[PATCH v2 5/8] serve.c: add call_{advertise,command}() indirection

[Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>]

Instead of directly calling the callbacks defined in the "struct
protocol_capability", let's call them via new
"call_{advertise,command}()" functions. There's no use in this
indirection now, but it'll be used in a subsequent commit to ensure
that config is read before they're called.

See ed10cb952d3 (serve: introduce git-serve, 2018-03-15) for the
introduction of the code being changed here.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
 serve.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/serve.c b/serve.c
index 49ea9fc8fd5..85cd3eab26e 100644
--- a/serve.c
+++ b/serve.c
@@ -42,6 +42,10 @@ static int session_id_advertise(struct repository *r, struct strbuf *value)
 	return 1;
 }
 
+typedef int (*advertise_fn_t)(struct repository *r, struct strbuf *value);
+typedef int (*command_fn_t)(struct repository *r, struct strvec *keys,
+			    struct packet_reader *request);
+
 struct protocol_capability {
 	/*
 	 * The name of the capability.  The server uses this name when
@@ -56,7 +60,7 @@ struct protocol_capability {
 	 * If a value is added to 'value', the server will advertise this
 	 * capability as "<name>=<value>" instead of "<name>".
 	 */
-	int (*advertise)(struct repository *r, struct strbuf *value);
+	advertise_fn_t advertise;
 
 	/*
 	 * Function called when a client requests the capability as a command.
@@ -67,9 +71,7 @@ struct protocol_capability {
 	 *
 	 * This field should be NULL for capabilities which are not commands.
 	 */
-	int (*command)(struct repository *r,
-		       struct strvec *keys,
-		       struct packet_reader *request);
+	command_fn_t command;
 };
 
 static struct protocol_capability capabilities[] = {
@@ -106,6 +108,19 @@ static struct protocol_capability capabilities[] = {
 	},
 };
 
+static int call_advertise(struct protocol_capability *command,
+			  struct repository *r, struct strbuf *value)
+{
+	return command->advertise(r, value);
+}
+
+static int call_command(struct protocol_capability *command,
+			struct repository *r, struct strvec *keys,
+			struct packet_reader *request)
+{
+	return command->command(r, keys, request);
+}
+
 static void advertise_capabilities(void)
 {
 	struct strbuf capability = STRBUF_INIT;
@@ -115,7 +130,7 @@ static void advertise_capabilities(void)
 	for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
 		struct protocol_capability *c = &capabilities[i];
 
-		if (c->advertise(the_repository, &value)) {
+		if (call_advertise(c, the_repository, &value)) {
 			strbuf_addstr(&capability, c->name);
 
 			if (value.len) {
@@ -155,9 +170,9 @@ static struct protocol_capability *get_capability(const char *key)
 
 static int is_valid_capability(const char *key)
 {
-	const struct protocol_capability *c = get_capability(key);
+	struct protocol_capability *c = get_capability(key);
 
-	return c && c->advertise(the_repository, NULL);
+	return c && call_advertise(c, the_repository, NULL);
 }
 
 static int is_command(const char *key, struct protocol_capability **command)
@@ -170,7 +185,7 @@ static int is_command(const char *key, struct protocol_capability **command)
 		if (*command)
 			die("command '%s' requested after already requesting command '%s'",
 			    out, (*command)->name);
-		if (!cmd || !cmd->advertise(the_repository, NULL) || !cmd->command)
+		if (!cmd || !call_advertise(cmd, the_repository, NULL) || !cmd->command)
 			die("invalid command '%s'", out);
 
 		*command = cmd;
@@ -294,7 +309,7 @@ static int process_request(void)
 	if (has_capability(&keys, "session-id", &client_sid))
 		trace2_data_string("transfer", NULL, "client-sid", client_sid);
 
-	command->command(the_repository, &keys, &reader);
+	call_command(command, the_repository, &keys, &reader);
 
 	strvec_clear(&keys);
 	return 0;
-- 
2.32.0.611.gd4a17395dfa