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pacman/lib/libalpm/list.c
Aurelien Foret 03f2ec2d0b rewrote list_free to not be recursive anymore
(it can trigger segmentation faults when freeing long lists)
2005-03-26 20:56:08 +00:00

276 lines
5.0 KiB
C

/*
* list.c
*
* Copyright (c) 2002-2005 by Judd Vinet <jvinet@zeroflux.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
/* pacman */
#include "list.h"
/* Check PMList sanity
*
* 1: List seems to be OK.
* 0: We're in deep ...
*/
int _alpm_list_check(PMList* list)
{
PMList* it = NULL;
if(list == NULL) {
return(1);
}
if(list->last == NULL) {
return(0);
}
for(it = list; it && it->next; it = it->next);
if(it != list->last) {
return(0);
}
return(1);
}
PMList* pm_list_new()
{
PMList *list = NULL;
list = (PMList *)malloc(sizeof(PMList));
if(list == NULL) {
return(NULL);
}
list->data = NULL;
list->prev = NULL;
list->next = NULL;
list->last = list;
return(list);
}
void pm_list_free(PMList *list)
{
PMList *ptr, *it = list;
while(it) {
ptr = it->next;
free(it->data);
free(it);
it = ptr;
}
}
PMList* pm_list_add(PMList *list, void *data)
{
PMList *ptr, *lp;
ptr = list;
if(ptr == NULL) {
ptr = pm_list_new();
if(ptr == NULL) {
return(NULL);
}
}
lp = pm_list_last(ptr);
if(lp == ptr && lp->data == NULL) {
/* nada */
} else {
lp->next = pm_list_new();
if(lp->next == NULL) {
return(NULL);
}
lp->next->prev = lp;
lp->last = NULL;
lp = lp->next;
}
lp->data = data;
ptr->last = lp;
return(ptr);
}
/* Add items to a list in sorted order. Use the given comparision func to
* determine order.
*/
PMList* pm_list_add_sorted(PMList *list, void *data, pm_fn_cmp fn)
{
PMList *add;
PMList *prev = NULL;
PMList *iter = list;
add = pm_list_new();
add->data = data;
/* Find insertion point. */
while(iter) {
if(fn(add->data, iter->data) <= 0) break;
prev = iter;
iter = iter->next;
}
/* Insert node before insertion point. */
add->prev = prev;
add->next = iter;
if(iter != NULL) {
iter->prev = add; /* Not at end. */
} else {
if (list != NULL) {
list->last = add; /* Added new to end, so update the link to last. */
}
}
if(prev != NULL) {
prev->next = add; /* In middle. */
} else {
if(list == NULL) {
add->last = add;
} else {
add->last = list->last;
list->last = NULL;
}
list = add; /* Start or empty, new list head. */
}
return(list);
}
/* list: the beginning of the list
* item: the item in the list to be removed
*
* returns:
* list with item removed
*/
PMList* _alpm_list_remove(PMList* list, PMList* item)
{
assert(_alpm_list_check(list));
if(list == NULL || item == NULL) {
return(NULL);
}
/* Remove first item in list. */
if(item == list) {
if(list->next == NULL) { /* Only item in list. */
pm_list_free(item);
return(NULL);
} else {
list->next->prev = NULL;
list->next->last = list->last;
list = list->next;
item->prev = item->next = NULL;
pm_list_free(item);
return(list);
}
}
/* Remove last item in list. */
if(list->last == item) {
list->last = item->prev;
item->prev->next = NULL;
item->prev = item->next = NULL;
pm_list_free(item);
return(list);
}
/* Remove middle item in list. */
assert(item->prev != NULL && item->next != NULL);
item->prev->next = item->next;
item->next->prev = item->prev;
item->prev = item->next = NULL;
pm_list_free(item);
assert(_alpm_list_check(list));
return(list);
}
int pm_list_count(PMList *list)
{
int i;
PMList *lp;
for(lp = list, i = 0; lp; lp = lp->next, i++);
return(i);
}
int pm_list_is_ptrin(PMList *haystack, void *needle)
{
PMList *lp;
for(lp = haystack; lp; lp = lp->next) {
if(lp->data == needle) {
return(1);
}
}
return(0);
}
/* Test for existence of a string in a PMList
*/
PMList *pm_list_is_strin(char *needle, PMList *haystack)
{
PMList *lp;
for(lp = haystack; lp; lp = lp->next) {
if(lp->data && !strcmp(lp->data, needle)) {
return(lp);
}
}
return(NULL);
}
PMList* pm_list_last(PMList *list)
{
if (list == NULL)
return(NULL);
assert(list->last != NULL);
return(list->last);
}
/* Reverse the order of a list
*
* The caller is responsible for freeing the old list
*/
PMList* _alpm_list_reverse(PMList *list)
{
/* simple but functional -- we just build a new list, starting
* with the old list's tail
*/
PMList *newlist = NULL;
PMList *lp;
for(lp = list->last; lp; lp = lp->prev) {
newlist = pm_list_add(newlist, lp->data);
}
return(newlist);
}
/* vim: set ts=2 sw=2 noet: */