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.runners.spark.metrics;
  
  import com.codahale.metrics.Counter;
  import com.codahale.metrics.Gauge;
  import com.codahale.metrics.Histogram;
  import com.codahale.metrics.Meter;
  import com.codahale.metrics.MetricFilter;
  import com.codahale.metrics.MetricRegistry;
  import com.codahale.metrics.Timer;
  import java.util.Map;
  import java.util.SortedMap;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableSortedMap;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Ordering;
  
  /**
   * A {@link MetricRegistry} decorator-like that supports {@link AggregatorMetric} and {@link
   * SparkBeamMetric} as {@link Gauge Gauges}.
   *
   * <p>{@link MetricRegistry} is not an interface, so this is not a by-the-book decorator. That said,
   * it delegates all metric related getters to the "decorated" instance.
   */
  @SuppressWarnings({"rawtypes"}) // required by interface
  public class WithMetricsSupport extends MetricRegistry {
  
    private final MetricRegistry internalMetricRegistry;
  
    private WithMetricsSupport(final MetricRegistry internalMetricRegistry) {
      this.internalMetricRegistry = internalMetricRegistry;
    }
  
    public static WithMetricsSupport forRegistry(final MetricRegistry metricRegistry) {
      return new WithMetricsSupport(metricRegistry);
    }
  
    @Override
    public SortedMap<String, Timer> getTimers(final MetricFilter filter) {
      return internalMetricRegistry.getTimers(filter);
    }
  
    @Override
    public SortedMap<String, Meter> getMeters(final MetricFilter filter) {
      return internalMetricRegistry.getMeters(filter);
    }
  
    @Override
    public SortedMap<String, Histogram> getHistograms(final MetricFilter filter) {
      return internalMetricRegistry.getHistograms(filter);
    }
  
    @Override
    public SortedMap<String, Counter> getCounters(final MetricFilter filter) {
      return internalMetricRegistry.getCounters(filter);
    }
  
    @Override
    public SortedMap<String, Gauge> getGauges(final MetricFilter filter) {
      ImmutableSortedMap.Builder<String, Gauge> builder =
          new ImmutableSortedMap.Builder<>(Ordering.from(String.CASE_INSENSITIVE_ORDER));
  
      Map<String, Gauge> gauges =
          internalMetricRegistry.getGauges(
              (n, m) -> filter.matches(n, m) || m instanceof BeamMetricSet);
  
      for (Map.Entry<String, Gauge> entry : gauges.entrySet()) {
        Gauge gauge = entry.getValue();
        if (gauge instanceof BeamMetricSet) {
          builder.putAll(((BeamMetricSet) gauge).getValue(entry.getKey(), filter));
        } else {
          builder.put(entry.getKey(), gauge);
        }
      }
      return builder.build();
    }
  }
  