extend smartlist with _remove() and _subtract()

svn:r922

src/common/util.c

@@ -92,6 +92,17 @@ void smartlist_add(smartlist_t *sl, void *element) {
     log_fn(LOG_WARN,"We've already got %d elements, discarding.",sl->max);
 }
 
+void smartlist_remove(smartlist_t *sl, void *element) {
+  int i;
+  if(element == NULL)
+    return;
+  for(i=0; i < sl->num_used; i++)
+    if(sl->list[i] == element) {
+      sl->list[i] = sl->list[--sl->num_used]; /* swap with the end */
+      i--; /* so we process the new i'th element */
+    }
+}
+
 int smartlist_isin(smartlist_t *sl, void *element) {
   int i;
   for(i=0; i < sl->num_used; i++)
@@ -118,6 +129,13 @@ void smartlist_intersect(smartlist_t *sl1, smartlist_t *sl2) {
     }
 }
 
+/* remove all elements of sl2 from sl1 */
+void smartlist_subtract(smartlist_t *sl1, smartlist *sl2) {
+  int i;
+  for(i=0; i < sl2->num_used; i++)
+    smartlist_remove(sl1, sl2->list[i]);
+}
+
 void *smartlist_choose(smartlist_t *sl) {
   if(sl->num_used)
     return sl->list[crypto_pseudo_rand_int(sl->num_used)];

src/common/util.h

@@ -48,9 +48,11 @@ typedef struct {
 smartlist_t *smartlist_create(int max_elements);
 void smartlist_free(smartlist_t *sl);
 void smartlist_add(smartlist_t *sl, void *element);
+void smartlist_remove(smartlist_t *sl, void *element);
 int smartlist_isin(smartlist_t *sl, void *element);
 int smartlist_overlap(smartlist_t *sl1, smartlist_t *sl2);
 void smartlist_intersect(smartlist_t *sl1, smartlist_t *sl2);
+void smartlist_subtract(smartlist_t *sl1, smartlist *sl2);
 void *smartlist_choose(smartlist_t *sl);
 
 const char *eat_whitespace(const char *s);