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.cassandra.metrics;
  
  import java.util.concurrent.TimeUnit;
  import javax.annotation.Nonnull;
  
  import com.codahale.metrics.Timer;
  import com.github.benmanes.caffeine.cache.RemovalCause;
  import com.github.benmanes.caffeine.cache.stats.CacheStats;
  import com.github.benmanes.caffeine.cache.stats.StatsCounter;
  import org.apache.cassandra.cache.ChunkCache;
  
  import static org.apache.cassandra.metrics.CassandraMetricsRegistry.Metrics;
  
  /**
   * Metrics for {@code ICache}.
   */
  public class ChunkCacheMetrics extends CacheMetrics implements StatsCounter
  {
      public static final String TYPE_NAME = "ChunkCache";
      /** Latency of misses */
      public final Timer missLatency;
  
      /**
       * Create metrics for the provided chunk cache.
       *
       * @param cache Chunk cache to measure metrics
       */
      public ChunkCacheMetrics(ChunkCache cache)
      {
          super(TYPE_NAME, cache);
          missLatency = Metrics.timer(factory.createMetricName("MissLatency"));
      }
  
      @Override
      public void recordHits(int count)
      {
          requests.mark(count);
          hits.mark(count);
      }
  
      @Override
      public void recordMisses(int count)
      {
          requests.mark(count);
          misses.mark(count);
      }
  
      @Override
      public void recordLoadSuccess(long loadTime)
      {
          missLatency.update(loadTime, TimeUnit.NANOSECONDS);
      }
  
      @Override
      public void recordLoadFailure(long loadTime)
      {
      }
  
      @Override
      public void recordEviction(int weight, RemovalCause cause)
      {
      }
  
      @Nonnull
      @Override
      public CacheStats snapshot()
      {
          return CacheStats.of(hits.getCount(), misses.getCount(), missLatency.getCount(), 0L, missLatency.getCount(), 0L, 0L);
      }
  }
  