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/* 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 <http://www.gnu.org/licenses/>.
*/
#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. Maps keys to values.
*
* The hash table associates keys (e.g. strings) to data, with
* 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.
*
* There are optimized implementations for some common key types, such
* as strings, integers, pointers, and stringshared; custom optimizations
* are also permitted.
*
* The hash table keys can be either copied or non-copied, using
* eina_hash_add() or eina_hash_direct_add(), respectively.
*
* @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 <a
* href="http://en.wikipedia.org/wiki/Red-black_tree">red-black tree</a>. 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 a
* 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 illustrates the
* basic idea:
*
* @image latex 01_hash-table.eps
* @image html 01_hash-table.png
*
* Adding an element to the hash table involves the following steps:
* @li calculate 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 first two steps have constant time, proportional to the hash function
* being used. Adding the key to the rbtree will be proportional to the number
* of keys in that bucket.
*
* The average lookup cost depends on the number of keys per bucket
* (load factor) of the table, assuming the distribution of keys is
* sufficiently uniform.
*
* @section hashtable_perf Performance
*
* Keeping the load factor small will improve the hash table performance. But
* increasing the buckets_power_size will also increase the memory consumption.
* The default hash table creation functions provides enough
* buckets for most cases. If just a few string keys
* (less than 30) will be added to the hash table, @ref
* eina_hash_string_small_new should be used, since it reduces the memory
* consumption for the buckets without causing too 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 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) - not randomized, avoid it on public remote interface.
*
* 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 preferred if not used on a
* public remote interface.
*
* 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, rather than checking with
* @ref eina_hash_find followed by @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:
* <ul>
* <li> @ref hash_01_example_page
* <li> @ref hash_02_example_page
* <li> Different types of hash in use:
* <ul>
* <li> @ref eina_hash_03.c "string small"
* <li> @ref eina_hash_04.c "string djb2"
* <li> @ref eina_hash_05.c "int32"
* <li> @ref eina_hash_06.c "int64"
* <li> @ref eina_hash_07.c "pointer"
* </ul>
* <li> @ref eina_hash_08.c "Different add and delete functions"
* </ul>
*/
/**
* @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 Eina_Hash_Tuple
* Type for a hash table of key/value pairs.
*/
typedef struct _Eina_Hash_Tuple Eina_Hash_Tuple;
/**
* @struct _Eina_Hash_Tuple
* Data for a hash table of key/value pairs.
*/
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 Eina_Key_Length
* Type for a function to determine the length of a hash key.
*/
typedef unsigned int (*Eina_Key_Length)(const void *key);
/**
* @def EINA_KEY_LENGTH
* @param[in] Function The function used to calculate length of hash key.
*/
#define EINA_KEY_LENGTH(Function) ((Eina_Key_Length)Function)
/**
* @typedef Eina_Key_Cmp
* Type for a function to compare two hash keys.
*/
typedef int (*Eina_Key_Cmp)(const void *key1, int key1_length, const void *key2, int key2_length);
/**
* @def EINA_KEY_CMP
* @param[in]Function The function used to compare hash key.
*/
#define EINA_KEY_CMP(Function) ((Eina_Key_Cmp)Function)
/**
* @typedef Eina_Key_Hash
* Type for a function to create a hash key.
*/
typedef int (*Eina_Key_Hash)(const void *key, int key_length);
/**
* @def EINA_KEY_HASH
* @param[in] Function The function used to hash key.
*/
#define EINA_KEY_HASH(Function) ((Eina_Key_Hash)Function)
/**
* @typedef Eina_Hash_Foreach
* Type for a function to iterate over a hash table.
*/
typedef Eina_Bool (*Eina_Hash_Foreach)(const Eina_Hash *hash, const void *key, void *data, void *fdata);
/**
* @brief Creates a new hash table.
*
* @param[in] key_length_cb The function called when getting the size of the key.
* @param[in] key_cmp_cb The function called when comparing the keys.
* @param[in] key_hash_cb The function called when getting the values.
* @param[in] 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 a
* callback.
* @param[in] buckets_power_size The size of the buckets.
* @return The new hash table, or @c NULL on failure.
*
* This function creates a new hash table using user-defined callbacks
* to manage the hash table.
* 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, whereas 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 Sets the data cleanup callback for a hash.
*
* @param[in,out] hash The given hash table.
* @param[in] 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 to remove an existing callback.
*
* The argument received by @p data_free_cb will be the data of the item being
* removed.
*
* @since 1.1
* @see eina_hash_new.
*/
EAPI void eina_hash_free_cb_set(Eina_Hash *hash, Eina_Free_Cb data_free_cb) EINA_ARG_NONNULL(1);
/**
* @brief Creates a new hash table using the djb2 algorithm.
*
* @param[in] 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, or @c NULL on failure.
*
* 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.
*/
EAPI Eina_Hash *eina_hash_string_djb2_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table for use with strings.
*
* @param[in] 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, or @c NULL on failure.
*
* 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.
*
* @warning Don't use this kind of hash when there is a possibility to
* remotely request and push data in it. This hash is subject to denial
* of service.
*/
EAPI Eina_Hash *eina_hash_string_superfast_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table for use with strings with small bucket size.
*
* @param[in] 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, or @c NULL on failure.
*
* 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.
*/
EAPI Eina_Hash *eina_hash_string_small_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table for use with 32bit integers.
*
* @param[in] 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, or @c NULL on failure.
*
* 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.
*/
EAPI Eina_Hash *eina_hash_int32_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table for use with 64bit integers.
*
* @param[in] 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, or @c NULL on failure.
*
* 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.
*/
EAPI Eina_Hash *eina_hash_int64_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table for use with pointers.
*
* @param[in] 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, or @c NULL on failure.
*
* 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, but actually it only matches
* the first character.
*
* @code
* // For a hash that will have only one pointer to each structure
* extern Eina_Hash *hash;
* extern void *data;
*
* if (!eina_hash_find(hash, &data))
* eina_hash_add(hash, &data, data);
* @endcode
*/
EAPI Eina_Hash *eina_hash_pointer_new(Eina_Free_Cb data_free_cb);
/**
* @brief Creates a new hash table optimized for stringshared values.
*
* @param[in] 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, or @c NULL on failure.
*
* This function creates a new hash table optimized for stringshared
* values. Values CANNOT be looked up with pointers not
* equal to the original key pointer that was used to add a value.
*
* 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 Adds an entry to the given hash table.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key A unique key. Cannot be @c NULL.
* @param[in] data The 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 must be unique within
* the hash table so that @ref eina_hash_find() and @ref eina_hash_del()
* operate on the correct data item.
*
* Key uniqueness varies depending on the type of @p hash: a
* stringshared @ref Eina_Hash needs unique pointers (which implies
* unique strings). All other string hash types require that the
* strings themselves are unique. Pointer, int32 and int64 hashes need
* to have unique values. Failure to use sufficient uniqueness will
* result in unexpected results when inserting data pointers accessed
* with @ref eina_hash_find(), and removed with @ref eina_hash_del().
*
* Key strings are case sensitive.
*/
EAPI Eina_Bool eina_hash_add(Eina_Hash *hash,
const void *key,
const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Adds an entry to the given hash table without duplicating the string.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key A unique key. Cannot be @c NULL.
* @param[in] data The 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 must be unique within
* the hash table so that @ref eina_hash_find() and @ref eina_hash_del()
* operate on the correct data item.
*
* Key uniqueness varies depending on the type of @p hash: a
* stringshared @ref Eina_Hash needs unique pointers (which implies
* unique strings). All other string hash types require that the
* strings themselves are unique. Pointer, int32 and int64 hashes need
* to have unique values. Failure to use sufficient uniqueness will
* result in unexpected results when inserting data pointers accessed
* with @ref eina_hash_find(), and removed with @ref eina_hash_del().
*
* Unlike @ref eina_hash_add(), this function does not make a copy of
* @p key, so it must be a string constant or stored elsewhere (such as
* in the object being added). Key strings are case sensitive.
*/
EAPI Eina_Bool eina_hash_direct_add(Eina_Hash *hash,
const void *key,
const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Removes the entry identified by a key or a data from the given
* hash table.
*
* @param[in,out] hash The given hash table.
* @param[in] key The key.
* @param[in] 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 function 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.
*
* @note If you already have the key, use eina_hash_del_by_key() or
* eina_hash_del_by_key_hash(). If 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 Retrieves a specific entry in the given hash table.
*
* @param[in] hash The given hash table.
* @param[in] key The key of the entry to find.
* @return The data pointer for the stored entry on success, or @c NULL
* otherwise.
*
* This function retrieves the entry associated with @p key in
* @p hash. If @p hash is @c NULL, this function returns @c NULL.
*/
EAPI void *eina_hash_find(const Eina_Hash *hash,
const void *key) EINA_ARG_NONNULL(2);
/**
* @brief Modifies the entry pointer at the specified key and returns
* the previous entry.
* @param[in,out] hash The given hash table.
* @param[in] key The key of the entry to modify.
* @param[in] data The new data.
* @return The data pointer for the previously 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.
*/
EAPI void *eina_hash_modify(Eina_Hash *hash,
const void *key,
const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Modifies the entry pointer at the specified key and returns the
* previous entry or adds the entry if not found.
*
* @param[in,out] hash The given hash table.
* @param[in] key The key of the entry to modify.
* @param[in] data The data to replace the previous entry.
* @return The data pointer for the previous stored entry, or @c NULL
* otherwise.
*
* This function modifies the value of @p key to @p data in @p
* hash. If no entry is found, @p data is added to @p hash with the
* key @p key.
*/
EAPI void *eina_hash_set(Eina_Hash *hash,
const void *key,
const void *data) EINA_ARG_NONNULL(1, 2);
/**
* @brief Changes the key of an entry in a hash without triggering the
* free callback.
*
* @param[in,out] hash The given hash table.
* @param[in] old_key The current key associated with the data.
* @param[in] new_key The new key to associate data with.
* @return #EINA_FALSE in any case but success, #EINA_TRUE on success.
*
* This function moves 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);
/**
* @brief Frees the given hash table's resources.
*
* @param[in] hash The hash table to be freed.
*
* This function frees memory allocated for the @p hash and to its
* internal buckets.
*
* If @p data_free_cb was specified at creation time in
* @ref eina_hash_new, it will be called for each element as it gets
* freed. If the callback was not specified, then any data in these
* elements may now be lost, if not stored or freed elsewhere.
*
* 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);
/**
* @brief Frees the given hash table buckets resources.
*
* @param[in] hash The hash table whose buckets have to be freed.
*
* This function frees memory allocated to internal buckets for @p hash.
*
* If @p data_free_cb was specified at creation time in
* @ref eina_hash_new(), it will be called for each element as it gets
* freed. If the callback was not specified, then any data in these
* elements may now be lost, if not stored or freed elsewhere.
*
* 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[in] hash The given hash table.
* @return The number of entries in the hash table, or @c 0 on error or
* if @p hash is @c NULL.
*/
EAPI int eina_hash_population(const Eina_Hash *hash) EINA_ARG_NONNULL(1);
/**
* @brief Adds an entry to the given hash table by its key hash.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key A unique key. Cannot be @c NULL.
* @param[in] key_length The length of @p key (including terminating '\\0').
* @param[in] key_hash The hash of @p key.
* @param[in] 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 key must be unique within the hash table so that
* @ref eina_hash_find() and @ref eina_hash_del() operate on the correct
* data item. @p key_hash must match @p key so that the correct item can
* be found by @ref eina_hash_find_by_hash(). Key strings are case
* sensitive.
*
* @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 Adds an entry to a hash table by its key hash without duplicating the string key.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key A unique key. Cannot be @c NULL.
* @param[in] key_length The length of @p key (including terminating '\\0').
* @param[in] key_hash The hash of @p key.
* @param[in] data The 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 must be unique within the hash table so that
* @ref eina_hash_find() and @ref eina_hash_del() operate on the correct
* data item. @p key_hash must match @p key so that the correct item can
* be found by @ref eina_hash_find_by_hash(). Key strings are case
* sensitive.
*
* Unlike @ref eina_hash_add_by_hash(), this function does not make a
* copy of @p key, so it must be a string constant or stored elsewhere
* (such as inside the object being added).
*
* @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 Removes the entry identified by a key and a key hash from the given
* hash table.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key The key. Cannot be @c NULL.
* @param[in] key_length The length of the key (including terminating '\\0').
* @param[in] key_hash The hash that always matches 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. If @p hash or @p key are @c NULL, the
* function returns #EINA_FALSE immediately.
*
* @note If you don't have the key_hash, use eina_hash_del_by_key()
* instead. If you don't have the key, use eina_hash_del_by_data().
*/
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 Removes the entry identified by a key from the given hash table.
*
* This version will calculate key length and hash by using functions
* provided to the hash creation function.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] 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 via
* a function provided to the hash 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
* function returns #EINA_FALSE immediately.
*
* @note If you already have the key_hash, use eina_hash_del_by_key_hash().
* 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 Removes an entry from a hash table identified by its data value.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] data The data value to search and remove. Cannot be @c NULL.
* @return #EINA_FALSE if an error occurred or if @p hash or @p data are
* @c NULL, #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.
*
* @note This version is slow since there is no quick access to nodes
* based on data.
*
* @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 Removes the entry identified by a key and a key hash, or a
* data value from the given hash table.
*
* If @p key is @c NULL, then @p data is used to find a match to
* remove.
*
* @param[in,out] hash The given hash table. Cannot be @c NULL.
* @param[in] key The key.
* @param[in] key_length The length of the key.
* @param[in] key_hash The hash that always match the key.
* @param[in] 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 function returns #EINA_FALSE
* immediately. 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.
*
* @note If you already have the key, use eina_hash_del_by_key_hash().
* If 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 Retrieves a specific entry from the given hash table.
*
* @param[in] hash The given hash table. Cannot be @c NULL.
* @param[in] key The key of the entry to find.
* @param[in] key_length The length of the key.
* @param[in] key_hash The hash that always matches the key
* @return The data pointer for the stored entry on success, or @c NULL
* if @p hash is @c NULL or if the data pointer could not be retrieved.
*
* This function retrieves the entry associated with @p key of length
* @p key_length in @p hash. @p key_hash is the hash that always matches
* @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.
*/
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 Modifies the entry pointer at the specified key and returns
* the previous entry.
*
* @param[in,out] hash The given hash table.
* @param[in] key The key of the entry to modify.
* @param[in] key_length Should be the length of @p key (don't forget to count
* '\\0' for string).
* @param[in] key_hash The hash that always matches the key. Ignored if @p
* key is @c NULL.
* @param[in] data The data to replace the current entry, if it exists.
* @return The data pointer for the previously 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 Returns a new iterator associated with hash keys.
*
* @param[in] hash The hash.
* @return A new iterator, or @c NULL if memory could not be allocated.
*
* This function returns a newly allocated iterator associated with @p
* hash. If @p hash is not populated, this function still returns a
* valid iterator that will always return false on
* eina_iterator_next().
*
* @warning If the hash structure changes then the iterator becomes
* invalid; adding or removing items may lead to program crash.
*/
EAPI Eina_Iterator *eina_hash_iterator_key_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
/**
* @brief Returns a new iterator associated with a hash.
*
* @param[in] hash The hash.
* @return A new iterator, or @c NULL if memory could not be allocated.
*
* This function returns a newly allocated iterator associated with
* @p hash. If @p hash is not populated, this function still returns a
* valid iterator that will always return false on
* eina_iterator_next().
*
* @warning If the hash structure changes then the iterator becomes
* invalid; adding or removing items may lead to program 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 with hash keys and data.
*
* @param[in] hash The hash.
* @return A new iterator, or @c NULL if memory could not be allocated.
*
* This function returns a newly allocated iterator associated with @p
* hash. If @p hash is not populated, this function still returns a
* valid iterator that will always return false on
* eina_iterator_next().
*
* @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; adding or removing items may lead to program crash.
*/
EAPI Eina_Iterator *eina_hash_iterator_tuple_new(const Eina_Hash *hash) EINA_MALLOC EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
/**
* @brief Calls a function on every member stored in the hash table.
*
* @param[in] hash The hash table whose members will be walked.
* @param[in] func The function to call on each parameter.
* @param[in] fdata The data pointer to pass to the function being called.
*
* This function iterates over the hash table @p hash, calling the
* function @p func on each member. If @p func modifies the contents
* of the hash table, or wishes to stop processing it should return
* #EINA_FALSE. If @p func returns #EINA_TRUE the foreach loop will
* 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 EINA_TRUE;
* }
*
* 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 func,
const void *fdata) EINA_ARG_NONNULL(1, 2);
/**
* @brief Appends data to an #Eina_List inside a hash.
*
* This function is identical to the sequence of calling
* eina_hash_find(), eina_list_append(), eina_hash_set(),
* but with one fewer required hash lookup.
*
* @param[in,out] hash The hash table.
* @param[in] key The key associated with the data.
* @param[in] data The data to append to the list.
*
* @since 1.10
*/
EAPI void eina_hash_list_append(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Appends data to an #Eina_List inside a hash using eina_hash_direct_add().
*
* This function is identical to the sequence of calling
* eina_hash_find(), eina_list_append(), eina_hash_set(),
* but with one fewer required hash lookup.
*
* @param[in,out] hash The hash table.
* @param[in] key The key associated with the data.
* @param[in] data The data to append to the list.
*
* @since 1.23
*/
EAPI void eina_hash_list_direct_append(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Prepends data to an #Eina_List inside a hash.
*
* This function is identical to the sequence of calling
* eina_hash_find(), eina_list_prepend(), eina_hash_set(),
* but with one fewer required hash lookup.
*
* @param[in,out] hash The hash table.
* @param[in] key The key associated with the data.
* @param[in] data The data to prepend to the list.
*
* @since 1.10
*/
EAPI void eina_hash_list_prepend(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Prepends data to an #Eina_List inside a hash using eina_hash_direct_add().
*
* This function is identical to the sequence of calling
* eina_hash_find(), eina_list_prepend(), eina_hash_set(),
* but with one fewer required hash lookup.
*
* @param[in,out] hash The hash table.
* @param[in] key The key associated with the data.
* @param[in] data The data to prepend to the list.
*
* @since 1.23
*/
EAPI void eina_hash_list_direct_prepend(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief Removes data from an #Eina_List inside a hash.
*
* This function is identical to the sequence of calling
* eina_hash_find(), eina_list_remove(), eina_hash_set(),
* but with one fewer required hash lookup.
*
* @param[in,out] hash The hash table.
* @param[in] key The key associated with the data.
* @param[in] data The data to remove from the list.
*
* @since 1.10
*/
EAPI void eina_hash_list_remove(Eina_Hash *hash, const void *key, const void *data) EINA_ARG_NONNULL(1, 2, 3);
/**
* @brief
* Paul Hsieh (http://www.azillionmonkeys.com/qed/hash.html) hash function used by WebCore (http://webkit.org/blog/8/hashtables-part-2/)
*
* @param[in] key The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
EAPI int eina_hash_superfast(const char *key,
int len) EINA_ARG_NONNULL(1);
/**
* @brief
* Hash function first reported by Dan Bernstein many years ago in comp.lang.c
*
* @param[in] key The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
static inline int eina_hash_djb2(const char *key,
int len) EINA_ARG_NONNULL(1);
/**
* @brief
* Hash function first reported by Dan Bernstein many years ago in comp.lang.c
*
* @param[in] key The key to hash.
* @param[in] plen The length of the key.
* @return The hash value.
*/
static inline int eina_hash_djb2_len(const char *key,
int *plen) EINA_ARG_NONNULL(1, 2);
/**
* @brief
* Hash function from http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm
*
* @param[in] pkey The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
static inline int eina_hash_int32(const unsigned int *pkey,
int len) EINA_ARG_NONNULL(1);
/**
* @brief
* Hash function from http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm
*
* @param[in] pkey The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
static inline int eina_hash_int64(const unsigned long long int *pkey,
int len) EINA_ARG_NONNULL(1);
/**
* @brief
* Hash function from http://sites.google.com/site/murmurhash/
*
* @param[in] key The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
static inline int eina_hash_murmur3(const char *key,
int len) EINA_ARG_NONNULL(1);
/**
* @brief
* Hash function using crc-32 algorithm and and 0xEDB88320 polynomial
*
* @param[in] key The key to hash.
* @param[in] len The length of the key.
* @return The hash value.
*/
static inline int eina_hash_crc(const char *key,
int len) EINA_ARG_NONNULL(1);
#include "eina_inline_hash.x"
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
#endif /*EINA_HASH_H_*/