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* 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.reducer;
import java.util.List;
import java.util.Map;
import java.util.Objects;
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.util.core.flags.SetFromFlag;
import org.apache.brooklyn.util.core.sensor.SensorPredicates;
import org.apache.brooklyn.util.core.task.Tasks;
import org.apache.brooklyn.util.core.task.ValueResolver;
import org.apache.brooklyn.util.text.StringFunctions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.reflect.TypeToken;
@SuppressWarnings("serial")
public class Reducer extends AbstractEnricher implements SensorEventListener<Object> {
private static final Logger LOG = LoggerFactory.getLogger(Reducer.class);
@SetFromFlag("producer")
public static ConfigKey<Entity> PRODUCER = ConfigKeys.newConfigKey(Entity.class, "enricher.producer");
public static ConfigKey<Sensor<?>> TARGET_SENSOR = ConfigKeys.newConfigKey(new TypeToken<Sensor<?>>() {}, "enricher.targetSensor");
public static ConfigKey<List<? extends AttributeSensor<?>>> SOURCE_SENSORS = ConfigKeys.newConfigKey(new TypeToken<List<? extends AttributeSensor<?>>>() {}, "enricher.sourceSensors");
public static ConfigKey<Function<List<?>,?>> REDUCER_FUNCTION = ConfigKeys.newConfigKey(new TypeToken<Function<List<?>, ?>>() {}, "enricher.reducerFunction");
@SetFromFlag("transformation")
public static final ConfigKey<String> REDUCER_FUNCTION_TRANSFORMATION = ConfigKeys.newStringConfigKey("enricher.reducerFunction.transformation",
"A string matching a pre-defined named reducer function, such as joiner");
public static final ConfigKey<Map<String, Object>> PARAMETERS = ConfigKeys.newConfigKey(new TypeToken<Map<String, Object>>() {}, "enricher.reducerFunction.parameters",
"A map of parameters to pass into the reducer function");
protected Entity producer;
protected List<AttributeSensor<?>> subscribedSensors;
protected Sensor<?> targetSensor;
protected Function<Iterable<?>, ?> reducerFunction;
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public void setEntity(EntityLocal entity) {
super.setEntity(entity);
Preconditions.checkNotNull(getConfig(SOURCE_SENSORS), "source sensors");
this.producer = getConfig(PRODUCER) == null ? entity : getConfig(PRODUCER);
List<AttributeSensor<?>> sensorListTemp = Lists.newArrayList();
for (Object sensorO : getConfig(SOURCE_SENSORS)) {
AttributeSensor<?> sensor = Tasks.resolving(sensorO).as(AttributeSensor.class).timeout(ValueResolver.REAL_QUICK_WAIT).context(producer).get();
Optional<? extends Sensor<?>> foundSensor = Iterables.tryFind(sensorListTemp,
SensorPredicates.nameEqualTo(sensor.getName()));
if(!foundSensor.isPresent()) {
sensorListTemp.add(sensor);
}
}
String reducerName = config().get(REDUCER_FUNCTION_TRANSFORMATION);
Function<Iterable<?>, ?> reducerFunction = (Function) config().get(REDUCER_FUNCTION);
if(reducerFunction == null){
Map<String, ?> parameters = config().get(PARAMETERS);
reducerFunction = createReducerFunction(reducerName, parameters);
}
this.reducerFunction = reducerFunction;
Preconditions.checkState(sensorListTemp.size() > 0, "Nothing to reduce");
for (Sensor<?> sensor : sensorListTemp) {
subscribe(producer, sensor, this);
}
subscribedSensors = ImmutableList.copyOf(sensorListTemp);
}
// Default implementation, subclasses should override
protected Function<Iterable<?>, ?> createReducerFunction(String reducerName, Map<String, ?> parameters){
if(Objects.equals(reducerName, "joiner")){
String separator = (String) parameters.get("separator");
return StringFunctions.joiner(separator == null ? ", " : separator);
}
if (Objects.equals(reducerName, "formatString")){
String format = Preconditions.checkNotNull((String)parameters.get("format"), "format");
return StringFunctions.formatterForIterable(format);
}
throw new IllegalStateException("unknown function: " + reducerName);
}
@Override
public void onEvent(SensorEvent<Object> event) {
Sensor<?> destinationSensor = getConfig(TARGET_SENSOR);
List<Object> values = Lists.newArrayList();
for (AttributeSensor<?> sourceSensor : subscribedSensors) {
Object resolvedSensorValue = entity.sensors().get(sourceSensor);
values.add(resolvedSensorValue);
}
Object result = reducerFunction.apply(values);
if (LOG.isTraceEnabled()) LOG.trace("enricher {} got {}, propagating via {} as {}",
new Object[] {this, event, entity, reducerFunction, destinationSensor});
emit(destinationSensor, result);
}
}