Convert message_router routes to ao2. Add support for removal.

Review: https://reviewboard.asterisk.org/r/2591/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@390698 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/stasis_message_router.h

@@ -47,9 +47,12 @@ struct stasis_message_router;
 
 /*!
  * \brief Create a new message router object.
+ *
  * \param topic Topic to subscribe route to.
+ *
  * \return New \ref stasis_message_router.
  * \return \c NULL on error.
+ *
  * \since 12
  */
 struct stasis_message_router *stasis_message_router_create(
@@ -59,6 +62,7 @@ struct stasis_message_router *stasis_message_router_create(
  * \brief Unsubscribe the router from the upstream topic.
  *
  * \param router Router to unsubscribe.
+ *
  * \since 12
  */
 void stasis_message_router_unsubscribe(struct stasis_message_router *router);
@@ -71,6 +75,7 @@ void stasis_message_router_unsubscribe(struct stasis_message_router *router);
  * vs. stasis_message_router_unsubscribe().
  *
  * \param router Router to unsubscribe.
+ *
  * \since 12
  */
 void stasis_message_router_unsubscribe_and_join(
@@ -80,6 +85,7 @@ void stasis_message_router_unsubscribe_and_join(
  * \brief Returns whether \a router has received its final message.
  *
  * \param router Router.
+ *
  * \return True (non-zero) if stasis_subscription_final_message() has been
  *         received.
  * \return False (zero) if waiting for the end.
@@ -88,10 +94,15 @@ int stasis_message_router_is_done(struct stasis_message_router *router);
 
 /*!
  * \brief Add a route to a message router.
+ *
  * \param router Router to add the route to.
  * \param message_type Type of message to route.
  * \param callback Callback to forard messages of \a message_type to.
  * \param data Data pointer to pass to \a callback.
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
  * \since 12
  */
 int stasis_message_router_add(struct stasis_message_router *router,
@@ -99,11 +110,27 @@ int stasis_message_router_add(struct stasis_message_router *router,
 			      stasis_subscription_cb callback,
 			      void *data);
 
+/*!
+ * \brief Remove a route from a message router.
+ *
+ * \param router Router to remove the route from.
+ * \param message_type Type of message to route.
+ *
+ * \since 12
+ */
+void stasis_message_router_remove(struct stasis_message_router *router,
+			      struct stasis_message_type *message_type);
+
 /*!
  * \brief Sets the default route of a router.
+ *
  * \param router Router to set the default route of.
  * \param callback Callback to forard messages which otherwise have no home.
  * \param data Data pointer to pass to \a callback.
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
  * \since 12
  */
 int stasis_message_router_set_default(struct stasis_message_router *router,

main/stasis_message_router.c

@@ -34,8 +34,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/astobj2.h"
 #include "asterisk/stasis_message_router.h"
 
-#define INITIAL_ROUTES_MAX 8
-
 /*! \internal */
 struct stasis_message_route {
 	/*! Message type handle by this route. */
@@ -54,38 +52,53 @@ static void route_dtor(void *obj)
 	route->message_type = NULL;
 }
 
+static int route_hash(const void *obj, const int flags)
+{
+	const struct stasis_message_route *route = obj;
+	const struct stasis_message_type *message_type = (flags & OBJ_KEY) ? obj : route->message_type;
+
+	return ast_str_hash(stasis_message_type_name(message_type));
+}
+
+static int route_cmp(void *obj, void *arg, int flags)
+{
+	const struct stasis_message_route *left = obj;
+	const struct stasis_message_route *right = arg;
+	const struct stasis_message_type *message_type = (flags & OBJ_KEY) ? arg : right->message_type;
+
+	return (left->message_type == message_type) ? CMP_MATCH | CMP_STOP : 0;
+}
+
 /*! \internal */
 struct stasis_message_router {
 	/*! Subscription to the upstream topic */
 	struct stasis_subscription *subscription;
-	/*! Variable length array of the routes */
+	/*! Subscribed routes */
-	struct stasis_message_route **routes;
+	struct ao2_container *routes;
 	/*! Route of last resort */
 	struct stasis_message_route *default_route;
-	/*! Allocated length of the routes array */
-	size_t num_routes_max;
-	/*! Current size of the routes array */
-	size_t num_routes_current;
 };
 
 static void router_dtor(void *obj)
 {
 	struct stasis_message_router *router = obj;
-	size_t i;
 
 	ast_assert(!stasis_subscription_is_subscribed(router->subscription));
 	ast_assert(stasis_subscription_is_done(router->subscription));
 	router->subscription = NULL;
-	for (i = 0; i < router->num_routes_current; ++i) {
+
-		ao2_cleanup(router->routes[i]);
+	ao2_cleanup(router->routes);
-		router->routes[i] = NULL;
-	}
-	ast_free(router->routes);
 	router->routes = NULL;
+
 	ao2_cleanup(router->default_route);
 	router->default_route = NULL;
 }
 
+static struct stasis_message_route *find_route(struct stasis_message_router *router, struct stasis_message_type *message_type)
+{
+	return ao2_find(router->routes, message_type, OBJ_KEY);
+}
+
 static void router_dispatch(void *data,
 			    struct stasis_subscription *sub,
 			    struct stasis_topic *topic,
@@ -95,29 +108,15 @@ static void router_dispatch(void *data,
 	RAII_VAR(struct stasis_message_router *, router_needs_cleanup, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
 	struct stasis_message_type *type = stasis_message_type(message);
-	size_t i;
 
 	{
 		SCOPED_AO2LOCK(lock, router);
 
-		/* We don't expect many message types, so a simple loop should
+		if (!(route = find_route(router, type))) {
-		 * be adequate, even if the complexity is O(n). Sorting the list
+			if ((route = router->default_route)) {
-		 * would be an easy way to bring that down to O(log(n)). Using a
+				ao2_ref(route, +1);
-		 * hashtable/ao2_container could be even better. Just be sure to
-		 * profile before you optimize!
-		 */
-		route = router->default_route;
-		for (i = 0; i < router->num_routes_current; ++i) {
-			if (router->routes[i]->message_type == type) {
-				route = router->routes[i];
-				break;
 			}
 		}
-
-		/* Ref the route before leaving the scoped lock */
-		if (route) {
-			ao2_ref(route, +1);
-		}
 	}
 
 	if (route) {
@@ -141,10 +140,7 @@ struct stasis_message_router *stasis_message_router_create(
 		return NULL;
 	}
 
-	router->num_routes_max = INITIAL_ROUTES_MAX;
+	if (!(router->routes = ao2_container_alloc(7, route_hash, route_cmp))) {
-	router->routes = ast_calloc(router->num_routes_max,
-				    sizeof(*router->routes));
-	if (!router->routes) {
 		return NULL;
 	}
 
@@ -212,31 +208,14 @@ static struct stasis_message_route *route_create(
 static int add_route(struct stasis_message_router *router,
 		     struct stasis_message_route *route)
 {
-	struct stasis_message_route **routes;
-	size_t i;
 	SCOPED_AO2LOCK(lock, router);
+	RAII_VAR(struct stasis_message_route *, existing_route, NULL, ao2_cleanup);
 
-	/* Check for route conflicts */
+	if ((existing_route = find_route(router, route->message_type))) {
-	for (i = 0; i < router->num_routes_current; ++i) {
+		return -1;
-		if (router->routes[i]->message_type == route->message_type) {
-			return -1;
-		}
 	}
 
-	/* Increase list size, if needed */
+	ao2_link(router->routes, route);
-	if (router->num_routes_current + 1 > router->num_routes_max) {
-		routes = realloc(router->routes,
-				 2 * router->num_routes_max * sizeof(*routes));
-		if (!routes) {
-			return -1;
-		}
-		router->routes = routes;
-		router->num_routes_max *= 2;
-	}
-
-
-	ao2_ref(route, +1);
-	router->routes[router->num_routes_current++] = route;
 	return 0;
 }
 
@@ -255,6 +234,14 @@ int stasis_message_router_add(struct stasis_message_router *router,
 	return add_route(router, route);
 }
 
+void stasis_message_router_remove(struct stasis_message_router *router,
+			      struct stasis_message_type *message_type)
+{
+	SCOPED_AO2LOCK(lock, router);
+
+	ao2_find(router->routes, message_type, OBJ_UNLINK | OBJ_NODATA | OBJ_KEY);
+}
+
 int stasis_message_router_set_default(struct stasis_message_router *router,
 				      stasis_subscription_cb callback,
 				      void *data)