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-rw-r--r--lib/libalpm/filelist.c64
1 files changed, 46 insertions, 18 deletions
diff --git a/lib/libalpm/filelist.c b/lib/libalpm/filelist.c
index 04075a52..f6c0ed45 100644
--- a/lib/libalpm/filelist.c
+++ b/lib/libalpm/filelist.c
@@ -22,16 +22,12 @@
/* libalpm */
#include "filelist.h"
-/* Returns a set operation on the provided two lists of files.
+/* 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.
- *
- * Operations:
- * DIFFERENCE - a difference operation is performed. filesA - filesB.
- * INTERSECT - an intersection operation is performed. filesA & filesB.
*/
-alpm_list_t *_alpm_filelist_operation(alpm_filelist_t *filesA,
- alpm_filelist_t *filesB, enum filelist_op operation)
+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;
@@ -49,26 +45,20 @@ alpm_list_t *_alpm_filelist_operation(alpm_filelist_t *filesA,
} else {
int cmp = strcmp(strA, strB);
if(cmp < 0) {
- if(operation == DIFFERENCE) {
- /* item only in filesA, qualifies as a difference */
- ret = alpm_list_add(ret, fileA);
- }
+ /* item only in filesA, qualifies as a difference */
+ ret = alpm_list_add(ret, fileA);
ctrA++;
} else if(cmp > 0) {
ctrB++;
} else {
- if(operation == INTERSECT) {
- /* item in both, qualifies as an intersect */
- ret = alpm_list_add(ret, fileA);
- }
ctrA++;
ctrB++;
}
- }
+ }
}
- /* if doing a difference, ensure we have completely emptied pA */
- while(operation == DIFFERENCE && ctrA < filesA->count) {
+ /* ensure we have completely emptied pA */
+ while(ctrA < filesA->count) {
alpm_file_t *fileA = filesA->files + ctrA;
const char *strA = fileA->name;
/* skip directories */
@@ -81,6 +71,44 @@ alpm_list_t *_alpm_filelist_operation(alpm_filelist_t *filesA,
return ret;
}
+/* 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;
+
+ while(ctrA < filesA->count && ctrB < filesB->count) {
+ alpm_file_t *fileA = filesA->files + ctrA;
+ alpm_file_t *fileB = filesB->files + ctrB;
+ const char *strA = fileA->name;
+ const char *strB = fileB->name;
+ /* skip directories, we don't care about them */
+ if(strA[strlen(strA)-1] == '/') {
+ ctrA++;
+ } else if(strB[strlen(strB)-1] == '/') {
+ ctrB++;
+ } else {
+ int cmp = strcmp(strA, strB);
+ if(cmp < 0) {
+ ctrA++;
+ } else if(cmp > 0) {
+ ctrB++;
+ } else {
+ /* item in both, qualifies as an intersect */
+ ret = alpm_list_add(ret, fileA);
+ ctrA++;
+ ctrB++;
+ }
+ }
+ }
+
+ return ret;
+}
+
/* Helper function for comparing files list entries
*/
int _alpm_files_cmp(const void *f1, const void *f2)