[PATCH v3 06/12] serve: add support for a "startup" git_config() callback

@@ -7,37 +7,26 @@
 #include "pkt-line.h"
 #include "config.h"
 
-static int config_read;
-static int advertise_unborn;
-static int allow_unborn;
+/* "unborn" is on by default if there's no lsrefs.unborn config */
+static int advertise_unborn = 1;
+static int allow_unborn = 1;
 
-static void ensure_config_read(void)
+int ls_refs_startup_config(const char *var, const char *value, void *data)
 {
-	const char *str = NULL;
-
-	if (config_read)
-		return;
-
-	if (repo_config_get_string_tmp(the_repository, "lsrefs.unborn", &str)) {
-		/*
-		 * If there is no such config, advertise and allow it by
-		 * default.
-		 */
-		advertise_unborn = 1;
-		allow_unborn = 1;
-	} else {
-		if (!strcmp(str, "advertise")) {
-			advertise_unborn = 1;
+	if (!strcmp(var, "lsrefs.unborn")) {
+		if (!strcmp(value, "advertise")) {
+			/* Allowed and advertised by default */
+		} else if (!strcmp(value, "allow")) {
+			advertise_unborn = 0;
 			allow_unborn = 1;
-		} else if (!strcmp(str, "allow")) {
-			allow_unborn = 1;
-		} else if (!strcmp(str, "ignore")) {
-			/* do nothing */
+		} else if (!strcmp(value, "ignore")) {
+			advertise_unborn = 0;
+			allow_unborn = 0;
 		} else {
-			die(_("invalid value '%s' for lsrefs.unborn"), str);
+			die(_("invalid value '%s' for lsrefs.unborn"), value);
 		}
 	}
-	config_read = 1;
+	return 0;
 }
 
 /*

@@ -145,8 +134,6 @@ int ls_refs(struct repository *r, struct strvec *keys,
 
 	memset(&data, 0, sizeof(data));
 	strvec_init(&data.prefixes);
-
-	ensure_config_read();
 	git_config(ls_refs_config, NULL);
 
 	while (packet_reader_read(request) == PACKET_READ_NORMAL) {

@@ -179,7 +166,6 @@ int ls_refs(struct repository *r, struct strvec *keys,
 int ls_refs_advertise(struct repository *r, struct strbuf *value)
 {
 	if (value) {
-		ensure_config_read();
 		if (advertise_unborn)
 			strbuf_addstr(value, "unborn");
 	}

@@ -6,6 +6,7 @@ struct strvec;
 struct packet_reader;
 int ls_refs(struct repository *r, struct strvec *keys,
 	    struct packet_reader *request);
+int ls_refs_startup_config(const char *var, const char *value, void *data);
 int ls_refs_advertise(struct repository *r, struct strbuf *value);
 
 #endif /* LS_REFS_H */

@@ -33,6 +33,13 @@ static int object_format_advertise(struct repository *r,
 	return 1;
 }
 
+static int session_id_startup_config(const char *var, const char *value, void *data)
+{
+	if (!strcmp(var, "transfer.advertisesid"))
+		advertise_sid = git_config_bool(var, value);
+	return 0;
+}
+
 static int session_id_advertise(struct repository *r, struct strbuf *value)
 {
 	if (!advertise_sid)

@@ -54,6 +61,24 @@ struct protocol_capability {
 	 */
 	const char *name;
 
+	/*
+	 * A git_config() callback that'll be called only once for the
+	 * lifetime of the process, possibly over many different
+	 * requests. Used for reading config that's expected to be
+	 * static.
+	 *
+	 * The "command" or "advertise" callbacks themselves are
+	 * expected to read config that needs to be more current than
+	 * that, or which is dependent on request data.
+	 */
+	int (*startup_config)(const char *var, const char *value, void *data);
+
+	/*
+	 * A boolean to check if we've called our "startup_config"
+	 * callback.
+	 */
+	int have_startup_config;
+
 	/*
 	 * Function queried to see if a capability should be advertised.
 	 * Optionally a value can be specified by adding it to 'value'.

@@ -81,6 +106,7 @@ static struct protocol_capability capabilities[] = {
 	},
 	{
 		.name = "ls-refs",
+		.startup_config = ls_refs_startup_config,
 		.advertise = ls_refs_advertise,
 		.command = ls_refs,
 	},

@@ -99,6 +125,7 @@ static struct protocol_capability capabilities[] = {
 	},
 	{
 		.name = "session-id",
+		.startup_config = session_id_startup_config,
 		.advertise = session_id_advertise,
 	},
 	{

@@ -108,9 +135,20 @@ static struct protocol_capability capabilities[] = {
 	},
 };
 
+static void read_startup_config(struct protocol_capability *command)
+{
+	if (!command->startup_config)
+		return;
+	if (command->have_startup_config++)
+		return;
+	git_config(command->startup_config, NULL);
+}
+
 static int call_advertise(struct protocol_capability *command,
 			  struct repository *r, struct strbuf *value)
 {
+	read_startup_config(command);
+
 	return command->advertise(r, value);
 }
 

@@ -118,6 +156,9 @@ static int call_command(struct protocol_capability *command,
 			struct repository *r, struct strvec *keys,
 			struct packet_reader *request)
 {
+
+	read_startup_config(command);
+
 	return command->command(r, keys, request);
 }
 

@@ -318,8 +359,6 @@ static int process_request(void)
 /* Main serve loop for protocol version 2 */
 void serve(struct serve_options *options)
 {
-	git_config_get_bool("transfer.advertisesid", &advertise_sid);
-
 	if (options->advertise_capabilities || !options->stateless_rpc) {
 		/* serve by default supports v2 */
 		packet_write_fmt(1, "version 2\n");