io.opencensus.metrics.export.MetricProducerManager Maven / Gradle / Ivy
/*
* Copyright 2018, OpenCensus Authors
*
* Licensed 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 io.opencensus.metrics.export;
import io.opencensus.common.ExperimentalApi;
import io.opencensus.internal.Utils;
import java.util.Collections;
import java.util.Set;
import javax.annotation.concurrent.ThreadSafe;
/**
* Keeps a set of {@link MetricProducer} that is used by exporters to determine the metrics that
* need to be exported.
*
* @since 0.17
*/
@ExperimentalApi
@ThreadSafe
public abstract class MetricProducerManager {
/**
* Adds the {@link MetricProducer} to the manager if it is not already present.
*
* @param metricProducer the {@code MetricProducer} to be added to the manager.
* @since 0.17
*/
public abstract void add(MetricProducer metricProducer);
/**
* Removes the {@link MetricProducer} to the manager if it is present.
*
* @param metricProducer the {@code MetricProducer} to be removed from the manager.
* @since 0.17
*/
public abstract void remove(MetricProducer metricProducer);
/**
* Returns all registered {@link MetricProducer}s that should be exported.
*
* This method should be used by any metrics exporter that automatically exports data for
* {@code MetricProducer} registered with the {@code MetricProducerManager}.
*
* @return all registered {@code MetricProducer}s that should be exported.
* @since 0.17
*/
public abstract Set getAllMetricProducer();
/**
* Returns a no-op implementation for {@link MetricProducerManager}.
*
* @return a no-op implementation for {@code MetricProducerManager}.
*/
static MetricProducerManager newNoopMetricProducerManager() {
return new NoopMetricProducerManager();
}
private static final class NoopMetricProducerManager extends MetricProducerManager {
@Override
public void add(MetricProducer metricProducer) {
Utils.checkNotNull(metricProducer, "metricProducer");
}
@Override
public void remove(MetricProducer metricProducer) {
Utils.checkNotNull(metricProducer, "metricProducer");
}
@Override
public Set getAllMetricProducer() {
return Collections.emptySet();
}
}
}