1
0
mirror of https://github.com/moparisthebest/pacman synced 2024-12-22 15:58:50 -05:00
pacman/lib/libalpm/alpm_list.c
Dan McGee bf56fb6eb8 alpm_list: use malloc instead of calloc
In every case we were calling calloc, the struct we allocated (or the
memory to be used) is fully specified later in the method.

For alpm_list_t allocations, we always set all of data, next, and prev.

For list copying and transforming to an array, we always copy the entire
data element, so no need to zero it first.

Signed-off-by: Dan McGee <dan@archlinux.org>
2011-09-27 17:49:27 -05:00

791 lines
17 KiB
C

/*
* alpm_list.c
*
* Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
* Copyright (c) 2002-2006 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, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <string.h>
/* libalpm */
#include "alpm_list.h"
/* check exported library symbols with: nm -C -D <lib> */
#define SYMEXPORT __attribute__((visibility("default")))
#define SYMHIDDEN __attribute__((visibility("internal")))
/**
* @addtogroup alpm_list List Functions
* @brief Functions to manipulate alpm_list_t lists.
*
* These functions are designed to create, destroy, and modify lists of
* type alpm_list_t. This is an internal list type used by libalpm that is
* publicly exposed for use by frontends if desired.
*
* @{ */
/* Allocation */
/**
* @brief Free a list, but not the contained data.
*
* @param list the list to free
*/
void SYMEXPORT alpm_list_free(alpm_list_t *list)
{
alpm_list_t *it = list;
while(it) {
alpm_list_t *tmp = it->next;
free(it);
it = tmp;
}
}
/**
* @brief Free the internal data of a list structure.
*
* @param list the list to free
* @param fn a free function for the internal data
*/
void SYMEXPORT alpm_list_free_inner(alpm_list_t *list, alpm_list_fn_free fn)
{
alpm_list_t *it = list;
while(it) {
if(fn && it->data) {
fn(it->data);
}
it = it->next;
}
}
/* Mutators */
/**
* @brief Add a new item to the end of the list.
*
* @param list the list to add to
* @param data the new item to be added to the list
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_add(alpm_list_t *list, void *data)
{
alpm_list_t *ptr, *lp;
ptr = malloc(sizeof(alpm_list_t));
if(ptr == NULL) {
return list;
}
ptr->data = data;
ptr->next = NULL;
/* Special case: the input list is empty */
if(list == NULL) {
ptr->prev = ptr;
return ptr;
}
lp = alpm_list_last(list);
lp->next = ptr;
ptr->prev = lp;
list->prev = ptr;
return list;
}
/**
* @brief Add items to a list in sorted order.
*
* @param list the list to add to
* @param data the new item to be added to the list
* @param fn the comparison function to use to determine order
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_add_sorted(alpm_list_t *list, void *data, alpm_list_fn_cmp fn)
{
if(!fn || !list) {
return alpm_list_add(list, data);
} else {
alpm_list_t *add = NULL, *prev = NULL, *next = list;
add = malloc(sizeof(alpm_list_t));
if(add == NULL) {
return list;
}
add->data = data;
/* Find insertion point. */
while(next) {
if(fn(add->data, next->data) <= 0) break;
prev = next;
next = next->next;
}
/* Insert the add node to the list */
if(prev == NULL) { /* special case: we insert add as the first element */
add->prev = list->prev; /* list != NULL */
add->next = list;
list->prev = add;
return add;
} else if(next == NULL) { /* another special case: add last element */
add->prev = prev;
add->next = NULL;
prev->next = add;
list->prev = add;
return list;
} else {
add->prev = prev;
add->next = next;
next->prev = add;
prev->next = add;
return list;
}
}
}
/**
* @brief Join two lists.
* The two lists must be independent. Do not free the original lists after
* calling this function, as this is not a copy operation. The list pointers
* passed in should be considered invalid after calling this function.
*
* @param first the first list
* @param second the second list
*
* @return the resultant joined list
*/
alpm_list_t SYMEXPORT *alpm_list_join(alpm_list_t *first, alpm_list_t *second)
{
alpm_list_t *tmp;
if(first == NULL) {
return second;
}
if(second == NULL) {
return first;
}
/* tmp is the last element of the first list */
tmp = first->prev;
/* link the first list to the second */
tmp->next = second;
/* link the second list to the first */
first->prev = second->prev;
/* set the back reference to the tail */
second->prev = tmp;
return first;
}
/**
* @brief Merge the two sorted sublists into one sorted list.
*
* @param left the first list
* @param right the second list
* @param fn comparison function for determining merge order
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_mmerge(alpm_list_t *left, alpm_list_t *right, alpm_list_fn_cmp fn)
{
alpm_list_t *newlist, *lp, *tail_ptr, *left_tail_ptr, *right_tail_ptr;
if(left == NULL) {
return right;
}
if(right == NULL) {
return left;
}
/* Save tail node pointers for future use */
left_tail_ptr = left->prev;
right_tail_ptr = right->prev;
if(fn(left->data, right->data) <= 0) {
newlist = left;
left = left->next;
}
else {
newlist = right;
right = right->next;
}
newlist->prev = NULL;
newlist->next = NULL;
lp = newlist;
while((left != NULL) && (right != NULL)) {
if(fn(left->data, right->data) <= 0) {
lp->next = left;
left->prev = lp;
left = left->next;
}
else {
lp->next = right;
right->prev = lp;
right = right->next;
}
lp = lp->next;
lp->next = NULL;
}
if(left != NULL) {
lp->next = left;
left->prev = lp;
tail_ptr = left_tail_ptr;
}
else if(right != NULL) {
lp->next = right;
right->prev = lp;
tail_ptr = right_tail_ptr;
}
else {
tail_ptr = lp;
}
newlist->prev = tail_ptr;
return newlist;
}
/**
* @brief Sort a list of size `n` using mergesort algorithm.
*
* @param list the list to sort
* @param n the size of the list
* @param fn the comparison function for determining order
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_msort(alpm_list_t *list, size_t n, alpm_list_fn_cmp fn)
{
if(n > 1) {
alpm_list_t *left = list;
alpm_list_t *lastleft = alpm_list_nth(list, n/2 - 1);
alpm_list_t *right = lastleft->next;
/* terminate first list */
lastleft->next = NULL;
left = alpm_list_msort(left, n/2, fn);
right = alpm_list_msort(right, n - (n/2), fn);
list = alpm_list_mmerge(left, right, fn);
}
return list;
}
/**
* @brief Remove an item from the list.
* item is not freed; this is the responsibility 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.
*
* @param haystack the list to remove the item from
* @param needle the data member of the item we're removing
* @param fn the comparison function for searching
* @param data output parameter containing data of the removed item
*
* @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 *i = haystack;
if(data) {
*data = NULL;
}
if(needle == NULL) {
return haystack;
}
while(i) {
if(i->data == NULL) {
i = i->next;
continue;
}
if(fn(i->data, needle) == 0) {
haystack = alpm_list_remove_item(haystack, i);
if(data) {
*data = i->data;
}
free(i);
break;
} else {
i = i->next;
}
}
return haystack;
}
/**
* @brief Remove a string from a list.
*
* @param haystack the list to remove the item from
* @param needle the data member of the item we're removing
* @param data output parameter containing data of the removed item
*
* @return the resultant list
*/
alpm_list_t SYMEXPORT *alpm_list_remove_str(alpm_list_t *haystack,
const char *needle, char **data)
{
return alpm_list_remove(haystack, (const void *)needle,
(alpm_list_fn_cmp)strcmp, (void **)data);
}
/**
* @brief Create a new list without any duplicates.
*
* This does NOT copy data members.
*
* @param list the list to copy
*
* @return a new list containing non-duplicate items
*/
alpm_list_t SYMEXPORT *alpm_list_remove_dupes(const alpm_list_t *list)
{
const alpm_list_t *lp = list;
alpm_list_t *newlist = NULL;
while(lp) {
if(!alpm_list_find_ptr(newlist, lp->data)) {
newlist = alpm_list_add(newlist, lp->data);
}
lp = lp->next;
}
return newlist;
}
/**
* @brief Copy a string list, including data.
*
* @param list the list to copy
*
* @return a copy of the original list
*/
alpm_list_t SYMEXPORT *alpm_list_strdup(const alpm_list_t *list)
{
const alpm_list_t *lp = list;
alpm_list_t *newlist = NULL;
while(lp) {
newlist = alpm_list_add(newlist, strdup(lp->data));
lp = lp->next;
}
return newlist;
}
/**
* @brief Copy a list, without copying data.
*
* @param list the list to copy
*
* @return a copy of the original list
*/
alpm_list_t SYMEXPORT *alpm_list_copy(const alpm_list_t *list)
{
const alpm_list_t *lp = list;
alpm_list_t *newlist = NULL;
while(lp) {
newlist = alpm_list_add(newlist, lp->data);
lp = lp->next;
}
return newlist;
}
/**
* @brief Copy a list and copy the data.
* Note that the data elements to be copied should not contain pointers
* and should also be of constant size.
*
* @param list the list to copy
* @param size the size of each data element
*
* @return a copy of the original list, data copied as well
*/
alpm_list_t SYMEXPORT *alpm_list_copy_data(const alpm_list_t *list,
size_t size)
{
const alpm_list_t *lp = list;
alpm_list_t *newlist = NULL;
while(lp) {
void *newdata = malloc(size);
if(newdata) {
memcpy(newdata, lp->data, size);
newlist = alpm_list_add(newlist, newdata);
lp = lp->next;
}
}
return newlist;
}
/**
* @brief Create a new list in reverse order.
*
* @param list the list to copy
*
* @return a new list in reverse order
*/
alpm_list_t SYMEXPORT *alpm_list_reverse(alpm_list_t *list)
{
const alpm_list_t *lp;
alpm_list_t *newlist = NULL, *backup;
if(list == NULL) {
return NULL;
}
lp = alpm_list_last(list);
/* break our reverse circular list */
backup = list->prev;
list->prev = NULL;
while(lp) {
newlist = alpm_list_add(newlist, lp->data);
lp = lp->prev;
}
list->prev = backup; /* restore tail pointer */
return newlist;
}
/* Accessors */
/**
* @brief Return nth element from list (starting from 0).
*
* @param list the list
* @param n the index of the item to find (n < alpm_list_count(list) IS needed)
*
* @return an alpm_list_t node for index `n`
*/
alpm_list_t SYMEXPORT *alpm_list_nth(const alpm_list_t *list, size_t n)
{
const alpm_list_t *i = list;
while(n--) {
i = i->next;
}
return (alpm_list_t *)i;
}
/**
* @brief Get the next element of a list.
*
* @param node the list node
*
* @return the next element, or NULL when no more elements exist
*/
inline alpm_list_t SYMEXPORT *alpm_list_next(const alpm_list_t *node)
{
if(node) {
return node->next;
} else {
return NULL;
}
}
/**
* @brief Get the previous element of a list.
*
* @param list the list head
*
* @return the previous element, or NULL when no previous element exist
*/
inline alpm_list_t SYMEXPORT *alpm_list_previous(const alpm_list_t *list)
{
if(list && list->prev->next) {
return list->prev;
} else {
return NULL;
}
}
/**
* @brief Get the last item in the list.
*
* @param list the list
*
* @return the last element in the list
*/
alpm_list_t SYMEXPORT *alpm_list_last(const alpm_list_t *list)
{
if(list) {
return list->prev;
} else {
return NULL;
}
}
/**
* @brief Get the data member of a list node.
*
* @param node the list node
*
* @return the contained data, or NULL if none
*/
void SYMEXPORT *alpm_list_getdata(const alpm_list_t *node)
{
if(node == NULL) return NULL;
return node->data;
}
/* Misc */
/**
* @brief Get the number of items in a list.
*
* @param list the list
*
* @return the number of list items
*/
size_t SYMEXPORT alpm_list_count(const alpm_list_t *list)
{
size_t i = 0;
const alpm_list_t *lp = list;
while(lp) {
++i;
lp = lp->next;
}
return i;
}
/**
* @brief Find an item in a list.
*
* @param needle the item to search
* @param haystack the list
* @param fn the comparison function for searching (!= NULL)
*
* @return `needle` if found, NULL otherwise
*/
void SYMEXPORT *alpm_list_find(const alpm_list_t *haystack, const void *needle,
alpm_list_fn_cmp fn)
{
const alpm_list_t *lp = haystack;
while(lp) {
if(lp->data && fn(lp->data, needle) == 0) {
return lp->data;
}
lp = lp->next;
}
return NULL;
}
/* trivial helper function for alpm_list_find_ptr */
static int ptr_cmp(const void *p, const void *q)
{
return (p != q);
}
/**
* @brief Find an item in a list.
*
* Search for the item whose data matches that of the `needle`.
*
* @param needle the data to search for (== comparison)
* @param haystack the list
*
* @return `needle` if found, NULL otherwise
*/
void SYMEXPORT *alpm_list_find_ptr(const alpm_list_t *haystack,
const void *needle)
{
return alpm_list_find(haystack, needle, ptr_cmp);
}
/**
* @brief Find a string in a list.
*
* @param needle the string to search for
* @param haystack the list
*
* @return `needle` if found, NULL otherwise
*/
char SYMEXPORT *alpm_list_find_str(const alpm_list_t *haystack,
const char *needle)
{
return (char *)alpm_list_find(haystack, (const void *)needle,
(alpm_list_fn_cmp)strcmp);
}
/**
* @brief Find the differences between list `left` and list `right`
*
* The two lists must be sorted. Items only in list `left` are added to the
* `onlyleft` list. Items only in list `right` are added to the `onlyright`
* list.
*
* @param left the first list
* @param right the second list
* @param fn the comparison function
* @param onlyleft pointer to the first result list
* @param onlyright pointer to the second result list
*
*/
void SYMEXPORT alpm_list_diff_sorted(const alpm_list_t *left,
const alpm_list_t *right, alpm_list_fn_cmp fn,
alpm_list_t **onlyleft, alpm_list_t **onlyright)
{
const alpm_list_t *l = left;
const alpm_list_t *r = right;
if(!onlyleft && !onlyright) {
return;
}
while(l != NULL && r != NULL) {
int cmp = fn(l->data, r->data);
if(cmp < 0) {
if(onlyleft) {
*onlyleft = alpm_list_add(*onlyleft, l->data);
}
l = l->next;
}
else if(cmp > 0) {
if(onlyright) {
*onlyright = alpm_list_add(*onlyright, r->data);
}
r = r->next;
} else {
l = l->next;
r = r->next;
}
}
while(l != NULL) {
if(onlyleft) {
*onlyleft = alpm_list_add(*onlyleft, l->data);
}
l = l->next;
}
while(r != NULL) {
if(onlyright) {
*onlyright = alpm_list_add(*onlyright, r->data);
}
r = r->next;
}
}
/**
* @brief Find the items in list `lhs` that are not present in list `rhs`.
*
* @param lhs the first list
* @param rhs the second list
* @param fn the comparison function
*
* @return a list containing all items in `lhs` not present in `rhs`
*/
alpm_list_t SYMEXPORT *alpm_list_diff(const alpm_list_t *lhs,
const alpm_list_t *rhs, alpm_list_fn_cmp fn)
{
alpm_list_t *left, *right;
alpm_list_t *ret = NULL;
left = alpm_list_copy(lhs);
left = alpm_list_msort(left, alpm_list_count(left), fn);
right = alpm_list_copy(rhs);
right = alpm_list_msort(right, alpm_list_count(right), fn);
alpm_list_diff_sorted(left, right, fn, &ret, NULL);
alpm_list_free(left);
alpm_list_free(right);
return ret;
}
/**
* @brief Copy a list and data into a standard C array of fixed length.
* Note that the data elements are shallow copied so any contained pointers
* will point to the original data.
*
* @param list the list to copy
* @param n the size of the list
* @param size the size of each data element
*
* @return an array version of the original list, data copied as well
*/
void SYMEXPORT *alpm_list_to_array(const alpm_list_t *list, size_t n,
size_t size)
{
size_t i;
const alpm_list_t *item;
char *array;
if(n == 0) {
return NULL;
}
array = malloc(n * size);
if(array == NULL) {
return NULL;
}
for(i = 0, item = list; i < n && item; i++, item = item->next) {
memcpy(array + i * size, item->data, size);
}
return array;
}
/** @} */
/* vim: set ts=2 sw=2 noet: */