/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* 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
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.brooklyn.core.mgmt.internal;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.Collections;
import java.util.Map;
import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.Group;
import org.apache.brooklyn.api.mgmt.SubscriptionHandle;
import org.apache.brooklyn.api.mgmt.SubscriptionManager;
import org.apache.brooklyn.api.sensor.Sensor;
import org.apache.brooklyn.api.sensor.SensorEvent;
import org.apache.brooklyn.api.sensor.SensorEventListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Objects;
import com.google.common.base.Predicate;
public abstract class AbstractSubscriptionManager implements SubscriptionManager {
// TODO Perhaps could use guava's SynchronizedSetMultimap? But need to check its synchronization guarantees.
// That would replace the utils used for subscriptionsBySubscriber etc.
@SuppressWarnings("unused")
private static final Logger LOG = LoggerFactory.getLogger(AbstractSubscriptionManager.class);
/** performs the actual subscription; should return the subscription parameter as the handle */
protected abstract <T> SubscriptionHandle subscribe(Map<String, Object> flags, Subscription<T> s);
/** performs the actual publishing -- ie distribution to subscriptions */
public abstract <T> void publish(final SensorEvent<T> event);
public static class EntitySensorToken {
Entity e;
Sensor<?> s;
String sName;
public EntitySensorToken(Entity e, Sensor<?> s) {
this.e = e;
this.s = s;
this.sName = (s == null) ? null : checkNotNull(s.getName(), "sensor must have non-null name: %s", s);
}
@Override
public int hashCode() {
return Objects.hashCode(e, sName);
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (!(obj instanceof EntitySensorToken)) return false;
if (!Objects.equal(e, ((EntitySensorToken)obj).e)) return false;
if (!Objects.equal(sName, ((EntitySensorToken)obj).sName)) return false;
return true;
}
@Override
public String toString() {
return (e != null ? e.getId() : "*")+":"+(s != null ? sName : "*");
}
}
static Object makeEntitySensorToken(Entity e, Sensor<?> s) {
return new EntitySensorToken(e, s);
}
static Object makeEntitySensorToken(SensorEvent<?> se) {
return makeEntitySensorToken(se.getSource(), se.getSensor());
}
/** @see SubscriptionManager#subscribe(Map, Entity, Sensor, SensorEventListener) */
public final <T> SubscriptionHandle subscribe(Entity producer, Sensor<T> sensor, SensorEventListener<? super T> listener) {
return subscribe(Collections.<String,Object>emptyMap(), producer, sensor, listener);
}
/**
* This implementation handles the following flags, in addition to those described in the {@link SubscriptionManager}
* interface:
* <ul>
* <li>subscriberExecutionManagerTag - a tag to pass to execution manager (without setting any execution semantics / TaskPreprocessor);
* if not supplied and there is a subscriber, this will be inferred from the subscriber and set up with SingleThreadedScheduler
* <li>eventFilter - a Predicate<SensorEvent> instance to filter what events are delivered
* </ul>
*
* @see SubscriptionManager#subscribe(Map, Entity, Sensor, SensorEventListener)
*/
public final <T> SubscriptionHandle subscribe(Map<String, Object> flags, Entity producer, Sensor<T> sensor, SensorEventListener<? super T> listener) {
return subscribe(flags, new Subscription<T>(producer, sensor, listener));
}
/** @see SubscriptionManager#subscribeToChildren(Map, Entity, Sensor, SensorEventListener) */
public final <T> SubscriptionHandle subscribeToChildren(Entity parent, Sensor<T> sensor, SensorEventListener<? super T> listener) {
return subscribeToChildren(Collections.<String,Object>emptyMap(), parent, sensor, listener);
}
/** @see SubscriptionManager#subscribe(Map, Entity, Sensor, SensorEventListener) */
public final <T> SubscriptionHandle subscribeToChildren(Map<String, Object> flags, final Entity parent, Sensor<T> sensor, SensorEventListener<? super T> listener) {
Predicate<SensorEvent<T>> eventFilter = new Predicate<SensorEvent<T>>() {
public boolean apply(SensorEvent<T> input) {
return parent != null && input.getSource() != null && parent.equals(input.getSource().getParent());
}
};
flags.put("eventFilter", eventFilter);
return subscribe(flags, null, sensor, listener);
}
/** @see SubscriptionManager#subscribeToChildren(Map, Entity, Sensor, SensorEventListener) */
public final <T> SubscriptionHandle subscribeToMembers(Group parent, Sensor<T> sensor, SensorEventListener<? super T> listener) {
return subscribeToMembers(Collections.<String,Object>emptyMap(), parent, sensor, listener);
}
/** @see SubscriptionManager#subscribe(Map, Entity, Sensor, SensorEventListener) */
public final <T> SubscriptionHandle subscribeToMembers(Map<String, Object> flags, final Group parent, Sensor<T> sensor, SensorEventListener<? super T> listener) {
Predicate<SensorEvent<T>> eventFilter = new Predicate<SensorEvent<T>>() {
public boolean apply(SensorEvent<T> input) {
return parent.getMembers().contains(input.getSource());
}
};
flags.put("eventFilter", eventFilter);
return subscribe(flags, null, sensor, listener);
}
protected <T> Object getSubscriber(Map<String, Object> flags, Subscription<T> s) {
return s.subscriber!=null ? s.subscriber : flags.containsKey("subscriber") ? flags.remove("subscriber") : s.listener;
}
}