malltime.c test malloc strategies

// читаем построчно файлы из арг. ком. стр. 2-мя разными способами malloc/realloc
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/time.h>

#define LIMIT 100000000

double getusec()
{
  struct timeval tm;

  gettimeofday(&tm, 0);
  return tm.tv_sec * 1.0e6 + tm.tv_usec;
}

char *
getaline (FILE *in)
{
// ./a.out /usr/include/*.h
#if QUICK // read 1403382 bytes in 39654 lines in 145 files (131.525 msec) maxcap: 3415 (2796)
  static int cap = 0;
  static char *str = 0;
#else // read 1403382 bytes in 39654 lines in 145 files (152.583 msec) maxcap: 3415 (2796)
  int cap = 0;
  char *str = 0;
#endif // сам удивился, что не влияет
  int c,  n = 0, incr = 10;

  if (feof(in))
    return 0;
  while ((c = fgetc(in)) != EOF) {
    if (n + 2 > cap) {
      str = realloc(str, (cap += incr));
#if QUICK
      incr <<= 1;
#endif
    }
    str[n++] = c;
    if (c == '\n')
      break;
  }
  if (n) {
    str[n] = 0;
#if QUICK
    char *t = malloc(n + 1);
    memcpy(t, str, n + 1);
    return t;
#else
    return realloc(str, n + 1);
#endif
  }
  return 0;
}

int
read_filines (FILE *in, int *lines, int *pcap, int *pn)
{
  int i, size = 0, acap = 0, n = 0, incr = 300;
  char *str, **arr = 0;

  while (str = getaline(in)) {
    size += strlen(str);
    if (n == acap) {
      arr = realloc(arr, (acap += incr) * sizeof(*arr));
      if ((incr = acap / 2) > 10000)
    incr = 16000;
    }
    arr[n++] = str;
  }
  (*lines) += n;

  for (i = 0; i < n; i++)
    free(arr[i]);
  free(arr);

  *pn = n;
  *pcap = acap;
  return size;
}

int
main (int ac, char *av[])
{
#if QUICK
  puts("Quick test");
#else
  puts("Slow test");
#endif
  double t1 = getusec();
  FILE *in;
  int i, n = 0, tot = 0, size = 0, cap, maxcap = 0, na, maxna = 0;


  for (i = 1; i < ac; i++) {
    if (in = fopen(av[i], "r")) {
      n++;
      size += read_filines(in, &tot, &cap, &na);
      if (cap > maxcap)
    maxcap = cap;
      if (na > maxna)
    maxna = na;
      if (size > LIMIT)
    break;
      fclose(in);
    } else
      perror(av[i]);
  }

  printf ("read %d bytes in %d lines in %d files (%.3f msec) maxcap: %d (%d)\n",
      size, tot, n, (getusec() - t1) / 1000, maxcap, maxna);
  return 0;
}