/*************************************************
* Timestamp Functions Source File                *
* (C) 1999-2007 The Botan Project                *
*************************************************/

#include <botan/timers.h>
#include <botan/loadstor.h>
#include <ctime>

namespace Botan {

/*************************************************
* Get the system clock                           *
*************************************************/
u64bit system_time()
   {
   return static_cast<u64bit>(std::time(0));
   }

/*************************************************
* Default Timer clock reading                    *
*************************************************/
u64bit Timer::clock() const
   {
   return combine_timers(std::time(0), std::clock(), CLOCKS_PER_SEC);
   }

/*************************************************
* Read the clock and return the output           *
*************************************************/
u32bit Timer::slow_poll(byte out[], u32bit length)
   {
   const u64bit clock_value = this->clock();

   for(u32bit j = 0; j != sizeof(clock_value); ++j)
      out[j % length] ^= get_byte(j, clock_value);

   return (length < 8) ? length : 8;
   }

/*************************************************
* Combine a two time values into a single one    *
*************************************************/
u64bit Timer::combine_timers(u32bit seconds, u32bit parts, u32bit parts_hz)
   {
   static const u64bit NANOSECONDS_UNITS = 1000000000;
   parts *= (NANOSECONDS_UNITS / parts_hz);
   return ((seconds * NANOSECONDS_UNITS) + parts);
   }

}