moparisthebest/pacman
1
0
Fork 0
mirror of https://github.com/moparisthebest/pacman synced 2024-12-22 15:58:50 -05:00
Code Issues Releases Wiki Activity

Add new alpm_list_remove_item() function

Browse Source 
This takes in the list and a list item, and does the pointer dance necessary
to remove it from the list regardless of whether it is first, last, or
somewhere in the middle. It is useful for callers that already know what
item needs to be removed and have a pointer to it rather than doing a search
by data that the plain alpm_list_remove() does.

Refactor alpm_list_remove() to use this function as well.

Signed-off-by: Dan McGee <dan@archlinux.org>
This commit is contained in:
Dan McGee 2011-02-02 20:46:28 -06:00 committed by Allan McRae
parent 09e582b411
commit 14fd1e63a2
2 changed files with 54 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
lib/libalpm/alpm_list.c
View File

@ -285,6 +285,53 @@ alpm_list_t SYMEXPORT *alpm_list_msort(alpm_list_t *list, size_t n, alpm_list_fn
return(list);
}
/**
* @brief Remove an item from the list.
* item is not freed; this is the respnsiblity of the caller.
*
* @param haystack the list to remove the item from
* @param item the item to remove from the list
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_remove_item(alpm_list_t *haystack,
alpm_list_t *item)
{
if(haystack == NULL || item == NULL) {
return(haystack);
}
if(item == haystack) {
/* Special case: removing the head node which has a back reference to
* the tail node */
haystack = item->next;
if(haystack) {
haystack->prev = item->prev;
}
item->prev = NULL;
} else if(item == haystack->prev) {
/* Special case: removing the tail node, so we need to fix the back
* reference on the head node. We also know tail != head. */
if(item->prev) {
/* i->next should always be null */
item->prev->next = item->next;
haystack->prev = item->prev;
item->prev = NULL;
}
} else {
/* Normal case, non-head and non-tail node */
if(item->next) {
item->next->prev = item->prev;
}
if(item->prev) {
item->prev->next = item->next;
}
}
return(haystack);
}
/**
* @brief Remove an item from the list.
*
@ -295,9 +342,10 @@ alpm_list_t SYMEXPORT *alpm_list_msort(alpm_list_t *list, size_t n, alpm_list_fn
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_remove(alpm_list_t *haystack, const void *needle, alpm_list_fn_cmp fn, void **data)
alpm_list_t SYMEXPORT *alpm_list_remove(alpm_list_t *haystack,
const void *needle, alpm_list_fn_cmp fn, void **data)
{
alpm_list_t *i = haystack, *tmp = NULL;
alpm_list_t *i = haystack;
if(data) {
*data = NULL;
@ -312,44 +360,16 @@ alpm_list_t SYMEXPORT *alpm_list_remove(alpm_list_t *haystack, const void *needl
i = i->next;
continue;
}
tmp = i->next;
if(fn(i->data, needle) == 0) {
/* we found a matching item */
if(i == haystack) {
/* Special case: removing the head node which has a back reference to
* the tail node */
haystack = i->next;
if(haystack) {
haystack->prev = i->prev;
}
i->prev = NULL;
} else if(i == haystack->prev) {
/* Special case: removing the tail node, so we need to fix the back
* reference on the head node. We also know tail != head. */
if(i->prev) {
/* i->next should always be null */
i->prev->next = i->next;
haystack->prev = i->prev;
i->prev = NULL;
}
} else {
/* Normal case, non-head and non-tail node */
if(i->next) {
i->next->prev = i->prev;
}
if(i->prev) {
i->prev->next = i->next;
}
}
haystack = alpm_list_remove_item(haystack, i);
if(data) {
*data = i->data;
}
i->data = NULL;
free(i);
i = NULL;
break;
} else {
i = tmp;
i = i->next;
}
}

1
lib/libalpm/alpm_list.h
View File

@ -57,6 +57,7 @@ alpm_list_t *alpm_list_add_sorted(alpm_list_t *list, void *data, alpm_list_fn_cm
alpm_list_t *alpm_list_join(alpm_list_t *first, alpm_list_t *second);
alpm_list_t *alpm_list_mmerge(alpm_list_t *left, alpm_list_t *right, alpm_list_fn_cmp fn);
alpm_list_t *alpm_list_msort(alpm_list_t *list, size_t n, alpm_list_fn_cmp fn);
alpm_list_t *alpm_list_remove_item(alpm_list_t *haystack, alpm_list_t *item);
alpm_list_t *alpm_list_remove(alpm_list_t *haystack, const void *needle, alpm_list_fn_cmp fn, void **data);
alpm_list_t *alpm_list_remove_str(alpm_list_t *haystack, const char *needle, char **data);
alpm_list_t *alpm_list_remove_dupes(const alpm_list_t *list);