1 /* EINA - EFL data type library
2 * Copyright (C) 2002-2008 Carsten Haitzler, Gustavo Sverzut Barbieri,
3 * Vincent Torri, Jorge Luis Zapata Muga, Cedric Bail
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library;
17 * if not, see <http://www.gnu.org/licenses/>.
23 #include "eina_types.h"
24 #include "eina_iterator.h"
27 * @page hash_01_example_page Eina_Hash in action
28 * @dontinclude eina_hash_01.c
30 * We are going to store some tuples into our table, that will map each @a name
31 * to a @a number. The cost to access a given number from the name should be
32 * very small, even with many entries in our table. This is the initial data:
34 * @until // _start_entries
36 * Before starting to play with the hash, let's write a callback that will be
37 * used to free the elements from it. Since we are just storing strduped
38 * strings, we just need to free them:
43 * We also need a callback to iterate over the elements of the list later, so
44 * we are defining it now:
49 * Now let's create our @ref Eina_Hash using @ref
50 * eina_hash_string_superfast_new :
55 * Now we add the keys and data to the hash using @ref eina_hash_add . This
56 * means that the key is copied inside the table, together with the pointer to
57 * the data (phone numbers).
62 * Some basic manipulations with the hash, like finding a value given a key,
63 * deleting an entry, modifying an entry are exemplified in the following lines.
64 * Notice that the @ref eina_hash_modify function returns the old value stored
65 * in that entry, and it needs to be freed, while the @ref eina_hash_del
66 * function already calls our free callback:
71 * The @ref eina_hash_set function can be used to set a key-value entry to the
72 * table if it doesn't exist, or to modify an existent entry. It returns the old
73 * entry if it was already set, and NULL otherwise. But since it will
74 * return NULL on error too, we need to check if an error has occurred:
77 * @until printf("\n");
79 * There are different ways of iterate over the entries of a hash. Here we show
80 * two of them: using @ref eina_hash_foreach and @ref Eina_Iterator .
82 * @skip List of phones
83 * @until eina_iterator_free(it);
85 * It's also possible to change the key for a specific entry, without having to
86 * remove the entry from the table and adding it again:
88 * @skipline eina_hash_move
90 * We can remove all the elements from the table without free the table itself:
92 * @skip Empty the phone book
93 * @until eina_hash_population
95 * Or free the the entire table with its content:
97 * @skipline eina_hash_free
100 * The full code for this example can be seen here: @ref eina_hash_01_c
104 * @page eina_hash_01_c Hash table in action
106 * @include eina_hash_01.c
107 * @example eina_hash_01.c
111 * @page hash_02_example_page Different types of tables
113 * This example shows two more types of hash tables that can be created using
114 * @ref Eina_Hash . For more types, consult the reference documentation of @ref
116 * @include eina_hash_02.c
117 * @example eina_hash_02.c
121 * @example eina_hash_03.c
122 * Same example as @ref hash_01_example_page but using a "string small" hash
123 * table instead of "string superfast".
127 * @example eina_hash_04.c
128 * Same example as @ref hash_01_example_page but using a "string djb2" hash
129 * table instead of "string superfast".
133 * @example eina_hash_05.c
134 * Same example as @ref hash_01_example_page but using a "int32" hash
135 * table instead of "string superfast".
139 * @example eina_hash_06.c
140 * Same example as @ref hash_01_example_page but using a "int64" hash
141 * table instead of "string superfast".
145 * @example eina_hash_07.c
146 * Same example as @ref hash_01_example_page but using a "pointer" hash
147 * table instead of "string superfast".
151 * @example eina_hash_08.c
152 * This example shows the the usage of eina_hash_add(), eina_hash_add_by_hash(),
153 * eina_hash_direct_add_by_hash(), eina_hash_del(), eina_hash_del_by_key_hash(),
154 * eina_hash_del_by_key(), eina_hash_del_by_data(), eina_hash_find_by_hash() and
155 * eina_hash_modify_by_hash().
159 * @addtogroup Eina_Hash_Group Hash Table
161 * @brief Hash table management. Useful for mapping keys to values.
163 * The hash table is useful for when one wants to implement a table that maps
164 * keys (usually strings) to data, and have relatively fast access time. The
165 * performance is proportional to the load factor of the table (number of
166 * elements / number of buckets). See @ref hashtable_algo for implementation
169 * Different implementations exists depending on what kind of key will be used
170 * to access the data: strings, integers, pointers, stringshared or your own.
172 * Eina hash tables can copy the keys when using eina_hash_add() or not when
173 * using eina_hash_direct_add().
175 * @section hashtable_algo Algorithm
177 * The Eina_Hash is implemented using an array of N "buckets", where each
178 * bucket is a pointer to a structure that is the head of a <a
179 * href="http://en.wikipedia.org/wiki/Red-black_tree">red-black tree</a>. The
180 * array can then be indexed by the [hash_of_element mod N]. The
181 * hash_of_element is calculated using the hashing function, passed as
182 * parameter to the @ref eina_hash_new function. N is the number of buckets
183 * (array positions), and is calculated based on the buckets_power_size
184 * (argument of @ref eina_hash_new too). The following picture ilustrates the
188 * <img src="01_hash-table.png" width="500" />
190 * @image latex 01_hash-table.eps
192 * Adding an element to the hash table is made of:
193 * @li calculating the hash for that key (using the specified hash function);
194 * @li calculate the array position [hash mod N];
195 * @li add the element to the rbtree on that position.
197 * The two first steps have constant time, proportional to the hash function
198 * being used. Adding the key to the rbtree will be proportional on the number
199 * of keys on that bucket.
201 * The average cost of lookup depends on the number of keys per
202 * bucket (load factor) of the table, if the distribution of keys is
203 * sufficiently uniform.
205 * @section hashtable_perf Performance
207 * As said before, the performance depends on the load factor. So trying to keep
208 * the load factor as small as possible will improve the hash table performance. But
209 * increasing the buckets_power_size will also increase the memory consumption.
210 * The default hash table creation functions already have a good number of
211 * buckets, enough for most cases. Particularly for strings, if just a few keys
212 * (less than 30) will be added to the hash table, @ref
213 * eina_hash_string_small_new should be used, since it will reduce the memory
214 * consumption for the buckets, and you still won't have many collisions.
215 * However, @ref eina_hash_string_small_new still uses the same hash calculation
216 * function that @ref eina_hash_string_superfast_new, which is more complex than
217 * @ref eina_hash_string_djb2_new. The latter has a faster hash computation
218 * function, but that will imply on a not so good distribution. But if just a
219 * few keys are being added, this is not a problem, it will still have not many
220 * collisions and be faster to calculate the hash than in a hash created with
221 * @ref eina_hash_string_small_new and @ref eina_hash_string_superfast_new.
223 * A simple comparison between them would be:
225 * @li @c djb2 - faster hash function - 256 buckets (higher memory consumption)
226 * @li @c string_small - slower hash function but less collisions - 32 buckets
227 * (lower memory consumption)
228 * @li @c string_superfast - slower hash function but less collisions - 256 buckets
229 * (higher memory consumption)
231 * Basically for a very small number of keys (10 or less), @c djb2 should be
232 * used, or @c string_small if you have a restriction on memory usage. And for a
233 * higher number of keys, @c string_superfast should be always preferred.
235 * If just stringshared keys are being added, use @ref
236 * eina_hash_stringshared_new. If a lot of keys will be added to the hash table
237 * (e.g. more than 1000), then it's better to increase the buckets_power_size.
238 * See @ref eina_hash_new for more details.
240 * When adding a new key to a hash table, use @ref eina_hash_add or @ref
241 * eina_hash_direct_add (the latter if this key is already stored elsewhere). If
242 * the key may be already inside the hash table, instead of checking with
243 * @ref eina_hash_find and then doing @ref eina_hash_add, one can use just @ref
244 * eina_hash_set (this will change the data pointed by this key if it was
245 * already present in the table).
247 * @section hashtable_tutorial Tutorial
249 * These examples show many Eina_Hash functions in action:
251 * <li> @ref hash_01_example_page
252 * <li> @ref hash_02_example_page
253 * <li> Different types of hash in use:
255 * <li> @ref eina_hash_03.c "string small"
256 * <li> @ref eina_hash_04.c "string djb2"
257 * <li> @ref eina_hash_05.c "int32"
258 * <li> @ref eina_hash_06.c "int64"
259 * <li> @ref eina_hash_07.c "pointer"
261 * <li> @ref eina_hash_08.c "Different add and delete functions"
266 * @addtogroup Eina_Data_Types_Group Data Types
272 * @addtogroup Eina_Containers_Group Containers
278 * @defgroup Eina_Hash_Group Hash Table
285 * Type for a generic hash table.
287 typedef struct _Eina_Hash Eina_Hash;
289 typedef struct _Eina_Hash_Tuple Eina_Hash_Tuple;
291 struct _Eina_Hash_Tuple
293 const void *key; /**< The key */
294 void *data; /**< The data associated to the key */
295 unsigned int key_length; /**< The length of the key */
298 typedef unsigned int (*Eina_Key_Length)(const void *key);
300 * @def EINA_KEY_LENGTH
301 * @param Function The function used to hash calculation.
303 #define EINA_KEY_LENGTH(Function) ((Eina_Key_Length)Function)
304 typedef int (*Eina_Key_Cmp)(const void *key1, int key1_length, const void *key2, int key2_length);
307 * @param Function The function used to hash calculation.
309 #define EINA_KEY_CMP(Function) ((Eina_Key_Cmp)Function)
310 typedef int (*Eina_Key_Hash)(const void *key, int key_length);
313 * @param Function The function used to hash calculation.
315 #define EINA_KEY_HASH(Function) ((Eina_Key_Hash)Function)
316 typedef Eina_Bool (*Eina_Hash_Foreach)(const Eina_Hash *hash, const void *key, void *data, void *fdata);
320 * @brief Create a new hash table.
322 * @param key_length_cb The function called when getting the size of the key.
323 * @param key_cmp_cb The function called when comparing the keys.
324 * @param key_hash_cb The function called when getting the values.
325 * @param data_free_cb The function called on each value when the hash table is
326 * freed, or when an item is deleted from it. @c NULL can be passed as
328 * @param buckets_power_size The size of the buckets.
329 * @return The new hash table.
331 * This function creates a new hash table using user-defined callbacks
332 * to manage the hash table. On failure, @c NULL is returned
333 * and #EINA_ERROR_OUT_OF_MEMORY is set. If @p key_cmp_cb or @p key_hash_cb
334 * are @c NULL, @c NULL is returned. If @p buckets_power_size is
335 * smaller or equal than 2, or if it is greater or equal than 17,
336 * @c NULL is returned.
338 * The number of buckets created will be 2 ^ @p buckets_power_size. This means
339 * that if @p buckets_power_size is 5, there will be created 32 buckets. for a
340 * @p buckets_power_size of 8, there will be 256 buckets.
342 * Pre-defined functions are available to create a hash table. See
343 * eina_hash_string_djb2_new(), eina_hash_string_superfast_new(),
344 * eina_hash_string_small_new(), eina_hash_int32_new(),
345 * eina_hash_int64_new(), eina_hash_pointer_new() and
346 * eina_hash_stringshared_new().
348 EAPI Eina_Hash *eina_hash_new(Eina_Key_Length key_length_cb,
349 Eina_Key_Cmp key_cmp_cb,
350 Eina_Key_Hash key_hash_cb,
351 Eina_Free_Cb data_free_cb,
352 int buckets_power_size) EINA_MALLOC EINA_WARN_UNUSED_RESULT EINA_ARG_NONNULL(2, 3);
355 * @brief Redefine the callback that clean the data of a hash
357 * @param hash The given hash table
358 * @param data_free_cb The function called on each value when the hash
359 * table is freed, or when an item is deleted from it. @c NULL can be passed as
362 * See @ref eina_hash_new.
364 EAPI void eina_hash_free_cb_set(Eina_Hash *hash, Eina_Free_Cb data_free_cb) EINA_ARG_NONNULL(1);
367 * @brief Create a new hash table using the djb2 algorithm.
369 * @param data_free_cb The function called on each value when the hash table
370 * is freed, or when an item is deleted from it. @c NULL can be passed as
372 * @return The new hash table.
374 * This function creates a new hash table using the djb2 algorithm for
375 * table management and strcmp() to compare the keys. Values can then
376 * be looked up with pointers other than the original key pointer that
377 * was used to add values. On failure, this function returns @c NULL.
379 EAPI Eina_Hash *eina_hash_string_djb2_new(Eina_Free_Cb data_free_cb);
382 * @brief Create a new hash table for use with strings.
384 * @param data_free_cb The function called on each value when the hash table
385 * is freed, or when an item is deleted from it. @c NULL can be passed as
387 * @return The new hash table.
389 * This function creates a new hash table using the superfast algorithm
390 * for table management and strcmp() to compare the keys. Values can
391 * then be looked up with pointers other than the original key pointer
392 * that was used to add values. On failure, this function returns
395 EAPI Eina_Hash *eina_hash_string_superfast_new(Eina_Free_Cb data_free_cb);
398 * @brief Create a new hash table for use with strings with small bucket size.
400 * @param data_free_cb The function called on each value when the hash table
401 * is freed, or when an item is deleted from it. @c NULL can be passed as
403 * @return The new hash table.
405 * This function creates a new hash table using the superfast algorithm
406 * for table management and strcmp() to compare the keys, but with a
407 * smaller bucket size (compared to eina_hash_string_superfast_new())
408 * which will minimize the memory used by the returned hash
409 * table. Values can then be looked up with pointers other than the
410 * original key pointer that was used to add values. On failure, this
411 * function returns @c NULL.
413 EAPI Eina_Hash *eina_hash_string_small_new(Eina_Free_Cb data_free_cb);
416 * @brief Create a new hash table for use with 32bit integers.
418 * @param data_free_cb The function called on each value when the hash table
419 * is freed, or when an item is deleted from it. @c NULL can be passed as
421 * @return The new hash table.
423 * This function creates a new hash table where keys are 32bit integers.
424 * When adding or looking up in the hash table, pointers to 32bit integers
425 * must be passed. They can be addresses on the stack if you let the
426 * eina_hash copy the key. Values can then
427 * be looked up with pointers other than the original key pointer that was
428 * used to add values. This method is not suitable to match string keys as
429 * it would only match the first character.
430 * On failure, this function returns @c NULL.
432 EAPI Eina_Hash *eina_hash_int32_new(Eina_Free_Cb data_free_cb);
435 * @brief Create a new hash table for use with 64bit integers.
437 * @param data_free_cb The function called on each value when the hash table
438 * is freed, or when an item is deleted from it. @c NULL can be passed as
440 * @return The new hash table.
442 * This function creates a new hash table where keys are 64bit integers.
443 * When adding or looking up in the hash table, pointers to 64bit integers
444 * must be passed. They can be addresses on the stack. Values can then
445 * be looked up with pointers other than the original key pointer that was
446 * used to add values. This method is not suitable to match string keys as
447 * it would only match the first character.
448 * On failure, this function returns @c NULL.
450 EAPI Eina_Hash *eina_hash_int64_new(Eina_Free_Cb data_free_cb);
453 * @brief Create a new hash table for use with pointers.
455 * @param data_free_cb The function called on each value when the hash table
456 * is freed, or when an item is deleted from it. @c NULL can be passed as
458 * @return The new hash table.
460 * This function creates a new hash table using the int64/int32 algorithm for
461 * table management and dereferenced pointers to compare the
462 * keys. Values can then be looked up with pointers other than the
463 * original key pointer that was used to add values. This method may
464 * appear to be able to match string keys, actually it only matches
465 * the first character. On failure, this function returns @c NULL.
467 EAPI Eina_Hash *eina_hash_pointer_new(Eina_Free_Cb data_free_cb);
470 * @brief Create a new hash table optimized for stringshared values.
472 * @param data_free_cb The function called on each value when the hash table
473 * is freed, or when an item is deleted from it. @c NULL can be passed as
475 * @return The new hash table.
477 * This function creates a new hash table optimized for stringshared
478 * values. Values CAN NOT be looked up with pointers not
479 * equal to the original key pointer that was used to add a value. On failure,
480 * this function returns @c NULL.
482 * Excerpt of code that will NOT work with this type of hash:
485 * extern Eina_Hash *hash;
486 * extern const char *value;
487 * const char *a = eina_stringshare_add("key");
489 * eina_hash_add(hash, a, value);
490 * eina_hash_find(hash, "key")
493 EAPI Eina_Hash *eina_hash_stringshared_new(Eina_Free_Cb data_free_cb);
496 * @brief Add an entry to the given hash table.
498 * @param hash The given hash table. Cannot be @c NULL.
499 * @param key A unique key. Cannot be @c NULL.
500 * @param data Data to associate with the string given by @p key. Cannot be @c
502 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
504 * This function adds @p key to @p hash. @p key is
505 * expected to be unique within the hash table. Key uniqueness varies
506 * depending on the type of @p hash: a stringshared @ref Eina_Hash
507 * need to have unique pointers (which implies unique strings).
508 * All other string hash types require the strings
509 * themselves to be unique. Pointer, int32 and int64 hashes need to have these
510 * values as unique. Failure to use sufficient uniqueness will
511 * result in unexpected results when inserting data pointers accessed
512 * with eina_hash_find(), and removed with eina_hash_del(). Key
513 * strings are case sensitive. If an error occurs, eina_error_get()
514 * should be used to determine if an allocation error occurred during
515 * this function. This function returns #EINA_FALSE if an error
516 * occurred, #EINA_TRUE otherwise.
518 EAPI Eina_Bool eina_hash_add(Eina_Hash *hash,
520 const void *data) EINA_ARG_NONNULL(1, 2, 3);
523 * @brief Add an entry to the given hash table without duplicating the string
526 * @param hash The given hash table. Cannot be @c NULL.
527 * @param key A unique key. Cannot be @c NULL.
528 * @param data Data to associate with the string given by @p key. Cannot be @c
530 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
532 * This function adds @p key to @p hash. @p key is
533 * expected to be unique within the hash table. Key uniqueness varies
534 * depending on the type of @p hash: a stringshared @ref Eina_Hash
535 * need have unique pointers (which implies unique strings).
536 * All other string hash types require the strings
537 * themselves to be unique. Pointer, int32 and int64 hashes need to have these
538 * values as unique. Failure to use sufficient uniqueness will
539 * result in unexpected results when inserting data pointers accessed
540 * with eina_hash_find(), and removed with eina_hash_del(). This
541 * function does not make a copy of @p key, so it must be a string
542 * constant or stored elsewhere ( in the object being added). Key
543 * strings are case sensitive. If an error occurs, eina_error_get()
544 * should be used to determine if an allocation error occurred during
545 * this function. This function returns #EINA_FALSE if an error
546 * occurred, #EINA_TRUE otherwise.
548 EAPI Eina_Bool eina_hash_direct_add(Eina_Hash *hash,
550 const void *data) EINA_ARG_NONNULL(1, 2, 3);
553 * @brief Remove the entry identified by a key or a data from the given
556 * @param hash The given hash table.
557 * @param key The key.
558 * @param data The data pointer to remove if the key is @c NULL.
559 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
561 * This function removes the entry identified by @p key or @p data
562 * from @p hash. If a free function was given to the
563 * callback on creation, it will be called for the data being
564 * deleted. If @p hash is @c NULL, the functions returns immediately #EINA_FALSE.
565 * If @p key is @c NULL, then @p data is used to find the a
566 * match to remove, otherwise @p key is used and @p data is not
567 * required and can be @c NULL. This function returns #EINA_FALSE if
568 * an error occurred, #EINA_TRUE otherwise.
570 * @note if you know you already have the key, use
571 * eina_hash_del_by_key() or eina_hash_del_by_key_hash(). If you
572 * know you don't have the key, use eina_hash_del_by_data()
575 EAPI Eina_Bool eina_hash_del(Eina_Hash *hash,
577 const void *data) EINA_ARG_NONNULL(1);
580 * @brief Retrieve a specific entry in the given hash table.
582 * @param hash The given hash table.
583 * @param key The key of the entry to find.
584 * @return The data pointer for the stored entry on success, @c NULL
587 * This function retrieves the entry associated to @p key in
588 * @p hash. If @p hash is @c NULL, this function returns immediately
589 * @c NULL. This function returns the data pointer on success, @c NULL
592 EAPI void *eina_hash_find(const Eina_Hash *hash,
593 const void *key) EINA_ARG_NONNULL(2);
596 * @brief Modify the entry pointer at the specified key and return the old
598 * @param hash The given hash table.
599 * @param key The key of the entry to modify.
600 * @param data The data to replace the old entry.
601 * @return The data pointer for the old stored entry on success, or
604 * This function modifies the data of @p key with @p data in @p
605 * hash. If no entry is found, nothing is added to @p hash. On success
606 * this function returns the old entry, otherwise it returns @c NULL.
608 EAPI void *eina_hash_modify(Eina_Hash *hash,
610 const void *data) EINA_ARG_NONNULL(1, 2, 3);
613 * @brief Modify the entry pointer at the specified key and return the
614 * old entry or add the entry if not found.
616 * @param hash The given hash table.
617 * @param key The key of the entry to modify.
618 * @param data The data to replace the old entry
619 * @return The data pointer for the old stored entry, or @c NULL
622 * This function modifies the data of @p key with @p data in @p
623 * hash. If no entry is found, @p data is added to @p hash with the
624 * key @p key. On success this function returns the old entry,
625 * otherwise it returns @c NULL. To check for errors, use
628 EAPI void *eina_hash_set(Eina_Hash *hash,
630 const void *data) EINA_ARG_NONNULL(1, 2);
633 * @brief Change the key associated with a data without triggering the
636 * @param hash The given hash table.
637 * @param old_key The current key associated with the data
638 * @param new_key The new key to associate data with
639 * @return #EINA_FALSE in any case but success, #EINA_TRUE on success.
641 * This function allows for the move of data from one key to another,
642 * but does not call the Eina_Free_Cb associated with the hash table
643 * when destroying the old key.
645 EAPI Eina_Bool eina_hash_move(Eina_Hash *hash,
647 const void *new_key) EINA_ARG_NONNULL(1, 2, 3);
650 * Free the given hash table resources.
652 * @param hash The hash table to be freed.
654 * This function frees up all the memory allocated to storing @p hash,
655 * and call the free callback if it has been passed to the hash table
656 * at creation time. If no free callback has been passed, any entries
657 * in the table that the program has no more pointers for elsewhere
658 * may now be lost, so this should only be called if the program has
659 * already freed any allocated data in the hash table or has the
660 * pointers for data in the table stored elsewhere as well. If @p hash
661 * is @c NULL, the function returns immediately.
665 * extern Eina_Hash *hash;
667 * eina_hash_free(hash);
671 EAPI void eina_hash_free(Eina_Hash *hash) EINA_ARG_NONNULL(1);
674 * Free the given hash table buckets resources.
676 * @param hash The hash table whose buckets have to be freed.
678 * This function frees up all the memory allocated to storing the
679 * buckets of @p hash, and calls the free callback on all hash table
680 * buckets if it has been passed to the hash table at creation time,
681 * then frees the buckets. If no free callback has been passed, no
682 * buckets value will be freed. If @p hash is @c NULL, the function
683 * returns immediately.
685 EAPI void eina_hash_free_buckets(Eina_Hash *hash) EINA_ARG_NONNULL(1);
688 * @brief Returns the number of entries in the given hash table.
690 * @param hash The given hash table.
691 * @return The number of entries in the hash table.
693 * This function returns the number of entries in @p hash, or 0 on
694 * error. If @p hash is @c NULL, @c 0 is returned.
696 EAPI int eina_hash_population(const Eina_Hash *hash) EINA_ARG_NONNULL(1);
699 * @brief Add an entry to the given hash table.
701 * @param hash The given hash table. Cannot be @c NULL.
702 * @param key A unique key. Cannot be @c NULL.
703 * @param key_length The length of the key.
704 * @param key_hash The hash that will always match key.
705 * @param data The data to associate with the string given by the key. Cannot be
707 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
709 * This function adds @p key to @p hash. @p hash, @p key and @p data
710 * cannot be @c NULL, in that case #EINA_FALSE is returned. @p key is
711 * expected to be a unique within the hash table. Otherwise,
712 * one cannot be sure which inserted data pointer will be accessed
713 * with @ref eina_hash_find, and removed with @ref eina_hash_del. Do
714 * not forget to count '\\0' for string when setting the value of
715 * @p key_length. @p key_hash is expected to always match
716 * @p key. Otherwise, one cannot be sure to find it again with @ref
717 * eina_hash_find_by_hash. Key strings are case sensitive. If an error
718 * occurs, eina_error_get() should be used to determine if an
719 * allocation error occurred during this function. This function
720 * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
722 * @see eina_hash_add()
724 EAPI Eina_Bool eina_hash_add_by_hash(Eina_Hash *hash,
728 const void *data) EINA_ARG_NONNULL(1, 2, 5);
731 * @brief Add an entry to the given hash table and do not duplicate the string
734 * @param hash The given hash table. Cannot be @c NULL.
735 * @param key A unique key. Cannot be @c NULL.
736 * @param key_length Should be the length of @p key (don't forget to count
738 * @param key_hash The hash that will always match key.
739 * @param data Data to associate with the string given by @p key. Cannot be @c
741 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
743 * This function adds @p key to @p hash. @p hash, @p key and @p data
744 * can be @c NULL, in that case #EINA_FALSE is returned. @p key is
745 * expected to be unique within the hash table. Otherwise,
746 * one cannot be sure which inserted data pointer will be accessed
747 * with @ref eina_hash_find, and removed with @ref eina_hash_del. This
748 * function does not make a copy of @p key so it must be a string
749 * constant or stored elsewhere (in the object being added). Do
750 * not forget to count '\\0' for string when setting the value of
751 * @p key_length. @p key_hash is expected to always match
752 * @p key. Otherwise, one cannot be sure to find it again with @ref
753 * eina_hash_find_by_hash. Key strings are case sensitive. If an error
754 * occurs, eina_error_get() should be used to determine if an
755 * allocation error occurred during this function. This function
756 * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
758 * @see eina_hash_direct_add()
760 EAPI Eina_Bool eina_hash_direct_add_by_hash(Eina_Hash *hash,
764 const void *data) EINA_ARG_NONNULL(1, 2, 5);
767 * @brief Remove the entry identified by a key and a key hash from the given
770 * @param hash The given hash table. Cannot be @c NULL.
771 * @param key The key. Cannot be @c NULL.
772 * @param key_length The length of the key.
773 * @param key_hash The hash that always match the key.
774 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
776 * This function removes the entry identified by @p key and
777 * @p key_hash from @p hash. If a free function was given to the
778 * callback on creation, it will be called for the data being
779 * deleted. Do not forget to count '\\0' for string when setting the
780 * value of @p key_length. If @p hash or @p key are @c NULL, the
781 * functions returns immediately #EINA_FALSE. This function
782 * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
784 * @note if you don't have the key_hash, use eina_hash_del_by_key() instead.
785 * @note if you don't have the key, use eina_hash_del_by_data() instead.
787 EAPI Eina_Bool eina_hash_del_by_key_hash(Eina_Hash *hash,
790 int key_hash) EINA_ARG_NONNULL(1, 2);
793 * @brief Remove the entry identified by a key from the given hash table.
795 * This version will calculate key length and hash by using functions
796 * provided to hash creation function.
798 * @param hash The given hash table. Cannot be @c NULL.
799 * @param key The key. Cannot be @c NULL.
800 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
802 * This function removes the entry identified by @p key from @p
803 * hash. The key length and hash will be calculated automatically by
804 * using functiond provided to has creation function. If a free
805 * function was given to the callback on creation, it will be called
806 * for the data being deleted. If @p hash or @p key are @c NULL, the
807 * functions returns immediately #EINA_FALSE. This function
808 * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
810 * @note if you already have the key_hash, use eina_hash_del_by_key_hash()
812 * @note if you don't have the key, use eina_hash_del_by_data() instead.
814 EAPI Eina_Bool eina_hash_del_by_key(Eina_Hash *hash,
815 const void *key) EINA_ARG_NONNULL(1, 2);
818 * @brief Remove the entry identified by a data from the given hash table.
820 * This version is slow since there is no quick access to nodes based on data.
822 * @param hash The given hash table. Cannot be @c NULL.
823 * @param data The data value to search and remove. Cannot be @c NULL.
824 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
827 * This function removes the entry identified by @p data from @p
828 * hash. If a free function was given to the callback on creation, it
829 * will be called for the data being deleted. If @p hash or @p data
830 * are @c NULL, the functions returns immediately #EINA_FALSE. This
831 * function returns #EINA_FALSE if an error occurred, #EINA_TRUE
834 * @note if you already have the key, use eina_hash_del_by_key() or
835 * eina_hash_del_by_key_hash() instead.
837 EAPI Eina_Bool eina_hash_del_by_data(Eina_Hash *hash,
838 const void *data) EINA_ARG_NONNULL(1, 2);
841 * @brief Remove the entry identified by a key and a key hash or a
842 * data from the given hash table.
844 * If @p key is @c NULL, then @p data is used to find a match to
847 * @param hash The given hash table. Cannot be @c NULL.
848 * @param key The key.
849 * @param key_length The length of the key.
850 * @param key_hash The hash that always match the key.
851 * @param data The data pointer to remove if the key is @c NULL.
852 * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
854 * This function removes the entry identified by @p key and
855 * @p key_hash, or @p data, from @p hash. If a free function was given to
856 * the callback on creation, it will be called for the data being
857 * deleted. If @p hash is @c NULL, the functions returns immediately #EINA_FALSE.
858 * If @p key is @c NULL, then @p key_length and @p key_hash
859 * are ignored and @p data is used to find a match to remove,
860 * otherwise @p key and @p key_hash are used and @p data is not
861 * required and can be @c NULL. Do not forget to count '\\0' for
862 * string when setting the value of @p key_length. This function
863 * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise.
865 * @note if you know you already have the key, use eina_hash_del_by_key_hash(),
866 * if you know you don't have the key, use eina_hash_del_by_data()
869 EAPI Eina_Bool eina_hash_del_by_hash(Eina_Hash *hash,
873 const void *data) EINA_ARG_NONNULL(1);
876 * @brief Retrieve a specific entry in the given hash table.
878 * @param hash The given hash table. Cannot be @c NULL.
879 * @param key The key of the entry to find.
880 * @param key_length The length of the key.
881 * @param key_hash The hash that always match the key
882 * @return The data pointer for the stored entry on success, @c NULL
885 * This function retrieves the entry associated to @p key of length
886 * @p key_length in @p hash. @p key_hash is the hash that always match
887 * @p key. It is ignored if @p key is @c NULL. Do not forget to count
888 * '\\0' for string when setting the value of @p key_length. If
889 * @p hash is @c NULL, this function returns immediately @c NULL. This
890 * function returns the data pointer on success, @c NULL otherwise.
892 EAPI void *eina_hash_find_by_hash(const Eina_Hash *hash,
895 int key_hash) EINA_ARG_NONNULL(1, 2);
898 * @brief Modify the entry pointer at the specified key and returns
901 * @param hash The given hash table.
902 * @param key The key of the entry to modify.
903 * @param key_length Should be the length of @p key (don't forget to count
905 * @param key_hash The hash that always match the key. Ignored if @p key is
907 * @param data The data to replace the old entry, if it exists.
908 * @return The data pointer for the old stored entry, or @c NULL if not
909 * found. If an existing entry is not found, nothing is added to the
912 EAPI void *eina_hash_modify_by_hash(Eina_Hash *hash,
916 const void *data) EINA_ARG_NONNULL(1, 2, 5);
919 * @brief Returned a new iterator associated to hash keys.
921 * @param hash The hash.
922 * @return A new iterator.
924 * This function returns a newly allocated iterator associated to @p
925 * hash. If @p hash is not populated, this function still returns a
926 * valid iterator that will always return false on
927 * eina_iterator_next(), thus keeping API sane.
929 * If the memory can not be allocated, NULL is returned
930 * and #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is
933 * @warning if the hash structure changes then the iterator becomes
934 * invalid! That is, if you add or remove items this iterator
935 * behavior is undefined and your program may crash!
937 EAPI Eina_Iterator *eina_hash_iterator_key_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
940 * @brief Returned a new iterator associated to hash data.
942 * @param hash The hash.
943 * @return A new iterator.
945 * This function returns a newly allocated iterator associated to
946 * @p hash. If @p hash is not populated, this function still returns a
947 * valid iterator that will always return false on
948 * eina_iterator_next(), thus keeping API sane.
950 * If the memory can not be allocated, @c NULL is returned
951 * and #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is
954 * @warning if the hash structure changes then the iterator becomes
955 * invalid. That is, if you add or remove items this iterator behavior
956 * is undefined and your program may crash.
958 EAPI Eina_Iterator *eina_hash_iterator_data_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
961 * @brief Returned a new iterator associated to hash keys and data.
963 * @param hash The hash.
964 * @return A new iterator.
966 * This function returns a newly allocated iterator associated to @p
967 * hash. If @p hash is not populated, this function still returns a
968 * valid iterator that will always return false on
969 * eina_iterator_next(), thus keeping API sane.
971 * If the memory can not be allocated, @c NULL is returned
972 * and #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is
975 * @note iterator data will provide values as Eina_Hash_Tuple that should not
978 * @warning if the hash structure changes then the iterator becomes
979 * invalid! That is, if you add or remove items this iterator
980 * behavior is undefined and your program may crash!
982 EAPI Eina_Iterator *eina_hash_iterator_tuple_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
985 * @brief Call a function on every member stored in the hash table
987 * @param hash The hash table whose members will be walked
988 * @param func The function to call on each parameter
989 * @param fdata The data pointer to pass to the function being called
991 * This function goes through every entry in the hash table @p hash and calls
992 * the function @p func on each member. The function should @b not modify the
993 * hash table contents if it returns @c 1. @b If the hash table contents are
994 * modified by this function or the function wishes to stop processing it must
995 * return @c 0, otherwise return @c 1 to keep processing.
999 * extern Eina_Hash *hash;
1001 * Eina_Bool hash_fn(const Eina_Hash *hash, const void *key,
1002 * void *data, void *fdata)
1004 * printf("Func data: %s, Hash entry: %s / %p\n",
1005 * fdata, (const char *)key, data);
1009 * int main(int argc, char **argv)
1011 * char *hash_fn_data;
1013 * hash_fn_data = strdup("Hello World");
1014 * eina_hash_foreach(hash, hash_fn, hash_fn_data);
1015 * free(hash_fn_data);
1019 EAPI void eina_hash_foreach(const Eina_Hash *hash,
1020 Eina_Hash_Foreach func,
1021 const void *fdata) EINA_ARG_NONNULL(1, 2);
1022 /* Paul Hsieh (http://www.azillionmonkeys.com/qed/hash.html) hash function used by WebCore (http://webkit.org/blog/8/hashtables-part-2/) */
1023 EAPI int eina_hash_superfast(const char *key,
1024 int len) EINA_ARG_NONNULL(1);
1025 /* Hash function first reported by dan bernstein many years ago in comp.lang.c */
1026 static inline int eina_hash_djb2(const char *key,
1027 int len) EINA_ARG_NONNULL(1);
1028 static inline int eina_hash_djb2_len(const char *key,
1029 int *plen) EINA_ARG_NONNULL(1, 2);
1030 /* Hash function from http://www.concentric.net/~Ttwang/tech/inthash.htm */
1031 static inline int eina_hash_int32(const unsigned int *pkey,
1032 int len) EINA_ARG_NONNULL(1);
1033 static inline int eina_hash_int64(const unsigned long int *pkey,
1034 int len) EINA_ARG_NONNULL(1);
1035 /* http://sites.google.com/site/murmurhash/ */
1036 static inline int eina_hash_murmur3(const char *key,
1037 int len) EINA_ARG_NONNULL(1);
1038 #include "eina_inline_hash.x"
1052 #endif /*EINA_HASH_H_*/