1 #include "hashmap.h"
2 #include <string.h>
3 
4 uint32_t ext2fs_djb2_hash(const void *str, size_t size)
5 {
6 	int c;
7 	const char *s = str;
8 	uint32_t hash = 5381;
9 
10 	while (size-- > 0) {
11 		c = *s++;
12 		hash = ((hash << 5) + hash) + c;
13 	}
14 	return hash;
15 }
16 
17 struct ext2fs_hashmap *ext2fs_hashmap_create(
18 				uint32_t(*hash_fct)(const void*, size_t),
19 				void(*free_fct)(void*), size_t size)
20 {
21 	struct ext2fs_hashmap *h = calloc(sizeof(struct ext2fs_hashmap) +
22 				sizeof(struct ext2fs_hashmap_entry) * size, 1);
23 	h->size = size;
24 	h->free = free_fct;
25 	h->hash = hash_fct;
26 	h->first = h->last = NULL;
27 	return h;
28 }
29 
30 void ext2fs_hashmap_add(struct ext2fs_hashmap *h, void *data, const void *key,
31 			size_t key_len)
32 {
33 	uint32_t hash = h->hash(key, key_len) % h->size;
34 	struct ext2fs_hashmap_entry *e = malloc(sizeof(*e));
35 
36 	e->data = data;
37 	e->key = key;
38 	e->key_len = key_len;
39 	e->next = h->entries[hash];
40 	h->entries[hash] = e;
41 
42 	e->list_prev = NULL;
43 	e->list_next = h->first;
44 	if (h->first)
45 		h->first->list_prev = e;
46 	h->first = e;
47 	if (!h->last)
48 		h->last = e;
49 }
50 
51 void *ext2fs_hashmap_lookup(struct ext2fs_hashmap *h, const void *key,
52 			    size_t key_len)
53 {
54 	struct ext2fs_hashmap_entry *iter;
55 	uint32_t hash = h->hash(key, key_len) % h->size;
56 
57 	for (iter = h->entries[hash]; iter; iter = iter->next)
58 		if (iter->key_len == key_len && !memcmp(iter->key, key, key_len))
59 			return iter->data;
60 	return NULL;
61 }
62 
63 void *ext2fs_hashmap_iter_in_order(struct ext2fs_hashmap *h,
64 				   struct ext2fs_hashmap_entry **it)
65 {
66 	*it = *it ? (*it)->list_next : h->first;
67 	return *it ? (*it)->data : NULL;
68 }
69 
70 void ext2fs_hashmap_free(struct ext2fs_hashmap *h)
71 {
72 	for (size_t i = 0; i < h->size; ++i) {
73 		struct ext2fs_hashmap_entry *it = h->entries[i];
74 		while (it) {
75 			struct ext2fs_hashmap_entry *tmp = it->next;
76 			if (h->free)
77 				h->free(it->data);
78 			free(it);
79 			it = tmp;
80 		}
81 	}
82 	free(h);
83 }
84