content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.metrics;
  
  import java.util.Map;
  import java.util.Set;
  
  /**
   * An interface for the aggregator that aggregates metrics of different hosts into multiple
   * cluster-level metrics.
   */
  public interface MultiValueMetricsAggregator {
    /**
     * @return the metric name to use for filter metrics
     */
    String getFilterMetricName();
  
    /**
     * Updates the aggregated values from the filtered metrics. The values of map will be the filtered
     * metrics using the metric name defined in {@link #getFilterMetricName()}. The returned values
     * are organized as a map from the metric name to metric value.
     *
     * @param map a map of metric name to the set of metrics that have the metric name
     * @return the aggregated values
     */
    Map<String, Long> updateValues(Set<Metric> map);
  
    /**
     * Gets the metric value of the given fully qualified metric name.
     *
     * @param name the fully qualified metric name
     * @return the metric value, 0 if the metric name does not exist
     */
    long getValue(String name);
  }
  