content: /*
   * 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.beam.sdk.metrics;
  
  import java.io.Serializable;
  import org.apache.beam.model.pipeline.v1.MetricsApi;
  import org.apache.beam.sdk.util.HistogramData;
  
  /**
   * Holds the metrics for a single step. Each of the methods should return an implementation of the
   * appropriate metrics interface for the "current" step.
   */
  public interface MetricsContainer extends Serializable {
    /**
     * Return the {@link Counter} that should be used for implementing the given {@code metricName} in
     * this container.
     */
    Counter getCounter(MetricName metricName);
  
    /**
     * Return the {@link Counter} that should be used for implementing the given per-worker {@code metricName)
     * in this container.
     */
    default Counter getPerWorkerCounter(MetricName metricName) {
      return NoOpCounter.getInstance();
    }
  
    /**
     * Return the {@link Distribution} that should be used for implementing the given {@code
     * metricName} in this container.
     */
    Distribution getDistribution(MetricName metricName);
  
    /**
     * Return the {@link Gauge} that should be used for implementing the given {@code metricName} in
     * this container.
     */
    Gauge getGauge(MetricName metricName);
  
    /**
     * Return the {@link StringSet} that should be used for implementing the given {@code metricName}
     * in this container.
     */
    StringSet getStringSet(MetricName metricName);
  
    /**
     * Return the {@link BoundedTrie} that should be used for implementing the given {@code
     * metricName} in this container.
     */
    BoundedTrie getBoundedTrie(MetricName metricName);
  
    /**
     * Return the {@link Histogram} that should be used for implementing the given {@code metricName}
     * in this container.
     */
    default Histogram getHistogram(MetricName metricName, HistogramData.BucketType bucketType) {
      return NoOpHistogram.getInstance();
    }
  
    /** Return the cumulative values for any metrics in this container as MonitoringInfos. */
    default Iterable<MetricsApi.MonitoringInfo> getMonitoringInfos() {
      throw new RuntimeException("getMonitoringInfos is not implemented on this MetricsContainer.");
    }
  }
  