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.atomic.AtomicLong;
  
  import org.apache.cassandra.utils.ReflectionUtils;
  
  /**
   * This type of Counter is more efficient (from CPU and memory usage point of view)
   *   than LondAdder-based {@link com.codahale.metrics.Counter} for non-highly contented write scenarios.
   * It is also fast to read and should be used instead of {@link ThreadLocalCounter} when getCount performance is critical.
   */
  public class AtomicLongCounter extends com.codahale.metrics.Counter implements Counter
  {
      private final AtomicLong counter = new AtomicLong();
  
      public AtomicLongCounter()
      {
          // to reduce metrics memory footprint
          ReflectionUtils.setFieldToNull(this, com.codahale.metrics.Counter.class, "count");
      }
  
      @Override
      public void inc()
      {
          counter.incrementAndGet();
      }
  
      @Override
      public void inc(long n)
      {
          counter.addAndGet(n);
      }
  
      @Override
      public void dec()
      {
          counter.decrementAndGet();
      }
  
      @Override
      public void dec(long n)
      {
          counter.addAndGet(-n);
      }
  
      @Override
      public long getCount()
      {
          return counter.get();
      }
  }
  