added EndNodeFinder

arangod/Aql/NodeFinder.cpp

@@ -32,6 +32,10 @@
 namespace triagens {
   namespace aql {
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                                  class NodeFinder
+// -----------------------------------------------------------------------------
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                        constructors / destructors
 // -----------------------------------------------------------------------------
@@ -96,6 +100,45 @@ bool NodeFinder<std::vector<ExecutionNode::NodeType>>::before (ExecutionNode* en
   return false;
 }
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                               class EndNodeFinder
+// -----------------------------------------------------------------------------
+
+// -----------------------------------------------------------------------------
+// --SECTION--                                        constructors / destructors
+// -----------------------------------------------------------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief node finder for one node type
+////////////////////////////////////////////////////////////////////////////////
+
+EndNodeFinder::EndNodeFinder (std::vector<ExecutionNode*>& out,
+                              bool enterSubqueries) 
+  : _out(out), 
+    _found({ false }),
+    _enterSubqueries(enterSubqueries) {
+}
+
+// -----------------------------------------------------------------------------
+// --SECTION--                                                    public methods
+// -----------------------------------------------------------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief before method for one node type
+////////////////////////////////////////////////////////////////////////////////
+
+bool EndNodeFinder::before (ExecutionNode* en) {
+  TRI_ASSERT(! _found.empty());
+  if (! _found.back()) {
+    // no node found yet. note that we found one on this level
+    _out.emplace_back(en);
+    _found[_found.size() - 1] = true;
+  }
+
+  // if we don't need to enter subqueries, we can stop after the first node that we found
+  return (! _enterSubqueries);
+}
+
   }  // namespace triagens::aql
 }  // namespace triagens
 

arangod/Aql/NodeFinder.h

@@ -63,6 +63,36 @@ namespace triagens {
         }
 
     };
+
+// -----------------------------------------------------------------------------
+// --SECTION--                                               class EndNodeFinder
+// -----------------------------------------------------------------------------
+
+    class EndNodeFinder final : public WalkerWorker<ExecutionNode> {
+
+        std::vector<ExecutionNode*>& _out;
+
+        std::vector<bool> _found;
+
+        bool _enterSubqueries;
+
+      public:
+
+        EndNodeFinder (std::vector<ExecutionNode*>&,
+                       bool);
+
+        bool before (ExecutionNode*) override final;
+
+        bool enterSubquery (ExecutionNode*, ExecutionNode*) override final {
+          _found.push_back(false);
+          return _enterSubqueries;
+        }
+        
+        void leaveSubquery (ExecutionNode*, ExecutionNode*) override final {
+          _found.pop_back();
+        }
+
+    };
   }
 }