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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.bookkeeper.common.router;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.util.ReferenceCountUtil;
  import org.apache.bookkeeper.common.hash.Murmur3;
  
  /**
   * The base hash router.
   */
  public abstract class AbstractHashRouter<K> implements HashRouter<K> {
  
      private static final long serialVersionUID = -7979076779920023308L;
      public static final long HASH_SEED = 383242705L;
  
      protected AbstractHashRouter() {
      }
  
      @Override
      public Long getRoutingKey(K key) {
          ByteBuf keyData = getRoutingKeyData(key);
          try {
              return Murmur3.hash128(
                  keyData, keyData.readerIndex(), keyData.readableBytes(), HASH_SEED)[0];
          } finally {
              ReferenceCountUtil.release(keyData);
          }
      }
  
      abstract ByteBuf getRoutingKeyData(K key);
  }
  