projtimer.c

/*
cc projtimer.c -I/usr/local/include -L/usr/local/lib -lproj -o projtimer
./projtimer epsg:4326 epsg:4326
./projtimer epsg:4326 epsg:26910
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/resource.h>

#include "proj.h"

static double
time_difference_us(struct timeval start, struct timeval end)
{
    int64_t diff_us = (int64_t)(end.tv_usec - start.tv_usec);
    if (start.tv_sec == end.tv_sec) {
        return (double)diff_us;
    }
    else {
        int64_t diff_s = (int64_t)(end.tv_sec - start.tv_sec);
        return (double)(diff_s)*1000000 + (double)(diff_us);
    }
}

int main(int argnum, const char** args) 
{
    int iterations = 1000;
    const char *pj_from_str = "epsg:4326";
    const char *pj_to_str = "epsg:4326";
    struct timeval start, end;
    double diff;

    if (argnum >= 3 && args[1] && args[2]) {
        pj_from_str = args[1];
        pj_to_str = args[2];
    }

    PJ_INFO info = proj_info();
    printf("Proj version '%s'\n", info.version);

    printf("Using '%s' as from-srid\n", pj_from_str);
    printf("Using '%s' as to-srid\n", pj_to_str);

    gettimeofday(&start, NULL);
    for (int i = 0; i < iterations; i++) {
        PJ* projpj = proj_create_crs_to_crs(NULL, pj_from_str, pj_to_str, NULL);
        PJ* dpj = proj_destroy(projpj);
    }
    gettimeofday(&end, NULL);
    diff = time_difference_us(start, end);
    printf("Ran %d iterations, %g us per iteration\n", iterations, diff/iterations);
    exit(0);
}