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 com.codahale.metrics.Snapshot;
  import org.agrona.UnsafeAccess;
  
  public abstract class OverrideHistogram extends com.codahale.metrics.Histogram
  {
      private static final CassandraReservoir NO_RESERVOIR = new CassandraReservoir() {
          @Override public Snapshot getPercentileSnapshot() { return null; }
          @Override public long[] buckets(int length) { return new long[0]; }
          @Override public BucketStrategy bucketStrategy() { return BucketStrategy.none; }
          @Override public int size() { return 0; }
          @Override public void update(long value) {}
          @Override public Snapshot getSnapshot() { return null; }
      };
  
      protected OverrideHistogram()
      {
          this(NO_RESERVOIR);
          try
          {
              UnsafeAccess.UNSAFE.putObject(this, UnsafeAccess.UNSAFE.objectFieldOffset(com.codahale.metrics.Histogram.class.getDeclaredField("count")), null);
          }
          catch (Throwable t)
          {
              // best effort, don't worry if this fails
          }
      }
  
      final CassandraReservoir reservoir;
      protected OverrideHistogram(CassandraReservoir reservoir)
      {
          super(reservoir);
          this.reservoir = reservoir;
      }
  
      public CassandraReservoir.BucketStrategy bucketStrategy()
      {
          return reservoir.bucketStrategy();
      }
  
      public long[] bucketStarts(int length)
      {
          return reservoir.buckets(length);
      }
  }
  