source: GTP/trunk/Lib/Vis/Preprocessing/src/sparsehash/experimental/example.c @ 2162

Revision 2162, 1.4 KB checked in by mattausch, 18 years ago (diff)

improved hash performance with google hashmap

Line 
1#include <stdlib.h>
2#include <stdio.h>
3#include <assert.h>
4#include "libchash.h"
5
6static void TestInsert() {
7  struct HashTable* ht;
8  HTItem* bck;
9
10  ht = AllocateHashTable(1, 0);    /* value is 1 byte, 0: don't copy keys */
11
12  HashInsert(ht, PTR_KEY(ht, "January"), 31);  /* 0: don't overwrite old val */
13  bck = HashInsert(ht, PTR_KEY(ht, "February"), 28);
14  bck = HashInsert(ht, PTR_KEY(ht, "March"), 31);
15
16  bck = HashFind(ht, PTR_KEY(ht, "February"));
17  assert(bck);
18  assert(bck->data == 28);
19
20  FreeHashTable(ht);
21}
22
23static void TestFindOrInsert() {
24  struct HashTable* ht;
25  int i;
26  int iterations = 1000000;
27  int range = 30;         /* random number between 1 and 30 */
28
29  ht = AllocateHashTable(4, 0);    /* value is 4 bytes, 0: don't copy keys */
30
31  /* We'll test how good rand() is as a random number generator */
32  for (i = 0; i < iterations; ++i) {
33    int key = rand() % range;
34    HTItem* bck = HashFindOrInsert(ht, key, 0);     /* initialize to 0 */
35    bck->data++;                   /* found one more of them */
36  }
37
38  for (i = 0; i < range; ++i) {
39    HTItem* bck = HashFind(ht, i);
40    if (bck) {
41      printf("%3d: %d\n", bck->key, bck->data);
42    } else {
43      printf("%3d: 0\n", i);
44    }
45  }
46
47  FreeHashTable(ht);
48}
49
50int main(int argc, char** argv) {
51  TestInsert();
52  TestFindOrInsert();
53  return 0;
54}
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