Eina_Array_Group(3)

NAME
Eina_Array_Group - Array

 - These functions provide array management.

SYNOPSIS

  Data Structures
struct _Eina_Array
Type for an array of data.

  Macros
#define EINA_ARRAY_ITER_NEXT(array, index, item, iterator)
Iterates through an array's elements.

  Typedefs
typedef struct _Eina_Array Eina_Array
Type for a generic one-dimensional linear data structure.
typedef void ** Eina_Array_Iterator
Type for an iterator on arrays, used with EINA_ARRAY_ITER_NEXT.

  Functions
EINA_API Eina_Array * eina_array_new (unsigned int step)
Creates a new array.
EINA_API void eina_array_free (Eina_Array *array)
Frees an array.
EINA_API void eina_array_step_set (Eina_Array *array, unsigned int sizeof_eina_array, unsigned int step)
Sets the step of an array.
static void eina_array_clean (Eina_Array *array)
Clears an array of its elements, without deallocating memory.
EINA_API void eina_array_flush (Eina_Array *array)
Clears an array's elements and deallocates the memory.
EINA_API Eina_Bool eina_array_remove (Eina_Array *array, Eina_Bool(*keep)(void *data, void *gdata), void *gdata)
Rebuilds an array by specifying the data to keep.
static Eina_Bool eina_array_push (Eina_Array *array, const void *data)
Appends a data item to an array.
static void * eina_array_pop (Eina_Array *array)
Removes the last data item in an array.
static void * eina_array_data_get (const Eina_Array *array, unsigned int idx)
Returns the data at a given position in an array.
static void eina_array_data_set (const Eina_Array *array, unsigned int idx, const void *data)
Sets the data at a given position in an array.
static unsigned int eina_array_count_get (const Eina_Array *array)
Returns the number of elements in an array.
static unsigned int eina_array_count (const Eina_Array *array)
Returns the number of elements in an array.
static Eina_Bool eina_array_find (const Eina_Array *array, const void *data, unsigned int *out_idx)
Search for the given data in an array.
EINA_API Eina_Iterator * eina_array_iterator_new (const Eina_Array *array)
Gets a new iterator associated with an array.
EINA_API Eina_Accessor * eina_array_accessor_new (const Eina_Array *array)
Gets a new accessor associated with an array.
static Eina_Bool eina_array_foreach (Eina_Array *array, Eina_Each_Cb cb, void *fdata)
Iterates over an array using a callback function.

Detailed Description

These functions provide array management. The Array data type in Eina is designed to have very fast access to its data (compared to the Eina List). On the other hand, data can be added or removed only at the end of the array. To insert data at arbitrary positions, the Eina List is the correct container to use.

To use the array data type, eina_init() must be called before any other array functions. When no more eina array functions are used, eina_shutdown() must be called to free all the resources.

An array must be created with eina_array_new(). It allocates all the necessary data for an array. When not needed anymore, an array is freed with eina_array_free(). This frees the memory used by the Eina_Array itself, but does not free any memory used to store the data of each element. To free that memory you must iterate over the array and free each data element individually. A convenient way to do that is by using EINA_ARRAY_ITER_NEXT. An example of that pattern is given in the description of EINA_ARRAY_ITER_NEXT.

Warning
    Functions do not check if the used array is valid or not. It's up to the user to be sure of that. It is designed like that for performance reasons.

The usual features of an array are classic ones: to append an element, use eina_array_push() and to remove the last element, use eina_array_pop(). To retrieve the element at a given position, use eina_array_data_get(). The number of elements can be retrieved with eina_array_count().

An Eina_Array differs most notably from a conventional C array in that it can grow and shrink dynamically as elements are added and removed. Since allocating memory is expensive, when the array needs to grow it adds enough memory to hold step additional elements, not just the element currently being added. Similarly when elements are removed, it won't deallocate until step elements are removed.

The following image illustrates how an Eina_Array grows:

Eina_Array only stores pointers but it can store data of any type in the form of void pointers.

See here some examples:
•   Basic array usage
•   Removing array elements

Macro Definition Documentation

  #define EINA_ARRAY_ITER_NEXT(array, index, item, iterator)
Value:
  for (index = 0, iterator = (array)->data;                                        (index < eina_array_count(array)) && ((item = *((iterator)++)));                                                       ++(index))
Iterates through an array's elements.
Parameters
    array The array to iterate over.
    index The integer number that is increased while iterating.
    item The data
    iterator The Eina_Array_Iterator.
This macro iterates over array in order, increasing index from the first to last element and setting item to each element's data item in turn.
This macro can be used for freeing the data of an array, such as the following example:
Eina_Array         *array;
char               *item;
Eina_Array_Iterator iterator;
unsigned int        i;
// array is already filled,
// its elements are just duplicated strings,
// EINA_ARRAY_ITER_NEXT will be used to free those strings
EINA_ARRAY_ITER_NEXT(array, i, item, iterator)
  free(item);

Examples
eina_array_02.c.

Function Documentation

  EINA_API Eina_Array* eina_array_new (unsigned int step)
Creates a new array.
Parameters
    step The count of pointers to add when increasing the array size.
Returns
    NULL on failure, non NULL otherwise.
This function creates a new array. When adding an element, the array allocates step elements. When that buffer is full, adding another element will increase the buffer by step elements again.
This function return a valid array on success, or NULL if memory allocation fails.
References _Eina_Array::count, _Eina_Array::data, EINA_MAGIC_SET, _Eina_Array::step, _Eina_Array::total, and _Eina_Array::version.
Referenced by eina_benchmark_run(), eina_file_split(), eina_module_arch_list_get(), eina_module_list_get(), eina_thread_create(), eina_thread_self(), eldbus_service_property_changed(), elm_win_available_profiles_set(), and evas_device_push().

  EINA_API void eina_array_free (Eina_Array * array)
Frees an array.
Parameters
    array The array to free.
This function finalizes array by flushing (see eina_array_flush()), and then freeing the memory of the pointer. It does not free the memory allocated for the elements of array. To free them, walk the array with EINA_ARRAY_ITER_NEXT.
References eina_array_flush().
Referenced by ecore_buffer_shutdown(), eina_benchmark_free(), eina_thread_create(), eina_thread_join(), elm_cnp_selection_set(), elm_drag_start(), elm_drop_target_del(), elm_object_focus_next(), and elm_win_available_profiles_set().

  EINA_API void eina_array_step_set (Eina_Array * array, unsigned int sizeof_eina_array, unsigned int step)
Sets the step of an array.
Parameters
    array The array.
    sizeof_eina_array Should be the value returned by sizeof(Eina_Array).
    step The count of pointers to add when increasing the array size.
This function sets the step of array to step. For performance reasons, there is no check of array. If it is NULL or invalid, the program may crash.
Warning
    This function can only be called on uninitialized arrays.
References _Eina_Array::count, _Eina_Array::data, EINA_MAGIC_SET, EINA_SAFETY_ON_NULL_RETURN, ERR, _Eina_Array::step, _Eina_Array::total, and _Eina_Array::version.

  static void eina_array_clean (Eina_Array * array) [inline], [static]
Clears an array of its elements, without deallocating memory.
Parameters
    array The array to clean.
This function sets the array's member count to 0 without freeing memory. This facilitates emptying an array and quickly refilling it with new elements. For performance reasons, there is no check of array. If it is NULL or invalid, the program may crash.
Examples
eina_array_02.c.

  EINA_API void eina_array_flush (Eina_Array * array)
Clears an array's elements and deallocates the memory.
Parameters
    array The array to flush.
This function sets the count and total members of array to 0, and frees its data member and sets it to NULL. For performance reasons, there is no check of array. If it is NULL or invalid, the program may crash.
References _Eina_Array::count, _Eina_Array::data, EINA_SAFETY_ON_NULL_RETURN, and _Eina_Array::total.
Referenced by eina_array_free(), and eina_module_list_free().

  EINA_API Eina_Bool eina_array_remove (Eina_Array * array, Eina_Bool(*)(void *data, void *gdata) keep, void * gdata)
Rebuilds an array by specifying the data to keep.
Parameters
    array The array.
    keep The functions which selects the data to keep.
    gdata The data to pass to the function keep.
Returns
    EINA_TRUE on success, EINA_FALSE otherwise.
This function rebuilds array by specifying the elements to keep with the function keep. No empty/invalid fields are left in the array. gdata is an additional data to pass to keep. For performance reasons, there is no check of array. If it is NULL or invalid, the program may crash.
If it wasn't able to remove items due to an allocation failure, it will return EINA_FALSE.
References _Eina_Array::count, _Eina_Array::data, EINA_FALSE, EINA_SAFETY_ON_NULL_RETURN_VAL, EINA_TRUE, _Eina_Array::step, and _Eina_Array::total.

  static Eina_Bool eina_array_push (Eina_Array * array, const void * data) [inline], [static]
Appends a data item to an array.
Parameters
    array The array.
    data The data to add.
Returns
    EINA_TRUE on success, EINA_FALSE if allocation is necessary and fails or if data is NULL.
This function appends data to array. For performance reasons, there is no check of array. If it is NULL or invalid, the program may crash.
Examples
eina_accessor_01.c, eina_array_01.c, eina_array_02.c, eina_iterator_01.c, and eina_simple_xml_parser_01.c.
Referenced by eina_benchmark_run(), eina_file_split(), eldbus_service_property_changed(), elm_win_available_profiles_set(), and evas_device_push().

  static void* eina_array_pop (Eina_Array * array) [inline], [static]
Removes the last data item in an array.
Parameters
    array The array.
Returns
    The retrieved data, or NULL if there are no remaining items.
This function removes the last data item from array, decreases the length of array and returns the data item. For performance reasons, there is no check of array, so if it is NULL or invalid, the program may crash.
Examples
eina_array_01.c.
Referenced by eina_thread_cancel_checkpoint(), elm_object_focus_next(), and evas_device_pop().

  static void* eina_array_data_get (const Eina_Array * array, unsigned int idx) [inline], [static]
Returns the data at a given position in an array.
Parameters
    array The array.
    idx The position of the data to retrieve.
Returns
    The retrieved data.
This function returns the data at the position idx in array. For performance reasons, there is no check of array or idx. If array is NULL or invalid, or if idx is larger than the array's size, the program may crash.
Examples
eina_array_01.c.
Referenced by eldbus_service_signal_emit(), elm_cnp_selection_set(), elm_drag_start(), and elm_object_focus_next().

  static void eina_array_data_set (const Eina_Array * array, unsigned int idx, const void * data) [inline], [static]
Sets the data at a given position in an array.
Parameters
    array The array.
    idx The position of the data to set.
    data The data to set.
This function sets the data at the position idx in array to data, this effectively replaces the previously held data, you must therefore get a pointer to it first if you need to free it. For performance reasons, there is no check of array or idx. If array is NULL or invalid, or if idx is larger than the array's size, the program may crash.
Examples
eina_array_02.c.

  static unsigned int eina_array_count_get (const Eina_Array * array) [inline], [static]
Returns the number of elements in an array.
Deprecated
    use eina_array_count()
Parameters
    array The array.
Returns
    The number of elements.
This function returns the number of elements in array (array->count). For performance reasons, there is no check of array, so if it is NULL or invalid, the program may crash.

  static unsigned int eina_array_count (const Eina_Array * array) [inline], [static]
Returns the number of elements in an array.
Parameters
    array The array.
Returns
    The number of elements.
This function returns the number of elements in array (array->count). For performance reasons, there is no check of array, so if it is NULL or invalid, the program may crash.
Examples
eina_array_01.c.
Referenced by ecore_buffer_init(), eina_thread_cancel_checkpoint(), eldbus_service_signal_emit(), eldbus_service_signal_new(), elm_cnp_selection_set(), elm_drag_start(), elm_object_focus_next(), and elm_win_profile_set().

  static Eina_Bool eina_array_find (const Eina_Array * array, const void * data, unsigned int * out_idx) [inline], [static]
Search for the given data in an array.
Parameters
    array The array.
    data need to be found.
    out_idx The position of the data in the array if found.
Returns
    EINA_TRUE if found otherwise returns EINA_FALSE.
This function searches for the data pointer data inside array, returning EINA_TRUE if found. The exact position where the pointer is found can be retrieved through out_idx. Please note that only the pointer is compared, not the actual data pointed by it.
Since
    1.23

  EINA_API Eina_Iterator* eina_array_iterator_new (const Eina_Array * array)
Gets a new iterator associated with an array.
Parameters
    array The array.
Returns
    A new iterator, or NULL if array is NULL or has no items, or if memory could not be allocated.
This function allocates a new iterator associated with array. Use EINA_ARRAY_ITER_NEXT() to iterate through the array's data items in order of entry.
See also
    Iterator Functions
References EINA_MAGIC_SET, EINA_SAFETY_ON_NULL_RETURN_VAL, FUNC_ITERATOR_FREE, FUNC_ITERATOR_GET_CONTAINER, FUNC_ITERATOR_NEXT, and _Eina_Array::version.
Referenced by elm_cnp_selection_get().

  EINA_API Eina_Accessor* eina_array_accessor_new (const Eina_Array * array)
Gets a new accessor associated with an array.
Parameters
    array The array.
Returns
    A new accessor, or NULL if array is NULL or has no items, or if memory could not be allocated.
This function returns a newly allocated accessor associated with array. Accessors differ from iterators in that they permit random access.
See also
    Accessor Functions
References EINA_MAGIC_SET, EINA_SAFETY_ON_NULL_RETURN_VAL, FUNC_ACCESSOR_CLONE, FUNC_ACCESSOR_FREE, FUNC_ACCESSOR_GET_AT, FUNC_ACCESSOR_GET_CONTAINER, and _Eina_Array::version.
Referenced by ecore_evas_drop_available_types_get().

  static Eina_Bool eina_array_foreach (Eina_Array * array, Eina_Each_Cb cb, void * fdata) [inline], [static]
Iterates over an array using a callback function.
Parameters
    array The array to iterate over.
    cb The callback to invoke for each item.
    fdata The user data to pass to the callback.
Returns
    EINA_TRUE if it successfully iterated all items of the array.
This function iterates over an array in order, calling cb for each item. cb should return EINA_TRUE if the loop should continue, or EINA_FALSE to exit the loop, in which case eina_array_foreach() will return EINA_FALSE.
Examples
eina_array_01.c, and eina_simple_xml_parser_01.c.
Referenced by ecore_wl2_offer_mimes_set(), and ecore_wl2_offer_supports_mime().

Author
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