Merge pull request #4316 from wwmayer/J-Dunn-master

Path: fix unnecessary copy on read for Command.parameters dict

src/Mod/Path/App/CommandPy.xml

@@ -43,7 +43,7 @@ pairs, or a placement, or a vector</UserDocu>
         </Methode>
         <Methode Name="setFromGCode">
             <Documentation>
-                <UserDocu>toGCode(): returns a GCode representation of the command</UserDocu>
+                <UserDocu>setFromGCode(): sets the path from the contents of the given GCode string</UserDocu>
             </Documentation>
         </Methode>
         <Methode Name="transform">
@@ -51,5 +51,8 @@ pairs, or a placement, or a vector</UserDocu>
                 <UserDocu>transform(Placement): returns a copy of this command transformed by the given placement</UserDocu>
             </Documentation>
         </Methode>
+        <ClassDeclarations>
+            mutable Py::Dict parameters_copy_dict;
+        </ClassDeclarations>
     </PythonExport>
 </GenerateModel>

src/Mod/Path/App/CommandPyImp.cpp

@@ -56,6 +56,11 @@ std::string CommandPy::representation(void) const
     return str.str();
 }
 
+// 
+// Py::Dict parameters_copy_dict is now a class member to avoid delete/create/copy on every read access from python code
+// Now the pre-filled Py::Dict is returned which is more consistent with normal python behaviour.
+// It should be cleared whenever the c++ Parameters object is changed eg setParameters() or other objects invalidate its content, eg setPlacement()
+// https://forum.freecadweb.org/viewtopic.php?f=15&t=50583
 
 PyObject *CommandPy::PyMake(struct _typeobject *, PyObject *, PyObject *)  // Python wrapper
 {
@@ -117,6 +122,7 @@ int CommandPy::PyInit(PyObject* args, PyObject* kwd)
             }
             getCommandPtr()->Parameters[ckey]=cvalue;
         }
+          parameters_copy_dict.clear();
         return 0;
     }
     PyErr_Clear(); // set by PyArg_ParseTuple()
@@ -157,11 +163,13 @@ void CommandPy::setName(Py::String arg)
 
 Py::Dict CommandPy::getParameters(void) const
 {
-    Py::Dict dict;
-    for(std::map<std::string,double>::iterator i = getCommandPtr()->Parameters.begin(); i != getCommandPtr()->Parameters.end(); ++i) {
-        dict.setItem(i->first, Py::Float(i->second));
+    // dict now a class member , https://forum.freecadweb.org/viewtopic.php?f=15&t=50583
+    if (parameters_copy_dict.length()==0) {    
+      for(std::map<std::string,double>::iterator i = getCommandPtr()->Parameters.begin(); i != getCommandPtr()->Parameters.end(); ++i) {
+          parameters_copy_dict.setItem(i->first, Py::Float(i->second));
+      }
     }
-    return dict;
+    return parameters_copy_dict;
 }
 
 void CommandPy::setParameters(Py::Dict arg)
@@ -200,6 +208,7 @@ void CommandPy::setParameters(Py::Dict arg)
             throw Py::TypeError("The dictionary can only contain number values");
         }
         getCommandPtr()->Parameters[ckey]=cvalue;
+        parameters_copy_dict.clear();
     }
 }
 
@@ -224,6 +233,7 @@ PyObject* CommandPy::setFromGCode(PyObject *args)
         std::string gcode(pstr);
         try {
             getCommandPtr()->setFromGCode(gcode);
+            parameters_copy_dict.clear();
         }
         catch (const Base::Exception& e) {
             PyErr_SetString(PyExc_ValueError, e.what());
@@ -249,6 +259,7 @@ void CommandPy::setPlacement(Py::Object arg)
     Py::Type PlacementType(pyType.o);
     if(arg.isType(PlacementType)) {
         getCommandPtr()->setFromPlacement( *static_cast<Base::PlacementPy*>((*arg))->getPlacementPtr() );
+        parameters_copy_dict.clear();
     } else
     throw Py::TypeError("Argument must be a placement");
 }
@@ -259,6 +270,7 @@ PyObject* CommandPy::transform(PyObject *args)
     if ( PyArg_ParseTuple(args, "O!", &(Base::PlacementPy::Type), &placement) ) {
         Base::PlacementPy *p = static_cast<Base::PlacementPy*>(placement);
         Path::Command trCmd = getCommandPtr()->transform( *p->getPlacementPtr() );
+        parameters_copy_dict.clear();
         return new CommandPy(new Path::Command(trCmd));
     } else
     throw Py::TypeError("Argument must be a placement");
@@ -302,6 +314,7 @@ int CommandPy::setCustomAttributes(const char* attr, PyObject* obj)
                 return 0;
             }
             getCommandPtr()->Parameters[satt]=cvalue;
+            parameters_copy_dict.clear();
             return 1;
         }
     }