reverse string lookup listbase function BLI_findstring counterparts, added BLI_rfindstring, BLI_rfindstring_ptr, these search from the end of the listbase (like pythons rfind).

2 files changed, 49 insertions, 9 deletions

diff --git a/source/blender/blenlib/BLI_listbase.h b/source/blender/blenlib/BLI_listbase.h
index 73af9a3738c..90556ea4b05 100644
--- a/source/blender/blenlib/BLI_listbase.h
+++ b/source/blender/blenlib/BLI_listbase.h
@@ -45,9 +45,16 @@ extern "C" {
 void BLI_insertlink(struct ListBase *listbase, void *vprevlink, void *vnewlink);
 void *BLI_findlink(const struct ListBase *listbase, int number);
 int BLI_findindex(const struct ListBase *listbase, void *vlink);
+int BLI_findstringindex(const struct ListBase *listbase, const char *id, const int offset);
+
+/* find forwards */
 void *BLI_findstring(const struct ListBase *listbase, const char *id, const int offset);
 void *BLI_findstring_ptr(const struct ListBase *listbase, const char *id, const int offset);
-int BLI_findstringindex(const struct ListBase *listbase, const char *id, const int offset);
+
+/* find backwards */
+void *BLI_rfindstring(const struct ListBase *listbase, const char *id, const int offset);
+void *BLI_rfindstring_ptr(const struct ListBase *listbase, const char *id, const int offset);
+
 void BLI_freelistN(struct ListBase *listbase);
 void BLI_addtail(struct ListBase *listbase, void *vlink);
 void BLI_remlink(struct ListBase *listbase, void *vlink);
diff --git a/source/blender/blenlib/intern/listbase.c b/source/blender/blenlib/intern/listbase.c
index 15bdb4a446f..05f71e0c01f 100644
--- a/source/blender/blenlib/intern/listbase.c
+++ b/source/blender/blenlib/intern/listbase.c
@@ -366,14 +366,30 @@ void *BLI_findstring(const ListBase *listbase, const char *id, const int offset)
 
 	if (listbase == NULL) return NULL;
 
-	link= listbase->first;
-	while (link) {
+	for (link= listbase->first; link; link= link->next) {
 		id_iter= ((const char *)link) + offset;
 
-		if(id[0] == id_iter[0] && strcmp(id, id_iter)==0)
+		if (id[0] == id_iter[0] && strcmp(id, id_iter)==0) {
 			return link;
+		}
+	}
 
-		link= link->next;
+	return NULL;
+}
+/* same as above but find reverse */
+void *BLI_rfindstring(const ListBase *listbase, const char *id, const int offset)
+{
+	Link *link= NULL;
+	const char *id_iter;
+
+	if (listbase == NULL) return NULL;
+
+	for (link= listbase->last; link; link= link->prev) {
+		id_iter= ((const char *)link) + offset;
+
+		if (id[0] == id_iter[0] && strcmp(id, id_iter)==0) {
+			return link;
+		}
 	}
 
 	return NULL;
@@ -386,15 +402,32 @@ void *BLI_findstring_ptr(const ListBase *listbase, const char *id, const int off
 
 	if (listbase == NULL) return NULL;
 
-	link= listbase->first;
-	while (link) {
+	for (link= listbase->first; link; link= link->next) {
 		/* exact copy of BLI_findstring(), except for this line */
 		id_iter= *((const char **)(((const char *)link) + offset));
 
-		if(id[0] == id_iter[0] && strcmp(id, id_iter)==0)
+		if (id[0] == id_iter[0] && strcmp(id, id_iter)==0) {
 			return link;
+		}
+	}
 
-		link= link->next;
+	return NULL;
+}
+/* same as above but find reverse */
+void *BLI_rfindstring_ptr(const ListBase *listbase, const char *id, const int offset)
+{
+	Link *link= NULL;
+	const char *id_iter;
+
+	if (listbase == NULL) return NULL;
+
+	for (link= listbase->last; link; link= link->prev) {
+		/* exact copy of BLI_rfindstring(), except for this line */
+		id_iter= *((const char **)(((const char *)link) + offset));
+
+		if (id[0] == id_iter[0] && strcmp(id, id_iter)==0) {
+			return link;
+		}
 	}
 
 	return NULL;