/* EINA - EFL data type library * Copyright (C) 2002-2008 Carsten Haitzler, Gustavo Sverzut Barbieri, * Vincent Torri, Jorge Luis Zapata Muga, Cedric Bail * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; * if not, see . */ #ifndef EINA_HASH_H_ #define EINA_HASH_H_ #include "eina_types.h" #include "eina_iterator.h" /** * @page hash_01_example_page Eina_Hash in action * @dontinclude eina_hash_01.c * * We are going to store some tuples into our table, that will map each @a name * to a @a number. The cost to access a given number from the name should be * very small, even with many entries in our table. This is the initial data: * @skip _Phone_Entry * @until // _start_entries * * Before starting to play with the hash, let's write a callback that will be * used to free the elements from it. Since we are just storing strduped * strings, we just need to free them: * * @skip static * @until } * * We also need a callback to iterate over the elements of the list later, so * we are defining it now: * * @skip Eina_Bool * @until } * * Now let's create our @ref Eina_Hash using @ref * eina_hash_string_superfast_new : * * @skip eina_init * @until phone_book * * Now we add the keys and data to the hash using @ref eina_hash_add . This * means that the key is copied inside the table, together with the pointer to * the data (phone numbers). * * @skip for * @until } * * Some basic manipulations with the hash, like finding a value given a key, * deleting an entry, modifying an entry are exemplified in the following lines. * Notice that the @ref eina_hash_modify function returns the old value stored * in that entry, and it needs to be freed, while the @ref eina_hash_del * function already calls our free callback: * * @skip Look for * @until free( * * The @ref eina_hash_set function can be used to set a key-value entry to the * table if it doesn't exist, or to modify an existent entry. It returns the old * entry if it was already set, and NULL otherwise. But since it will * return NULL on error too, we need to check if an error has occurred: * * @skip Modify * @until printf("\n"); * * There are different ways of iterate over the entries of a hash. Here we show * two of them: using @ref eina_hash_foreach and @ref Eina_Iterator . * * @skip List of phones * @until eina_iterator_free(it); * * It's also possible to change the key for a specific entry, without having to * remove the entry from the table and adding it again: * * @skipline eina_hash_move * * We can remove all the elements from the table without free the table itself: * * @skip Empty the phone book * @until eina_hash_population * * Or free the the entire table with its content: * * @skipline eina_hash_free * * * The full code for this example can be seen here: @ref eina_hash_01_c */ /** * @page eina_hash_01_c Hash table in action * * @include eina_hash_01.c * @example eina_hash_01.c */ /** * @page hash_02_example_page Different types of tables * * This example shows two more types of hash tables that can be created using * @ref Eina_Hash . For more types, consult the reference documentation of @ref * eina_hash_new. * @include eina_hash_02.c * @example eina_hash_02.c */ /** * @example eina_hash_03.c * Same example as @ref hash_01_example_page but using a "string small" hash * table instead of "string superfast". */ /** * @example eina_hash_04.c * Same example as @ref hash_01_example_page but using a "string djb2" hash * table instead of "string superfast". */ /** * @example eina_hash_05.c * Same example as @ref hash_01_example_page but using a "int32" hash * table instead of "string superfast". */ /** * @example eina_hash_06.c * Same example as @ref hash_01_example_page but using a "int64" hash * table instead of "string superfast". */ /** * @example eina_hash_07.c * Same example as @ref hash_01_example_page but using a "pointer" hash * table instead of "string superfast". */ /** * @example eina_hash_08.c * This example shows the the usage of eina_hash_add(), eina_hash_add_by_hash(), * eina_hash_direct_add_by_hash(), eina_hash_del(), eina_hash_del_by_key_hash(), * eina_hash_del_by_key(), eina_hash_del_by_data(), eina_hash_find_by_hash() and * eina_hash_modify_by_hash(). */ /** * @addtogroup Eina_Hash_Group Hash Table * * @brief Hash table management. Useful for mapping keys to values. * * The hash table is useful for when one wants to implement a table that maps * keys (usually strings) to data, and have relatively fast access time. The * performance is proportional to the load factor of the table (number of * elements / number of buckets). See @ref hashtable_algo for implementation * details. * * Different implementations exists depending on what kind of key will be used * to access the data: strings, integers, pointers, stringshared or your own. * * Eina hash tables can copy the keys when using eina_hash_add() or not when * using eina_hash_direct_add(). * * @section hashtable_algo Algorithm * * The Eina_Hash is implemented using an array of N "buckets", where each * bucket is a pointer to a structure that is the head of a red-black tree. The * array can then be indexed by the [hash_of_element mod N]. The * hash_of_element is calculated using the hashing function, passed as * parameter to the @ref eina_hash_new function. N is the number of buckets * (array positions), and is calculated based on the buckets_power_size * (argument of @ref eina_hash_new too). The following picture ilustrates the * basic idea: * * @htmlonly * * @endhtmlonly * @image latex 01_hash-table.eps * * Adding an element to the hash table is made of: * @li calculating the hash for that key (using the specified hash function); * @li calculate the array position [hash mod N]; * @li add the element to the rbtree on that position. * * The two first steps have constant time, proportional to the hash function * being used. Adding the key to the rbtree will be proportional on the number * of keys on that bucket. * * The average cost of lookup depends on the number of keys per * bucket (load factor) of the table, if the distribution of keys is * sufficiently uniform. * * @section hashtable_perf Performance * * As said before, the performance depends on the load factor. So trying to keep * the load factor as small as possible will improve the hash table performance. But * increasing the buckets_power_size will also increase the memory consumption. * The default hash table creation functions already have a good number of * buckets, enough for most cases. Particularly for strings, if just a few keys * (less than 30) will be added to the hash table, @ref * eina_hash_string_small_new should be used, since it will reduce the memory * consumption for the buckets, and you still won't have many collisions. * However, @ref eina_hash_string_small_new still uses the same hash calculation * function that @ref eina_hash_string_superfast_new, which is more complex than * @ref eina_hash_string_djb2_new. The latter has a faster hash computation * function, but that will imply on a not so good distribution. But if just a * few keys are being added, this is not a problem, it will still have not many * collisions and be faster to calculate the hash than in a hash created with * @ref eina_hash_string_small_new and @ref eina_hash_string_superfast_new. * * A simple comparison between them would be: * * @li @c djb2 - faster hash function - 256 buckets (higher memory consumption) * @li @c string_small - slower hash function but less collisions - 32 buckets * (lower memory consumption) * @li @c string_superfast - slower hash function but less collisions - 256 buckets * (higher memory consumption) * * Basically for a very small number of keys (10 or less), @c djb2 should be * used, or @c string_small if you have a restriction on memory usage. And for a * higher number of keys, @c string_superfast should be always preferred. * * If just stringshared keys are being added, use @ref * eina_hash_stringshared_new. If a lot of keys will be added to the hash table * (e.g. more than 1000), then it's better to increase the buckets_power_size. * See @ref eina_hash_new for more details. * * When adding a new key to a hash table, use @ref eina_hash_add or @ref * eina_hash_direct_add (the latter if this key is already stored elsewhere). If * the key may be already inside the hash table, instead of checking with * @ref eina_hash_find and then doing @ref eina_hash_add, one can use just @ref * eina_hash_set (this will change the data pointed by this key if it was * already present in the table). * * @section hashtable_tutorial Tutorial * * These examples show many Eina_Hash functions in action: * */ /** * @addtogroup Eina_Data_Types_Group Data Types * * @{ */ /** * @addtogroup Eina_Containers_Group Containers * * @{ */ /** * @defgroup Eina_Hash_Group Hash Table * * @{ */ /** * @typedef Eina_Hash * Type for a generic hash table. */ typedef struct _Eina_Hash Eina_Hash; typedef struct _Eina_Hash_Tuple Eina_Hash_Tuple; struct _Eina_Hash_Tuple { const void *key; /**< The key */ void *data; /**< The data associated to the key */ unsigned int key_length; /**< The length of the key */ }; typedef unsigned int (*Eina_Key_Length)(const void *key); #define EINA_KEY_LENGTH(Function) ((Eina_Key_Length)Function) typedef int (*Eina_Key_Cmp)(const void *key1, int key1_length, const void *key2, int key2_length); #define EINA_KEY_CMP(Function) ((Eina_Key_Cmp)Function) typedef int (*Eina_Key_Hash)(const void *key, int key_length); #define EINA_KEY_HASH(Function) ((Eina_Key_Hash)Function) typedef Eina_Bool (*Eina_Hash_Foreach)(const Eina_Hash *hash, const void *key, void *data, void *fdata); /** * @brief Create a new hash table. * * @param key_length_cb The function called when getting the size of the key. * @param key_cmp_cb The function called when comparing the keys. * @param key_hash_cb The function called when getting the values. * @param data_free_cb The function called on each value when the hash table is * freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @param buckets_power_size The size of the buckets. * @return The new hash table. * * This function creates a new hash table using user-defined callbacks * to manage the hash table. On failure, @c NULL is returned and * #EINA_ERROR_OUT_OF_MEMORY is set. If @p key_cmp_cb or @p key_hash_cb * are @c NULL, @c NULL is returned. If @p buckets_power_size is * smaller or equal than 2, or if it is greater or equal than 17, * @c NULL is returned. * * The number of buckets created will be 2 ^ @p buckets_power_size. This means * that if @p buckets_power_size is 5, there will be created 32 buckets. for a * @p buckets_power_size of 8, there will be 256 buckets. * * Pre-defined functions are available to create a hash table. See * eina_hash_string_djb2_new(), eina_hash_string_superfast_new(), * eina_hash_string_small_new(), eina_hash_int32_new(), * eina_hash_int64_new(), eina_hash_pointer_new() and * eina_hash_stringshared_new(). */ EAPI Eina_Hash *eina_hash_new(Eina_Key_Length key_length_cb, Eina_Key_Cmp key_cmp_cb, Eina_Key_Hash key_hash_cb, Eina_Free_Cb data_free_cb, int buckets_power_size) EINA_MALLOC EINA_WARN_UNUSED_RESULT EINA_ARG_NONNULL(2, 3); /** * @brief Redefine the callback that clean the data of a hash * * @param hash The given hash table * @param data_free_cb The function called on each value when the hash * table is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @since 1.1 * See @ref eina_hash_new. */ EAPI void eina_hash_free_cb_set(Eina_Hash *hash, Eina_Free_Cb data_free_cb) EINA_ARG_NONNULL(1); /** * @brief Create a new hash table using the djb2 algorithm. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table using the djb2 algorithm for * table management and strcmp() to compare the keys. Values can then * be looked up with pointers other than the original key pointer that * was used to add values. On failure, this function returns @c NULL. */ EAPI Eina_Hash *eina_hash_string_djb2_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table for use with strings. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table using the superfast algorithm * for table management and strcmp() to compare the keys. Values can * then be looked up with pointers other than the original key pointer * that was used to add values. On failure, this function returns * @c NULL. */ EAPI Eina_Hash *eina_hash_string_superfast_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table for use with strings with small bucket size. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table using the superfast algorithm * for table management and strcmp() to compare the keys, but with a * smaller bucket size (compared to eina_hash_string_superfast_new()) * which will minimize the memory used by the returned hash * table. Values can then be looked up with pointers other than the * original key pointer that was used to add values. On failure, this * function returns @c NULL. */ EAPI Eina_Hash *eina_hash_string_small_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table for use with 32bit integers. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table where keys are 32bit integers. * When adding or looking up in the hash table, pointers to 32bit integers * must be passed. They can be addresses on the stack if you let the * eina_hash copy the key. Values can then * be looked up with pointers other than the original key pointer that was * used to add values. This method is not suitable to match string keys as * it would only match the first character. * On failure, this function returns @c NULL. */ EAPI Eina_Hash *eina_hash_int32_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table for use with 64bit integers. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table where keys are 64bit integers. * When adding or looking up in the hash table, pointers to 64bit integers * must be passed. They can be addresses on the stack. Values can then * be looked up with pointers other than the original key pointer that was * used to add values. This method is not suitable to match string keys as * it would only match the first character. * On failure, this function returns @c NULL. */ EAPI Eina_Hash *eina_hash_int64_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table for use with pointers. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table using the int64/int32 algorithm for * table management and dereferenced pointers to compare the * keys. Values can then be looked up with pointers other than the * original key pointer that was used to add values. This method may * appear to be able to match string keys, actually it only matches * the first character. On failure, this function returns @c NULL. */ EAPI Eina_Hash *eina_hash_pointer_new(Eina_Free_Cb data_free_cb); /** * @brief Create a new hash table optimized for stringshared values. * * @param data_free_cb The function called on each value when the hash table * is freed, or when an item is deleted from it. @c NULL can be passed as * callback. * @return The new hash table. * * This function creates a new hash table optimized for stringshared * values. Values CAN NOT be looked up with pointers not * equal to the original key pointer that was used to add a value. On failure, * this function returns @c NULL. * * Excerpt of code that will NOT work with this type of hash: * * @code * extern Eina_Hash *hash; * extern const char *value; * const char *a = eina_stringshare_add("key"); * * eina_hash_add(hash, a, value); * eina_hash_find(hash, "key") * @endcode */ EAPI Eina_Hash *eina_hash_stringshared_new(Eina_Free_Cb data_free_cb); /** * @brief Add an entry to the given hash table. * * @param hash The given hash table. Cannot be @c NULL. * @param key A unique key. Cannot be @c NULL. * @param data Data to associate with the string given by @p key. Cannot be @c * NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function adds @p key to @p hash. @p key is * expected to be unique within the hash table. Key uniqueness varies * depending on the type of @p hash: a stringshared @ref Eina_Hash * need to have unique pointers (which implies unique strings). * All other string hash types require the strings * themselves to be unique. Pointer, int32 and int64 hashes need to have these * values as unique. Failure to use sufficient uniqueness will * result in unexpected results when inserting data pointers accessed * with eina_hash_find(), and removed with eina_hash_del(). Key * strings are case sensitive. If an error occurs, eina_error_get() * should be used to determine if an allocation error occurred during * this function. This function returns #EINA_FALSE if an error * occurred, #EINA_TRUE otherwise. */ EAPI Eina_Bool eina_hash_add(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3); /** * @brief Add an entry to the given hash table without duplicating the string * key. * * @param hash The given hash table. Cannot be @c NULL. * @param key A unique key. Cannot be @c NULL. * @param data Data to associate with the string given by @p key. Cannot be @c * NULL * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function adds @p key to @p hash. @p key is * expected to be unique within the hash table. Key uniqueness varies * depending on the type of @p hash: a stringshared @ref Eina_Hash * need have unique pointers (which implies unique strings). * All other string hash types require the strings * themselves to be unique. Pointer, int32 and int64 hashes need to have these * values as unique. Failure to use sufficient uniqueness will * result in unexpected results when inserting data pointers accessed * with eina_hash_find(), and removed with eina_hash_del(). This * function does not make a copy of @p key, so it must be a string * constant or stored elsewhere ( in the object being added). Key * strings are case sensitive. If an error occurs, eina_error_get() * should be used to determine if an allocation error occurred during * this function. This function returns #EINA_FALSE if an error * occurred, #EINA_TRUE otherwise. */ EAPI Eina_Bool eina_hash_direct_add(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3); /** * @brief Remove the entry identified by a key or a data from the given * hash table. * * @param hash The given hash table. * @param key The key. * @param data The data pointer to remove if the key is @c NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function removes the entry identified by @p key or @p data * from @p hash. If a free function was given to the * callback on creation, it will be called for the data being * deleted. If @p hash is @c NULL, the functions returns immediately * #EINA_FALSE. If @p key is @c NULL, then @p data is used to find the a * match to remove, otherwise @p key is used and @p data is not * required and can be @c NULL. This function returns #EINA_FALSE if * an error occurred, #EINA_TRUE otherwise. * * @note if you know you already have the key, use * eina_hash_del_by_key() or eina_hash_del_by_key_hash(). If you * know you don't have the key, use eina_hash_del_by_data() * directly. */ EAPI Eina_Bool eina_hash_del(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1); /** * @brief Retrieve a specific entry in the given hash table. * * @param hash The given hash table. * @param key The key of the entry to find. * @return The data pointer for the stored entry on success, @c NULL * otherwise. * * This function retrieves the entry associated to @p key in * @p hash. If @p hash is @c NULL, this function returns immediately * @c NULL. This function returns the data pointer on success, @c NULL * otherwise. */ EAPI void *eina_hash_find(const Eina_Hash *hash, const void *key) EINA_ARG_NONNULL(1, 2); /** * @brief Modify the entry pointer at the specified key and return the old * entry. * @param hash The given hash table. * @param key The key of the entry to modify. * @param data The data to replace the old entry. * @return The data pointer for the old stored entry on success, or * @c NULL otherwise. * * This function modifies the data of @p key with @p data in @p * hash. If no entry is found, nothing is added to @p hash. On success * this function returns the old entry, otherwise it returns @c NULL. */ EAPI void *eina_hash_modify(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3); /** * @brief Modify the entry pointer at the specified key and return the * old entry or add the entry if not found. * * @param hash The given hash table. * @param key The key of the entry to modify. * @param data The data to replace the old entry * @return The data pointer for the old stored entry, or @c NULL * otherwise. * * This function modifies the data of @p key with @p data in @p * hash. If no entry is found, @p data is added to @p hash with the * key @p key. On success this function returns the old entry, * otherwise it returns @c NULL. To check for errors, use * eina_error_get(). */ EAPI void *eina_hash_set(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2); /** * @brief Change the key associated with a data without triggering the * free callback. * * @param hash The given hash table. * @param old_key The current key associated with the data * @param new_key The new key to associate data with * @return EINA_FALSE in any case but success, EINA_TRUE on success. * * This function allows for the move of data from one key to another, * but does not call the Eina_Free_Cb associated with the hash table * when destroying the old key. */ EAPI Eina_Bool eina_hash_move(Eina_Hash *hash, const void *old_key, const void *new_key) EINA_ARG_NONNULL(1, 2, 3); /** * Free the given hash table resources. * * @param hash The hash table to be freed. * * This function frees up all the memory allocated to storing @p hash, * and call the free callback if it has been passed to the hash table * at creation time. If no free callback has been passed, any entries * in the table that the program has no more pointers for elsewhere * may now be lost, so this should only be called if the program has * already freed any allocated data in the hash table or has the * pointers for data in the table stored elsewhere as well. If @p hash * is @c NULL, the function returns immediately. * * Example: * @code * extern Eina_Hash *hash; * * eina_hash_free(hash); * hash = NULL; * @endcode */ EAPI void eina_hash_free(Eina_Hash *hash) EINA_ARG_NONNULL(1); /** * Free the given hash table buckets resources. * * @param hash The hash table whose buckets have to be freed. * * This function frees up all the memory allocated to storing the * buckets of @p hash, and calls the free callback on all hash table * buckets if it has been passed to the hash table at creation time, * then frees the buckets. If no free callback has been passed, no * buckets value will be freed. If @p hash is @c NULL, the function * returns immediately. */ EAPI void eina_hash_free_buckets(Eina_Hash *hash) EINA_ARG_NONNULL(1); /** * @brief Returns the number of entries in the given hash table. * * @param hash The given hash table. * @return The number of entries in the hash table. * * This function returns the number of entries in @p hash, or 0 on * error. If @p hash is @c NULL, 0 is returned. */ EAPI int eina_hash_population(const Eina_Hash *hash) EINA_ARG_NONNULL(1); /** * @brief Add an entry to the given hash table. * * @param hash The given hash table. Cannot be @c NULL. * @param key A unique key. Cannot be @c NULL. * @param key_length The length of the key. * @param key_hash The hash that will always match key. * @param data The data to associate with the string given by the key. Cannot be * @c NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function adds @p key to @p hash. @p hash, @p key and @p data * cannot be @c NULL, in that case #EINA_FALSE is returned. @p key is * expected to be a unique within the hash table. Otherwise, * one cannot be sure which inserted data pointer will be accessed * with @ref eina_hash_find, and removed with @ref eina_hash_del. Do * not forget to count '\\0' for string when setting the value of * @p key_length. @p key_hash is expected to always match * @p key. Otherwise, one cannot be sure to find it again with @ref * eina_hash_find_by_hash. Key strings are case sensitive. If an error * occurs, eina_error_get() should be used to determine if an * allocation error occurred during this function. This function * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * @see eina_hash_add() */ EAPI Eina_Bool eina_hash_add_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data) EINA_ARG_NONNULL(1, 2, 5); /** * @brief Add an entry to the given hash table and do not duplicate the string * key. * * @param hash The given hash table. Cannot be @c NULL. * @param key A unique key. Cannot be @c NULL. * @param key_length Should be the length of @p key (don't forget to count * '\\0' for string). * @param key_hash The hash that will always match key. * @param data Data to associate with the string given by @p key. Cannot be @c * NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function adds @p key to @p hash. @p hash, @p key and @p data * can be @c NULL, in that case #EINA_FALSE is returned. @p key is * expected to be unique within the hash table. Otherwise, * one cannot be sure which inserted data pointer will be accessed * with @ref eina_hash_find, and removed with @ref eina_hash_del. This * function does not make a copy of @p key so it must be a string * constant or stored elsewhere (in the object being added). Do * not forget to count '\\0' for string when setting the value of * @p key_length. @p key_hash is expected to always match * @p key. Otherwise, one cannot be sure to find it again with @ref * eina_hash_find_by_hash. Key strings are case sensitive. If an error * occurs, eina_error_get() should be used to determine if an * allocation error occurred during this function. This function * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * @see eina_hash_direct_add() */ EAPI Eina_Bool eina_hash_direct_add_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data) EINA_ARG_NONNULL(1, 2, 5); /** * @brief Remove the entry identified by a key and a key hash from the given * hash table. * * @param hash The given hash table. Cannot be @c NULL. * @param key The key. Cannot be @c NULL. * @param key_length The length of the key. * @param key_hash The hash that always match the key. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function removes the entry identified by @p key and * @p key_hash from @p hash. If a free function was given to the * callback on creation, it will be called for the data being * deleted. Do not forget to count '\\0' for string when setting the * value of @p key_length. If @p hash or @p key are @c NULL, the * functions returns immediately #EINA_FALSE. This function returns * #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * @note if you don't have the key_hash, use eina_hash_del_by_key() instead. * @note if you don't have the key, use eina_hash_del_by_data() instead. */ EAPI Eina_Bool eina_hash_del_by_key_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash) EINA_ARG_NONNULL(1, 2); /** * @brief Remove the entry identified by a key from the given hash table. * * This version will calculate key length and hash by using functions * provided to hash creation function. * * @param hash The given hash table. Cannot be @c NULL. * @param key The key. Cannot be @c NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function removes the entry identified by @p key from @p * hash. The key length and hash will be calculated automatically by * using functiond provided to has creation function. If a free * function was given to the callback on creation, it will be called * for the data being deleted. If @p hash or @p key are @c NULL, the * functions returns immediately #EINA_FALSE. This function returns * #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * @note if you already have the key_hash, use eina_hash_del_by_key_hash() * instead. * @note if you don't have the key, use eina_hash_del_by_data() instead. */ EAPI Eina_Bool eina_hash_del_by_key(Eina_Hash *hash, const void *key) EINA_ARG_NONNULL(1, 2); /** * @brief Remove the entry identified by a data from the given hash table. * * This version is slow since there is no quick access to nodes based on data. * * @param hash The given hash table. Cannot be @c NULL. * @param data The data value to search and remove. Cannot be @c NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * thing goes fine. * * This function removes the entry identified by @p data from @p * hash. If a free function was given to the callback on creation, it * will be called for the data being deleted. If @p hash or @p data * are @c NULL, the functions returns immediately #EINA_FALSE. This * function returns #EINA_FALSE if an error occurred, #EINA_TRUE * otherwise. * * @note if you already have the key, use eina_hash_del_by_key() or * eina_hash_del_by_key_hash() instead. */ EAPI Eina_Bool eina_hash_del_by_data(Eina_Hash *hash, const void *data) EINA_ARG_NONNULL(1, 2); /** * @brief Remove the entry identified by a key and a key hash or a * data from the given hash table. * * If @p key is @c NULL, then @p data is used to find a match to * remove. * * @param hash The given hash table. Cannot be @c NULL. * @param key The key. * @param key_length The length of the key. * @param key_hash The hash that always match the key. * @param data The data pointer to remove if the key is @c NULL. * @return #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * This function removes the entry identified by @p key and * @p key_hash, or @p data, from @p hash. If a free function was given to * the callback on creation, it will be called for the data being * deleted. If @p hash is @c NULL, the functions returns immediately * #EINA_FALSE. If @p key is @c NULL, then @p key_length and @p key_hash * are ignored and @p data is used to find a match to remove, * otherwise @p key and @p key_hash are used and @p data is not * required and can be @c NULL. Do not forget to count '\\0' for * string when setting the value of @p key_length. This function * returns #EINA_FALSE if an error occurred, #EINA_TRUE otherwise. * * @note if you know you already have the key, use eina_hash_del_by_key_hash(), * if you know you don't have the key, use eina_hash_del_by_data() * directly. */ EAPI Eina_Bool eina_hash_del_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data) EINA_ARG_NONNULL(1); /** * @brief Retrieve a specific entry in the given hash table. * * @param hash The given hash table. Cannot be @c NULL. * @param key The key of the entry to find. * @param key_length The length of the key. * @param key_hash The hash that always match the key * @return The data pointer for the stored entry on success, @c NULL * otherwise. * * This function retrieves the entry associated to @p key of length * @p key_length in @p hash. @p key_hash is the hash that always match * @p key. It is ignored if @p key is @c NULL. Do not forget to count * '\\0' for string when setting the value of @p key_length. If * @p hash is @c NULL, this function returns immediately @c NULL. This * function returns the data pointer on success, @c NULL otherwise. */ EAPI void *eina_hash_find_by_hash(const Eina_Hash *hash, const void *key, int key_length, int key_hash) EINA_ARG_NONNULL(1, 2); /** * @brief Modify the entry pointer at the specified key and returns * the old entry. * * @param hash The given hash table. * @param key The key of the entry to modify. * @param key_length Should be the length of @p key (don't forget to count * '\\0' for string). * @param key_hash The hash that always match the key. Ignored if @p key is * @c NULL. * @param data The data to replace the old entry, if it exists. * @return The data pointer for the old stored entry, or @c NULL if not * found. If an existing entry is not found, nothing is added to the * hash. */ EAPI void *eina_hash_modify_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data) EINA_ARG_NONNULL(1, 2, 5); /** * @brief Returned a new iterator associated to hash keys. * * @param hash The hash. * @return A new iterator. * * This function returns a newly allocated iterator associated to @p * hash. If @p hash is not populated, this function still returns a * valid iterator that will always return false on * eina_iterator_next(), thus keeping API sane. * * If the memory can not be allocated, NULL is returned and * #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is * returned. * * @warning if the hash structure changes then the iterator becomes * invalid! That is, if you add or remove items this iterator * behavior is undefined and your program may crash! */ EAPI Eina_Iterator *eina_hash_iterator_key_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT; /** * @brief Returned a new iterator associated to hash data. * * @param hash The hash. * @return A new iterator. * * This function returns a newly allocated iterator associated to * @p hash. If @p hash is not populated, this function still returns a * valid iterator that will always return false on * eina_iterator_next(), thus keeping API sane. * * If the memory can not be allocated, @c NULL is returned and * #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is * returned. * * @warning if the hash structure changes then the iterator becomes * invalid. That is, if you add or remove items this iterator behavior * is undefined and your program may crash. */ EAPI Eina_Iterator *eina_hash_iterator_data_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT; /** * @brief Returned a new iterator associated to hash keys and data. * * @param hash The hash. * @return A new iterator. * * This function returns a newly allocated iterator associated to @p * hash. If @p hash is not populated, this function still returns a * valid iterator that will always return false on * eina_iterator_next(), thus keeping API sane. * * If the memory can not be allocated, NULL is returned and * #EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid iterator is * returned. * * @note iterator data will provide values as Eina_Hash_Tuple that should not * be modified! * * @warning if the hash structure changes then the iterator becomes * invalid! That is, if you add or remove items this iterator * behavior is undefined and your program may crash! */ EAPI Eina_Iterator *eina_hash_iterator_tuple_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT; /** * @brief Call a function on every member stored in the hash table * * @param hash The hash table whose members will be walked * @param func The function to call on each parameter * @param fdata The data pointer to pass to the function being called * * This function goes through every entry in the hash table @p hash and calls * the function @p func on each member. The function should @b not modify the * hash table contents if it returns 1. @b If the hash table contents are * modified by this function or the function wishes to stop processing it must * return 0, otherwise return 1 to keep processing. * * Example: * @code * extern Eina_Hash *hash; * * Eina_Bool hash_fn(const Eina_Hash *hash, const void *key, * void *data, void *fdata) * { * printf("Func data: %s, Hash entry: %s / %p\n", * fdata, (const char *)key, data); * return 1; * } * * int main(int argc, char **argv) * { * char *hash_fn_data; * * hash_fn_data = strdup("Hello World"); * eina_hash_foreach(hash, hash_fn, hash_fn_data); * free(hash_fn_data); * } * @endcode */ EAPI void eina_hash_foreach(const Eina_Hash *hash, Eina_Hash_Foreach cb, const void *fdata) EINA_ARG_NONNULL(1, 2); /* Paul Hsieh (http://www.azillionmonkeys.com/qed/hash.html) hash function used by WebCore (http://webkit.org/blog/8/hashtables-part-2/) */ EAPI int eina_hash_superfast(const char *key, int len) EINA_ARG_NONNULL(1); /* Hash function first reported by dan bernstein many years ago in comp.lang.c */ static inline int eina_hash_djb2(const char *key, int len) EINA_ARG_NONNULL(1); static inline int eina_hash_djb2_len(const char *key, int *plen) EINA_ARG_NONNULL(1, 2); /* Hash function from http://www.concentric.net/~Ttwang/tech/inthash.htm */ static inline int eina_hash_int32(const unsigned int *pkey, int len) EINA_ARG_NONNULL(1); static inline int eina_hash_int64(const unsigned long int *pkey, int len) EINA_ARG_NONNULL(1); /* http://sites.google.com/site/murmurhash/ */ static inline int eina_hash_murmur3(const char *key, int len) EINA_ARG_NONNULL(1); #include "eina_inline_hash.x" /** * @} */ /** * @} */ /** * @} */ #endif /*EINA_HASH_H_*/