From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Mon, 30 Sep 2019 08:30:25 +0000 (+0200)
Subject: iputils.hh: NetmaskTree::TreeNode: Implement tree traversal methods.
X-Git-Tag: auth-4.3.0-beta2~20^2~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fddcd1ccfcf8621acb478a6aedd1f08971460843;p=thirdparty%2Fpdns.git

iputils.hh: NetmaskTree::TreeNode: Implement tree traversal methods.
---

diff --git a/pdns/iputils.hh b/pdns/iputils.hh
index 9a66e13b84..ce938c7b43 100644
--- a/pdns/iputils.hh
+++ b/pdns/iputils.hh
@@ -761,6 +761,51 @@ private:
       return new_node;
     }
 
+    //<! Traverse left branch depth-first
+    TreeNode *traverse_l()
+    {
+      TreeNode *tnode = this;
+
+      while (tnode->left)
+        tnode = tnode->left.get();
+      return tnode;
+    }
+
+    //<! Traverse tree depth-first and in-order (L-N-R)
+    TreeNode *traverse_lnr()
+    {
+      TreeNode *tnode = this;
+
+      // precondition: descended left as deep as possible
+      if (tnode->right) {
+        // descend right
+        tnode = tnode->right.get();
+        // descend left as deep as possible and return next node
+        return tnode->traverse_l();
+      }
+
+      // ascend to parent
+      while (tnode->parent != nullptr) {
+        TreeNode *prev_child = tnode;
+        tnode = tnode->parent;
+
+        // return this node, but only when we come from the left child branch
+        if (tnode->left && tnode->left.get() == prev_child)
+          return tnode;
+      }
+      return nullptr;
+    }
+
+    //<! Traverse only assigned nodes
+    TreeNode *traverse_lnr_assigned()
+    {
+      TreeNode *tnode = traverse_lnr();
+
+      while (tnode != nullptr && !tnode->assigned)
+        tnode = tnode->traverse_lnr();
+      return tnode;
+    }
+
     unique_ptr<TreeNode> left;
     unique_ptr<TreeNode> right;
     TreeNode* parent;