lib/str-test.c

   1 /*
   2  *      Checking the correctness of str_len() and str_hash() and proving, that
   3  *      it is faster than the classical version ;-)
   4  */
   5
   6 #include "lib/str_hash.h"
   7
   8 #include <stdlib.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/time.h>
  12
  13 /* It will be divided by (10 + strlen()).  */
  14 #define TEST_TIME       1000000
  15
  16 static void
  17 random_string(char *str, int len)
  18 {
  19         int i;
  20         for (i=0; i<len; i++)
  21                 str[i] = random() % 255 + 1;
  22         str[len] = 0;
  23 }
  24
  25 static uns
  26 elapsed_time(void)
  27 {
  28         static struct timeval last_tv, tv;
  29         uns elapsed;
  30         gettimeofday(&tv, NULL);
  31         elapsed = (tv.tv_sec - last_tv.tv_sec) * 1000000 + (tv.tv_usec - last_tv.tv_usec);
  32         last_tv = tv;
  33         return elapsed;
  34 }
  35
  36 int
  37 main(void)
  38 {
  39         char *strings[] = {
  40                 "",
  41                 "a",
  42                 "aa",
  43                 "aaa",
  44                 "aaaa",
  45                 "aaaaa",
  46                 "aaaaaa",
  47                 "aaaaaaa",
  48                 "aaaaaaaa",
  49                 "aaaaaaaaa",
  50                 "aaaaaaaaaa",
  51                 "\200aaaa",
  52                 "\200",
  53                 "\200\200",
  54                 "\200\200\200",
  55                 "\200\200\200\200",
  56                 "\200\200\200\200\200",
  57                 "kelapS treboR",
  58                 "Robert Spalek",
  59                 "uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu",
  60                 "********************************",
  61                 "****************************************************************",
  62                 NULL
  63         };
  64         int lengths[] = {
  65                 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
  66                 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
  67                 30, 40, 50, 60, 70, 80, 90, 100,
  68                 200, 300, 400, 500, 600, 700, 800, 900, 1000,
  69                 2000, 4000, 8000, 16000, 32000, 64000,
  70                 -1
  71         };
  72         int i;
  73         for (i=0; strings[i]; i++)
  74                 if (strlen(strings[i]) != str_len(strings[i]))
  75                         die("Internal error on string %d", i);
  76         printf("%d strings tested OK\n", i);
  77         for (i=0; strings[i]; i++)
  78                 printf("hash %2d = %08x\n", i, str_hash(strings[i]));
  79         for (i=0; lengths[i] >= 0; i++)
  80         {
  81                 char str[lengths[i] + 1];
  82                 uns count = TEST_TIME / (lengths[i] + 10);
  83                 uns el1 = 0, el2 = 0, elh = 0;
  84                 uns tot1 = 0, tot2 = 0, hash = 0;
  85                 uns j;
  86                 for (j=0; j<count; j++)
  87                 {
  88                         random_string(str, lengths[i]);
  89                         elapsed_time();
  90                         /* Avoid "optimizing" by gcc, since the functions are
  91                          * attributed as ((const)).  */
  92                         tot1 += strlen(str);
  93                         el1 += elapsed_time();
  94                         tot2 += str_len(str);
  95                         el2 += elapsed_time();
  96                         hash ^= str_hash(str);
  97                         elh += elapsed_time();
  98                 }
  99                 if (tot1 != tot2)
 100                         die("Internal error during test %d", i);
 101                 printf("Test %d: strlen = %d, passes = %d, classical = %d usec, speedup = %.4f\n",
 102                         i, lengths[i], count, el1, (el1 + 0.) / el2);
 103                 printf("\t\t total hash = %08x, hash time = %d usec\n", hash, elh);
 104         }
 105 /*
 106         printf("test1: %d\n", hash_modify(10000000, 10000000, 99777555));
 107         printf("test1: %d, %d\n", i, hash_modify(i, lengths[i-2], 99777333));
 108         printf("test1: %d, %d\n", i, hash_modify(lengths[i-2], i, 99777333));
 109         printf("test1: %d,%d,%d->%d\n", i, i*3-2, i*i, hash_modify(4587, i*3-2, i*i));
 110         printf("test1: %d\n", hash_modify(lengths[5], 345, i));
 111 */
 112         return 0;
 113 }