code.grnet.gr Git - pithos-ms-client/blob - trunk/Libraries/Json40r2/Source/Src/Newtonsoft.Json/Utilities/Base64Encoder.cs

   1 using System;
   2 using System.IO;
   3
   4 namespace Newtonsoft.Json.Utilities
   5 {
   6   internal class Base64Encoder
   7   {
   8     private const int Base64LineSize = 76;
   9     private const int LineSizeInBytes = 57;
  10
  11     private readonly char[] _charsLine = new char[Base64LineSize];
  12     private readonly TextWriter _writer;
  13
  14     private byte[] _leftOverBytes;
  15     private int _leftOverBytesCount;
  16
  17     public Base64Encoder(TextWriter writer)
  18     {
  19       ValidationUtils.ArgumentNotNull(writer, "writer");
  20       _writer = writer;
  21     }
  22
  23     public void Encode(byte[] buffer, int index, int count)
  24     {
  25       if (buffer == null)
  26         throw new ArgumentNullException("buffer");
  27
  28       if (index < 0)
  29         throw new ArgumentOutOfRangeException("index");
  30
  31       if (count < 0)
  32         throw new ArgumentOutOfRangeException("count");
  33
  34       if (count > (buffer.Length - index))
  35         throw new ArgumentOutOfRangeException("count");
  36
  37       if (_leftOverBytesCount > 0)
  38       {
  39         int leftOverBytesCount = _leftOverBytesCount;
  40         while (leftOverBytesCount < 3 && count > 0)
  41         {
  42           _leftOverBytes[leftOverBytesCount++] = buffer[index++];
  43           count--;
  44         }
  45         if (count == 0 && leftOverBytesCount < 3)
  46         {
  47           _leftOverBytesCount = leftOverBytesCount;
  48           return;
  49         }
  50         int num2 = Convert.ToBase64CharArray(_leftOverBytes, 0, 3, _charsLine, 0);
  51         WriteChars(_charsLine, 0, num2);
  52       }
  53       _leftOverBytesCount = count % 3;
  54       if (_leftOverBytesCount > 0)
  55       {
  56         count -= _leftOverBytesCount;
  57         if (_leftOverBytes == null)
  58         {
  59           _leftOverBytes = new byte[3];
  60         }
  61         for (int i = 0; i < _leftOverBytesCount; i++)
  62         {
  63           _leftOverBytes[i] = buffer[(index + count) + i];
  64         }
  65       }
  66       int num4 = index + count;
  67       int length = LineSizeInBytes;
  68       while (index < num4)
  69       {
  70         if ((index + length) > num4)
  71         {
  72           length = num4 - index;
  73         }
  74         int num6 = Convert.ToBase64CharArray(buffer, index, length, _charsLine, 0);
  75         WriteChars(_charsLine, 0, num6);
  76         index += length;
  77       }
  78     }
  79
  80     public void Flush()
  81     {
  82       if (_leftOverBytesCount > 0)
  83       {
  84         int count = Convert.ToBase64CharArray(_leftOverBytes, 0, _leftOverBytesCount, _charsLine, 0);
  85         WriteChars(_charsLine, 0, count);
  86         _leftOverBytesCount = 0;
  87       }
  88     }
  89
  90     private void WriteChars(char[] chars, int index, int count)
  91     {
  92       _writer.Write(chars, index, count);
  93     }
  94   }
  95 }