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 com.alipay.remoting.util;
  
  import java.util.zip.CRC32;
  
  /**
   * CRC32 utility.
   * @author jiangping
   * @version $Id: CrcUtil2, v 0.1 2017-06-05 11:29 Timo Exp $
   */
  public class CrcUtil {
  
      private static final ThreadLocal<CRC32> CRC_32_THREAD_LOCAL = new ThreadLocal<CRC32>() {
                                                                      @Override
                                                                      protected CRC32 initialValue() {
                                                                          return new CRC32();
                                                                      }
                                                                  };
  
      /**
       * Compute CRC32 code for byte[].
       *
       * @param array
       * @return
       */
      public static final int crc32(byte[] array) {
          if (array != null) {
              return crc32(array, 0, array.length);
          }
  
          return 0;
      }
  
      /**
       * Compute CRC32 code for byte[].
       *
       * @param array
       * @param offset
       * @param length
       * @return
       */
      public static final int crc32(byte[] array, int offset, int length) {
          CRC32 crc32 = CRC_32_THREAD_LOCAL.get();
          crc32.update(array, offset, length);
          int ret = (int) crc32.getValue();
          crc32.reset();
          return ret;
      }
  
  }
  