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.spark.unsafe.array;
  
  import org.apache.spark.unsafe.Platform;
  
  public class ByteArrayMethods {
  
    private ByteArrayMethods() {
      // Private constructor, since this class only contains static methods.
    }
  
    /** Returns the next number greater or equal num that is power of 2. */
    public static long nextPowerOf2(long num) {
      final long highBit = Long.highestOneBit(num);
      return (highBit == num) ? num : highBit << 1;
    }
  
    public static int roundNumberOfBytesToNearestWord(int numBytes) {
      int remainder = numBytes & 0x07;  // This is equivalent to `numBytes % 8`
      if (remainder == 0) {
        return numBytes;
      } else {
        return numBytes + (8 - remainder);
      }
    }
  
    private static final boolean unaligned = Platform.unaligned();
    /**
     * Optimized byte array equality check for byte arrays.
     * @return true if the arrays are equal, false otherwise
     */
    public static boolean arrayEquals(
        Object leftBase, long leftOffset, Object rightBase, long rightOffset, final long length) {
      int i = 0;
  
      // check if stars align and we can get both offsets to be aligned
      if ((leftOffset % 8) == (rightOffset % 8)) {
        while ((leftOffset + i) % 8 != 0 && i < length) {
          if (Platform.getByte(leftBase, leftOffset + i) !=
              Platform.getByte(rightBase, rightOffset + i)) {
                return false;
          }
          i += 1;
        }
      }
      // for architectures that suport unaligned accesses, chew it up 8 bytes at a time
      if (unaligned || (((leftOffset + i) % 8 == 0) && ((rightOffset + i) % 8 == 0))) {
        while (i <= length - 8) {
          if (Platform.getLong(leftBase, leftOffset + i) !=
              Platform.getLong(rightBase, rightOffset + i)) {
                return false;
          }
          i += 8;
        }
      }
      // this will finish off the unaligned comparisons, or do the entire aligned
      // comparison whichever is needed.
      while (i < length) {
        if (Platform.getByte(leftBase, leftOffset + i) !=
            Platform.getByte(rightBase, rightOffset + i)) {
              return false;
        }
        i += 1;
      }
      return true;
    }
  }
  