/*
* 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.enricher.stock;
import static com.google.common.base.Preconditions.checkState;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.EntityLocal;
import org.apache.brooklyn.api.sensor.AttributeSensor;
import org.apache.brooklyn.api.sensor.Sensor;
import org.apache.brooklyn.api.sensor.SensorEvent;
import org.apache.brooklyn.api.sensor.SensorEventListener;
import org.apache.brooklyn.config.ConfigKey;
import org.apache.brooklyn.core.config.ConfigKeys;
import org.apache.brooklyn.core.enricher.AbstractEnricher;
import org.apache.brooklyn.core.sensor.BasicSensorEvent;
import org.apache.brooklyn.util.collections.MutableList;
import org.apache.brooklyn.util.exceptions.Exceptions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.Iterables;
import com.google.common.reflect.TypeToken;
@SuppressWarnings("serial")
//@Catalog(name="Combiner", description="Combines attributes; see Enrichers.builder().combining(...)")
public class Combiner<T,U> extends AbstractEnricher implements SensorEventListener<T> {
private static final Logger LOG = LoggerFactory.getLogger(Combiner.class);
public static ConfigKey<Function<?, ?>> TRANSFORMATION = ConfigKeys.newConfigKey(new TypeToken<Function<?, ?>>() {}, "enricher.transformation");
public static ConfigKey<Entity> PRODUCER = ConfigKeys.newConfigKey(Entity.class, "enricher.producer");
public static ConfigKey<Set<Sensor<?>>> SOURCE_SENSORS = ConfigKeys.newConfigKey(new TypeToken<Set<Sensor<?>>>() {}, "enricher.sourceSensors");
public static ConfigKey<Sensor<?>> TARGET_SENSOR = ConfigKeys.newConfigKey(new TypeToken<Sensor<?>>() {}, "enricher.targetSensor");
public static final ConfigKey<Predicate<?>> VALUE_FILTER = ConfigKeys.newConfigKey(new TypeToken<Predicate<?>>() {}, "enricher.aggregating.valueFilter");
protected Function<? super Collection<T>, ? extends U> transformation;
protected Entity producer;
protected Set<Sensor<T>> sourceSensors;
protected Sensor<U> targetSensor;
protected Predicate<? super T> valueFilter;
/**
* Users of values should either on it synchronize when iterating over its entries or use
* copyOfValues to obtain an immutable copy of the map.
*/
// We use a synchronizedMap over a ConcurrentHashMap for entities that store null values.
protected final Map<Sensor<T>, T> values = Collections.synchronizedMap(new LinkedHashMap<Sensor<T>, T>());
public Combiner() {
}
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public void setEntity(EntityLocal entity) {
super.setEntity(entity);
this.transformation = (Function<? super Collection<T>, ? extends U>) getRequiredConfig(TRANSFORMATION);
this.producer = getConfig(PRODUCER) == null ? entity: getConfig(PRODUCER);
this.sourceSensors = (Set) getRequiredConfig(SOURCE_SENSORS);
this.targetSensor = (Sensor<U>) getRequiredConfig(TARGET_SENSOR);
this.valueFilter = (Predicate<? super T>) (getConfig(VALUE_FILTER) == null ? Predicates.alwaysTrue() : getConfig(VALUE_FILTER));
checkState(sourceSensors.size() > 0, "must specify at least one sourceSensor");
for (Sensor<T> sourceSensor : sourceSensors) {
subscriptions().subscribe(producer, sourceSensor, this);
}
for (Sensor<T> sourceSensor : sourceSensors) {
if (sourceSensor instanceof AttributeSensor) {
Object value = producer.getAttribute((AttributeSensor<?>)sourceSensor);
// TODO Aled didn't you write a convenience to "subscribeAndRunIfSet" ? (-Alex)
// Unfortunately not yet!
if (value != null) {
onEvent(new BasicSensorEvent(sourceSensor, producer, value, -1));
}
}
}
}
@Override
public void onEvent(SensorEvent<T> event) {
synchronized (values) {
values.put(event.getSensor(), event.getValue());
}
onUpdated();
}
/**
* Called whenever the values for the set of producers changes (e.g. on an event, or on a member added/removed).
*/
protected void onUpdated() {
try {
emit(targetSensor, compute());
} catch (Throwable t) {
LOG.warn("Error calculating and setting combination for enricher "+this, t);
throw Exceptions.propagate(t);
}
}
protected Object compute() {
synchronized (values) {
// TODO Could avoid copying when filter not needed
List<T> vs = MutableList.copyOf(Iterables.filter(values.values(), valueFilter));
return transformation.apply(vs);
}
}
}