source/utility.cxx

   1 #include <source/utility.hxx>
   2 #include <cassert>
   3
   4 namespace libsex {
   5
   6 bool vformat(
   7         char* const buffer,
   8         size_t length,
   9         const char* const file,
  10         unsigned short line,
  11         const char* const message,
  12         va_list ap) throw()
  13 {
  14         size_t chars
  15                 = snprintf(
  16                         buffer, length,
  17                         "%s:%d: ", file, line);
  18
  19         // If buffer was too small, chars contains length
  20         // of chars that would've been written. Chars must
  21         // be lower than length or else we could not fit
  22         // the message into buffer, too.
  23         bool didFitIntoBuffer = chars < length;
  24
  25         if (didFitIntoBuffer) {
  26                 size_t      newLength = length - chars;
  27                 char* const newBuffer = buffer + chars;
  28                 chars = vsnprintf(
  29                         newBuffer, newLength,
  30                         message, ap);
  31                 // See comment above.
  32                 didFitIntoBuffer = chars <= newLength;
  33         }
  34
  35         return didFitIntoBuffer;
  36 }
  37
  38 bool format(
  39         char* const buffer,
  40         size_t length,
  41         const char* const file,
  42         unsigned short line,
  43         const char* const message,
  44         ...) throw()
  45 {
  46         va_list ap;
  47         va_start(ap, message);
  48
  49         bool result = vformat(
  50                 buffer, length, file, line, message, ap);
  51
  52         va_end(ap);
  53         return result;
  54 }
  55
  56 } // namespace