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 org.apache.beam.sdk.PipelineResult;
  
  /**
   * Methods for interacting with the metrics of a pipeline that has been executed. Accessed via
   * {@link PipelineResult#metrics()}.
   */
  public abstract class MetricResults {
    /**
     * Query for all metric values that match a given filter.
     *
     * <p>The {@code filter} may filter based on the namespace and/or name of the metric, as well as
     * the step that reported the metric.
     *
     * <p>For each type of metric, the result contains an iterable of all metrics of that type that
     * matched the filter. Each {@link MetricResult} includes the name of the metric, the step in
     * which it was reported and the {@link MetricResult#getCommitted} and {@link
     * MetricResult#getAttempted} values.
     *
     * <p>Note that runners differ in their support for committed and attempted values.
     *
     * <p>Example: Querying the metrics reported from the {@code SomeDoFn} example in {@link Metrics}
     * could be done as follows:
     *
     * <pre>{@code
     * Pipeline p = ...;
     * p.apply("create1", Create.of("hello")).apply("myStepName1", ParDo.of(new SomeDoFn()));
     * p.apply("create2", Create.of("world")).apply("myStepName2", ParDo.of(new SomeDoFn()));
     * PipelineResult result = p.run();
     * MetricResults metrics = result.metrics();
     * MetricQueryResults metricResults = metrics.queryMetrics(new MetricsFilter.Builder()
     *     .addNameFilter("my-counter")
     *     .addStepFilter("myStepName1").addStepFilter("myStepName2")
     *     .build());
     * Iterable<MetricResult<Long>> counters = metricResults.getCounters();
     * // counters should contain the value of my-counter reported from each of the ParDo
     * // applications.
     * }</pre>
     */
    public abstract MetricQueryResults queryMetrics(MetricsFilter filter);
  
    public MetricQueryResults allMetrics() {
      return queryMetrics(MetricsFilter.builder().build());
    }
  
    @Override
    public String toString() {
      return allMetrics().toString();
    }
  }
  