HexConversions.cpp

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00032 
00033 #include <cctype>
00034 #include <cstdio>
00035 #include <cstdlib>
00036 #include "HexConversions.hpp"
00037 
00038 using std::string;
00039 using std::vector;
00040 
00041 namespace MaximInterface {
00042 
00043 static const int charsPerByte = 2;
00044 
00045 string byteArrayToHexString(span<const uint_least8_t> byteArray) {
00046   string hexString;
00047   hexString.reserve(byteArray.size() * charsPerByte);
00048   for (span<const uint_least8_t>::index_type i = 0; i < byteArray.size(); ++i) {
00049     char hexBuf[charsPerByte + 1];
00050     std::sprintf(hexBuf, "%2.2X", byteArray[i] & 0xFF);
00051     hexString.append(hexBuf, charsPerByte);
00052   }
00053   return hexString;
00054 }
00055 
00056 optional<vector<uint_least8_t> >
00057 hexStringToByteArray(const string & hexString) {
00058   optional<vector<uint_least8_t> > byteArray = vector<uint_least8_t>();
00059   byteArray->reserve(hexString.size() / charsPerByte);
00060   char hexBuf[charsPerByte + 1];
00061   char * const hexBufEnd = hexBuf + charsPerByte;
00062   *hexBufEnd = '\0';
00063   char * hexBufIt = hexBuf;
00064   for (string::const_iterator hexStringIt = hexString.begin(),
00065                               hexStringEnd = hexString.end();
00066        hexStringIt != hexStringEnd; ++hexStringIt) {
00067     if (!std::isspace(*hexStringIt)) {
00068       *hexBufIt = *hexStringIt;
00069       if (++hexBufIt == hexBufEnd) {
00070         char * hexBufParseEnd;
00071         byteArray->push_back(static_cast<uint_least8_t>(
00072             std::strtoul(hexBuf, &hexBufParseEnd, 16)));
00073         if (hexBufParseEnd != hexBufEnd) {
00074           break;
00075         }
00076         hexBufIt = hexBuf;
00077       }
00078     }
00079   }
00080   if (hexBufIt != hexBuf) {
00081     byteArray.reset();
00082   }
00083   return byteArray;
00084 }
00085 
00086 } // namespace MaximInterface