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/*
$Id: ll.c,v 1.1 2005/05/29 08:24:05 airborne Exp $
Copyright (C) 2005 Kris Verbeeck <airborne@advalvas.be>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include "cddb/ll.h"
/* --- type and structure definitions */
/**
* Linked list element.
*/
struct elem_s {
struct elem_s *prev; /**< previous element */
struct elem_s *next; /**< next element */
void *data; /**< the actual data of the element */
};
struct list_s {
int cnt; /**< number of elements in the list */
elem_destroy_cb *free_data; /**< callback used to free element data */
elem_t *first; /**< the first element in the list */
elem_t *last; /**< the last element in the list */
elem_t *it; /**< iterator element */
};
/* --- private prototypes */
static elem_t *elem_construct(void *data);
/**
* @return The next element.
*/
static elem_t *elem_destroy(elem_t *elem, elem_destroy_cb *cb);
/* --- private functions */
static elem_t *elem_construct(void *data)
{
elem_t *elem;
elem = (elem_t*)calloc(1, sizeof(elem_t));
elem->data = data;
return elem;
}
static elem_t *elem_destroy(elem_t *elem, elem_destroy_cb *cb)
{
elem_t *next = NULL;
if (elem) {
next = elem->next;
if (cb) {
cb(elem->data);
}
free(elem);
}
return next;
}
/* --- construction / destruction */
list_t *list_new(elem_destroy_cb *cb)
{
list_t *list;
list = (list_t*)calloc(1, sizeof(list_t));
list->free_data = cb;
return list;
}
void list_destroy(list_t *list)
{
list_flush(list);
if (list) {
free(list);
}
}
void list_flush(list_t *list)
{
elem_t *elem;
if (list) {
elem = list->first;
while (elem) {
elem = elem_destroy(elem, list->free_data);
}
list->first = list->last = NULL;
list->cnt = 0;
}
}
/* --- list elements --- */
void *element_data(elem_t *elem)
{
if (elem) {
return elem->data;
}
return NULL;
}
/* --- getters & setters --- */
elem_t *list_append(list_t *list, void *data)
{
elem_t *elem = NULL;
if (list) {
elem = elem_construct(data);
if (elem) {
if (list->cnt == 0) {
list->first = list->last = elem;
} else {
list->last->next = elem;
elem->prev = list->last;
list->last = elem;
}
list->cnt++;
}
}
return elem;
}
int list_size(list_t *list)
{
if (list) {
return list->cnt;
}
return 0;
}
elem_t *list_get(list_t *list, int idx)
{
elem_t *elem = NULL;
if (list) {
if ((idx >= 0) && (idx < list->cnt)) {
elem = list->first;
while (idx) {
elem = elem->next;
idx--;
}
}
}
return elem;
}
elem_t *list_first(list_t *list)
{
if (list) {
list->it = list->first;
return list->it;
}
return NULL;
}
elem_t *list_next(list_t *list)
{
if (list) {
if (list->it) {
list->it = list->it->next;
}
return list->it;
}
return NULL;
}
/* --- iteration */
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