[RFC PATCH 03/13] connect.c: refactor sending of agent & object-format

From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: "Jeff King" <peff@peff.net>, "Patrick Steinhardt" <ps@pks.im>,
	"Christian Couder" <christian.couder@gmail.com>,
	"Albert Cui" <albertqcui@gmail.com>,
	"Jonathan Tan" <jonathantanmy@google.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: [RFC PATCH 03/13] connect.c: refactor sending of agent & object-format
Date: Thu,  5 Aug 2021 17:07:19 +0200	[thread overview]
Message-ID: <RFC-patch-03.13-fc5c725307-20210805T150534Z-avarab@gmail.com> (raw)
In-Reply-To: <RFC-cover-00.13-0000000000-20210805T150534Z-avarab@gmail.com>

Refactor the sending of the "agent" and "object-format" capabilities
into a function.

This was added in its current form in ab67235bc4 (connect: parse v2
refs with correct hash algorithm, 2020-05-25). When we connect to a v2
server we need to know about its object-format, and it needs to know
about ours. Since most things in connect.c and transport.c piggy-back
on the eager getting of remote refs via the handshake() those commands
can make use of the just-sent-over object-format by ls-refs.

But I'm about to add a command that may come after ls-refs, and may
not, but we need the server to know about our user-agent and
object-format. So let's split this into a function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 connect.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/connect.c b/connect.c
index 70b13389ba..18dfeae2b8 100644
--- a/connect.c
+++ b/connect.c
@@ -471,6 +471,24 @@ void check_stateless_delimiter(int stateless_rpc,
 		die("%s", error);
 }
 
+static void send_capabilities(int fd_out, struct packet_reader *reader)
+{
+	const char *hash_name;
+
+	if (server_supports_v2("agent", 0))
+		packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
+
+	if (server_feature_v2("object-format", &hash_name)) {
+		int hash_algo = hash_algo_by_name(hash_name);
+		if (hash_algo == GIT_HASH_UNKNOWN)
+			die(_("unknown object format '%s' specified by server"), hash_name);
+		reader->hash_algo = &hash_algos[hash_algo];
+		packet_write_fmt(fd_out, "object-format=%s", reader->hash_algo->name);
+	} else {
+		reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
+	}
+}
+
 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 			     struct ref **list, int for_push,
 			     struct transport_ls_refs_options *transport_options,
@@ -478,7 +496,6 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 			     int stateless_rpc)
 {
 	int i;
-	const char *hash_name;
 	struct strvec *ref_prefixes = transport_options ?
 		&transport_options->ref_prefixes : NULL;
 	char **unborn_head_target = transport_options ?
@@ -488,18 +505,8 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 	if (server_supports_v2("ls-refs", 1))
 		packet_write_fmt(fd_out, "command=ls-refs\n");
 
-	if (server_supports_v2("agent", 0))
-		packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
-
-	if (server_feature_v2("object-format", &hash_name)) {
-		int hash_algo = hash_algo_by_name(hash_name);
-		if (hash_algo == GIT_HASH_UNKNOWN)
-			die(_("unknown object format '%s' specified by server"), hash_name);
-		reader->hash_algo = &hash_algos[hash_algo];
-		packet_write_fmt(fd_out, "object-format=%s", reader->hash_algo->name);
-	} else {
-		reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
-	}
+	/* Send capabilities */
+	send_capabilities(fd_out, reader);
 
 	if (server_options && server_options->nr &&
 	    server_supports_v2("server-option", 1))
-- 
2.33.0.rc0.646.g585563e77f

