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.kafka.coordinator.common.runtime;
  
  import org.apache.kafka.common.TopicPartition;
  import org.apache.kafka.server.metrics.KafkaYammerMetrics;
  import org.apache.kafka.timeline.SnapshotRegistry;
  
  import com.yammer.metrics.core.MetricName;
  import com.yammer.metrics.core.MetricsRegistry;
  
  /**
   * CoordinatorMetrics contain all coordinator related metrics. It delegates metrics collection to
   * {@link CoordinatorMetricsShard}s and aggregates them all when it reports to the metrics registry.
   */
  public abstract class CoordinatorMetrics {
  
      /**
       * Create a new metrics shard.
       * @param snapshotRegistry  The snapshot registry.
       * @param tp                The topic partition corresponding to the shard.
       *
       * @return The metrics shard.
       */
      public abstract CoordinatorMetricsShard newMetricsShard(SnapshotRegistry snapshotRegistry, TopicPartition tp);
  
      /**
       * Activate the metrics shard. This shard is now able to collect metrics.
       *
       * @param shard  The metrics shard.
       */
      public abstract void activateMetricsShard(CoordinatorMetricsShard shard);
  
      /**
       * Deactivate the metrics shard. This shard should not be part of the metrics aggregation.
       *
       * @param shard  The metrics shard.
       */
      public abstract void deactivateMetricsShard(CoordinatorMetricsShard shard);
  
      /**
       * @return The metrics registry.
       */
      public abstract MetricsRegistry registry();
  
      /**
       * Generate the Yammer MetricName.
       *
       * @param group The metric group.
       * @param type  The metric type.
       * @param name  The metric name.
       *
       * @return the yammer metric name.
       */
      public static MetricName getMetricName(String group, String type, String name) {
          return KafkaYammerMetrics.getMetricName(group, type, name);
      }
  
      /**
       * Invoked when the last committed offset has been updated. This is used as a listener for metrics
       * relying on a snapshot registry.
       *
       * @param tp      The topic partition.
       * @param offset  The updated offset.
       */
      public abstract void onUpdateLastCommittedOffset(TopicPartition tp, long offset);
  }
  