content: /*
   * [The "BSD licence"]
   * Copyright (c) 2010 Ben Gruver (JesusFreke)
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package org.jf.dexlib.Util;
  
  public class EncodedValueUtils {
      public static byte getRequiredBytesForSignedIntegralValue(long value) {
          /*
           * Figure out how many bits are needed to represent the value,
           * including a sign bit: The bit count is subtracted from 65
           * and not 64 to account for the sign bit. The xor operation
           * has the effect of leaving non-negative values alone and
           * unary complementing negative values (so that a leading zero
           * count always returns a useful number for our present
           * purpose).
           */
          int requiredBits =
              65 - Long.numberOfLeadingZeros(value ^ (value >> 63));
  
          // Round up the requiredBits to a number of bytes.
          return (byte)((requiredBits + 0x07) >> 3);
      }
  
      public static long decodeSignedIntegralValue(byte[] bytes) {
          long value = 0;
          for (int i = 0; i < bytes.length; i++) {
              value |= (((long)(bytes[i] & 0xFF)) << (i * 8));
          }
  
          int shift = (8 - bytes.length) * 8;
          return  value << shift >> shift;
      }
  
      public static byte[] encodeSignedIntegralValue(long value) {
          int requiredBytes = getRequiredBytesForSignedIntegralValue(value);
  
          byte[] bytes = new byte[requiredBytes];
  
          for (int i = 0; i < requiredBytes; i++) {
              bytes[i] = (byte) value;
              value >>= 8;
          }
          return bytes;
      }
  
  
  
  
  
      public static byte getRequiredBytesForUnsignedIntegralValue(long value) {
          // Figure out how many bits are needed to represent the value.
          int requiredBits = 64 - Long.numberOfLeadingZeros(value);
          if (requiredBits == 0) {
              requiredBits = 1;
          }
  
          // Round up the requiredBits to a number of bytes.
          return (byte)((requiredBits + 0x07) >> 3);
      }
  
      public static long decodeUnsignedIntegralValue(byte[] bytes) {
          long value = 0;
          for (int i = 0; i < bytes.length; i++) {
              value |= (((long)(bytes[i] & 0xFF)) << i * 8);
          }
          return value;
      }
  
      public static byte[] encodeUnsignedIntegralValue(long value) {
          int requiredBytes = getRequiredBytesForUnsignedIntegralValue(value);
  
          byte[] bytes = new byte[requiredBytes];
  
          for (int i = 0; i < requiredBytes; i++) {
              bytes[i] = (byte) value;
              value >>= 8;
          }
          return bytes;
      }
  
  
  
  
  
      public static int getRequiredBytesForRightZeroExtendedValue(long value) {
          // Figure out how many bits are needed to represent the value.
          int requiredBits = 64 - Long.numberOfTrailingZeros(value);
          if (requiredBits == 0) {
              requiredBits = 1;
          }
  
          // Round up the requiredBits to a number of bytes.
          return (requiredBits + 0x07) >> 3;
      }
  
      public static long decodeRightZeroExtendedValue(byte[] bytes) {
          long value = 0;
          for (int i = 0; i < bytes.length; i++) {
              value |= (((long)(bytes[i] & 0xFF)) << (i * 8));
          }
          return value << (8 - bytes.length) * 8;
      }
  
      public static byte[] encodeRightZeroExtendedValue(long value) {
          int requiredBytes = getRequiredBytesForRightZeroExtendedValue(value);
  
          // Scootch the first bits to be written down to the low-order bits.
          value >>= 64 - (requiredBytes * 8);
  
          byte[] bytes = new byte[requiredBytes];
  
          for(int i = 0; i < requiredBytes; i++) {
              bytes[i] = (byte)value;
              value >>= 8;
          }
          return bytes;
      }
  }
  