danicoin/external/glim/NsecTimer.hpp
Thomas Winget 90d6f8bf62 Adding libglim as an external library
libglim is an Apache-licensed C++ wrapper for lmdb, and rather than
rolling our own it seems prudent to use it.

Note: lmdb is not included in it, and unless something happens as did
with libunbound, should be installed via each OS' package manager or
equivalent.
2015-01-04 18:41:44 -08:00

51 lines
1.5 KiB
C++

#ifndef _NSEC_TIMER_H
#define _NSEC_TIMER_H
#include <time.h> // clock_gettime, CLOCK_MONOTONIC
#include <stdint.h>
#include <string>
#include <sstream>
namespace glim {
//! Safe nanoseconds timer.
struct NsecTimer {
timespec start;
NsecTimer () {restart();}
//! Nanoseconds since the creation or restart of the timer.
int64_t operator()() const {
timespec nsecStop; clock_gettime (CLOCK_MONOTONIC, &nsecStop);
return (int64_t) (nsecStop.tv_sec - start.tv_sec) * 1000000000LL + (int64_t) (nsecStop.tv_nsec - start.tv_nsec);
}
/** Seconds since the creation or restart of the timer. */
double sec() const {
timespec nsecStop; clock_gettime (CLOCK_MONOTONIC, &nsecStop);
double seconds = nsecStop.tv_sec - start.tv_sec;
seconds += (double)(nsecStop.tv_nsec - start.tv_nsec) / 1000000000.0;
return seconds;
}
//! Seconds since the creation or restart of the timer.
std::string seconds (int precision = 9) const {
// The trick is to avoid the scientific notation by printing integers.
double sec = this->sec();
std::ostringstream buf;
int isec = (int) sec;
buf << isec;
sec -= isec;
for (int pc = precision; pc; --pc) sec *= 10.0;
int ifrac = (int) sec;
if (ifrac > 0) {
buf << '.';
buf.fill ('0'); buf.width (precision);
buf << ifrac;
}
return buf.str();
}
void restart() {clock_gettime (CLOCK_MONOTONIC, &start);}
int64_t getAndRestart() {int64_t tmp = operator()(); restart(); return tmp;}
};
}
#endif // _NSEC_TIMER_H