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.common.telemetry.internals;
  
  import org.apache.kafka.common.MetricName;
  
  /**
   * {@code MetricNamingStrategy} provides a strategy pattern-based means of converting from an
   * implementation-specific metric name (e.g. Kafka {@link MetricName}) representing a
   * particular metric name and associated tags into a canonical {@link MetricKey}
   * (name and tags) representation.
   *
   * <p>
   *
   * Each strategy may define its own conventions for how the resulting metric should be named,
   * including things such conforming name and tags to use specific casing and separators for
   * different parts of the metric name.
   *
   * <p>
   *
   * In general, a {@code MetricNamingStrategy} implementation is closely managed by another entity,
   * referred to as the "telemetry reporter", as that reporter handles the conversion between different
   * representations of metric names and keys.
   *
   * <p>
   *
   * This class is primarily used by the telemetry reporter, {@link MetricsCollector}, and
   * {@link MetricsEmitter} layers.
   */
  public interface MetricNamingStrategy<T> {
  
      /**
       * Converts the given metric name into a {@link MetricKey} representation.
       *
       * @param metricName Implementation-specific metric
       * @return {@link MetricKey}
       */
      MetricKey metricKey(T metricName);
  
      /**
       * Creates a derived {@link MetricKey} from an existing {@link MetricKey}.
       *
       * <p>
       *
       * Some metrics may include multiple components derived from the same underlying source
       * of data (e.g. a Meter that exposes multiple rates and a counter) in which case it may
       * be desirable to create a new metric key derived from the primary one, with a different
       * name for each component of the metric.
       *
       * <p>
       *
       * Some metrics may be derived from others by the collector itself. For example, a delta
       * metric might be created from a cumulative counter.
       *
       * <p>
       *
       * This method exists so each strategy can define its own convention for how to name
       * derived metrics keys.
       *
       * <p>
       *
       * The derived key should have the same tags as the input key, and its name new name
       * will typically be composed of the input key name and the component name.
       *
       * @param key Input {@link MetricKey} used to construct the derived key
       * @param derivedComponent Name to use for the derived component of the input metric
       * @return Derived {@link MetricKey} with a new metric name composed of the input key
       * name and the additional name
       */
      MetricKey derivedMetricKey(MetricKey key, String derivedComponent);
  }
  