diff options
Diffstat (limited to 'libkmod/libkmod-list.c')
-rw-r--r-- | libkmod/libkmod-list.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/libkmod/libkmod-list.c b/libkmod/libkmod-list.c new file mode 100644 index 0000000..7623693 --- /dev/null +++ b/libkmod/libkmod-list.c @@ -0,0 +1,314 @@ +/* + * libkmod - interface to kernel module operations + * + * Copyright (C) 2011-2013 ProFUSION embedded systems + * + * 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/>. + */ + +#include <stdlib.h> + +#include "libkmod.h" +#include "libkmod-internal.h" + +/** + * SECTION:libkmod-list + * @short_description: general purpose list + */ + +static inline struct list_node *list_node_init(struct list_node *node) +{ + node->next = node; + node->prev = node; + + return node; +} + +static inline void list_node_append(struct list_node *list, + struct list_node *node) +{ + if (list == NULL) { + list_node_init(node); + return; + } + + node->prev = list->prev; + list->prev->next = node; + list->prev = node; + node->next = list; +} + +static inline struct list_node *list_node_remove(struct list_node *node) +{ + if (node->prev == node || node->next == node) + return NULL; + + node->prev->next = node->next; + node->next->prev = node->prev; + + return node->next; +} + +static inline void list_node_insert_after(struct list_node *list, + struct list_node *node) +{ + if (list == NULL) { + list_node_init(node); + return; + } + + node->prev = list; + node->next = list->next; + list->next->prev = node; + list->next = node; +} + +static inline void list_node_insert_before(struct list_node *list, + struct list_node *node) +{ + if (list == NULL) { + list_node_init(node); + return; + } + + node->next = list; + node->prev = list->prev; + list->prev->next = node; + list->prev = node; +} + +static inline void list_node_append_list(struct list_node *list1, + struct list_node *list2) +{ + struct list_node *list1_last; + + if (list1 == NULL) { + list_node_init(list2); + return; + } + + list1->prev->next = list2; + list2->prev->next = list1; + + /* cache the last, because we will lose the pointer */ + list1_last = list1->prev; + + list1->prev = list2->prev; + list2->prev = list1_last; +} + +struct kmod_list *kmod_list_append(struct kmod_list *list, const void *data) +{ + struct kmod_list *new; + + new = malloc(sizeof(*new)); + if (new == NULL) + return NULL; + + new->data = (void *)data; + list_node_append(list ? &list->node : NULL, &new->node); + + return list ? list : new; +} + +struct kmod_list *kmod_list_insert_after(struct kmod_list *list, + const void *data) +{ + struct kmod_list *new; + + if (list == NULL) + return kmod_list_append(list, data); + + new = malloc(sizeof(*new)); + if (new == NULL) + return NULL; + + new->data = (void *)data; + list_node_insert_after(&list->node, &new->node); + + return list; +} + +struct kmod_list *kmod_list_insert_before(struct kmod_list *list, + const void *data) +{ + struct kmod_list *new; + + if (list == NULL) + return kmod_list_append(list, data); + + new = malloc(sizeof(*new)); + if (new == NULL) + return NULL; + + new->data = (void *)data; + list_node_insert_before(&list->node, &new->node); + + return new; +} + +struct kmod_list *kmod_list_append_list(struct kmod_list *list1, + struct kmod_list *list2) +{ + if (list1 == NULL) + return list2; + + if (list2 == NULL) + return list1; + + list_node_append_list(&list1->node, &list2->node); + + return list1; +} + +struct kmod_list *kmod_list_prepend(struct kmod_list *list, const void *data) +{ + struct kmod_list *new; + + new = malloc(sizeof(*new)); + if (new == NULL) + return NULL; + + new->data = (void *)data; + list_node_append(list ? &list->node : NULL, &new->node); + + return new; +} + +struct kmod_list *kmod_list_remove(struct kmod_list *list) +{ + struct list_node *node; + + if (list == NULL) + return NULL; + + node = list_node_remove(&list->node); + free(list); + + if (node == NULL) + return NULL; + + return container_of(node, struct kmod_list, node); +} + +struct kmod_list *kmod_list_remove_data(struct kmod_list *list, + const void *data) +{ + struct kmod_list *itr; + struct list_node *node; + + for (itr = list; itr != NULL; itr = kmod_list_next(list, itr)) { + if (itr->data == data) + break; + } + + if (itr == NULL) + return list; + + node = list_node_remove(&itr->node); + free(itr); + + if (node == NULL) + return NULL; + + return container_of(node, struct kmod_list, node); +} + +/* + * n must be greater to or equal the number of elements (we don't check the + * condition) + */ +struct kmod_list *kmod_list_remove_n_latest(struct kmod_list *list, + unsigned int n) +{ + struct kmod_list *l = list; + unsigned int i; + + for (i = 0; i < n; i++) { + l = kmod_list_last(l); + l = kmod_list_remove(l); + } + + return l; +} + +/** + * kmod_list_prev: + * @list: the head of the list + * @curr: the current node in the list + * + * Get the previous node in @list relative to @curr as if @list was not a + * circular list. I.e.: the previous of the head is NULL. It can be used to + * iterate a list by checking for NULL return to know when all elements were + * iterated. + * + * Returns: node previous to @curr or NULL if either this node is the head of + * the list or the list is empty. + */ +KMOD_EXPORT struct kmod_list *kmod_list_prev(const struct kmod_list *list, + const struct kmod_list *curr) +{ + if (list == NULL || curr == NULL) + return NULL; + + if (list == curr) + return NULL; + + return container_of(curr->node.prev, struct kmod_list, node); +} + +/** + * kmod_list_next: + * @list: the head of the list + * @curr: the current node in the list + * + * Get the next node in @list relative to @curr as if @list was not a circular + * list. I.e. calling this function in the last node of the list returns + * NULL.. It can be used to iterate a list by checking for NULL return to know + * when all elements were iterated. + * + * Returns: node next to @curr or NULL if either this node is the last of or + * list is empty. + */ +KMOD_EXPORT struct kmod_list *kmod_list_next(const struct kmod_list *list, + const struct kmod_list *curr) +{ + if (list == NULL || curr == NULL) + return NULL; + + if (curr->node.next == &list->node) + return NULL; + + return container_of(curr->node.next, struct kmod_list, node); +} + +/** + * kmod_list_last: + * @list: the head of the list + * + * Get the last element of the @list. As @list is a circular list, + * this is a cheap operation O(1) with the last element being the + * previous element. + * + * If the list has a single element it will return the list itself (as + * expected, and this is what differentiates from kmod_list_prev()). + * + * Returns: last node at @list or NULL if the list is empty. + */ +KMOD_EXPORT struct kmod_list *kmod_list_last(const struct kmod_list *list) +{ + if (list == NULL) + return NULL; + return container_of(list->node.prev, struct kmod_list, node); +} |