Approximate 20% reduction in runtime on long running scripts, based on profiling data. Reduce number of execution of object cache culling, reduction of copies of the stack and reduction of Boxed_Value copies

include/chaiscript/dispatchkit/boxed_value.hpp

@@ -116,6 +116,11 @@ namespace chaiscript
        */
       struct Object_Cache
       {
+        Object_Cache()
+          : m_cullcount(0)
+        {
+        }
+
         boost::shared_ptr<Data> get(Boxed_Value::Void_Type)
         {
           return boost::shared_ptr<Data> (new Data(
@@ -219,6 +224,12 @@ namespace chaiscript
          */
         void cull()
         {
+          ++m_cullcount;
+          if (m_cullcount % 10 != 0)
+          {
+            return;
+          }
+
           std::map<const void *, Data >::iterator itr = m_ptrs.begin();
 
           while (itr != m_ptrs.end())
@@ -235,6 +246,7 @@ namespace chaiscript
         }
 
         std::map<const void *, Data > m_ptrs;
+        int m_cullcount;
       };
 
     public:
@@ -472,7 +484,7 @@ namespace chaiscript
   template<>
     struct Cast_Helper<Boxed_Value>
     {
-      typedef Boxed_Value Result_Type;
+      typedef const Boxed_Value & Result_Type;
 
       static Result_Type cast(const Boxed_Value &ob)
       {
@@ -486,7 +498,7 @@ namespace chaiscript
   template<>
     struct Cast_Helper<const Boxed_Value &>
     {
-      typedef Boxed_Value Result_Type;
+      typedef const Boxed_Value & Result_Type;
 
       static Result_Type cast(const Boxed_Value &ob)
       {

include/chaiscript/dispatchkit/dispatchkit.hpp

@@ -133,12 +133,13 @@ namespace chaiscript
     public:
       typedef std::map<std::string, chaiscript::Type_Info> Type_Name_Map;
       typedef std::map<std::string, Boxed_Value> Scope;
-      typedef std::deque<Scope> Stack;
+      typedef boost::shared_ptr<std::deque<Scope> > Stack;
 
       Dispatch_Engine()
-        : m_place_holder(boost::shared_ptr<Placeholder_Object>(new Placeholder_Object()))
+        : m_scopes(new Stack::element_type()),
+          m_place_holder(boost::shared_ptr<Placeholder_Object>(new Placeholder_Object()))
       {
-        m_scopes.push_back(Scope());
+        m_scopes->push_back(Scope());
       }
 
       /**
@@ -163,12 +164,12 @@ namespace chaiscript
        */
       void add(const Boxed_Value &obj, const std::string &name)
       {
-        for (int i = m_scopes.size()-1; i >= 0; --i)
+        for (int i = m_scopes->size()-1; i >= 0; --i)
         {
-          std::map<std::string, Boxed_Value>::const_iterator itr = m_scopes[i].find(name);
-          if (itr != m_scopes[i].end())
+          std::map<std::string, Boxed_Value>::const_iterator itr = (*m_scopes)[i].find(name);
+          if (itr != (*m_scopes)[i].end())
           {
-            m_scopes[i][name] = Boxed_Value(obj);
+            (*m_scopes)[i][name] = Boxed_Value(obj);
             return;
           }
         }
@@ -181,7 +182,7 @@ namespace chaiscript
        */
       void add_object(const std::string &name, const Boxed_Value &obj)
       {
-        m_scopes.back()[name] = Boxed_Value(obj);
+        m_scopes->back()[name] = Boxed_Value(obj);
       }
 
       /**
@@ -189,7 +190,7 @@ namespace chaiscript
        */
       void new_scope()
       {
-        m_scopes.push_back(Scope());
+        m_scopes->push_back(Scope());
       }
 
       /**
@@ -197,9 +198,9 @@ namespace chaiscript
        */
       void pop_scope()
       {
-        if (m_scopes.size() > 1)
+        if (m_scopes->size() > 1)
         {
-          m_scopes.pop_back();
+          m_scopes->pop_back();
         } else {
           throw std::range_error("Unable to pop global stack");
         }
@@ -218,10 +219,16 @@ namespace chaiscript
        * \returns the old stack
        * \param[in] s The new stack
        */
-      Stack set_stack(Stack s)
+      Stack set_stack(const Stack &s)
       {
-        std::swap(s, m_scopes);
-        return s;
+        Stack old = m_scopes;
+        m_scopes = s;
+        return old;
+      }
+
+      Stack new_stack()
+      {
+        return Stack(new Stack::element_type());
       }
 
       /**
@@ -236,10 +243,10 @@ namespace chaiscript
           return m_place_holder;
         }
 
-        for (int i = m_scopes.size()-1; i >= 0; --i)
+        for (int i = m_scopes->size()-1; i >= 0; --i)
         {
-          std::map<std::string, Boxed_Value>::const_iterator itr = m_scopes[i].find(name);
-          if (itr != m_scopes[i].end())
+          std::map<std::string, Boxed_Value>::const_iterator itr = (*m_scopes)[i].find(name);
+          if (itr != (*m_scopes)[i].end())
           {
             return itr->second;
           }
@@ -377,7 +384,7 @@ namespace chaiscript
         return true;
       }
 
-      std::deque<Scope> m_scopes;
+      Stack m_scopes;
 
       std::multimap<std::string, Proxy_Function > m_functions;
       Type_Name_Map m_types;

include/chaiscript/language/chaiscript_eval.hpp

@@ -405,10 +405,10 @@ namespace chaiscript
         Boxed_Value retval;
         Param_List_Builder plb;
         Dispatch_Engine::Stack prev_stack = ss.get_stack();
-        Dispatch_Engine::Stack new_stack;
+        Dispatch_Engine::Stack new_stack = ss.new_stack();
         unsigned int i;
 
-        new_stack.push_back(Dispatch_Engine::Scope());
+        new_stack->push_back(Dispatch_Engine::Scope());
 
         if ((node->children.size() > 1) && (node->children[1]->identifier == Token_Type::Arg_List)) {
             for (i = 0; i < node->children[1]->children.size(); ++i) {
@@ -452,10 +452,10 @@ namespace chaiscript
         Boxed_Value retval;
         std::vector<std::pair<std::string, Proxy_Function > > fn;
         Dispatch_Engine::Stack prev_stack = ss.get_stack();
-        Dispatch_Engine::Stack new_stack;
+        Dispatch_Engine::Stack new_stack = ss.new_stack();
         unsigned int i, j;
 
-        new_stack.push_back(Dispatch_Engine::Scope());
+        new_stack->push_back(Dispatch_Engine::Scope());
 
         //todo: Please extract a single way of doing function calls between this and eval_fun_call