// 
// Cforall Version 1.0.0 Copyright (C) 2018 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
// 
// time -- 
// 
// Author           : Peter A. Buhr
// Created On       : Wed Mar 14 23:18:57 2018
// Last Modified By : Peter A. Buhr
// Last Modified On : Mon Apr  9 13:10:23 2018
// Update Count     : 616
// 

#pragma once

// http://en.cppreference.com/w/cpp/header/chrono
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0355r5.html#refcc

#include <time.h>										// timespec
extern "C" {
#include <sys/time.h>									// timeval
}
#include <iostream>										// istype/ostype

enum { TIMEGRAN = 1_000_000_000LL };					// nanosecond granularity, except for timeval


//######################### Duration #########################

struct Duration {										// private
	int64_t tv;											// nanoseconds
}; // Duration

static inline void ?{}( Duration & dur ) with( dur ) { tv = 0; }
static inline void ?{}( Duration & dur, Duration d ) with( dur ) { tv = d.tv; }

static inline void ?{}( Duration & dur, zero_t ) with( dur ) { tv = 0; }
static inline Duration ?=?( Duration & dur, zero_t ) { return dur{ 0 }; }

static inline Duration +?( Duration rhs ) with( rhs ) {	return (Duration)@{ +tv }; }
static inline Duration ?+?( Duration & lhs, Duration rhs ) { return (Duration)@{ lhs.tv + rhs.tv }; }
static inline Duration ?+=?( Duration & lhs, Duration rhs ) { lhs = lhs + rhs; return lhs; }

static inline Duration -?( Duration rhs ) with( rhs ) { return (Duration)@{ -tv }; }
static inline Duration ?-?( Duration & lhs, Duration rhs ) { return (Duration)@{ lhs.tv - rhs.tv }; }
static inline Duration ?-=?( Duration & lhs, Duration rhs ) { lhs = lhs - rhs; return lhs; }

static inline Duration ?*?( Duration lhs, int64_t rhs ) { return (Duration)@{ lhs.tv * rhs }; }
static inline Duration ?*?( int64_t lhs, Duration rhs ) { return (Duration)@{ lhs * rhs.tv }; }
static inline Duration ?*=?( Duration & lhs, int64_t rhs ) { lhs = lhs * rhs; return lhs; }

static inline int64_t ?/?( Duration lhs, Duration rhs ) { return lhs.tv / rhs.tv; }
static inline Duration ?/?( Duration lhs, int64_t rhs ) { return (Duration)@{ lhs.tv / rhs }; }
static inline Duration ?/=?( Duration & lhs, int64_t rhs ) { lhs = lhs / rhs; return lhs; }
static inline double div( Duration lhs, Duration rhs ) { return (double)lhs.tv / (double)rhs.tv; }

static inline Duration ?%?( Duration lhs, Duration rhs ) { return (Duration)@{ lhs.tv % rhs.tv }; }
static inline Duration ?%=?( Duration & lhs, Duration rhs ) { lhs = lhs % rhs; return lhs; }

static inline _Bool ?==?( Duration lhs, Duration rhs ) { return lhs.tv == rhs.tv; }
static inline _Bool ?!=?( Duration lhs, Duration rhs ) { return lhs.tv != rhs.tv; }
static inline _Bool ?<? ( Duration lhs, Duration rhs ) { return lhs.tv <  rhs.tv; }
static inline _Bool ?<=?( Duration lhs, Duration rhs ) { return lhs.tv <= rhs.tv; }
static inline _Bool ?>? ( Duration lhs, Duration rhs ) { return lhs.tv >  rhs.tv; }
static inline _Bool ?>=?( Duration lhs, Duration rhs ) { return lhs.tv >= rhs.tv; }

static inline _Bool ?==?( Duration lhs, zero_t ) { return lhs.tv == 0; }
static inline _Bool ?!=?( Duration lhs, zero_t ) { return lhs.tv != 0; }
static inline _Bool ?<? ( Duration lhs, zero_t ) { return lhs.tv <  0; }
static inline _Bool ?<=?( Duration lhs, zero_t ) { return lhs.tv <= 0; }
static inline _Bool ?>? ( Duration lhs, zero_t ) { return lhs.tv >  0; }
static inline _Bool ?>=?( Duration lhs, zero_t ) { return lhs.tv >= 0; }

static inline Duration abs( Duration rhs ) { return rhs.tv >= 0 ? rhs : -rhs; }

forall( dtype ostype | ostream( ostype ) ) ostype & ?|?( ostype & os, Duration dur );

static inline Duration ?`ns( int64_t nsec ) { return (Duration)@{ nsec }; }
static inline Duration ?`us( int64_t usec ) { return (Duration)@{ usec * (TIMEGRAN / 1_000_000LL) }; }
static inline Duration ?`ms( int64_t msec ) { return (Duration)@{ msec * (TIMEGRAN / 1_000LL) }; }
static inline Duration ?`s( int64_t sec ) { return (Duration)@{ sec * TIMEGRAN }; }
static inline Duration ?`s( double sec ) { return (Duration)@{ sec * TIMEGRAN }; }
static inline Duration ?`m( int64_t min ) { return (Duration)@{ min * (60LL * TIMEGRAN) }; }
static inline Duration ?`m( double min ) { return (Duration)@{ min * (60LL * TIMEGRAN) }; }
static inline Duration ?`h( int64_t hours ) { return (Duration)@{ hours * (60LL * 60LL * TIMEGRAN) }; }
static inline Duration ?`h( double hours ) { return (Duration)@{ hours * (60LL * 60LL * TIMEGRAN) }; }
static inline Duration ?`d( int64_t days ) { return (Duration)@{ days * (24LL * 60LL * 60LL * TIMEGRAN) }; }
static inline Duration ?`d( double days ) { return (Duration)@{ days * (24LL * 60LL * 60LL * TIMEGRAN) }; }
static inline Duration ?`w( int64_t weeks ) { return (Duration)@{ weeks * (7LL * 24LL * 60LL * 60LL * TIMEGRAN) }; }
static inline Duration ?`w( double weeks ) { return (Duration)@{ weeks * (7LL * 24LL * 60LL * 60LL * TIMEGRAN) }; }

static inline int64_t ?`ns( Duration dur ) { return dur.tv; }
static inline int64_t ?`us( Duration dur ) { return dur.tv / (TIMEGRAN / 1_000_000LL); }
static inline int64_t ?`ms( Duration dur ) { return dur.tv / (TIMEGRAN / 1_000LL); }
static inline int64_t ?`s( Duration dur ) { return dur.tv / TIMEGRAN; }
static inline int64_t ?`m( Duration dur ) { return dur.tv / (60LL * TIMEGRAN); }
static inline int64_t ?`h( Duration dur ) { return dur.tv / (60LL * 60LL * TIMEGRAN); }
static inline int64_t ?`d( Duration dur ) { return dur.tv / (24LL * 60LL * 60LL * TIMEGRAN); }
static inline int64_t ?`w( Duration dur ) { return dur.tv / (7LL * 24LL * 60LL * 60LL * TIMEGRAN); }


//######################### C timeval #########################

static inline void ?{}( timeval & t ) {}
static inline void ?{}( timeval & t, time_t sec, suseconds_t usec ) { t.tv_sec = sec; t.tv_usec = usec; }
static inline void ?{}( timeval & t, time_t sec ) { t{ sec, 0 }; }
static inline void ?{}( timeval & t, zero_t ) { t{ 0, 0 }; }
static inline timeval ?=?( timeval & t, zero_t ) { return t{ 0 }; }
static inline timeval ?+?( timeval & lhs, timeval rhs ) { return (timeval)@{ lhs.tv_sec + rhs.tv_sec, lhs.tv_usec + rhs.tv_usec }; }
static inline timeval ?-?( timeval & lhs, timeval rhs ) { return (timeval)@{ lhs.tv_sec - rhs.tv_sec, lhs.tv_usec - rhs.tv_usec }; }
static inline _Bool ?==?( timeval lhs, timeval rhs ) { return lhs.tv_sec == rhs.tv_sec && lhs.tv_usec == rhs.tv_usec; }
static inline _Bool ?!=?( timeval lhs, timeval rhs ) { return lhs.tv_sec != rhs.tv_sec || lhs.tv_usec != rhs.tv_usec; }


//######################### C timespec #########################

static inline void ?{}( timespec & t ) {}
static inline void ?{}( timespec & t, time_t sec, __syscall_slong_t nsec ) { t.tv_sec = sec; t.tv_nsec = nsec; }
static inline void ?{}( timespec & t, time_t sec ) { t{ sec, 0}; }
static inline void ?{}( timespec & t, zero_t ) { t{ 0, 0 }; }
static inline timespec ?=?( timespec & t, zero_t ) { return t{ 0 }; }
static inline timespec ?+?( timespec & lhs, timespec rhs ) { return (timespec)@{ lhs.tv_sec + rhs.tv_sec, lhs.tv_nsec + rhs.tv_nsec }; }
static inline timespec ?-?( timespec & lhs, timespec rhs ) { return (timespec)@{ lhs.tv_sec - rhs.tv_sec, lhs.tv_nsec - rhs.tv_nsec }; }
static inline _Bool ?==?( timespec lhs, timespec rhs ) { return lhs.tv_sec == rhs.tv_sec && lhs.tv_nsec == rhs.tv_nsec; }
static inline _Bool ?!=?( timespec lhs, timespec rhs ) { return lhs.tv_sec != rhs.tv_sec || lhs.tv_nsec != rhs.tv_nsec; }


//######################### C itimerval #########################

static inline void ?{}( itimerval & itv, Duration alarm ) with( itv ) {
	// itimerval contains durations but but uses time data-structure timeval.
	it_value{ alarm`s, (alarm % 1`s)`us };				// seconds, microseconds
	it_interval{ 0 };									// 0 seconds, 0 microseconds
} // itimerval

static inline void ?{}( itimerval & itv, Duration alarm, Duration interval ) with( itv ) {
	// itimerval contains durations but but uses time data-structure timeval.
	it_value{ alarm`s, (alarm % 1`s)`us };				// seconds, microseconds
	it_interval{ interval`s, interval`us };				// seconds, microseconds
} // itimerval


//######################### C time #########################

static inline char * ctime( time_t tp ) { char * buf = ctime( &tp ); buf[24] = '\0'; return buf; }
static inline char * ctime_r( time_t tp, char * buf ) { ctime_r( &tp, buf ); buf[24] = '\0'; return buf; }
static inline tm * gmtime( time_t tp ) { return gmtime( &tp ); }
static inline tm * gmtime_r( time_t tp, tm * result ) { return gmtime_r( &tp, result ); }
static inline tm * localtime( time_t tp ) { return localtime( &tp ); }
static inline tm * localtime_r( time_t tp, tm * result ) { return localtime_r( &tp, result ); }


//######################### Time #########################

struct Time {											// private
	uint64_t tv;										// nanoseconds since UNIX epoch
}; // Time

static inline void ?{}( Time & t ) with( t ) { tv = 0; } // fast
void ?{}( Time & time, int year, int month = 0, int day = 0, int hour = 0, int min = 0, int sec = 0, int nsec = 0 ); // slow

static inline void ?{}( Time & t, zero_t ) { t.tv = 0; }
static inline Time ?=?( Time & t, zero_t ) { return t{ 0 }; }

static inline void ?{}( Time & time, timeval t ) with( time ) {
	tv = (int64_t)t.tv_sec * TIMEGRAN + t.tv_usec * 1000;
} // Time

static inline Time ?=?( Time & time, timeval t ) with( time ) {
	tv = (int64_t)t.tv_sec * TIMEGRAN + t.tv_usec * (TIMEGRAN / 1_000_000LL);
	return time;
} // ?=?

static inline void ?{}( Time & time, timespec t ) with( time ) {
	tv = (int64_t)t.tv_sec * TIMEGRAN + t.tv_nsec;
} // Time

static inline Time ?=?( Time & time, timespec t ) with( time ) {
	tv = (int64_t)t.tv_sec * TIMEGRAN + t.tv_nsec;
	return time;
} // ?=?

static inline Time ?+?( Time & lhs, Duration rhs ) { return (Time)@{ lhs.tv + rhs.tv }; }
static inline Time ?+?( Duration lhs, Time rhs ) { return rhs + lhs; }
static inline Time ?+=?( Time & lhs, Duration rhs ) { lhs = lhs + rhs; return lhs; }

static inline Duration ?-?( Time lhs, Time rhs ) { return (Duration)@{ lhs.tv - rhs.tv }; }
static inline Time ?-?( Time lhs, Duration rhs ) { return (Time)@{ lhs.tv - rhs.tv }; }
static inline Time ?-=?( Time & lhs, Duration rhs ) { lhs = lhs - rhs; return lhs; }
static inline _Bool ?==?( Time lhs, Time rhs ) { return lhs.tv == rhs.tv; }
static inline _Bool ?!=?( Time lhs, Time rhs ) { return lhs.tv != rhs.tv; }
static inline _Bool ?<?( Time lhs, Time rhs ) { return lhs.tv < rhs.tv; }
static inline _Bool ?<=?( Time lhs, Time rhs ) { return lhs.tv <= rhs.tv; }
static inline _Bool ?>?( Time lhs, Time rhs ) { return lhs.tv > rhs.tv; }
static inline _Bool ?>=?( Time lhs, Time rhs ) { return lhs.tv >= rhs.tv; }

char * yy_mm_dd( Time time, char * buf );
static inline char * ?`ymd( Time time, char * buf ) {	// short form
	return yy_mm_dd( time, buf );
} // ymd

char * mm_dd_yy( Time time, char * buf );
static inline char * ?`mdy( Time time, char * buf ) {	// short form
	return mm_dd_yy( time, buf );
} // mdy

char * dd_mm_yy( Time time, char * buf );
static inline char * ?`dmy( Time time, char * buf ) {	// short form
	return dd_mm_yy( time, buf );;
} // dmy

size_t strftime( char * buf, size_t size, const char * fmt, Time time );

forall( dtype ostype | ostream( ostype ) ) ostype & ?|?( ostype & os, Time time );

//------------------------- timeval (cont) -------------------------

static inline void ?{}( timeval & t, Time time ) with( t, time ) {
	tv_sec = tv / TIMEGRAN;								// seconds
	tv_usec = tv % TIMEGRAN / (TIMEGRAN / 1_000_000LL);	// microseconds
} // ?{}

//------------------------- timespec (cont) -------------------------

static inline void ?{}( timespec & t, Time time ) with( t, time ) {
	tv_sec = tv / TIMEGRAN;								// seconds
	tv_nsec = tv % TIMEGRAN;							// nanoseconds
} // ?{}


//######################### Clock #########################

struct Clock {											// private
	Duration offset;									// for virtual clock: contains offset from real-time
	int clocktype;										// implementation only -1 (virtual), CLOCK_REALTIME
};

static inline void resetClock( Clock & clk ) with( clk ) {
	clocktype = CLOCK_REALTIME_COARSE;
} // Clock::resetClock

static inline void resetClock( Clock & clk, Duration adj ) with( clk ) {
	clocktype = -1;
	offset = adj + timezone`s;							// timezone (global) is (UTC - local time) in seconds
} // resetClock

static inline void ?{}( Clock & clk ) {
	resetClock( clk );
} // Clock

static inline void ?{}( Clock & clk, Duration adj ) {
	resetClock( clk, adj );
} // Clock

static inline Duration getRes() {
	struct timespec res;
	clock_getres( CLOCK_REALTIME_COARSE, &res );
	return ((int64_t)res.tv_sec * TIMEGRAN + res.tv_nsec)`ns;
} // getRes

static inline Time getTimeNsec() {						// with nanoseconds
	timespec curr;
	clock_gettime( CLOCK_REALTIME_COARSE, &curr );
	return (Time){ curr };
} // getTime

static inline Time getTime() {							// without nanoseconds
	timespec curr;
	clock_gettime( CLOCK_REALTIME_COARSE, &curr );
	curr.tv_nsec = 0;
	return (Time){ curr };
} // getTime

static inline Time getTime( Clock & clk ) with( clk ) {
	return getTime() + offset;
} // getTime

static inline Time ?()( Clock & clk ) with( clk ) {		// alternative syntax
	return getTime() + offset;
} // getTime

static inline timeval getTime( Clock & clk ) {
	return (timeval){ clk() };
} // getTime

static inline tm getTime( Clock & clk ) with( clk ) {
	tm ret;
	localtime_r( getTime( clk ).tv_sec, &ret );
	return ret;
} // getTime

// Local Variables: //
// mode: c //
// tab-width: 4 //
// End: //