preparation work for index condition specialization

arangod/Aql/AstNode.cpp

@@ -680,6 +680,16 @@ std::string const& AstNode::getValueTypeString () const {
   THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_NOT_IMPLEMENTED, "missing node type in ValueTypeNames");
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief stringify the AstNode
+////////////////////////////////////////////////////////////////////////////////
+
+std::string AstNode::toString (AstNode const* node) {
+  std::unique_ptr<TRI_json_t> json(node->toJson(TRI_UNKNOWN_MEM_ZONE, false));
+
+  return triagens::basics::JsonHelper::toString(json.get());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief checks whether we know a type of this kind; throws exception if not.
 ////////////////////////////////////////////////////////////////////////////////
@@ -2033,6 +2043,31 @@ void AstNode::appendValue (triagens::basics::StringBuffer* buffer) const {
   }
 }
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                       public non-member functions
+// -----------------------------------------------------------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief append the AstNode to an output stream
+////////////////////////////////////////////////////////////////////////////////
+     
+std::ostream& operator<< (std::ostream& stream,
+                          triagens::aql::AstNode const* node) {
+  stream << triagens::aql::AstNode::toString(node);
+  return stream;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief append the AstNode to an output stream
+////////////////////////////////////////////////////////////////////////////////
+
+std::ostream& operator<< (std::ostream& stream,
+                          triagens::aql::AstNode const& node) {
+  stream << triagens::aql::AstNode::toString(&node);
+  return stream;
+}
+
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       END-OF-FILE
 // -----------------------------------------------------------------------------

arangod/Aql/AstNode.h

@@ -281,14 +281,20 @@ namespace triagens {
         std::string const& getValueTypeString () const;
 
 ////////////////////////////////////////////////////////////////////////////////
-/// @brief checks whether we know a type of this kind; throws exception if not.
+/// @brief stringify the AstNode
+////////////////////////////////////////////////////////////////////////////////
+
+        static std::string toString (AstNode const*);
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief checks whether we know a type of this kind; throws exception if not
 ////////////////////////////////////////////////////////////////////////////////
 
         static void validateType (int type);
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief checks whether we know a value type of this kind; 
-/// throws exception if not.
+/// throws exception if not
 ////////////////////////////////////////////////////////////////////////////////
 
         static void validateValueType (int type);
@@ -890,6 +896,13 @@ namespace triagens {
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief append the AstNode to an output stream
+////////////////////////////////////////////////////////////////////////////////
+
+std::ostream& operator<< (std::ostream&, triagens::aql::AstNode const*);
+std::ostream& operator<< (std::ostream&, triagens::aql::AstNode const&);
+
 #endif
 
 // -----------------------------------------------------------------------------

arangod/Aql/Condition.cpp

@@ -268,7 +268,7 @@ bool Condition::findIndexForAndNode (AstNode const* node,
 
   // This code is never responsible for the content of this pointer.
   Index const* bestIndex = nullptr;
-  double bestCost        = MaxFilterCost + MaxSortCost + std::numeric_limits<double>::epsilon(); 
+  double bestCost = MaxFilterCost + MaxSortCost + std::numeric_limits<double>::epsilon(); 
 
   std::vector<Index const*> indexes = colNode->collection()->getIndexes();
 

arangod/Aql/IndexNode.cpp

@@ -126,6 +126,8 @@ IndexNode::IndexNode (ExecutionPlan* plan,
   _condition = Condition::fromJson(plan, conditionJson);
 
   TRI_ASSERT(_condition != nullptr);
+
+  specializeConditions();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -175,6 +177,26 @@ void IndexNode::getVariablesUsedHere (std::unordered_set<Variable const*>& vars)
   vars.erase(_outVariable);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief specialize condition for the indexes picked
+////////////////////////////////////////////////////////////////////////////////
+
+void IndexNode::specializeConditions () {
+  auto root = _condition->root();
+  TRI_ASSERT(root->type == NODE_TYPE_OPERATOR_NARY_OR);
+
+  size_t const n = root->numMembers();
+  TRI_ASSERT(n == _indexes.size());
+  
+  for (size_t i = 0; i < n; ++i) {
+    auto andNode = root->getMemberUnchecked(i);
+
+    TRI_ASSERT(andNode->type == NODE_TYPE_OPERATOR_NARY_AND);
+    // std::cout << "ORIGINAL CONDITION:\n" << andNode << "\n";
+    // std::cout << "SPECIALIZED CONDITION: " << _indexes[i]->simplifyCondition(andNode) << "\n";
+  }
+}
+
 // Local Variables:
 // mode: outline-minor
 // outline-regexp: "^\\(/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|// --SECTION--\\|/// @\\}\\)"

arangod/Aql/IndexNode.h

@@ -76,6 +76,8 @@ namespace triagens {
           TRI_ASSERT(_collection != nullptr);
           TRI_ASSERT(_outVariable != nullptr);
           TRI_ASSERT(_condition != nullptr);
+
+          specializeConditions();
         }
 
         IndexNode (ExecutionPlan*, triagens::basics::Json const& base);
@@ -164,6 +166,18 @@ namespace triagens {
           return _indexes;
         }
 
+// -----------------------------------------------------------------------------
+// --SECTION--                                                   private methods
+// -----------------------------------------------------------------------------
+
+      private:
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief specialize condition for the indexes picked
+////////////////////////////////////////////////////////////////////////////////
+
+        void specializeConditions ();
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                 private variables
 // -----------------------------------------------------------------------------