/*
* 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);
}