Implemented external list traversing.

2 files changed, 37 insertions, 22 deletions

diff --git a/Zend/zend_llist.c b/Zend/zend_llist.c
index ffb535ab79..5ea65786c2 100644
--- a/Zend/zend_llist.c
+++ b/Zend/zend_llist.c
@@ -208,46 +208,54 @@ ZEND_API int zend_llist_count(zend_llist *l)
 }
 
 
-ZEND_API void *zend_llist_get_first(zend_llist *l)
+ZEND_API void *zend_llist_get_first_ex(zend_llist *l, zend_llist_position *pos)
 {
-	l->traverse_ptr = l->head;
-	if (l->traverse_ptr) {
-		return l->traverse_ptr->data;
+	zend_llist_position *current = pos ? pos : &l->traverse_ptr;
+
+	*current = l->head;
+	if (*current) {
+		return (*current)->data;
 	} else {
 		return NULL;
 	}
 }
 
 
-ZEND_API void *zend_llist_get_last(zend_llist *l)
+ZEND_API void *zend_llist_get_last_ex(zend_llist *l, zend_llist_position *pos)
 {
-	l->traverse_ptr = l->tail;
-	if (l->traverse_ptr) {
-		return l->traverse_ptr->data;
+	zend_llist_position *current = pos ? pos : &l->traverse_ptr;
+
+	*current = l->tail;
+	if (*current) {
+		return (*current)->data;
 	} else {
 		return NULL;
 	}
 }
 
 
-ZEND_API void *zend_llist_get_next(zend_llist *l)
+ZEND_API void *zend_llist_get_next_ex(zend_llist *l, zend_llist_position *pos)
 {
-	if (l->traverse_ptr) {
-		l->traverse_ptr = l->traverse_ptr->next;
-		if (l->traverse_ptr) {
-			return l->traverse_ptr->data;
+	zend_llist_position *current = pos ? pos : &l->traverse_ptr;
+
+	if (*current) {
+		*current = (*current)->next;
+		if (*current) {
+			return (*current)->data;
 		}
 	}
 	return NULL;
 }
 
 
-ZEND_API void *zend_llist_get_prev(zend_llist *l)
+ZEND_API void *zend_llist_get_prev_ex(zend_llist *l, zend_llist_position *pos)
 {
-	if (l->traverse_ptr) {
-		l->traverse_ptr = l->traverse_ptr->prev;
-		if (l->traverse_ptr) {
-			return l->traverse_ptr->data;
+	zend_llist_position *current = pos ? pos : &l->traverse_ptr;
+
+	if (*current) {
+		*current = (*current)->prev;
+		if (*current) {
+			return (*current)->data;
 		}
 	}
 	return NULL;
diff --git a/Zend/zend_llist.h b/Zend/zend_llist.h
index c51f9074a7..805859a8ff 100644
--- a/Zend/zend_llist.h
+++ b/Zend/zend_llist.h
@@ -39,6 +39,7 @@ typedef struct _zend_llist {
 } zend_llist;
 
 typedef int (*llist_compare_func_t) (const zend_llist_element *, const zend_llist_element *);
+typedef zend_llist_element* zend_llist_position;
 
 BEGIN_EXTERN_C()
 ZEND_API void zend_llist_init(zend_llist *l, size_t size, void (*dtor)(void *data), unsigned char persistent);
@@ -55,10 +56,16 @@ ZEND_API int zend_llist_count(zend_llist *l);
 ZEND_API void zend_llist_sort(zend_llist *l, llist_compare_func_t comp_func);
 
 /* traversal */
-ZEND_API void *zend_llist_get_first(zend_llist *l);
-ZEND_API void *zend_llist_get_last(zend_llist *l);
-ZEND_API void *zend_llist_get_next(zend_llist *l);
-ZEND_API void *zend_llist_get_prev(zend_llist *l);
+ZEND_API void *zend_llist_get_first_ex(zend_llist *l, zend_llist_position *pos);
+ZEND_API void *zend_llist_get_last_ex(zend_llist *l, zend_llist_position *pos);
+ZEND_API void *zend_llist_get_next_ex(zend_llist *l, zend_llist_position *pos);
+ZEND_API void *zend_llist_get_prev_ex(zend_llist *l, zend_llist_position *pos);
+
+#define zend_llist_get_first(l) zend_llist_get_first_ex(l, NULL)
+#define zend_llist_get_last(l) zend_llist_get_last_ex(l, NULL)
+#define zend_llist_get_next(l) zend_llist_get_next_ex(l, NULL)
+#define zend_llist_get_prev(l) zend_llist_get_prev_ex(l, NULL)
+
 END_EXTERN_C()
 
 #endif /* _ZEND_LLIST_H */