src/util/tests/hash_table/random_entry.c

   1 /*
   2  * Copyright © 2009 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  */
  26
  27 #undef NDEBUG
  28
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <assert.h>
  33 #include "hash_table.h"
  34
  35 static uint32_t
  36 key_value(const void *key)
  37 {
  38    return *(const uint32_t *)key;
  39 }
  40
  41 static bool
  42 uint32_t_key_equals(const void *a, const void *b)
  43 {
  44    return key_value(a) == key_value(b);
  45 }
  46
  47 static bool
  48 uint32_t_key_is_even(struct hash_entry *entry)
  49 {
  50    return (key_value(entry->key) & 1) == 0;
  51 }
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56    struct hash_table *ht;
  57    struct hash_entry *entry;
  58    unsigned size = 10000;
  59    uint32_t keys[size];
  60    uint32_t i, random_value;
  61
  62    (void) argc;
  63    (void) argv;
  64
  65    ht = _mesa_hash_table_create(NULL, key_value, uint32_t_key_equals);
  66
  67    for (i = 0; i < size; i++) {
  68       keys[i] = i;
  69
  70       _mesa_hash_table_insert(ht, keys + i, NULL);
  71    }
  72
  73    /* Test the no-predicate case. */
  74    entry = _mesa_hash_table_random_entry(ht, NULL);
  75    assert(entry);
  76
  77    /* Check that we're getting different entries and that the predicate
  78     * works.
  79     */
  80    for (i = 0; i < 100; i++) {
  81       entry = _mesa_hash_table_random_entry(ht, uint32_t_key_is_even);
  82       assert(entry);
  83       assert((key_value(entry->key) & 1) == 0);
  84       if (i == 0 || key_value(entry->key) != random_value)
  85          break;
  86       random_value = key_value(entry->key);
  87    }
  88    assert(i != 100);
  89
  90    _mesa_hash_table_destroy(ht, NULL);
  91
  92    return 0;
  93 }