Data Structures

struct  _Eina_Inlist
 Inlined list type. More...

Macros

#define EINA_INLIST   Eina_Inlist __in_list
 Used for declaring an inlist member in a struct.
#define EINA_INLIST_GET(Inlist)
 Utility macro to get the inlist object of a struct.
#define EINA_INLIST_CONTAINER_GET(ptr, type)
 Utility macro to get the container object of an inlist.
#define _EINA_INLIST_OFFSET(ref)
#define _EINA_INLIST_CONTAINER(ref, ptr)
#define EINA_INLIST_FOREACH(list, l)
 Macro to iterate over an inlist.
#define EINA_INLIST_FOREACH_SAFE(list, list2, l)
#define EINA_INLIST_REVERSE_FOREACH(list, l)

Typedefs

typedef struct _Eina_Inlist Eina_Inlist
 Inlined list type.
typedef struct _Eina_Inlist_Sorted_State Eina_Inlist_Sorted_State

Functions

Eina_Inlisteina_inlist_append (Eina_Inlist *in_list, Eina_Inlist *in_item)
 Add a new node to end of a list.
Eina_Inlisteina_inlist_prepend (Eina_Inlist *in_list, Eina_Inlist *in_item)
 Add a new node to beginning of list.
Eina_Inlisteina_inlist_append_relative (Eina_Inlist *in_list, Eina_Inlist *in_item, Eina_Inlist *in_relative)
 Add a new node after the given relative item in list.
Eina_Inlisteina_inlist_prepend_relative (Eina_Inlist *in_list, Eina_Inlist *in_item, Eina_Inlist *in_relative)
 Add a new node before the given relative item in list.
Eina_Inlisteina_inlist_remove (Eina_Inlist *in_list, Eina_Inlist *in_item)
 Remove node from list.
Eina_Inlisteina_inlist_find (Eina_Inlist *in_list, Eina_Inlist *in_item)
 Find given node in list, returns itself if found, NULL if not.
Eina_Inlisteina_inlist_promote (Eina_Inlist *list, Eina_Inlist *item)
 Move existing node to beginning of list.
Eina_Inlisteina_inlist_demote (Eina_Inlist *list, Eina_Inlist *item)
 Move existing node to end of list.
unsigned int eina_inlist_count (const Eina_Inlist *list)
 Get the count of the number of items in a list.
Eina_Iteratoreina_inlist_iterator_new (const Eina_Inlist *in_list)
 Returns a new iterator associated to list.
Eina_Accessoreina_inlist_accessor_new (const Eina_Inlist *in_list)
 Returns a new accessor associated to a list.
Eina_Inlisteina_inlist_sorted_insert (Eina_Inlist *list, Eina_Inlist *item, Eina_Compare_Cb func)
 Insert a new node into a sorted list.
Eina_Inlist_Sorted_Stateeina_inlist_sorted_state_new (void)
 Create state with valid data in it.
int eina_inlist_sorted_state_init (Eina_Inlist_Sorted_State *state, Eina_Inlist *list)
 Force an Eina_Inlist_Sorted_State to match the content of a list.
void eina_inlist_sorted_state_free (Eina_Inlist_Sorted_State *state)
 Free an Eina_Inlist_Sorted_State.
Eina_Inlisteina_inlist_sorted_state_insert (Eina_Inlist *list, Eina_Inlist *item, Eina_Compare_Cb func, Eina_Inlist_Sorted_State *state)
 Insert a new node into a sorted list.
Eina_Inlisteina_inlist_sort (Eina_Inlist *head, Eina_Compare_Cb func)
 Sort a list according to the ordering func will return.

Detailed Description

These functions provide inline list management.

Inline lists mean its nodes pointers are part of same memory as data. This has the benefit of fragmenting memory less and avoiding node->data indirection, but has the drawback of higher cost for some common operations like count and sort.

It is possible to have inlist nodes to be part of regular lists, created with eina_list_append() or eina_list_prepend(). It's also possible to have a structure with two inlist pointers, thus be part of two different inlists at the same time, but the current convenience macros provided won't work for both of them. Consult Advanced Usage for more info.

Inline lists have their purposes, but if you don't know what those purposes are, go with regular lists instead.

Tip: When using inlists in more than one place (that is, passing them around functions or keeping a pointer to them in a structure) it's more correct to keep a pointer to the first container, and not a pointer to the first inlist item (mostly they are the same, but that's not always correct). This lets the compiler to do type checking and let the programmer know exactly what type this list is.

A simple example demonstrating the basic usage of an inlist can be found here: Eina_Inlist basic usage

Algorithm

The basic structure can be represented by the following picture:

One data structure will also have the node information, with three pointers: prev, next and last. The last pointer is just valid for the first element (the list head), otherwise each insertion in the list would have to be done updating every node with the correct pointer. This means that it's always very important to keep a pointer to the first element of the list, since it is the only one that has the correct information to allow a proper O(1) append to the list.

Performance

Due to the nature of the inlist, there's no accounting information, and no easy access to the last element from each list node. This means that eina_inlist_count() is order-N, while eina_list_count() is order-1 (constant time).

Advanced Usage

The basic usage considers a struct that will have the user data, and also have an inlist node information (prev, next and last pointers) created with EINA_INLIST during the struct declaration. This allows one to use the convenience macros EINA_INLIST_GET(), EINA_INLIST_CONTAINER_GET(), EINA_INLIST_FOREACH() and so. This happens because the EINA_INLIST macro declares a struct member with the name __inlist, and all the other macros assume that this struct member has this name.

It may be the case that someone needs to have some inlist nodes added to a Eina_List too. If this happens, the inlist nodes can be added to the Eina_List without any problems. This example demonstrates this case: Eina_Inlist advanced usage - lists and inlists

It's also possible to have some data that is part of two different inlists. If this is the case, then it won't be possible to use the convenience macros to both of the lists. It will be necessary to create a new set of macros that will allow access to the second list node info. An example for this usage can be found here: Eina_Inlist advanced usage - multi-inlists

List of examples:

Macro Definition Documentation

◆ EINA_INLIST_GET

◆ EINA_INLIST_CONTAINER_GET

#define EINA_INLIST_CONTAINER_GET ( ptr,
type )
Value:
((type *)((char *)ptr - \
offsetof(type, __in_list)))

Utility macro to get the container object of an inlist.

◆ _EINA_INLIST_OFFSET

#define _EINA_INLIST_OFFSET ( ref)
Value:
((char *)&(ref)->__in_list - (char *)(ref))
Parameters
refThe reference to be used.

◆ _EINA_INLIST_CONTAINER

#define _EINA_INLIST_CONTAINER ( ref,
ptr )
Value:
(void *)((char *)(ptr) - \
#define _EINA_INLIST_OFFSET(ref)
Definition eina_inlist.h:774
Parameters
refThe reference to be used.
ptrThe pointer to be used.

◆ EINA_INLIST_FOREACH

#define EINA_INLIST_FOREACH ( list,
l )
Value:
for (l = NULL, l = (list ? _EINA_INLIST_CONTAINER(l, list) : NULL); l; \
l = (EINA_INLIST_GET(l)->next ? _EINA_INLIST_CONTAINER(l, EINA_INLIST_GET(l)->next) : NULL))
#define _EINA_INLIST_CONTAINER(ref, ptr)
Definition eina_inlist.h:782
#define EINA_INLIST_GET(Inlist)
Utility macro to get the inlist object of a struct.
Definition eina_inlist.h:415

Macro to iterate over an inlist.

Referenced by eina_benchmark_run(), eina_log_domain_level_get(), eina_log_domain_level_set(), and eina_threads_shutdown().

◆ EINA_INLIST_FOREACH_SAFE

#define EINA_INLIST_FOREACH_SAFE ( list,
list2,
l )
Value:
for (l = (list ? _EINA_INLIST_CONTAINER(l, list) : NULL), list2 = l ? ((EINA_INLIST_GET(l) ? EINA_INLIST_GET(l)->next : NULL)) : NULL; \
l; \
l = list2 ? _EINA_INLIST_CONTAINER(l, list2) : NULL, list2 = list2 ? list2->next : NULL)
Parameters
listThe first list to be used.
list2The second list to be used.
lThe auxiliar variable to be used.

◆ EINA_INLIST_REVERSE_FOREACH

#define EINA_INLIST_REVERSE_FOREACH ( list,
l )
Value:
for (l = NULL, l = (list ? _EINA_INLIST_CONTAINER(l, list->last) : NULL); \
l; l = (EINA_INLIST_GET(l)->prev ? _EINA_INLIST_CONTAINER(l, EINA_INLIST_GET(l)->prev) : NULL))
Parameters
listThe list to be reversed.
lThe auxiliar variable to be used.

Referenced by eina_counter_dump().

Typedef Documentation

◆ Eina_Inlist_Sorted_State

typedef struct _Eina_Inlist_Sorted_State Eina_Inlist_Sorted_State
Since
1.1.0 State of sorted Eina_Inlist

Function Documentation

◆ eina_inlist_append()

Eina_Inlist * eina_inlist_append ( Eina_Inlist * in_list,
Eina_Inlist * in_item )

Add a new node to end of a list.

Note
this code is meant to be fast: appends are O(1) and do not walk in_list.
in_item is considered to be in no list. If it was in another list before, eina_inlist_remove() it before adding. No check of new_l prev and next pointers is done, so it's safe to have them uninitialized.
Parameters
in_listexisting list head or NULL to create a new list.
in_itemnew list node, must not be NULL.
Returns
the new list head. Use it and not in_list anymore.

References _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

Referenced by eina_benchmark_register(), eina_inlist_append_relative(), eina_inlist_sorted_insert(), eina_inlist_sorted_state_insert(), eina_log_domain_level_set(), eina_simple_xml_attribute_new(), and eina_simple_xml_node_tag_new().

◆ eina_inlist_prepend()

Eina_Inlist * eina_inlist_prepend ( Eina_Inlist * in_list,
Eina_Inlist * in_item )

Add a new node to beginning of list.

Note
this code is meant to be fast: appends are O(1) and do not walk in_list.
new_l is considered to be in no list. If it was in another list before, eina_inlist_remove() it before adding. No check of new_l prev and next pointers is done, so it's safe to have them uninitialized.
Parameters
in_listexisting list head or NULL to create a new list.
in_itemnew list node, must not be NULL.
Returns
the new list head. Use it and not in_list anymore.

References _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

Referenced by eina_counter_start(), eina_inlist_prepend_relative(), eina_inlist_sorted_insert(), eina_inlist_sorted_state_insert(), and eina_rectangle_pool_request().

◆ eina_inlist_append_relative()

Eina_Inlist * eina_inlist_append_relative ( Eina_Inlist * in_list,
Eina_Inlist * in_item,
Eina_Inlist * in_relative )

Add a new node after the given relative item in list.

Note
this code is meant to be fast: appends are O(1) and do not walk in_list.
in_item_l is considered to be in no list. If it was in another list before, eina_inlist_remove() it before adding. No check of in_item prev and next pointers is done, so it's safe to have them uninitialized.
in_relative is considered to be inside in_list, no checks are done to confirm that and giving nodes from different lists will lead to problems. Giving NULL in_relative is the same as eina_list_append().
Parameters
in_listexisting list head or NULL to create a new list.
in_itemnew list node, must not be NULL.
in_relativereference node, in_item will be added after it.
Returns
the new list head. Use it and not list anymore.

References eina_inlist_append(), _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

Referenced by eina_inlist_sorted_insert(), and eina_inlist_sorted_state_insert().

◆ eina_inlist_prepend_relative()

Eina_Inlist * eina_inlist_prepend_relative ( Eina_Inlist * in_list,
Eina_Inlist * in_item,
Eina_Inlist * in_relative )

Add a new node before the given relative item in list.

Note
this code is meant to be fast: appends are O(1) and do not walk in_list.
in_item is considered to be in no list. If it was in another list before, eina_inlist_remove() it before adding. No check of in_item prev and next pointers is done, so it's safe to have them uninitialized.
in_relative is considered to be inside in_list, no checks are done to confirm that and giving nodes from different lists will lead to problems. Giving NULL in_relative is the same as eina_list_prepend().
Parameters
in_listexisting list head or NULL to create a new list.
in_itemnew list node, must not be NULL.
in_relativereference node, in_item will be added before it.
Returns
the new list head. Use it and not in_list anymore.

References eina_inlist_prepend(), _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

Referenced by eina_inlist_sorted_insert(), and eina_inlist_sorted_state_insert().

◆ eina_inlist_remove()

Eina_Inlist * eina_inlist_remove ( Eina_Inlist * in_list,
Eina_Inlist * in_item )

Remove node from list.

Note
this code is meant to be fast: appends are O(1) and do not walk list.
in_item is considered to be inside in_list, no checks are done to confirm that and giving nodes from different lists will lead to problems, especially if in_item is the head since it will be different from list and the wrong new head will be returned.
Parameters
in_listexisting list head, must not be NULL.
in_itemexisting list node, must not be NULL.
Returns
the new list head. Use it and not list anymore.

References EINA_ERROR_SAFETY_FAILED, eina_error_set(), EINA_LOG_ERR, EINA_UNLIKELY, _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

Referenced by eina_benchmark_free(), eina_counter_free(), eina_rectangle_pool_release(), and eina_simple_xml_attribute_free().

◆ eina_inlist_find()

Eina_Inlist * eina_inlist_find ( Eina_Inlist * in_list,
Eina_Inlist * in_item )

Find given node in list, returns itself if found, NULL if not.

Warning
this is an expensive call and has O(n) cost, possibly walking the whole list.
Parameters
in_listexisting list to search in_item in, must not be NULL.
in_itemwhat to search for, must not be NULL.
Returns
in_item if found, NULL if not.

References _Eina_Inlist::next.

◆ eina_inlist_promote()

Eina_Inlist * eina_inlist_promote ( Eina_Inlist * list,
Eina_Inlist * item )

Move existing node to beginning of list.

Note
this code is meant to be fast: appends are O(1) and do not walk list.
item is considered to be inside list. No checks are done to confirm this, and giving nodes from different lists will lead to problems.
Parameters
listexisting list head or NULL to create a new list.
itemlist node to move to beginning (head), must not be NULL.
Returns
the new list head. Use it and not list anymore.

References _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

◆ eina_inlist_demote()

Eina_Inlist * eina_inlist_demote ( Eina_Inlist * list,
Eina_Inlist * item )

Move existing node to end of list.

Note
this code is meant to be fast: appends are O(1) and do not walk list.
item is considered to be inside list. No checks are done to confirm this, and giving nodes from different lists will lead to problems.
Parameters
listexisting list head or NULL to create a new list.
itemlist node to move to end (tail), must not be NULL.
Returns
the new list head. Use it and not list anymore.

References _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.

◆ eina_inlist_count()

unsigned int eina_inlist_count ( const Eina_Inlist * list)

Get the count of the number of items in a list.

Parameters
listThe list whose count to return.
Returns
The number of members in the list.

This function returns how many members list contains. If the list is NULL, 0 is returned.

Warning
This is an order-N operation and so the time will depend on the number of elements on the list, so, it might become slow for big lists!

References _Eina_Inlist::next.

◆ eina_inlist_iterator_new()

Eina_Iterator * eina_inlist_iterator_new ( const Eina_Inlist * in_list)

Returns a new iterator associated to list.

Parameters
in_listThe list.
Returns
A new iterator.

This function returns a newly allocated iterator associated to in_list. If in_list is NULL or the count member of in_list is less or equal than 0, 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 list structure changes then the iterator becomes invalid, and if you add or remove nodes iterator behavior is undefined, and your program may crash!

References EINA_ERROR_OUT_OF_MEMORY, eina_error_set(), EINA_MAGIC_SET, FUNC_ITERATOR_FREE, FUNC_ITERATOR_GET_CONTAINER, and FUNC_ITERATOR_NEXT.

◆ eina_inlist_accessor_new()

Eina_Accessor * eina_inlist_accessor_new ( const Eina_Inlist * in_list)

Returns a new accessor associated to a list.

Parameters
in_listThe list.
Returns
A new accessor.

This function returns a newly allocated accessor associated to in_list. If in_list is NULL or the count member of in_list is less or equal than 0, this function returns NULL. If the memory can not be allocated, NULL is returned and EINA_ERROR_OUT_OF_MEMORY is set. Otherwise, a valid accessor is returned.

References EINA_ERROR_OUT_OF_MEMORY, eina_error_set(), EINA_MAGIC_SET, FUNC_ACCESSOR_FREE, FUNC_ACCESSOR_GET_AT, and FUNC_ACCESSOR_GET_CONTAINER.

◆ eina_inlist_sorted_insert()

Eina_Inlist * eina_inlist_sorted_insert ( Eina_Inlist * list,
Eina_Inlist * item,
Eina_Compare_Cb func )

Insert a new node into a sorted list.

Parameters
listThe given linked list, must be sorted.
itemlist node to insert, must not be NULL.
funcThe function called for the sort.
Returns
A list pointer.
Since
1.1.0

This function inserts item into a linked list assuming it was sorted and the result will be sorted. If list is NULLL, item is returned. On success, a new list pointer that should be used in place of the one given to this function is returned. Otherwise, the old pointer is returned. See eina_error_get().

Note
O(log2(n)) comparisons (calls to func) average/worst case performance. As said in eina_list_search_sorted_near_list(), lists do not have O(1) access time, so walking to the correct node can be costly, consider worst case to be almost O(n) pointer dereference (list walk).

References eina_inlist_append(), eina_inlist_append_relative(), eina_inlist_prepend(), eina_inlist_prepend_relative(), eina_inlist_sorted_state_init(), and _Eina_Inlist::next.

◆ eina_inlist_sorted_state_new()

Eina_Inlist_Sorted_State * eina_inlist_sorted_state_new ( void )

Create state with valid data in it.

Returns
A valid Eina_Inlist_Sorted_State.
Since
1.1.0

See eina_inlist_sorted_state_insert() for more information.

◆ eina_inlist_sorted_state_init()

int eina_inlist_sorted_state_init ( Eina_Inlist_Sorted_State * state,
Eina_Inlist * list )

Force an Eina_Inlist_Sorted_State to match the content of a list.

Parameters
stateThe state to update
listThe list to match
Returns
The number of item in the actually in the list
Since
1.1.0

See eina_inlist_sorted_state_insert() for more information. This function is usefull if you didn't use eina_inlist_sorted_state_insert() at some point, but still think you have a sorted list. It will only correctly work on a sorted list.

References _Eina_Inlist::next.

Referenced by eina_inlist_sorted_insert().

◆ eina_inlist_sorted_state_free()

void eina_inlist_sorted_state_free ( Eina_Inlist_Sorted_State * state)

Free an Eina_Inlist_Sorted_State.

Parameters
stateThe state to destroy
Since
1.1.0

See eina_inlist_sorted_state_insert() for more information.

◆ eina_inlist_sorted_state_insert()

Eina_Inlist * eina_inlist_sorted_state_insert ( Eina_Inlist * list,
Eina_Inlist * item,
Eina_Compare_Cb func,
Eina_Inlist_Sorted_State * state )

Insert a new node into a sorted list.

Parameters
listThe given linked list, must be sorted.
itemlist node to insert, must not be NULL.
funcThe function called for the sort.
stateThe current array for initial dichotomic search
Returns
A list pointer.
Since
1.1.0

This function inserts item into a linked list assuming state match the exact content order of the list. It use state to do a fast first step dichotomic search before starting to walk the inlist itself. This make this code much faster than eina_inlist_sorted_insert() as it doesn't need to walk the list at all. The result is of course a sorted list with an updated state.. If list is NULLL, item is returned. On success, a new list pointer that should be used in place of the one given to this function is returned. Otherwise, the old pointer is returned. See eina_error_get().

Note
O(log2(n)) comparisons (calls to func) average/worst case performance. As said in eina_list_search_sorted_near_list(), lists do not have O(1) access time, so walking to the correct node can be costly, but this version try to minimize that by making it a O(log2(n)) for number small number. After n == 256, it start to add a linear cost again. Consider worst case to be almost O(n) pointer dereference (list walk).

References eina_inlist_append(), eina_inlist_append_relative(), eina_inlist_prepend(), eina_inlist_prepend_relative(), and _Eina_Inlist::next.

◆ eina_inlist_sort()

Eina_Inlist * eina_inlist_sort ( Eina_Inlist * head,
Eina_Compare_Cb func )

Sort a list according to the ordering func will return.

Parameters
headThe list handle to sort.
funcA function pointer that can handle comparing the list data nodes.
Returns
the new head of list.

This function sorts all the elements of head. func is used to compare two elements of head. If head or func are NULL, this function returns NULL.

Note
in-place: this will change the given list, so you should now point to the new list head that is returned by this function.
Worst case is O(n * log2(n)) comparisons (calls to func()). That means that for 1,000,000 list elements, sort will do 20,000,000 comparisons.

Example:

typedef struct _Sort_Ex Sort_Ex;
struct _Sort_Ex
{
INLIST;
const char *text;
};
int
sort_cb(const Inlist *l1, const Inlist *l2)
{
const Sort_Ex *x1;
const Sort_Ex *x2;
x1 = EINA_INLIST_CONTAINER_GET(l1, Sort_Ex);
x2 = EINA_INLIST_CONTAINER_GET(l2, Sort_Ex);
return(strcmp(x1->text, x2->text));
}
extern Eina_Inlist *list;
list = eina_inlist_sort(list, sort_cb);
Eina_Inlist * eina_inlist_sort(Eina_Inlist *head, Eina_Compare_Cb func)
Sort a list according to the ordering func will return.
Definition eina_inlist.c:807
#define EINA_INLIST_CONTAINER_GET(ptr, type)
Utility macro to get the container object of an inlist.
Definition eina_inlist.h:417
struct _Eina_Inlist Eina_Inlist
Inlined list type.
Definition eina_inlist.h:393

References _Eina_Inlist::last, _Eina_Inlist::next, and _Eina_Inlist::prev.