ByteArray.cs 3.1 KB

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  1. #region Copyright notice and license
  2. // Protocol Buffers - Google's data interchange format
  3. // Copyright 2008 Google Inc. All rights reserved.
  4. // https://developers.google.com/protocol-buffers/
  5. //
  6. // Redistribution and use in source and binary forms, with or without
  7. // modification, are permitted provided that the following conditions are
  8. // met:
  9. //
  10. // * Redistributions of source code must retain the above copyright
  11. // notice, this list of conditions and the following disclaimer.
  12. // * Redistributions in binary form must reproduce the above
  13. // copyright notice, this list of conditions and the following disclaimer
  14. // in the documentation and/or other materials provided with the
  15. // distribution.
  16. // * Neither the name of Google Inc. nor the names of its
  17. // contributors may be used to endorse or promote products derived from
  18. // this software without specific prior written permission.
  19. //
  20. // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21. // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22. // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23. // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  24. // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25. // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26. // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27. // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28. // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29. // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  30. // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31. #endregion
  32. using System;
  33. namespace Google.Protobuf
  34. {
  35. /// <summary>
  36. /// Provides a utility routine to copy small arrays much more quickly than Buffer.BlockCopy
  37. /// </summary>
  38. internal static class ByteArray
  39. {
  40. /// <summary>
  41. /// The threshold above which you should use Buffer.BlockCopy rather than ByteArray.Copy
  42. /// </summary>
  43. private const int CopyThreshold = 12;
  44. /// <summary>
  45. /// Determines which copy routine to use based on the number of bytes to be copied.
  46. /// </summary>
  47. internal static void Copy(byte[] src, int srcOffset, byte[] dst, int dstOffset, int count)
  48. {
  49. if (count > CopyThreshold)
  50. {
  51. Buffer.BlockCopy(src, srcOffset, dst, dstOffset, count);
  52. }
  53. else
  54. {
  55. int stop = srcOffset + count;
  56. for (int i = srcOffset; i < stop; i++)
  57. {
  58. dst[dstOffset++] = src[i];
  59. }
  60. }
  61. }
  62. /// <summary>
  63. /// Reverses the order of bytes in the array
  64. /// </summary>
  65. internal static void Reverse(byte[] bytes)
  66. {
  67. for (int first = 0, last = bytes.Length - 1; first < last; first++, last--)
  68. {
  69. byte temp = bytes[first];
  70. bytes[first] = bytes[last];
  71. bytes[last] = temp;
  72. }
  73. }
  74. }
  75. }