Dogcows Code - chaz/yoink/blob - src/stlplus/persistence/persistent_inf.cpp

   1 ////////////////////////////////////////////////////////////////////////////////
   2
   3 //   Author:    Andy Rushton
   4 //   Copyright: (c) Southampton University 1999-2004
   5 //              (c) Andy Rushton           2004-2009
   6 //   License:   BSD License, see ../docs/license.html
   7
   8 ////////////////////////////////////////////////////////////////////////////////
   9
  10 // can be excluded to break the dependency on the portability library
  11 #ifndef NO_STLPLUS_INF
  12
  13 #include "persistent_int.hpp"
  14 #include "persistent_string.hpp"
  15 #include "persistent_inf.hpp"
  16
  17 ////////////////////////////////////////////////////////////////////////////////
  18
  19 void stlplus::dump_inf(stlplus::dump_context& context, const stlplus::inf& data)
  20   throw(stlplus::persistent_dump_failed)
  21 {
  22   // don't support dumping of old versions
  23   if (context.version() < 2)
  24     throw stlplus::persistent_dump_failed(std::string("stlplus::inf::dump: wrong version"));
  25   // just dump the string
  26   stlplus::dump_string(context,data.get_bytes());
  27 }
  28
  29 ////////////////////////////////////////////////////////////////////////////////
  30
  31 void stlplus::restore_inf(stlplus::restore_context& context, stlplus::inf& data)
  32   throw(stlplus::persistent_restore_failed)
  33 {
  34   if (context.version() < 1)
  35     throw stlplus::persistent_restore_failed(std::string("stlplus::inf::restore: wrong version"));
  36   if (context.version() == 1)
  37   {
  38     // old-style restore relies on the word size being the same - 32-bits - on all platforms
  39     // this can be restored on such machines but is not portable to 64-bit machines
  40     std::string value;
  41     unsigned bits = 0;
  42     stlplus::restore_unsigned(context,bits);
  43     unsigned words = (bits+7)/32;
  44     // inf was dumped msB first
  45     for (unsigned i = words; i--; )
  46     {
  47       // restore a word
  48       unsigned word = 0;
  49       stlplus::restore_unsigned(context,word);
  50       // now extract the bytes
  51       unsigned char* byte_ptr = (unsigned char*)(&word);
  52       for (unsigned b = 4; b--; )
  53         value.insert(value.begin(),byte_ptr[context.little_endian() ? b : 3 - b]);
  54     }
  55     data.set_bytes(value);
  56   }
  57   else
  58   {
  59     // new-style dump just uses the string persistence
  60     std::string value;
  61     stlplus::restore_string(context,value);
  62     data.set_bytes(value);
  63   }
  64 }
  65 ////////////////////////////////////////////////////////////////////////////////
  66 #endif