toaruos/userspace/lib/list.c
2012-01-29 17:05:42 -06:00

136 lines
2.7 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
*
* General-purpose list implementations.
*/
#include <stdlib.h>
#include "list.h"
void list_destroy(list_t * list) {
/* Free all of the contents of a list */
node_t * n = list->head;
while (n) {
free(n->value);
n = n->next;
}
}
void list_free(list_t * list) {
/* Free the actual structure of a list */
node_t * n = list->head;
while (n) {
node_t * s = n->next;
free(n);
n = s;
}
}
void list_append(list_t * list, node_t * node) {
/* Insert a node onto the end of a list */
if (!list->tail) {
list->head = node;
} else {
list->tail->next = node;
node->prev = list->tail;
}
list->tail = node;
list->length++;
}
void list_insert(list_t * list, void * item) {
/* Insert an item into a list */
node_t * node = malloc(sizeof(node_t));
node->value = item;
node->next = NULL;
node->prev = NULL;
list_append(list, node);
}
list_t * list_create() {
/* Create a fresh list */
list_t * out = malloc(sizeof(list_t));
out->head = NULL;
out->tail = NULL;
out->length = 0;
return out;
}
node_t * list_find(list_t * list, void * value) {
foreach(item, list) {
if (item->value == value) {
return item;
}
}
return NULL;
}
void list_remove(list_t * list, size_t index) {
/* remove index from the list */
if (index > list->length) return;
size_t i = 0;
node_t * n = list->head;
while (i < index) {
n = n->next;
i++;
}
list_delete(list, n);
}
void list_delete(list_t * list, node_t * node) {
/* remove node from the list */
if (node == list->head) {
list->head = node->next;
}
if (node == list->tail) {
list->tail = node->prev;
}
if (node->prev) {
node->prev->next = node->next;
}
if (node->next) {
node->next->prev = node->prev;
}
list->length--;
}
node_t * list_pop(list_t * list) {
/* Remove and return the last value in the list
* If you don't need it, you still probably want to free it!
* Try free(list_pop(list)); !
* */
if (!list->tail) return NULL;
node_t * out = list->tail;
list_delete(list, list->tail);
return out;
}
node_t * list_dequeue(list_t * list) {
if (!list->head) return NULL;
node_t * out = list->head;
list_delete(list, list->head);
return out;
}
list_t * list_copy(list_t * original) {
/* Create a new copy of original */
list_t * out = list_create();
node_t * node = original->head;
while (node) {
list_insert(out, node->value);
}
return out;
}
void list_merge(list_t * target, list_t * source) {
/* Destructively merges source into target */
if (target->tail) {
target->tail->next = source->head;
} else {
target->head = source->head;
}
if (source->tail) {
target->tail = source->tail;
}
target->length += source->length;
free(source);
}