mirror of http://gerrit.asterisk.org/asterisk
Often times, when subscribing to a topic, one wants to handle different message types differently. While one could cascade if/else statements through the subscription handler, it is much cleaner to specify a different callback for each message type. The stasis_message_router is here to help! A stasis_message_router is constructed for a particular stasis_topic, which is subscribes to. Call stasis_message_router_unsubscribe() to cancel that subscription. Once constructed, routes can be added using stasis_message_router_add() (or stasis_message_router_set_default() for any messages not handled by other routes). There may be only one route per stasis_message_type. The route's callback is invoked just as if it were a callback for a subscription; but it only gets called for messages of the specified type. (issue ASTERISK-20887) Review: https://reviewboard.asterisk.org/r/2390/ git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@383242 65c4cc65-6c06-0410-ace0-fbb531ad65f3changes/78/78/1
David M. Lee
12 years ago
parent
641fc7ea54
commit
49e3489cac
@ -0,0 +1,89 @@
|
||||
/*
|
||||
* Asterisk -- An open source telephony toolkit.
|
||||
*
|
||||
* Copyright (C) 2013, Digium, Inc.
|
||||
*
|
||||
* David M. Lee, II <dlee@digium.com>
|
||||
*
|
||||
* See http://www.asterisk.org for more information about
|
||||
* the Asterisk project. Please do not directly contact
|
||||
* any of the maintainers of this project for assistance;
|
||||
* the project provides a web site, mailing lists and IRC
|
||||
* channels for your use.
|
||||
*
|
||||
* This program is free software, distributed under the terms of
|
||||
* the GNU General Public License Version 2. See the LICENSE file
|
||||
* at the top of the source tree.
|
||||
*/
|
||||
|
||||
#ifndef _ASTERISK_STASIS_MESSAGE_ROUTER_H
|
||||
#define _ASTERISK_STASIS_MESSAGE_ROUTER_H
|
||||
|
||||
/*!
|
||||
* \brief A simplistic router for \ref stasis_message's.
|
||||
*
|
||||
* Often times, when subscribing to a topic, one wants to handle different
|
||||
* message types differently. While one could cascade if/else statements through
|
||||
* the subscription handler, it is much cleaner to specify a different callback
|
||||
* for each message type. The \ref stasis_message_router is here to help!
|
||||
*
|
||||
* A \ref stasis_message_router is constructed for a particular \ref
|
||||
* stasis_topic, which is subscribes to. Call
|
||||
* stasis_message_router_unsubscribe() to cancel that subscription.
|
||||
*
|
||||
* Once constructed, routes can be added using stasis_message_router_add() (or
|
||||
* stasis_message_router_set_default() for any messages not handled by other
|
||||
* routes). There may be only one route per \ref stasis_message_type. The
|
||||
* route's \a callback is invoked just as if it were a callback for a
|
||||
* subscription; but it only gets called for messages of the specified type.
|
||||
*
|
||||
* \since 12
|
||||
*/
|
||||
|
||||
#include "asterisk/stasis.h"
|
||||
|
||||
/*! \brief Stasis message routing object */
|
||||
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(
|
||||
struct stasis_topic *topic);
|
||||
|
||||
/*!
|
||||
* \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);
|
||||
|
||||
/*!
|
||||
* \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.
|
||||
* \since 12
|
||||
*/
|
||||
int stasis_message_router_add(struct stasis_message_router *router,
|
||||
struct stasis_message_type *message_type,
|
||||
stasis_subscription_cb callback,
|
||||
void *data);
|
||||
|
||||
/*!
|
||||
* \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.
|
||||
* \since 12
|
||||
*/
|
||||
int stasis_message_router_set_default(struct stasis_message_router *router,
|
||||
stasis_subscription_cb callback,
|
||||
void *data);
|
||||
|
||||
#endif /* _ASTERISK_STASIS_MESSAGE_ROUTER_H */
|
||||
@ -0,0 +1,244 @@
|
||||
/*
|
||||
* Asterisk -- An open source telephony toolkit.
|
||||
*
|
||||
* Copyright (C) 2013, Digium, Inc.
|
||||
*
|
||||
* David M. Lee, II <dlee@digium.com>
|
||||
*
|
||||
* See http://www.asterisk.org for more information about
|
||||
* the Asterisk project. Please do not directly contact
|
||||
* any of the maintainers of this project for assistance;
|
||||
* the project provides a web site, mailing lists and IRC
|
||||
* channels for your use.
|
||||
*
|
||||
* This program is free software, distributed under the terms of
|
||||
* the GNU General Public License Version 2. See the LICENSE file
|
||||
* at the top of the source tree.
|
||||
*/
|
||||
|
||||
/*! \file
|
||||
*
|
||||
* \brief Stasis message router implementation.
|
||||
*
|
||||
* \author David M. Lee, II <dlee@digium.com>
|
||||
*/
|
||||
|
||||
/*** MODULEINFO
|
||||
<support_level>core</support_level>
|
||||
***/
|
||||
|
||||
#include "asterisk.h"
|
||||
|
||||
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. */
|
||||
struct stasis_message_type *message_type;
|
||||
/*! Callback function for incoming message processing. */
|
||||
stasis_subscription_cb callback;
|
||||
/*! Data pointer to be handed to the callback. */
|
||||
void *data;
|
||||
};
|
||||
|
||||
static void route_dtor(void *obj)
|
||||
{
|
||||
struct stasis_message_route *route = obj;
|
||||
|
||||
ao2_cleanup(route->message_type);
|
||||
route->message_type = NULL;
|
||||
}
|
||||
|
||||
/*! \internal */
|
||||
struct stasis_message_router {
|
||||
/*! Subscription to the upstream topic */
|
||||
struct stasis_subscription *subscription;
|
||||
/*! Variable length array of the routes */
|
||||
struct stasis_message_route **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));
|
||||
router->subscription = NULL;
|
||||
for (i = 0; i < router->num_routes_current; ++i) {
|
||||
ao2_cleanup(router->routes[i]);
|
||||
router->routes[i] = NULL;
|
||||
}
|
||||
ast_free(router->routes);
|
||||
router->routes = NULL;
|
||||
ao2_cleanup(router->default_route);
|
||||
router->default_route = NULL;
|
||||
}
|
||||
|
||||
static void router_dispatch(void *data,
|
||||
struct stasis_subscription *sub,
|
||||
struct stasis_topic *topic,
|
||||
struct stasis_message *message)
|
||||
{
|
||||
struct stasis_message_router *router = data;
|
||||
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
|
||||
* be adequate, even if the complexity is O(n). Sorting the list
|
||||
* would be an easy way to bring that down to O(log(n)). Using a
|
||||
* 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) {
|
||||
route->callback(route->data, sub, topic, message);
|
||||
}
|
||||
|
||||
if (stasis_subscription_final_message(sub, message)) {
|
||||
ao2_cleanup(router);
|
||||
return;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
struct stasis_message_router *stasis_message_router_create(
|
||||
struct stasis_topic *topic)
|
||||
{
|
||||
RAII_VAR(struct stasis_message_router *, router, NULL, ao2_cleanup);
|
||||
|
||||
router = ao2_alloc(sizeof(*router), router_dtor);
|
||||
if (!router) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
router->num_routes_max = INITIAL_ROUTES_MAX;
|
||||
router->routes = ast_calloc(router->num_routes_max,
|
||||
sizeof(*router->routes));
|
||||
if (!router->routes) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
router->subscription = stasis_subscribe(topic, router_dispatch, router);
|
||||
if (!router->subscription) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
ao2_ref(router, +1);
|
||||
return router;
|
||||
}
|
||||
|
||||
void stasis_message_router_unsubscribe(struct stasis_message_router *router)
|
||||
{
|
||||
if (!router) {
|
||||
return;
|
||||
}
|
||||
|
||||
stasis_unsubscribe(router->subscription);
|
||||
}
|
||||
|
||||
static struct stasis_message_route *route_create(
|
||||
struct stasis_message_type *message_type,
|
||||
stasis_subscription_cb callback,
|
||||
void *data)
|
||||
{
|
||||
RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
|
||||
|
||||
route = ao2_alloc(sizeof(*route), route_dtor);
|
||||
if (!route) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (message_type) {
|
||||
ao2_ref(message_type, +1);
|
||||
}
|
||||
route->message_type = message_type;
|
||||
route->callback = callback;
|
||||
route->data = data;
|
||||
|
||||
ao2_ref(route, +1);
|
||||
return route;
|
||||
}
|
||||
|
||||
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);
|
||||
|
||||
/* Check for route conflicts */
|
||||
for (i = 0; i < router->num_routes_current; ++i) {
|
||||
if (router->routes[i]->message_type == route->message_type) {
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Increase list size, if needed */
|
||||
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;
|
||||
}
|
||||
|
||||
int stasis_message_router_add(struct stasis_message_router *router,
|
||||
struct stasis_message_type *message_type,
|
||||
stasis_subscription_cb callback,
|
||||
void *data)
|
||||
{
|
||||
RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
|
||||
|
||||
route = route_create(message_type, callback, data);
|
||||
if (!route) {
|
||||
return -1;
|
||||
}
|
||||
|
||||
return add_route(router, route);
|
||||
}
|
||||
|
||||
int stasis_message_router_set_default(struct stasis_message_router *router,
|
||||
stasis_subscription_cb callback,
|
||||
void *data)
|
||||
{
|
||||
SCOPED_AO2LOCK(lock, router);
|
||||
ao2_cleanup(router->default_route);
|
||||
router->default_route = route_create(NULL, callback, data);
|
||||
return router->default_route ? 0 : -1;
|
||||
}
|
||||
Loading…
Reference in new issue