rdlist: add remove_elem() and remove_multi_cmp()

confluentinc · Jan 2, 2018 · 91872da · 91872da
1 parent 4a86230
commit 91872da
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Showing 2 changed files with 44 additions and 4 deletions.
diff --git a/src/rdlist.c b/src/rdlist.c
@@ -110,7 +110,7 @@ void *rd_list_add (rd_list_t *rl, void *elem) {
 	return rl->rl_elems[rl->rl_cnt++];
 }
 
-static void rd_list_remove0 (rd_list_t *rl, int idx) {
+void rd_list_remove_elem (rd_list_t *rl, int idx) {
         rd_assert(idx < rl->rl_cnt);
 
         if (idx + 1 < rl->rl_cnt)
@@ -126,7 +126,7 @@ void *rd_list_remove (rd_list_t *rl, void *match_elem) {
 
         RD_LIST_FOREACH(elem, rl, i) {
                 if (elem == match_elem) {
-                        rd_list_remove0(rl, i);
+                        rd_list_remove_elem(rl, i);
                         return elem;
                 }
         }
@@ -143,7 +143,7 @@ void *rd_list_remove_cmp (rd_list_t *rl, void *match_elem,
         RD_LIST_FOREACH(elem, rl, i) {
                 if (elem == match_elem ||
                     !cmp(elem, match_elem)) {
-                        rd_list_remove0(rl, i);
+                        rd_list_remove_elem(rl, i);
                         return elem;
                 }
         }
@@ -152,6 +152,26 @@ void *rd_list_remove_cmp (rd_list_t *rl, void *match_elem,
 }
 
 
+int rd_list_remove_multi_cmp (rd_list_t *rl, void *match_elem,
+                              int (*cmp) (void *_a, void *_b)) {
+
+        void *elem;
+        int i;
+        int cnt = 0;
+
+        /* Scan backwards to minimize memmoves */
+        RD_LIST_FOREACH_REVERSE(elem, rl, i) {
+                if (match_elem == cmp ||
+                    !cmp(elem, match_elem)) {
+                        rd_list_remove_elem(rl, i);
+                        cnt++;
+                }
+        }
+
+        return cnt;
+}
+
+
 /**
  * Trampoline to avoid the double pointers in callbacks.
  *
@@ -267,7 +287,7 @@ void rd_list_apply (rd_list_t *rl,
 
         RD_LIST_FOREACH(elem, rl, i) {
                 if (!cb(elem, opaque)) {
-                        rd_list_remove0(rl, i);
+                        rd_list_remove_elem(rl, i);
                         i--;
                 }
         }

diff --git a/src/rdlist.h b/src/rdlist.h
@@ -123,6 +123,26 @@ void *rd_list_remove (rd_list_t *rl, void *match_elem);
 void *rd_list_remove_cmp (rd_list_t *rl, void *match_elem,
                          int (*cmp) (void *_a, void *_b));
 
+
+/**
+ * @brief Remove element at index \p idx.
+ *
+ * This is a O(1) + memmove operation
+ */
+void rd_list_remove_elem (rd_list_t *rl, int idx);
+
+
+/**
+ * @brief Remove all elements matching comparator.
+ *
+ * @returns the number of elements removed.
+ *
+ * @sa rd_list_remove()
+ */
+int rd_list_remove_multi_cmp (rd_list_t *rl, void *match_elem,
+                               int (*cmp) (void *_a, void *_b));
+
+
 /**
  * Sort list using comparator
  */