aa3d0 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -324,6 +324,7 @@ static int find_common(struct fetch_pack_args *args,
 			if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 			if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 			if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+			if (args->packv4)       strbuf_addstr(&c, " packv4");
 			if (agent_supported)    strbuf_addf(&c, " agent=%s",
 							    git_user_agent_sanitized());
 			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
@@ -869,6 +870,8 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 		args->no_progress = 0;
 	if (!server_supports("include-tag"))
 		args->include_tag = 0;
+	if (!server_supports("packv4"))
+		args->packv4 = 0;
 	if (server_supports("ofs-delta")) {
 		if (args->verbose)
 			fprintf(stderr, "Server supports ofs-delta\n");
diff --git a/fetch-pack.h b/fetch-pack.h
index 40f08ba..5f03739 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -17,6 +17,7 @@ struct fetch_pack_args {
 		no_progress:1,
 		include_tag:1,
 		stateless_rpc:1,
+		packv4:1,
 		check_self_contained_and_connected:1,
 		self_contained_and_connected:1;
 };
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index fde6891..d3da088 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -512,4 +512,17 @@ test_expect_success 'all boundary commits are excluded' '
 	test_bundle_object_count .git/objects/pack/pack-${pack##pack	}.pack 3
 '
 
+test_expect_success 'fetch --pack-version=4' '
+	git init pv4 &&
+	(
+		cd pv4 &&
+		git fetch --pack-version=4 --keep file://"$D"/.git &&
+		P=`ls .git/objects/pack/pack-*.pack` &&
+		# Offset 4 is pack version
+		test-dump ntohl "$P" 4 >ver.actual &&
+		echo 4 >ver.expected &&
+		test_cmp ver.expected ver.actual
+	)
+'
+
 test_done
diff --git a/transport.c b/transport.c
index e15db98..ad5a4f1 100644
--- a/transport.c
+++ b/transport.c
@@ -473,6 +473,9 @@ static int set_git_option(struct git_transport_options *opts,
 	} else if (!strcmp(name, TRANS_OPT_KEEP)) {
 		opts->keep = !!value;
 		return 0;
+	} else if (!strcmp(name, TRANS_OPT_PACKV4)) {
+		opts->packv4 = !!value;
+		return 0;
 	} else if (!strcmp(name, TRANS_OPT_DEPTH)) {
 		if (!value)
 			opts->depth = 0;
@@ -534,6 +537,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.quiet = (transport->verbose < 0);
 	args.no_progress = !transport->progress;
 	args.depth = data->options.depth;
+	args.packv4 = data->options.packv4;
 	args.check_self_contained_and_connected =
 		data->options.check_self_contained_and_connected;
 
diff --git a/transport.h b/transport.h
index ea70ea7..59785c0 100644
--- a/transport.h
+++ b/transport.h
@@ -8,6 +8,7 @@ struct git_transport_options {
 	unsigned thin : 1;
 	unsigned keep : 1;
 	unsigned followtags : 1;
+	unsigned packv4 : 1;
 	unsigned check_self_contained_and_connected : 1;
 	unsigned self_contained_and_connected : 1;
 	int depth;
@@ -135,6 +136,10 @@ struct transport *transport_get(struct remote *, const char *);
 /* Aggressively fetch annotated tags if possible */
 #define TRANS_OPT_FOLLOWTAGS "followtags"
 
+/* Prefer pack version 4 as the transport format */
+#define TRANS_OPT_PACKV4 "packv4"
+
+
 /**
  * Returns 0 if the option was used, non-zero otherwise. Prints a
  * message to stderr if the option is not used.
-- 
1.8.2.82.gc24b958