org.apache.brooklyn.api.mgmt.SubscriptionManager Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* specific language governing permissions and limitations
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*/
package org.apache.brooklyn.api.mgmt;
import java.util.Map;
import java.util.Set;
import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.Group;
import org.apache.brooklyn.api.sensor.Sensor;
import org.apache.brooklyn.api.sensor.SensorEvent;
import org.apache.brooklyn.api.sensor.SensorEventListener;
/**
* The management interface for subscriptions.
*
* Different implementations will handle entities subscribing and unsubscribing to {@link SensorEvent}s
* and their delivery.
*
* @see SubscriptionContext
*/
public interface SubscriptionManager {
/**
* Subscribe to {@link Sensor} data changes and events on a given {@link Entity}, supplying the {@link SensorEventListener}
* to invoke when they occur.
*
* The method returns an id which can be used to {@link #unsubscribe(SubscriptionHandle)} later.
*
* The listener callback is in-order single-threaded and synchronized on this object. The flags
* parameters can include the following:
*
* - subscriber - object to identify the subscriber (e.g. entity, or console session uid)
*
- in future - control parameters for the subscription (period, minimum delta for updates, etc)
*
*
* @param flags optional parameters to be associated with the subscription
* @param producer entity to listen to, or null to listen to all entities
* @param sensor sensor channel of events to listen to, or null for all sensors from the given producer(s)
* @param listener callback to invoke when an event occurs
* @return an id for this subscription
*
* @see #unsubscribe(SubscriptionHandle)
*/
SubscriptionHandle subscribe(Map flags, Entity producer, Sensor sensor, SensorEventListener super T> listener);
/** @see #subscribe(Map, Entity, Sensor, SensorEventListener) */
SubscriptionHandle subscribe(Entity producer, Sensor sensor, SensorEventListener super T> listener);
/**
* Subscribe to {@link Sensor} data changes and events on all children of a given {@link Entity}, supplying the
* {@link SensorEventListener} to invoke when they occur.
*
* The subscriptions will be created recursively for all children, and the same listener callback will be invoked for each
* sensor datum. The semantics are otherwise identical to the {@link #subscribe(Map, Entity, Sensor, SensorEventListener)} method.
*
* @see #subscribe(Map, Entity, Sensor, SensorEventListener)
*/
SubscriptionHandle subscribeToChildren(Map flags, Entity parent, Sensor sensor, SensorEventListener super T> listener);
/** @see #subscribeToChildren(Map, Entity, Sensor, SensorEventListener) */
SubscriptionHandle subscribeToChildren(Entity parent, Sensor sensor, SensorEventListener super T> listener);
/**
* Subscribe to {@link Sensor} data changes and events on all members of a given {@link Group}, supplying the
* {@link SensorEventListener} to invoke when they occur.
*
* The subscriptions will be created recursively for all children, and the same listener callback will be invoked for each
* sensor datum. The semantics are otherwise identical to the {@link #subscribe(Map, Entity, Sensor, SensorEventListener)} method.
*
* @see #subscribe(Map, Entity, Sensor, SensorEventListener)
*/
SubscriptionHandle subscribeToMembers(Map flags, Group parent, Sensor sensor, SensorEventListener super T> listener);
/** @see #subscribeToMembers(Map, Group, Sensor, SensorEventListener) */
SubscriptionHandle subscribeToMembers(Group parent, Sensor sensor, SensorEventListener super T> listener);
/**
* Unsubscribe the given subscription id.
*
* @return true if such a subscription was present (and it will now be removed)
*
* @see #subscribe(Map, Entity, Sensor, SensorEventListener)
*/
boolean unsubscribe(SubscriptionHandle subscriptionId);
/**
* Deliver a {@link SensorEvent} to all subscribed listeners.
*/
void publish(SensorEvent event);
/** Return the subscriptions requested by a given subscriber */
Set getSubscriptionsForSubscriber(Object subscriber);
/** Return the subscriptions on a given source-sensor pair */
Set getSubscriptionsForEntitySensor(Entity source, Sensor> sensor);
}
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