//| Copyright: (C) 2009-2020 Kevin Larke <contact AT larke DOT org> 
//| License: GNU GPL version 3.0 or above. See the accompanying LICENSE file.

//( { file_desc:"Time cand clock related functions." kw: [ time system ] }
//
//
// This interface is used to read the systems high resolution timer and 
// calculate elapsed time.
//)


#ifndef cmTime_h   
#define cmTime_h

#ifdef __cplusplus
extern "C" {
#endif

  //(
  typedef  struct timespec cmTimeSpec_t;

  // Get the time 
  void cmTimeGet( cmTimeSpec_t* t );

  // Return the elapsed time (t1 - t0) in microseconds
  // t1 is assumed to be at a later time than t0.
  unsigned cmTimeElapsedMicros( const cmTimeSpec_t*  t0, const cmTimeSpec_t* t1 );

  
  // Same as cmTimeElapsedMicros() but the times are not assumed to be ordered.
  // The function therefore begins by swapping t1 and t0 if t0 is after t1.
  unsigned cmTimeAbsElapsedMicros( const cmTimeSpec_t*  t0, const cmTimeSpec_t* t1 ); 


  // Same as cmTimeElapsedMicros() but returns a negative value if t0 is after t1.
  int cmTimeDiffMicros( const cmTimeSpec_t*  t0, const cmTimeSpec_t* t1 );


  // Returns true if t0 <=  t1.
  bool cmTimeIsLTE( const cmTimeSpec_t* t0, const cmTimeSpec_t* t1 );

  // Return true if t0 >= t1.
  bool cmTimeIsGTE( const cmTimeSpec_t* t0, const cmTimeSpec_t* t1 );

  bool cmTimeIsEqual( const cmTimeSpec_t* t0, const cmTimeSpec_t* t1 );

  bool cmTimeIsZero( const cmTimeSpec_t* t0 );

  void cmTimeSetZero( cmTimeSpec_t* t0 );

  //)

#ifdef __cplusplus
}
#endif


#endif