external_libraries/yaml-cpp-0.3.0/src/binary.cpp

   1 #include "yaml-cpp/binary.h"
   2 #include "yaml-cpp/node.h"
   3
   4 namespace YAML
   5 {
   6     static const char encoding[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
   7
   8     std::string EncodeBase64(const unsigned char *data, std::size_t size)
   9     {
  10         const char PAD = '=';
  11
  12         std::string ret;
  13         ret.resize(4 * size / 3 + 3);
  14         char *out = &ret[0];
  15
  16         std::size_t chunks = size / 3;
  17         std::size_t remainder = size % 3;
  18
  19         for(std::size_t i=0;i<chunks;i++, data += 3) {
  20             *out++ = encoding[data[0] >> 2];
  21             *out++ = encoding[((data[0] & 0x3) << 4) | (data[1] >> 4)];
  22             *out++ = encoding[((data[1] & 0xf) << 2) | (data[2] >> 6)];
  23             *out++ = encoding[data[2] & 0x3f];
  24         }
  25
  26         switch(remainder) {
  27             case 0:
  28                 break;
  29             case 1:
  30                 *out++ = encoding[data[0] >> 2];
  31                 *out++ = encoding[((data[0] & 0x3) << 4)];
  32                 *out++ = PAD;
  33                 *out++ = PAD;
  34                 break;
  35             case 2:
  36                 *out++ = encoding[data[0] >> 2];
  37                 *out++ = encoding[((data[0] & 0x3) << 4) | (data[1] >> 4)];
  38                 *out++ = encoding[((data[1] & 0xf) << 2)];
  39                 *out++ = PAD;
  40                 break;
  41         }
  42
  43         ret.resize(out - &ret[0]);
  44         return ret;
  45     }
  46
  47     static const unsigned char decoding[] = {
  48         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  49         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  50         255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63,
  51          52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,  0,255,255,
  52         255,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
  53          15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255,
  54         255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
  55          41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255,
  56         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  57         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  58         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  59         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  60         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  61         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  62         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  63         255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  64     };
  65
  66     std::vector<unsigned char> DecodeBase64(const std::string& input)
  67     {
  68         typedef std::vector<unsigned char> ret_type;
  69         if(input.empty())
  70             return ret_type();
  71
  72         ret_type ret(3 * input.size() / 4 + 1);
  73         unsigned char *out = &ret[0];
  74
  75         unsigned value = 0;
  76         for(std::size_t i=0;i<input.size();i++) {
  77             unsigned char d = decoding[static_cast<unsigned>(input[i])];
  78             if(d == 255)
  79                 return ret_type();
  80
  81             value = (value << 6) | d;
  82             if(i % 4 == 3) {
  83                 *out++ = value >> 16;
  84                 if(i > 0 && input[i - 1] != '=')
  85                     *out++ = value >> 8;
  86                 if(input[i] != '=')
  87                     *out++ = value;
  88             }
  89         }
  90
  91         ret.resize(out - &ret[0]);
  92         return ret;
  93     }
  94
  95     void operator >> (const Node& node, Binary& binary)
  96     {
  97         std::string scalar;
  98         node.GetScalar(scalar);
  99         std::vector<unsigned char> data = DecodeBase64(scalar);
 100         binary.swap(data);
 101     }
 102 }