1 /* dict - a generic dictionary, variation over hash table */
3 /* Copyright (c) 2004-2019. The SimGrid Team. All rights reserved. */
5 /* This program is free software; you can redistribute it and/or modify it
6 * under the terms of the license (GNU LGPL) which comes with this package. */
9 #include "dict_private.h"
10 #include "simgrid/Exception.hpp"
11 #include "src/xbt_modinter.h"
14 #include "xbt/mallocator.h"
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_dict, xbt, "Dictionaries provide the same functionalities as hash tables");
22 constexpr int MAX_FILL_PERCENT = 80;
26 * @param free_ctn function to call with (@a data as argument) when @a data is removed from the dictionary
27 * @return pointer to the destination
28 * @see xbt_dict_free()
30 * Creates and initialize a new dictionary with a default hashtable size.
31 * The dictionary is homogeneous: each element share the same free function.
33 xbt_dict_t xbt_dict_new_homogeneous(void_f_pvoid_t free_ctn)
35 if (dict_elm_mallocator == nullptr)
40 dict = xbt_new(s_xbt_dict_t, 1);
41 dict->free_f = free_ctn;
42 dict->table_size = 127;
43 dict->table = xbt_new0(xbt_dictelm_t, dict->table_size + 1);
52 * @param dict the dictionary to be freed
54 * Frees a dictionary with all the data
56 void xbt_dict_free(xbt_dict_t * dict)
58 if (dict != nullptr && *dict != nullptr) {
59 int table_size = (*dict)->table_size;
60 xbt_dictelm_t* table = (*dict)->table;
61 /* Warning: the size of the table is 'table_size+1'...
62 * This is because table_size is used as a binary mask in xbt_dict_rehash */
63 for (int i = 0; (*dict)->count && i <= table_size; i++) {
64 xbt_dictelm_t current = table[i];
65 xbt_dictelm_t previous;
67 while (current != nullptr) {
69 current = current->next;
70 xbt_dictelm_free(*dict, previous);
80 /** Returns the amount of elements in the dict */
81 unsigned int xbt_dict_size(xbt_dict_t dict)
83 return (dict != nullptr ? static_cast<unsigned int>(dict->count) : static_cast<unsigned int>(0));
86 /* Expend the size of the dict */
87 static void xbt_dict_rehash(xbt_dict_t dict)
89 const unsigned oldsize = dict->table_size + 1;
90 unsigned newsize = oldsize * 2;
92 xbt_dictelm_t *currcell = (xbt_dictelm_t *) xbt_realloc((char *) dict->table, newsize * sizeof(xbt_dictelm_t));
93 memset(&currcell[oldsize], 0, oldsize * sizeof(xbt_dictelm_t)); /* zero second half */
95 dict->table_size = newsize;
96 dict->table = currcell;
97 XBT_DEBUG("REHASH (%u->%u)", oldsize, newsize);
99 for (unsigned i = 0; i < oldsize; i++, currcell++) {
100 if (*currcell == nullptr) /* empty cell */
103 xbt_dictelm_t *twincell = currcell + oldsize;
104 xbt_dictelm_t *pprev = currcell;
105 xbt_dictelm_t bucklet = *currcell;
106 for (; bucklet != nullptr; bucklet = *pprev) {
107 /* Since we use "& size" instead of "%size" and since the size was doubled, each bucklet of this cell must either:
108 - stay in cell i (ie, currcell)
109 - go to the cell i+oldsize (ie, twincell) */
110 if ((bucklet->hash_code & newsize) != i) { /* Move to b */
111 *pprev = bucklet->next;
112 bucklet->next = *twincell;
113 if (*twincell == nullptr)
117 pprev = &bucklet->next;
121 if (*currcell == nullptr) /* everything moved */
127 * @brief Add data to the dict (arbitrary key)
128 * @param dict the container
129 * @param key the key to set the new data
130 * @param key_len the size of the @a key
131 * @param data the data to add in the dict
132 * @param free_ctn unused parameter (kept for compatibility)
134 * Set the @a data in the structure under the @a key, which can be any kind of data, as long as its length is provided
137 void xbt_dict_set_ext(xbt_dict_t dict, const char* key, int key_len, void* data,
138 XBT_ATTRIB_UNUSED void_f_pvoid_t free_ctn)
140 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
142 xbt_dictelm_t current;
143 xbt_dictelm_t previous = nullptr;
145 XBT_CDEBUG(xbt_dict, "ADD %.*s hash = %u, size = %d, & = %u", key_len, key, hash_code,
146 dict->table_size, hash_code & dict->table_size);
147 current = dict->table[hash_code & dict->table_size];
148 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
149 || memcmp(key, current->key, key_len))) {
151 current = current->next;
154 if (current == nullptr) {
155 /* this key doesn't exist yet */
156 current = xbt_dictelm_new(key, key_len, hash_code, data);
158 if (previous == nullptr) {
159 dict->table[hash_code & dict->table_size] = current;
161 if ((dict->fill * 100) / (dict->table_size + 1) > MAX_FILL_PERCENT)
162 xbt_dict_rehash(dict);
164 previous->next = current;
167 XBT_CDEBUG(xbt_dict, "Replace %.*s by %.*s under key %.*s",
168 key_len, (char *) current->content, key_len, (char *) data, key_len, (char *) key);
169 /* there is already an element with the same key: overwrite it */
170 xbt_dictelm_set_data(dict, current, data);
175 * @brief Add data to the dict (null-terminated key)
177 * @param dict the dict
178 * @param key the key to set the new data
179 * @param data the data to add in the dict
180 * @param free_ctn unused parameter (kept for compatibility)
182 * set the @a data in the structure under the @a key, which is anull terminated string.
184 void xbt_dict_set(xbt_dict_t dict, const char *key, void *data, void_f_pvoid_t free_ctn)
186 xbt_dict_set_ext(dict, key, strlen(key), data, free_ctn);
190 * @brief Retrieve data from the dict (arbitrary key)
192 * @param dict the dealer of data
193 * @param key the key to find data
194 * @param key_len the size of the @a key
195 * @return the data that we are looking for
197 * Search the given @a key. Throws not_found_error when not found.
199 void *xbt_dict_get_ext(xbt_dict_t dict, const char *key, int key_len)
201 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
202 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
204 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
205 || memcmp(key, current->key, key_len))) {
206 current = current->next;
209 if (current == nullptr)
210 THROWF(not_found_error, 0, "key %.*s not found", key_len, key);
212 return current->content;
215 /** @brief like xbt_dict_get_ext(), but returning nullptr when not found */
216 void *xbt_dict_get_or_null_ext(xbt_dict_t dict, const char *key, int key_len)
218 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
219 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
221 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
222 || memcmp(key, current->key, key_len))) {
223 current = current->next;
226 if (current == nullptr)
229 return current->content;
233 * @brief retrieve the key associated to that object. Warning, that's a linear search
235 * Returns nullptr if the object cannot be found
237 char *xbt_dict_get_key(xbt_dict_t dict, const void *data)
239 for (int i = 0; i <= dict->table_size; i++) {
240 xbt_dictelm_t current = dict->table[i];
241 while (current != nullptr) {
242 if (current->content == data)
244 current = current->next;
251 * @brief Retrieve data from the dict (null-terminated key)
253 * @param dict the dealer of data
254 * @param key the key to find data
255 * @return the data that we are looking for
257 * Search the given @a key. Throws not_found_error when not found.
258 * Check xbt_dict_get_or_null() for a version returning nullptr without exception when not found.
260 void *xbt_dict_get(xbt_dict_t dict, const char *key)
262 return xbt_dict_get_elm(dict, key)->content;
266 * @brief Retrieve element from the dict (null-terminated key)
268 * @param dict the dealer of data
269 * @param key the key to find data
270 * @return the s_xbt_dictelm_t that we are looking for
272 * Search the given @a key. Throws not_found_error when not found.
273 * Check xbt_dict_get_or_null() for a version returning nullptr without exception when not found.
275 xbt_dictelm_t xbt_dict_get_elm(xbt_dict_t dict, const char *key)
277 xbt_dictelm_t current = xbt_dict_get_elm_or_null(dict, key);
279 if (current == nullptr)
280 THROWF(not_found_error, 0, "key %s not found", key);
286 * @brief like xbt_dict_get(), but returning nullptr when not found
288 void *xbt_dict_get_or_null(xbt_dict_t dict, const char *key)
290 xbt_dictelm_t current = xbt_dict_get_elm_or_null(dict, key);
292 if (current == nullptr)
295 return current->content;
299 * @brief like xbt_dict_get_elm(), but returning nullptr when not found
301 xbt_dictelm_t xbt_dict_get_elm_or_null(xbt_dict_t dict, const char *key)
303 unsigned int hash_code = xbt_str_hash(key);
304 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
306 while (current != nullptr && (hash_code != current->hash_code || strcmp(key, current->key)))
307 current = current->next;
312 * @brief Remove data from the dict (arbitrary key)
314 * @param dict the trash can
315 * @param key the key of the data to be removed
316 * @param key_len the size of the @a key
318 * Remove the entry associated with the given @a key (throws not_found)
320 void xbt_dict_remove_ext(xbt_dict_t dict, const char *key, int key_len)
322 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
323 xbt_dictelm_t previous = nullptr;
324 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
326 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
327 || strncmp(key, current->key, key_len))) {
328 previous = current; /* save the previous node */
329 current = current->next;
332 if (current == nullptr)
333 THROWF(not_found_error, 0, "key %.*s not found", key_len, key);
335 if (previous != nullptr) {
336 previous->next = current->next;
338 dict->table[hash_code & dict->table_size] = current->next;
342 if (not dict->table[hash_code & dict->table_size])
345 xbt_dictelm_free(dict, current);
350 * @brief Remove data from the dict (null-terminated key)
352 * @param dict the dict
353 * @param key the key of the data to be removed
355 * Remove the entry associated with the given @a key
357 void xbt_dict_remove(xbt_dict_t dict, const char *key)
359 xbt_dict_remove_ext(dict, key, strlen(key));
362 /** @brief Remove all data from the dict */
363 void xbt_dict_reset(xbt_dict_t dict)
365 if (dict->count == 0)
368 for (int i = 0; i <= dict->table_size; i++) {
369 xbt_dictelm_t previous = nullptr;
370 xbt_dictelm_t current = dict->table[i];
371 while (current != nullptr) {
373 current = current->next;
374 xbt_dictelm_free(dict, previous);
376 dict->table[i] = nullptr;
384 * @brief Return the number of elements in the dict.
385 * @param dict a dictionary
387 int xbt_dict_length(xbt_dict_t dict)
393 * @brief test if the dict is empty or not
395 int xbt_dict_is_empty(xbt_dict_t dict)
397 return not dict || (xbt_dict_length(dict) == 0);
401 * Create the dict mallocators.
402 * This is an internal XBT function called during the lib initialization.
403 * It can be used several times to recreate the mallocator, for example when you switch to MC mode
405 void xbt_dict_preinit()
407 if (dict_elm_mallocator == nullptr)
408 dict_elm_mallocator = xbt_mallocator_new(256, dict_elm_mallocator_new_f, dict_elm_mallocator_free_f,
409 dict_elm_mallocator_reset_f);
413 * Destroy the dict mallocators.
414 * This is an internal XBT function during the lib initialization
416 void xbt_dict_postexit()
418 if (dict_elm_mallocator != nullptr) {
419 xbt_mallocator_free(dict_elm_mallocator);
420 dict_elm_mallocator = nullptr;