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"
16 #include "xbt/string.hpp"
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_dict, xbt, "Dictionaries provide the same functionalities as hash tables");
23 constexpr int MAX_FILL_PERCENT = 80;
27 * @param free_ctn function to call with (@a data as argument) when @a data is removed from the dictionary
28 * @return pointer to the destination
29 * @see xbt_dict_free()
31 * Creates and initialize a new dictionary with a default hashtable size.
32 * The dictionary is homogeneous: each element share the same free function.
34 xbt_dict_t xbt_dict_new_homogeneous(void_f_pvoid_t free_ctn)
36 if (dict_elm_mallocator == nullptr)
41 dict = xbt_new(s_xbt_dict_t, 1);
42 dict->free_f = free_ctn;
43 dict->table_size = 127;
44 dict->table = xbt_new0(xbt_dictelm_t, dict->table_size + 1);
53 * @param dict the dictionary to be freed
55 * Frees a dictionary with all the data
57 void xbt_dict_free(xbt_dict_t * dict)
59 if (dict != nullptr && *dict != nullptr) {
60 int table_size = (*dict)->table_size;
61 xbt_dictelm_t* table = (*dict)->table;
62 /* Warning: the size of the table is 'table_size+1'...
63 * This is because table_size is used as a binary mask in xbt_dict_rehash */
64 for (int i = 0; (*dict)->count && i <= table_size; i++) {
65 xbt_dictelm_t current = table[i];
66 xbt_dictelm_t previous;
68 while (current != nullptr) {
70 current = current->next;
71 xbt_dictelm_free(*dict, previous);
81 /** Returns the amount of elements in the dict */
82 unsigned int xbt_dict_size(xbt_dict_t dict)
84 return (dict != nullptr ? static_cast<unsigned int>(dict->count) : static_cast<unsigned int>(0));
87 /* Expend the size of the dict */
88 static void xbt_dict_rehash(xbt_dict_t dict)
90 const unsigned oldsize = dict->table_size + 1;
91 unsigned newsize = oldsize * 2;
93 xbt_dictelm_t *currcell = (xbt_dictelm_t *) xbt_realloc((char *) dict->table, newsize * sizeof(xbt_dictelm_t));
94 memset(&currcell[oldsize], 0, oldsize * sizeof(xbt_dictelm_t)); /* zero second half */
96 dict->table_size = newsize;
97 dict->table = currcell;
98 XBT_DEBUG("REHASH (%u->%u)", oldsize, newsize);
100 for (unsigned i = 0; i < oldsize; i++, currcell++) {
101 if (*currcell == nullptr) /* empty cell */
104 xbt_dictelm_t *twincell = currcell + oldsize;
105 xbt_dictelm_t *pprev = currcell;
106 xbt_dictelm_t bucklet = *currcell;
107 for (; bucklet != nullptr; bucklet = *pprev) {
108 /* Since we use "& size" instead of "%size" and since the size was doubled, each bucklet of this cell must either:
109 - stay in cell i (ie, currcell)
110 - go to the cell i+oldsize (ie, twincell) */
111 if ((bucklet->hash_code & newsize) != i) { /* Move to b */
112 *pprev = bucklet->next;
113 bucklet->next = *twincell;
114 if (*twincell == nullptr)
118 pprev = &bucklet->next;
122 if (*currcell == nullptr) /* everything moved */
128 * @brief Add data to the dict (arbitrary key)
129 * @param dict the container
130 * @param key the key to set the new data
131 * @param key_len the size of the @a key
132 * @param data the data to add in the dict
133 * @param free_ctn unused parameter (kept for compatibility)
135 * 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
138 void xbt_dict_set_ext(xbt_dict_t dict, const char* key, int key_len, void* data,
139 XBT_ATTRIB_UNUSED void_f_pvoid_t free_ctn)
141 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
143 xbt_dictelm_t current;
144 xbt_dictelm_t previous = nullptr;
146 XBT_CDEBUG(xbt_dict, "ADD %.*s hash = %u, size = %d, & = %u", key_len, key, hash_code,
147 dict->table_size, hash_code & dict->table_size);
148 current = dict->table[hash_code & dict->table_size];
149 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
150 || memcmp(key, current->key, key_len))) {
152 current = current->next;
155 if (current == nullptr) {
156 /* this key doesn't exist yet */
157 current = xbt_dictelm_new(key, key_len, hash_code, data);
159 if (previous == nullptr) {
160 dict->table[hash_code & dict->table_size] = current;
162 if ((dict->fill * 100) / (dict->table_size + 1) > MAX_FILL_PERCENT)
163 xbt_dict_rehash(dict);
165 previous->next = current;
168 XBT_CDEBUG(xbt_dict, "Replace %.*s by %.*s under key %.*s",
169 key_len, (char *) current->content, key_len, (char *) data, key_len, (char *) key);
170 /* there is already an element with the same key: overwrite it */
171 xbt_dictelm_set_data(dict, current, data);
176 * @brief Add data to the dict (null-terminated key)
178 * @param dict the dict
179 * @param key the key to set the new data
180 * @param data the data to add in the dict
181 * @param free_ctn unused parameter (kept for compatibility)
183 * set the @a data in the structure under the @a key, which is a null terminated string.
185 void xbt_dict_set(xbt_dict_t dict, const char *key, void *data, void_f_pvoid_t free_ctn)
187 xbt_dict_set_ext(dict, key, strlen(key), data, free_ctn);
191 * @brief Retrieve data from the dict (arbitrary key)
193 * @param dict the dealer of data
194 * @param key the key to find data
195 * @param key_len the size of the @a key
196 * @return the data that we are looking for
198 * Search the given @a key. Throws std::out_of_range when not found.
200 void *xbt_dict_get_ext(xbt_dict_t dict, const char *key, int key_len)
202 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
203 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
205 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
206 || memcmp(key, current->key, key_len))) {
207 current = current->next;
210 if (current == nullptr)
211 throw std::out_of_range(simgrid::xbt::string_printf("key %.*s not found", key_len, key));
213 return current->content;
216 /** @brief like xbt_dict_get_ext(), but returning nullptr when not found */
217 void *xbt_dict_get_or_null_ext(xbt_dict_t dict, const char *key, int key_len)
219 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
220 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
222 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
223 || memcmp(key, current->key, key_len))) {
224 current = current->next;
227 if (current == nullptr)
230 return current->content;
234 * @brief retrieve the key associated to that object. Warning, that's a linear search
236 * Returns nullptr if the object cannot be found
238 char *xbt_dict_get_key(xbt_dict_t dict, const void *data)
240 for (int i = 0; i <= dict->table_size; i++) {
241 xbt_dictelm_t current = dict->table[i];
242 while (current != nullptr) {
243 if (current->content == data)
245 current = current->next;
252 * @brief Retrieve data from the dict (null-terminated key)
254 * @param dict the dealer of data
255 * @param key the key to find data
256 * @return the data that we are looking for
258 * Search the given @a key. Throws std::out_of_range when not found.
259 * Check xbt_dict_get_or_null() for a version returning nullptr without exception when not found.
261 void *xbt_dict_get(xbt_dict_t dict, const char *key)
263 return xbt_dict_get_elm(dict, key)->content;
267 * @brief Retrieve element from the dict (null-terminated key)
269 * @param dict the dealer of data
270 * @param key the key to find data
271 * @return the s_xbt_dictelm_t that we are looking for
273 * Search the given @a key. Throws std::out_of_range when not found.
274 * Check xbt_dict_get_or_null() for a version returning nullptr without exception when not found.
276 xbt_dictelm_t xbt_dict_get_elm(xbt_dict_t dict, const char *key)
278 xbt_dictelm_t current = xbt_dict_get_elm_or_null(dict, key);
280 if (current == nullptr)
281 throw std::out_of_range(simgrid::xbt::string_printf("key %s not found", key));
287 * @brief like xbt_dict_get(), but returning nullptr when not found
289 void *xbt_dict_get_or_null(xbt_dict_t dict, const char *key)
291 xbt_dictelm_t current = xbt_dict_get_elm_or_null(dict, key);
293 if (current == nullptr)
296 return current->content;
300 * @brief like xbt_dict_get_elm(), but returning nullptr when not found
302 xbt_dictelm_t xbt_dict_get_elm_or_null(xbt_dict_t dict, const char *key)
304 unsigned int hash_code = xbt_str_hash(key);
305 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
307 while (current != nullptr && (hash_code != current->hash_code || strcmp(key, current->key)))
308 current = current->next;
313 * @brief Remove data from the dict (arbitrary key)
315 * @param dict the trash can
316 * @param key the key of the data to be removed
317 * @param key_len the size of the @a key
319 * Remove the entry associated with the given @a key (throws std::out_of_range)
321 void xbt_dict_remove_ext(xbt_dict_t dict, const char *key, int key_len)
323 unsigned int hash_code = xbt_str_hash_ext(key, key_len);
324 xbt_dictelm_t previous = nullptr;
325 xbt_dictelm_t current = dict->table[hash_code & dict->table_size];
327 while (current != nullptr && (hash_code != current->hash_code || key_len != current->key_len
328 || strncmp(key, current->key, key_len))) {
329 previous = current; /* save the previous node */
330 current = current->next;
333 if (current == nullptr)
334 throw std::out_of_range(simgrid::xbt::string_printf("key %.*s not found", key_len, key));
336 if (previous != nullptr) {
337 previous->next = current->next;
339 dict->table[hash_code & dict->table_size] = current->next;
343 if (not dict->table[hash_code & dict->table_size])
346 xbt_dictelm_free(dict, current);
351 * @brief Remove data from the dict (null-terminated key)
353 * @param dict the dict
354 * @param key the key of the data to be removed
356 * Remove the entry associated with the given @a key
358 void xbt_dict_remove(xbt_dict_t dict, const char *key)
360 xbt_dict_remove_ext(dict, key, strlen(key));
363 /** @brief Remove all data from the dict */
364 void xbt_dict_reset(xbt_dict_t dict)
366 if (dict->count == 0)
369 for (int i = 0; i <= dict->table_size; i++) {
370 xbt_dictelm_t previous = nullptr;
371 xbt_dictelm_t current = dict->table[i];
372 while (current != nullptr) {
374 current = current->next;
375 xbt_dictelm_free(dict, previous);
377 dict->table[i] = nullptr;
385 * @brief Return the number of elements in the dict.
386 * @param dict a dictionary
388 int xbt_dict_length(xbt_dict_t dict)
394 * @brief test if the dict is empty or not
396 int xbt_dict_is_empty(xbt_dict_t dict)
398 return not dict || (xbt_dict_length(dict) == 0);
402 * Create the dict mallocators.
403 * This is an internal XBT function called during the lib initialization.
404 * It can be used several times to recreate the mallocator, for example when you switch to MC mode
406 void xbt_dict_preinit()
408 if (dict_elm_mallocator == nullptr)
409 dict_elm_mallocator = xbt_mallocator_new(256, dict_elm_mallocator_new_f, dict_elm_mallocator_free_f,
410 dict_elm_mallocator_reset_f);
414 * Destroy the dict mallocators.
415 * This is an internal XBT function during the lib initialization
417 void xbt_dict_postexit()
419 if (dict_elm_mallocator != nullptr) {
420 xbt_mallocator_free(dict_elm_mallocator);
421 dict_elm_mallocator = nullptr;