pacman/lib/libalpm/filelist.c

137 lines
3.3 KiB
C

/*
* filelist.c
*
* Copyright (c) 2012-2016 Pacman Development Team <pacman-dev@archlinux.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 <limits.h>
#include <string.h>
#include <sys/stat.h>
/* libalpm */
#include "filelist.h"
#include "util.h"
/* Returns the difference of the provided two lists of files.
* Pre-condition: both lists are sorted!
* When done, free the list but NOT the contained data.
*/
alpm_list_t *_alpm_filelist_difference(alpm_filelist_t *filesA,
alpm_filelist_t *filesB)
{
alpm_list_t *ret = NULL;
size_t ctrA = 0, ctrB = 0;
while(ctrA < filesA->count && ctrB < filesB->count) {
char *strA = filesA->files[ctrA].name;
char *strB = filesB->files[ctrB].name;
int cmp = strcmp(strA, strB);
if(cmp < 0) {
/* item only in filesA, qualifies as a difference */
ret = alpm_list_add(ret, strA);
ctrA++;
} else if(cmp > 0) {
ctrB++;
} else {
ctrA++;
ctrB++;
}
}
/* ensure we have completely emptied pA */
while(ctrA < filesA->count) {
ret = alpm_list_add(ret, filesA->files[ctrA].name);
ctrA++;
}
return ret;
}
static int _alpm_filelist_pathcmp(const char *p1, const char *p2)
{
while(*p1 && *p1 == *p2) {
p1++;
p2++;
}
/* skip trailing '/' */
if(*p1 == '\0' && *p2 == '/') {
p2++;
} else if(*p2 == '\0' && *p1 == '/') {
p1++;
}
return *p1 - *p2;
}
/* Returns the intersection of the provided two lists of files.
* Pre-condition: both lists are sorted!
* When done, free the list but NOT the contained data.
*/
alpm_list_t *_alpm_filelist_intersection(alpm_filelist_t *filesA,
alpm_filelist_t *filesB)
{
alpm_list_t *ret = NULL;
size_t ctrA = 0, ctrB = 0;
alpm_file_t *arrA = filesA->files, *arrB = filesB->files;
while(ctrA < filesA->count && ctrB < filesB->count) {
const char *strA = arrA[ctrA].name, *strB = arrB[ctrB].name;
int cmp = _alpm_filelist_pathcmp(strA, strB);
if(cmp < 0) {
ctrA++;
} else if(cmp > 0) {
ctrB++;
} else {
/* when not directories, item in both qualifies as an intersect */
if(strA[strlen(strA) - 1] != '/' || strB[strlen(strB) - 1] != '/') {
ret = alpm_list_add(ret, arrA[ctrA].name);
}
ctrA++;
ctrB++;
}
}
return ret;
}
/* Helper function for comparing files list entries
*/
int _alpm_files_cmp(const void *f1, const void *f2)
{
const alpm_file_t *file1 = f1;
const alpm_file_t *file2 = f2;
return strcmp(file1->name, file2->name);
}
alpm_file_t SYMEXPORT *alpm_filelist_contains(alpm_filelist_t *filelist,
const char *path)
{
alpm_file_t key;
if(!filelist) {
return NULL;
}
key.name = (char *)path;
return bsearch(&key, filelist->files, filelist->count,
sizeof(alpm_file_t), _alpm_files_cmp);
}
/* vim: set noet: */