netbsd/genstructs/htable/test1.c

   1 /*
   2  * Compile with:
   3  * gcc test1.c htable.c -o test1 -Wall -W -Wextra -ansi -pedantic
   4  *
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <time.h>    /* for time() in srand() */
  11
  12 #include "htable.h"
  13
  14 /* Function prototypes */
  15 unsigned int myhashf(const void *key);
  16 int mystrcmp(const void *arg1, const void *arg2);
  17 void myprintf(const void *key, const void *data);
  18 void print_elm(void *data);
  19 void get_rand_string(char *str, size_t len);
  20
  21 int main(void)
  22 {
  23     htable_t htable;
  24     size_t i;
  25     char str[20][10+1];    /* +1 for '\0' */
  26
  27     /* Initialize random number generator */
  28     srand(time(NULL));
  29
  30     /* Produce some random strings to put in hash table */
  31     for (i = 0; i < sizeof str / sizeof *str; i++)
  32         get_rand_string(str[i], 10);
  33
  34     /* Initialize table */
  35     if (htable_init(&htable, 32, 2, myhashf, mystrcmp, myprintf) == HT_NOMEM) {
  36         perror("malloc");
  37         exit(EXIT_FAILURE);
  38     }
  39
  40     /* Add random entries in hash table */
  41     for (i = 0; i < sizeof str / sizeof *str; i++)
  42         htable_insert(&htable, str[i], str[i]);
  43     /* htable_print(&htable); */
  44
  45     /*
  46      * Traverse all elemets and print each one of them
  47      * using the print_elm() callback function
  48      */
  49     htable_traverse(&htable, print_elm);
  50
  51     /*
  52      * Print the length of every chain
  53      * This gives as a metric on how good or bad our hash function is
  54      */
  55     for (i = 0; i < htable_get_size(&htable); i++)
  56         printf("chain[%lu] = %lu\n",
  57                (unsigned long)i,
  58                (unsigned long)htable_stat_get_chain_len(&htable, i));
  59
  60     /* Print number of automatic resizes */
  61     printf("Automatic resizes: %lu\n", (unsigned long)htable_stat_get_grows(&htable));
  62
  63     /* Free memory */
  64     htable_free(&htable);
  65
  66     return EXIT_SUCCESS;
  67 }
  68
  69 unsigned int myhashf(const void *key)
  70 {
  71     unsigned int i, hash = 5381;
  72     char *str = (char *)key;
  73
  74     for (i = 0; i < strlen(str); i++)
  75         hash = ((hash << 5) + hash) + str[i];
  76
  77     return hash;
  78 }
  79
  80 int mystrcmp(const void *arg1, const void *arg2)
  81 {
  82     return (strcmp((char *)arg1, (char *)arg2));
  83 }
  84
  85 void myprintf(const void *key, const void *data)
  86 {
  87     printf("%s(%s) ", (char *)key, (char *)data);
  88 }
  89
  90 void print_elm(void *data)
  91 {
  92     printf("%s\n", (char *)data);
  93 }
  94
  95 void get_rand_string(char *str, size_t len)
  96 {
  97     size_t i;
  98
  99     for (i = 0; i < len; i++)
 100         str[i] = 65 + 32 + (rand() / (RAND_MAX / 26 + 1));    /* 'a' to 'z' */
 101     str[i] = '\0';
 102 }