Merge "devicestate: Don't create topic when change isn't cached." into 13

include/asterisk/stasis.h

@@ -756,6 +756,16 @@ struct stasis_topic_pool *stasis_topic_pool_create(struct stasis_topic *pooled_t
  */
 struct stasis_topic *stasis_topic_pool_get_topic(struct stasis_topic_pool *pool, const char *topic_name);
 
+/*!
+ * \brief Check if a topic exists in a pool
+ * \param pool Pool to check
+ * \param topic_name Name of the topic to check
+ * \retval 1 exists
+ * \retval 0 does not exist
+ * \since 13.23.0
+ */
+int stasis_topic_pool_topic_exists(const struct stasis_topic_pool *pool, const char *topic_name);
+
 /*! @} */
 
 /*! \addtogroup StasisTopicsAndMessages

main/devicestate.c

@@ -739,7 +739,7 @@ int ast_publish_device_state_full(
 {
 	RAII_VAR(struct ast_device_state_message *, device_state, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
-	struct stasis_topic *device_specific_topic;
+	struct stasis_topic *topic;
 
 	ast_assert(!ast_strlen_zero(device));
 
@@ -758,12 +758,28 @@ int ast_publish_device_state_full(
 		return -1;
 	}
 
-	device_specific_topic = ast_device_state_topic(device);
-	if (!device_specific_topic) {
+	/* When a device state is to be cached it is likely that something
+	 * external will either be monitoring it or will want to pull the
+	 * information from the cache, so we always publish to the device
+	 * specific topic. Cachable updates traditionally come from such things
+	 * as a SIP or PJSIP device.
+	 * When a device state is not to be cached we only publish to its
+	 * specific topic if something has already created the topic. Publishing
+	 * to its topic otherwise would create the topic, which may not be
+	 * necessary as it could be an ephemeral device. Uncachable updates
+	 * traditionally come from such things as Local channels.
+	 */
+	if (cachable || stasis_topic_pool_topic_exists(device_state_topic_pool, device)) {
+		topic = ast_device_state_topic(device);
+	} else {
+		topic = ast_device_state_topic_all();
+	}
+
+	if (!topic) {
 		return -1;
 	}
 
-	stasis_publish(device_specific_topic, message);
+	stasis_publish(topic, message);
 	return 0;
 }
 

main/stasis.c

@@ -1198,6 +1198,19 @@ struct stasis_topic *stasis_topic_pool_get_topic(struct stasis_topic_pool *pool,
 	return topic_pool_entry->topic;
 }
 
+int stasis_topic_pool_topic_exists(const struct stasis_topic_pool *pool, const char *topic_name)
+{
+	struct topic_pool_entry *topic_pool_entry;
+
+	topic_pool_entry = ao2_find(pool->pool_container, topic_name, OBJ_SEARCH_KEY);
+	if (!topic_pool_entry) {
+		return 0;
+	}
+
+	ao2_ref(topic_pool_entry, -1);
+	return 1;
+}
+
 void stasis_log_bad_type_access(const char *name)
 {
 #ifdef AST_DEVMODE