molamolamola / epoch

A high resolution, cross platform time library for C/C++

Epoch

Epoch is a high resolution, cross platform time library for C/C++. This library can provide time measurements of less than one microsecond (1E-6 seconds), as well as date and time information in both local and UTC time. See examples at the end to see the proper usage of functions and what header files to include.

Data types:

Epoch_t

• Essentially acts as a timer to hold elapsed time info

Epoch_SysInfo_t

• Holds current system time information.

    typedef struct
    {
    unsigned short year;      // current year
    unsigned short month;     // current month (0-11)
    unsigned short weekday;   // current weekday (0-6)
    unsigned short day;       // current day (0-364)
    unsigned short hour;      // current hour (0-23)
    unsigned short minute;    // current minute (0-59)
    unsigned short second;    // current second (0-59)
    } Epoch_SysInfo_t;
  

Constants:

EPOCH_LOCAL_TIME

• Used to query system time information in local time (the time on your machine).

EPOCH_UTC_TIME

• Used to query system time information in universal coordinated time (UTC).

Functions:

unsigned char Epoch__Init();

• Intializes internal variables for use. Needs to be called only once at the start of the program.

void Epoch__Start(Epoch_t*);

• Initializes an Epoch_t and resets it's elapsed time. This must be called to start an Epoch_t before it's elapsed time is ever queried.

double Epoch__QueryChange(Epoch_t*);

• Gets the elapsed time from an Epoch_t.

void Epoch__QuerySysInfo(Epoch_SysInfo_t*, unsigned char type);

• Fill a Epoch_SysInfo_t with system time information. "type" should be either EPOCH_LOCAL_TIME or EPOCH_UTC_TIME.

Examples:

Run a loop for five seconds

#include <stdio.h>
#include "epoch.h"

int main(int argc, char* argv[])
{
    // Initialize Epoch
    Epoch__Init();

    // Create a new timer
    Epoch_t timer;

    // Start the timer
    Epoch__Start(&timer);
    // Keep track of elapsed time
    double elapsed;

    // Print out elapsed time
    // for five seconds
    do
    {
        // Get change in time since the
        // timer was started
        elapsed = Epoch__QueryChange(&timer);
        printf("%f\n", elapsed);
    }
    while (elapsed < 5.0);
}

Get local time info

#include <stdio.h>
#include "epoch.h"

int main(int argc, char* argv[])
{
    // Initialize Epoch
    Epoch__Init();

    // Used to hold system information
    Epoch_SysInfo_t info;

    // Get current system information (local time)
    Epoch__QuerySysInfo(&info, EPOCH_LOCAL_TIME);

    // Print some info
    printf("Current Year: %d\n", info.year);
    printf("Current Month: %d\n", info.month);
    printf("Current Weekday: %d\n", info.weekday);
    printf("Current Day: %d\n", info.day);
    printf("Current Hour: %d\n", info.hour);
    printf("Current Minute: %d\n", info.minute);
    printf("Current Second: %d\n", info.second);
}