/* EINA - EFL data type library * Copyright (C) 2002-2008 Carsten Haitzler, Vincent Torri * * 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_INLIST_H_ #define EINA_INLIST_H_ #include "eina_types.h" #include "eina_iterator.h" #include "eina_accessor.h" #include /** * @page inlist_01_example_page Eina_Inlist basic usage * @dontinclude eina_inlist_01.c * * To see the full source for this example, click here: @ref * eina_inlist_01_c * * As explained before, inline lists mean its nodes pointers are part of same * memory block/blob. This is done by using the macro @ref EINA_INLIST inside the * data structure that will be used: * * @skip struct * @until }; * * The resulting node representing this struct can be exemplified by the * following picture: * * @image html eina_inlist-node_eg1-my-struct.png * @image rtf eina_inlist-node_eg1-my-struct.png * @image latex eina_inlist-node_eg1-my-struct.eps * * Let's define a comparison function that will be used later during the * sorting of the list: * * @skip int * @until } * * The @ref Eina_Inlist can be used exactly the same way as @ref Eina_List when * appending, prepending and removing items. But since we already have the node * pointers inside the structure, they need to be retrieved with the macro @ref * EINA_INLIST_GET : * * @skip malloc * @until append * * Notice that @ref eina_inlist_append always receives the head of the list as * first argument, and its return value should be used as the list pointer * (head): * * @skip malloc * @until append * * After appending 3 items, the list now should look similar to this: * * @image html eina_inlist-node_eg1-inlist.png * @image rtf eina_inlist-node_eg1-inlist.png * @image latex eina_inlist-node_eg1-inlist.eps width=\textwidth * * The macro @ref EINA_INLIST_FOREACH can be used to iterate over the list: * * @skip printf * @until cur->a * * @ref eina_inlist_promote(), @ref eina_inlist_demote(), @ref * eina_inlist_append_relative() and similar functions all work in the same way * as the @ref Eina_List : * * @skip eina_inlist_promote * @until eina_inlist_demote * * Now let's use the @c sort_cb function declared above to sort our list: * * @skipline eina_inlist_sort * * Removing an element from the inlist is also similar to @ref Eina_List : * * @skip inlist_remove * @until free * * Another way of walking through the inlist. * * @skip for * @until } * * Notice that in the previous piece of code, since we only have the pointers to * the inlist nodes, we have to use the @ref EINA_INLIST_CONTAINER_GET macro * that will return the pointer to the entire structure. Of course, in this case * it is the same as the list pointer, since the @ref EINA_INLIST macro was used * in the beginning of the structure. * * Now to finish this example, lets delete this list: * * @skip while * @until } */ /** * @page inlist_02_example_page Eina_Inlist advanced usage - lists and inlists * @dontinclude eina_inlist_02.c * * This example describes the usage of @ref Eina_Inlist mixed with @ref * Eina_List . We create and add elements to an inlist, and the even members * are also added to a normal list. Later we remove the elements divisible by 3 * from this normal list. * * The struct that is going to be used is the same used in @ref * inlist_01_example_page , since we still need the @ref EINA_INLIST macro to * declare the inlist node info: * * @skip struct * @until }; * * The resulting node representing this struct can be exemplified by the * following picture: * * @image html eina_inlist-node_eg2-my-struct.png * @image rtf eina_inlist-node_eg2-my-struct.png * @image latex eina_inlist-node_eg2-my-struct.eps * * Now we need some pointers and auxiliar variables that will help us iterate on * the lists: * * @skip struct * @until l_next; * * Allocating 100 elements and putting them into an inlist, and the even * elements also go to the normal list: * * @skip for * @until } * * After this point, what we have are two distinct lists that share some * elements. The first list (inlist) is defined by the pointers inside the * elements data structure, while the second list (normal list) has its own node * data structure that is kept outside of the elements. * * The two lists, sharing some elements, can be represented by the following * picture: * * * @image rtf eina_inlist-node_eg2-list-inlist.png * @image latex eina_inlist-node_eg2-list-inlist.eps width=\textwidth * * Accessing both lists is done normally, as if they didn't have any elements in * common: * * @skip printf * @until eina_list_count * * We can remove elements from the normal list, but we just don't free them * because they are still stored in the inlist: * * @skip EINA_LIST_FOREACH_SAFE * @until eina_list_count * * To finish this example, we want to free both lists, we can't just free all * elements on the second list (normal list) because they are still being used * in the inlist. So we first discard the normal list without freeing its * elements, then we free all elements in the inlist (that contains all elements * allocated until now): * * @skip eina_list_free * @until } * * Here is the full source code for this example: @ref eina_inlist_02_c */ /** * @page inlist_03_example_page Eina_Inlist advanced usage - multi-inlists * @dontinclude eina_inlist_03.c * * This example describes the usage of multiple inlists storing the same data. * It means that some data may appear in more than one inlist at the same time. * We will demonstrate this by creating an inlist with 100 numbers, and adding * the odd numbers to the second inlist, then remove the numbers divisible by 3 * from the second list. * * To accomplish this, it is necessary to have two inlist pointers in the struct * that is going to be stored. We are using the default inlist member @ref * EINA_INLIST, and adding another member @c even that is of type @ref * Eina_Inlist too: * * @skip struct * @until }; * * The representation for this struct is: * * @image html eina_inlist-node_eg3-my-struct.png * @image rtf eina_inlist-node_eg3-my-struct.png * @image latex eina_inlist-node_eg3-my-struct.eps * * And we will define some convenience macros that are equivalent to @ref * EINA_INLIST_GET and @ref EINA_INLIST_CONTAINER_GET : * * @skip define * @until offsetof * * We need two pointers, one for each list, and a pointer that will be used as * an iterator: * * @skipline Eina_Inlist * * Now we allocate and add to the first list every number from 0 to 99. These * nodes data also have the @ref Eina_Inlist node info for the second list (@c * even). We will use them to add just the even numbers to the second list, the * @c list_even. Also notice that we are using our macro @c EVEN_INLIST_GET to * get the pointer to the even list node info: * * @skip for * @until } * * And the resulting lists will be as follow: * * * @image rtf eina_inlist-node_eg3-two-inlists.png * @image latex eina_inlist-node_eg3-two-inlists.eps width=\textwidth * * For the first list, we can use the macro @ref EINA_INLIST_FOREACH to iterate * over its elements: * * @skip FOREACH * @until printf * * But for the second list, we have to do it manually. Of course we could create * a similar macro to @ref EINA_INLIST_FOREACH, but since this macro is more * complex than the other two and we are using it only once, it's better to just * do it manually: * * @skip for * @until } * * Let's just check that the two lists have the expected number of elements: * * @skip list count * @until list_even count * * And removing the numbers divisible by 3 only from the second list: * * @skip itr * @until list_even count * * Now that we don't need the two lists anymore, we can just free all the items. * Since all of the allocated data was put into the first list, and both lists * are made of pointers to inside the data structures, we can free only the * first list (that contains all the elements) and the second list will be gone * with it: * * @skip while * @until free * * To see the full source code for this example, click here: @ref * eina_inlist_03_c * */ /** * @page eina_inlist_01_c eina_inlist_01.c Eina_Inlist basic usage source * @include eina_inlist_01.c */ /** * @page eina_inlist_02_c eina_inlist_02.c Eina_Inlist advanced usage - lists and inlists source * @include eina_inlist_02.c */ /** * @page eina_inlist_03_c eina_inlist_03.c Eina_Inlist advanced usage - multi-inlists source * @include eina_inlist_03.c */ /** * @addtogroup Eina_Inline_List_Group Inline List * * @brief 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 * @c 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 * @ref eina_list_append() or @ref 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 @ref inlist_advanced 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: @ref inlist_01_example_page * * @section inlist_algo Algorithm * * The basic structure can be represented by the following picture: * * @image html eina_inlist-node.png * @image rtf eina_inlist-node.png * @image latex eina_inlist-node.eps * * One data structure will also have the node information, with three pointers: * @a prev, @a next and @a last. The @a 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. * * @section inlist_perf 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 @ref * eina_inlist_count() is order-N, while @ref eina_list_count() is order-1 (constant * time). * * For the same reasons, @ref eina_inlist_sort() is slower than @ref * eina_list_sort() . If the list is intended to have faster access, be * sorted/merged frequently, or needs to have other complex operations, consider * using @ref Eina_List instead. * * @section inlist_advanced 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 * @ref EINA_INLIST during the struct declaration. This allows one to use the * convenience macros @ref EINA_INLIST_GET(), @ref EINA_INLIST_CONTAINER_GET(), * @ref EINA_INLIST_FOREACH() and so. This happens because the @ref EINA_INLIST * macro declares a struct member with the name @a __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 * @ref Eina_List too. If this happens, the inlist nodes can be added to the * @ref Eina_List without any problems. This example demonstrates this case: * @ref inlist_02_example_page * * 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: * @ref inlist_03_example_page * * List of examples: * @li @ref inlist_01_example_page * @li @ref inlist_02_example_page * @li @ref inlist_03_example_page * * @{ */ /** * @addtogroup Eina_Data_Types_Group Data Types * * @{ */ /** * @addtogroup Eina_Containers_Group Containers * * @{ */ /** * @defgroup Eina_Inline_List_Group Inline List * * @{ */ /** * @typedef Eina_Inlist * Inlined list type. */ typedef struct _Eina_Inlist Eina_Inlist; /** * @struct _Eina_Inlist * Inlined list type. */ struct _Eina_Inlist { Eina_Inlist *next; /**< next node */ Eina_Inlist *prev; /**< previous node */ Eina_Inlist *last; /**< last node */ }; /** Used for declaring an inlist member in a struct */ #define EINA_INLIST Eina_Inlist __in_list /** Utility macro to get the inlist object of a struct */ #define EINA_INLIST_GET(Inlist) (& ((Inlist)->__in_list)) /** Utility macro to get the container object of an inlist */ #define EINA_INLIST_CONTAINER_GET(ptr, \ type) ((type *)((char *)ptr - \ offsetof(type, __in_list))) /** * 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 @a list. * * @note @a 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 @a new_l prev and next pointers is done, so it's safe * to have them uninitialized. * * @param list existing list head or NULL to create a new list. * @param new_l new list node, must not be NULL. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_append(Eina_Inlist *in_list, Eina_Inlist *in_item) EINA_ARG_NONNULL(2) EINA_WARN_UNUSED_RESULT; /** * Add a new node to beginning of list. * * @note this code is meant to be fast: appends are O(1) and do not * walk @a list. * * @note @a 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 @a new_l prev and next pointers is done, so it's safe * to have them uninitialized. * * @param list existing list head or NULL to create a new list. * @param new_l new list node, must not be NULL. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_prepend(Eina_Inlist *in_list, Eina_Inlist *in_item) EINA_ARG_NONNULL(2) EINA_WARN_UNUSED_RESULT; /** * 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 @a list. * * @note @a 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 @a new_l prev and next pointers is done, so it's safe * to have them uninitialized. * * @note @a relative is considered to be inside @a list, no checks are * done to confirm that and giving nodes from different lists * will lead to problems. Giving NULL @a relative is the same as * eina_list_append(). * * @param list existing list head or NULL to create a new list. * @param new_l new list node, must not be NULL. * @param relative reference node, @a new_l will be added after it. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_append_relative(Eina_Inlist *in_list, Eina_Inlist *in_item, Eina_Inlist *in_relative) EINA_ARG_NONNULL(2) EINA_WARN_UNUSED_RESULT; /** * 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 @a list. * * @note @a 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 @a new_l prev and next pointers is done, so it's safe * to have them uninitialized. * * @note @a relative is considered to be inside @a list, no checks are * done to confirm that and giving nodes from different lists * will lead to problems. Giving NULL @a relative is the same as * eina_list_prepend(). * * @param list existing list head or NULL to create a new list. * @param new_l new list node, must not be NULL. * @param relative reference node, @a new_l will be added before it. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_prepend_relative(Eina_Inlist *in_list, Eina_Inlist *in_item, Eina_Inlist *in_relative) EINA_ARG_NONNULL(2) EINA_WARN_UNUSED_RESULT; /** * Remove node from list. * * @note this code is meant to be fast: appends are O(1) and do not * walk @a list. * * @note @a item is considered to be inside @a list, no checks are * done to confirm that and giving nodes from different lists * will lead to problems, especially if @a item is the head since * it will be different from @a list and the wrong new head will * be returned. * * @param list existing list head, must not be NULL. * @param item existing list node, must not be NULL. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_remove(Eina_Inlist *in_list, Eina_Inlist *in_item) EINA_ARG_NONNULL(1, 2) EINA_WARN_UNUSED_RESULT; /** * 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. * * @param list existing list to search @a item in, must not be NULL. * @param item what to search for, must not be NULL. * * @return @a item if found, NULL if not. */ EAPI Eina_Inlist *eina_inlist_find(Eina_Inlist *in_list, Eina_Inlist *in_item) EINA_ARG_NONNULL(2) EINA_WARN_UNUSED_RESULT; /** * Move existing node to beginning of list. * * @note this code is meant to be fast: appends are O(1) and do not * walk @a list. * * @note @a item is considered to be inside @a list. No checks are * done to confirm this, and giving nodes from different lists * will lead to problems. * * @param list existing list head or NULL to create a new list. * @param item list node to move to beginning (head), must not be NULL. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_promote(Eina_Inlist *list, Eina_Inlist *item) EINA_ARG_NONNULL(1, 2) EINA_WARN_UNUSED_RESULT; /** * Move existing node to end of list. * * @note this code is meant to be fast: appends are O(1) and do not * walk @a list. * * @note @a item is considered to be inside @a list. No checks are * done to confirm this, and giving nodes from different lists * will lead to problems. * * @param list existing list head or NULL to create a new list. * @param item list node to move to end (tail), must not be NULL. * * @return the new list head. Use it and not @a list anymore. */ EAPI Eina_Inlist *eina_inlist_demote(Eina_Inlist *list, Eina_Inlist *item) EINA_ARG_NONNULL(1, 2) EINA_WARN_UNUSED_RESULT; /** * @brief Get the count of the number of items in a list. * * @param list The list whose count to return. * @return The number of members in the list. * * This function returns how many members @p list contains. If the * list is @c 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! */ EAPI unsigned int eina_inlist_count(const Eina_Inlist *list) EINA_WARN_UNUSED_RESULT; /** * @brief Returns a new iterator associated to @a list. * * @param list The list. * @return A new iterator. * * This function returns a newly allocated iterator associated to @p * list. If @p list is @c NULL or the count member of @p 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! */ EAPI Eina_Iterator *eina_inlist_iterator_new(const Eina_Inlist *in_list) EINA_MALLOC EINA_WARN_UNUSED_RESULT; /** * @brief Returns a new accessor associated to a list. * * @param list The list. * @return A new accessor. * * This function returns a newly allocated accessor associated to * @p list. If @p list is @c NULL or the count member of @p 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. */ EAPI Eina_Accessor *eina_inlist_accessor_new(const Eina_Inlist *in_list) EINA_MALLOC EINA_WARN_UNUSED_RESULT; /** * @brief Insert a new node into a sorted list. * * @param list The given linked list, @b must be sorted. * @param item list node to insert, must not be NULL. * @param func The function called for the sort. * @return 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 @p list is @c 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 @p func) average/worst case * performance as it uses eina_list_search_sorted_near_list() and thus * is bounded to that. 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). */ EAPI Eina_Inlist *eina_inlist_sorted_insert(Eina_Inlist *list, Eina_Inlist *item, Eina_Compare_Cb func) EINA_ARG_NONNULL(2, 3) EINA_WARN_UNUSED_RESULT; /** * @brief Sort a list according to the ordering func will return. * * @param list The list handle to sort. * @param func A function pointer that can handle comparing the list data * nodes. * @return the new head of list. * * This function sorts all the elements of @p list. @p func is used to * compare two elements of @p list. If @p list or @p func are @c NULL, * this function returns @c NULL. * * @note @b in-place: this will change the given list, so you should * now point to the new list head that is returned by this function. * * @note worst case is O(n * log2(n)) comparisons (calls to func()), * O(n) comparisons average case. That means that for 1,000,000 list * elements, sort will usually do 1,000,000 comparisons, but may do up * to 20,000,000. * * Example: * @code * 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); * @endcode */ EAPI Eina_Inlist *eina_inlist_sort(Eina_Inlist *head, Eina_Compare_Cb func); /* This two macros are helpers for the _FOREACH ones, don't use them */ #define _EINA_INLIST_OFFSET(ref) ((char *)&(ref)->__in_list - (char *)(ref)) #define _EINA_INLIST_CONTAINER(ref, ptr) (void *)((char *)(ptr) - \ _EINA_INLIST_OFFSET(ref)) #define EINA_INLIST_FOREACH(list, l) \ 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_FOREACH_SAFE(list, list2, l) \ for (l = (list ? _EINA_INLIST_CONTAINER(l, list) : NULL), list2 = l ? ((EINA_INLIST_GET(l) ? EINA_INLIST_GET(l)->next : NULL)) : NULL; \ l; \ l = _EINA_INLIST_CONTAINER(l, list2), list2 = list2 ? list2->next : NULL) #define EINA_INLIST_REVERSE_FOREACH(list, l) \ 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)) /** * @} */ /** * @} */ /** * @} */ /** * @} */ #endif /*EINA_INLIST_H_*/