2 * Copyright (c) 2009-2011 Petri Lehtinen <petri@digip.org>
4 * This library is free software; you can redistribute it and/or modify
5 * it under the terms of the MIT license. See LICENSE for details.
9 #include <jansson_config.h> /* for JSON_INLINE */
10 #include "jansson_private.h" /* for container_of() */
11 #include "hashtable.h"
13 typedef struct hashtable_list list_t;
14 typedef struct hashtable_pair pair_t;
15 typedef struct hashtable_bucket bucket_t;
17 #define list_to_pair(list_) container_of(list_, pair_t, list)
19 static JSON_INLINE void list_init(list_t *list)
25 static JSON_INLINE void list_insert(list_t *list, list_t *node)
28 node->prev = list->prev;
29 list->prev->next = node;
33 static JSON_INLINE void list_remove(list_t *list)
35 list->prev->next = list->next;
36 list->next->prev = list->prev;
39 static JSON_INLINE int bucket_is_empty(hashtable_t *hashtable, bucket_t *bucket)
41 return bucket->first == &hashtable->list && bucket->first == bucket->last;
44 static void insert_to_bucket(hashtable_t *hashtable, bucket_t *bucket,
47 if(bucket_is_empty(hashtable, bucket))
49 list_insert(&hashtable->list, list);
50 bucket->first = bucket->last = list;
54 list_insert(bucket->first, list);
59 static size_t primes[] = {
60 5, 13, 23, 53, 97, 193, 389, 769, 1543, 3079, 6151, 12289, 24593,
61 49157, 98317, 196613, 393241, 786433, 1572869, 3145739, 6291469,
62 12582917, 25165843, 50331653, 100663319, 201326611, 402653189,
65 static const size_t num_primes = sizeof(primes) / sizeof(size_t);
67 static JSON_INLINE size_t num_buckets(hashtable_t *hashtable)
69 return primes[hashtable->num_buckets];
73 static pair_t *hashtable_find_pair(hashtable_t *hashtable, bucket_t *bucket,
74 const void *key, size_t hash)
79 if(bucket_is_empty(hashtable, bucket))
85 pair = list_to_pair(list);
86 if(pair->hash == hash && hashtable->cmp_keys(pair->key, key))
89 if(list == bucket->last)
98 /* returns 0 on success, -1 if key was not found */
99 static int hashtable_do_del(hashtable_t *hashtable,
100 const void *key, size_t hash)
106 index = hash % num_buckets(hashtable);
107 bucket = &hashtable->buckets[index];
109 pair = hashtable_find_pair(hashtable, bucket, key, hash);
113 if(&pair->list == bucket->first && &pair->list == bucket->last)
114 bucket->first = bucket->last = &hashtable->list;
116 else if(&pair->list == bucket->first)
117 bucket->first = pair->list.next;
119 else if(&pair->list == bucket->last)
120 bucket->last = pair->list.prev;
122 list_remove(&pair->list);
124 if(hashtable->free_key)
125 hashtable->free_key(pair->key);
126 if(hashtable->free_value)
127 hashtable->free_value(pair->value);
135 static void hashtable_do_clear(hashtable_t *hashtable)
140 for(list = hashtable->list.next; list != &hashtable->list; list = next)
143 pair = list_to_pair(list);
144 if(hashtable->free_key)
145 hashtable->free_key(pair->key);
146 if(hashtable->free_value)
147 hashtable->free_value(pair->value);
152 static int hashtable_do_rehash(hashtable_t *hashtable)
156 size_t i, index, new_size;
158 jsonp_free(hashtable->buckets);
160 hashtable->num_buckets++;
161 new_size = num_buckets(hashtable);
163 hashtable->buckets = jsonp_malloc(new_size * sizeof(bucket_t));
164 if(!hashtable->buckets)
167 for(i = 0; i < num_buckets(hashtable); i++)
169 hashtable->buckets[i].first = hashtable->buckets[i].last =
173 list = hashtable->list.next;
174 list_init(&hashtable->list);
176 for(; list != &hashtable->list; list = next) {
178 pair = list_to_pair(list);
179 index = pair->hash % new_size;
180 insert_to_bucket(hashtable, &hashtable->buckets[index], &pair->list);
187 hashtable_t *hashtable_create(key_hash_fn hash_key, key_cmp_fn cmp_keys,
188 free_fn free_key, free_fn free_value)
190 hashtable_t *hashtable = jsonp_malloc(sizeof(hashtable_t));
194 if(hashtable_init(hashtable, hash_key, cmp_keys, free_key, free_value))
196 jsonp_free(hashtable);
203 void hashtable_destroy(hashtable_t *hashtable)
205 hashtable_close(hashtable);
206 jsonp_free(hashtable);
209 int hashtable_init(hashtable_t *hashtable,
210 key_hash_fn hash_key, key_cmp_fn cmp_keys,
211 free_fn free_key, free_fn free_value)
216 hashtable->num_buckets = 0; /* index to primes[] */
217 hashtable->buckets = jsonp_malloc(num_buckets(hashtable) * sizeof(bucket_t));
218 if(!hashtable->buckets)
221 list_init(&hashtable->list);
223 hashtable->hash_key = hash_key;
224 hashtable->cmp_keys = cmp_keys;
225 hashtable->free_key = free_key;
226 hashtable->free_value = free_value;
228 for(i = 0; i < num_buckets(hashtable); i++)
230 hashtable->buckets[i].first = hashtable->buckets[i].last =
237 void hashtable_close(hashtable_t *hashtable)
239 hashtable_do_clear(hashtable);
240 jsonp_free(hashtable->buckets);
243 int hashtable_set(hashtable_t *hashtable, void *key, void *value)
249 /* rehash if the load ratio exceeds 1 */
250 if(hashtable->size >= num_buckets(hashtable))
251 if(hashtable_do_rehash(hashtable))
254 hash = hashtable->hash_key(key);
255 index = hash % num_buckets(hashtable);
256 bucket = &hashtable->buckets[index];
257 pair = hashtable_find_pair(hashtable, bucket, key, hash);
261 if(hashtable->free_key)
262 hashtable->free_key(key);
263 if(hashtable->free_value)
264 hashtable->free_value(pair->value);
269 pair = jsonp_malloc(sizeof(pair_t));
276 list_init(&pair->list);
278 insert_to_bucket(hashtable, bucket, &pair->list);
285 void *hashtable_get(hashtable_t *hashtable, const void *key)
291 hash = hashtable->hash_key(key);
292 bucket = &hashtable->buckets[hash % num_buckets(hashtable)];
294 pair = hashtable_find_pair(hashtable, bucket, key, hash);
301 int hashtable_del(hashtable_t *hashtable, const void *key)
303 size_t hash = hashtable->hash_key(key);
304 return hashtable_do_del(hashtable, key, hash);
307 void hashtable_clear(hashtable_t *hashtable)
311 hashtable_do_clear(hashtable);
313 for(i = 0; i < num_buckets(hashtable); i++)
315 hashtable->buckets[i].first = hashtable->buckets[i].last =
319 list_init(&hashtable->list);
323 void *hashtable_iter(hashtable_t *hashtable)
325 return hashtable_iter_next(hashtable, &hashtable->list);
328 void *hashtable_iter_at(hashtable_t *hashtable, const void *key)
334 hash = hashtable->hash_key(key);
335 bucket = &hashtable->buckets[hash % num_buckets(hashtable)];
337 pair = hashtable_find_pair(hashtable, bucket, key, hash);
344 void *hashtable_iter_next(hashtable_t *hashtable, void *iter)
346 list_t *list = (list_t *)iter;
347 if(list->next == &hashtable->list)
352 void *hashtable_iter_key(void *iter)
354 pair_t *pair = list_to_pair((list_t *)iter);
358 void *hashtable_iter_value(void *iter)
360 pair_t *pair = list_to_pair((list_t *)iter);
364 void hashtable_iter_set(hashtable_t *hashtable, void *iter, void *value)
366 pair_t *pair = list_to_pair((list_t *)iter);
368 if(hashtable->free_value)
369 hashtable->free_value(pair->value);