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.bookkeeper.statelib.impl;
  
  import com.google.protobuf.ByteString;
  
  /**
   * Bytes related utils.
   */
  public class Bytes {
  
      /**
       * Get a long number from a bytes array starting from the provided {@code index}.
       *
       * @param memory the bytes array
       * @param index the starting index
       * @return the long number.
       */
      public static long toLong(byte[] memory, int index) {
          return ((long) memory[index] & 0xff) << 56
              | ((long) memory[index + 1] & 0xff) << 48
              | ((long) memory[index + 2] & 0xff) << 40
              | ((long) memory[index + 3] & 0xff) << 32
              | ((long) memory[index + 4] & 0xff) << 24
              | ((long) memory[index + 5] & 0xff) << 16
              | ((long) memory[index + 6] & 0xff) << 8
              | (long) memory[index + 7] & 0xff;
      }
  
      /**
       * Get a long number from a {@link ByteString}.
       *
       * @param bs byte string
       * @return the long number.
       */
      public static long toLong(ByteString bs) {
          return ((long) bs.byteAt(0) & 0xff) << 56
              | ((long) bs.byteAt(1) & 0xff) << 48
              | ((long) bs.byteAt(2) & 0xff) << 40
              | ((long) bs.byteAt(3) & 0xff) << 32
              | ((long) bs.byteAt(4) & 0xff) << 24
              | ((long) bs.byteAt(5) & 0xff) << 16
              | ((long) bs.byteAt(6) & 0xff) << 8
              | (long) bs.byteAt(7) & 0xff;
      }
  
      /**
       * Convert a long number to a bytes array.
       *
       * @param value the long number
       * @return the bytes array
       */
      public static byte[] toBytes(long value) {
          byte[] memory = new byte[8];
          toBytes(value, memory, 0);
          return memory;
      }
  
      public static void toBytes(long value, byte[] memory, int index) {
          memory[index] = (byte) (value >>> 56);
          memory[index + 1] = (byte) (value >>> 48);
          memory[index + 2] = (byte) (value >>> 40);
          memory[index + 3] = (byte) (value >>> 32);
          memory[index + 4] = (byte) (value >>> 24);
          memory[index + 5] = (byte) (value >>> 16);
          memory[index + 6] = (byte) (value >>> 8);
          memory[index + 7] = (byte) value;
      }
  
  }
  