printf

printf2.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

FILE *log_file;
int write_total;
char buffer[1024];

#ifdef _WIN32
#include <windows.h>
double
sec()
{
    LARGE_INTEGER freq, v;

    QueryPerformanceFrequency(&freq);
    QueryPerformanceCounter(&v);

    return v.QuadPart / (double)freq.QuadPart;
}
HANDLE log_file2;

#else
#include <sys/time.h>
#include <fcntl.h>
double
sec()
{
    struct timeval tv;

    gettimeofday(&tv, NULL);

    return tv.tv_sec + tv.tv_usec / 1000000.0;
}

int log_file2;
#endif

int
sum_digit(unsigned char *data, int w, int h)
{
    int ret = 0;
    int xi, yi;
    for (yi=0; yi<h; yi++) {
        for (xi=0; xi<w; xi++) {
            ret += data[yi*w + xi];
            //write_total += sprintf(buffer, "x=%d y=%d sum=%d\n", xi, yi, ret);
            //write_total += fprintf(log_file, "x=%d y=%d sum=%d\n", xi, yi, ret);
            //write_total += sprintf(buffer, "\n");
            isdigit((char)ret);
            //fputs("x=%d y=%d sum=%d\n", log_file);
            //WriteFile(log_file2, "0123456789\r\n", 12, NULL, NULL);
        }
    }
    return ret;
}

int
sum_sprintf(unsigned char *data, int w, int h)
{
    int ret = 0;
    int xi, yi;
    for (yi=0; yi<h; yi++) {
        for (xi=0; xi<w; xi++) {
            ret += data[yi*w + xi];
            write_total += sprintf(buffer, "x=%d y=%d sum=%d\n", xi, yi, ret);
        }
    }
    return ret;
}

int
sum_fprintf(unsigned char *data, int w, int h)
{
    int ret = 0;
    int xi, yi;
    for (yi=0; yi<h; yi++) {
        for (xi=0; xi<w; xi++) {
            ret += data[yi*w + xi];
            write_total += fprintf(log_file, "x=%d y=%d sum=%d\n", xi, yi, ret);
        }
    }
    return ret;
}

int
sum_fputs(unsigned char *data, int w, int h)
{
    int ret = 0;
    int xi, yi;
    int len=strlen("x=%d y=%d sum=%d\n");
    for (yi=0; yi<h; yi++) {
        for (xi=0; xi<w; xi++) {
            ret += data[yi*w + xi];
            fputs("x=%d y=%d sum=%d\n", log_file);
            write_total += len;
        }
    }
    return ret;
}

int main(int argc, char **argv)
{
    unsigned char *data;
    int w = 640, h = 480;
    int v;
    double start, end;
    int i;

    if (argc >= 3) {
        w = atoi(argv[1]);
        h = atoi(argv[2]);
    }

    log_file = fopen("log.txt", "w");

    data = malloc(w*h);
    memset(data, 0, w*h);

    for (i=0; i<4; i++) {
        double dt;
        const char *name = "??";
        write_total = 0;

        start = sec();
        switch (i) {
        case 0:
            v = sum_fputs(data, w, h);
            name = "fputs";
            break;
        case 1:
            v = sum_sprintf(data, w, h);
            name = "sprintf";
            break;
        case 2:
            v = sum_fprintf(data, w, h);
            name = "fprintf";
            break;
        case 3:
            v = sum_digit(data, w, h);
            name = "digit";
            break;
        }
        
        end = sec();

        dt = end-start;

        printf("%10s: %d %d %d %e[sec] %e[sec/byte]\n", name, w, h, v, dt, dt/write_total);
    }

    fclose(log_file);
}