Plan convert init part (facebookincubator#1)

velox/core/PlanNode.h

@@ -1001,6 +1001,32 @@ class LimitNode : public PlanNode {
   const std::vector<std::shared_ptr<const PlanNode>> sources_;
 };
 
+class JITedNode : public PlanNode {
+ public:
+  JITedNode(
+      const PlanNodeId& id,
+      const std::string jit_plan_str,
+      const std::shared_ptr<const PlanNode>& source)
+      : PlanNode(id), jit_plan_str_(jit_plan_str), sources_{source} {};
+
+  // TODO (Cheng) change to the right output types
+  const RowTypePtr& outputType() const override {
+    return sources_[0]->outputType();
+  }
+
+  const std::vector<std::shared_ptr<const PlanNode>>& sources() const override {
+    return sources_;
+  }
+
+  std::string_view name() const override {
+    return "JITed";
+  }
+
+ private:
+  const std::string jit_plan_str_;
+  const std::vector<std::shared_ptr<const PlanNode>> sources_;
+};
+
 /// Expands arrays and maps into separate columns. Arrays are expanded into a
 /// single column, and maps are expanded into two columns (key, value). Can be
 /// used to expand multiple columns. In this case will produce as many rows as

velox/core/QueryCtx.h

@@ -181,6 +181,12 @@ class QueryCtx : public Context {
   static constexpr const char* kCodegenLazyLoading =
       "driver.codegen.lazy_loading";
 
+  // Configuration to enable JITed engine and JIT backend
+  static constexpr const char* kJITEnabled = "driver.jit.enabled";
+  static constexpr const char* kJITBackend =
+      "driver.codegen.configuration_file_path";
+
+
   // User provided session timezone. Stores a string with the actual timezone
   // name, e.g: "America/Los_Angeles".
   static constexpr const char* kSessionTimezone = "driver.session.timezone";