reduce memory overhead of empty steps in model-based views

(best solution would be not to allocate empty steps at all -- todo...)

Post/PViewDataGModel.h

@@ -51,8 +51,6 @@ class stepData{
     : _model(model), _fileName(fileName), _fileIndex(fileIndex), _time(time),
       _min(min), _max(max), _numComp(numComp), _data(0)
   {
-    _model->getEntities(_entities);
-    _bbox = _model->bounds();
   }
   stepData(stepData<real> &other) : _data(0)
   {
@@ -82,6 +80,8 @@ class stepData{
     _partitions = other._partitions;
   }
   ~stepData(){ destroyData(); }
+  void fillEntities(){ _model->getEntities(_entities); }
+  void computeBoundingBox(){ _bbox = _model->bounds(); }
   GModel *getModel(){ return _model; }
   SBoundingBox3d getBoundingBox(){ return _bbox; }
   int getNumEntities(){ return _entities.size(); }
@@ -235,9 +235,10 @@ class PViewDataGModel : public PViewData {
                int step, double time, int partition, int numComp);
 
   // I/O routines
-  bool readMSH(const std::string &fileName, int fileIndex, FILE *fp, bool binary,
-               bool swap, int step, double time, int partition,
-               int numComp, int numNodes, const std::string &interpolationScheme);
+  bool readMSH(const std::string &viewName, const std::string &fileName,
+               int fileIndex, FILE *fp, bool binary, bool swap, int step,
+               double time, int partition, int numComp, int numNodes,
+               const std::string &interpolationScheme);
   bool writeMSH(const std::string &fileName, bool binary=false, bool savemesh=true);
   bool readMED(const std::string &fileName, int fileIndex);
   bool writeMED(const std::string &fileName);

Post/PViewDataGModelIO.cpp

@@ -25,7 +25,8 @@ bool PViewDataGModel::addData(GModel *model, std::map<int, std::vector<double> >
 
   while(step >= (int)_steps.size())
     _steps.push_back(new stepData<double>(model, numComp));
-
+  _steps[step]->fillEntities();
+  _steps[step]->computeBoundingBox();
   _steps[step]->setTime(time);
 
   int numEnt = (_type == NodeData) ? model->getNumMeshVertices() :
@@ -45,21 +46,18 @@ bool PViewDataGModel::addData(GModel *model, std::map<int, std::vector<double> >
   return true;
 }
 
-bool PViewDataGModel::readMSH(const std::string &fileName, int fileIndex, FILE *fp,
-                              bool binary, bool swap, int step, double time,
-                              int partition, int numComp, int numEnt,
-                              const std::string &interpolationScheme)
+bool PViewDataGModel::readMSH(const std::string &viewName, const std::string &fileName,
+                              int fileIndex, FILE *fp, bool binary, bool swap,
+                              int step, double time, int partition, int numComp,
+                              int numEnt, const std::string &interpolationScheme)
 {
-  Msg::Info("Reading step %d (time %g) partition %d: %d records",
-            step, time, partition, numEnt);
-
-  while(step >= (int)_steps.size()){
-    if(_steps.empty() || _steps.back()->getNumData())
-      _steps.push_back(new stepData<double>(GModel::current(), numComp));
-    else // faster since we avoid computing model bounds
-      _steps.push_back(new stepData<double>(*_steps.back()));
-  }
+  Msg::Info("Reading view `%s' step %d (time %g) partition %d: %d records",
+            viewName.c_str(), step, time, partition, numEnt);
 
+  while(step >= (int)_steps.size())
+    _steps.push_back(new stepData<double>(GModel::current(), numComp));
+  _steps[step]->fillEntities();
+  _steps[step]->computeBoundingBox();
   _steps[step]->setFileName(fileName);
   _steps[step]->setFileIndex(fileIndex);
   _steps[step]->setTime(time);
@@ -423,6 +421,8 @@ bool PViewDataGModel::readMED(const std::string &fileName, int fileIndex)
         }
         while(step >= (int)_steps.size())
           _steps.push_back(new stepData<double>(m, numCompMsh));
+        _steps[step]->fillEntities();
+        _steps[step]->computeBoundingBox();
         _steps[step]->setFileName(fileName);
         _steps[step]->setFileIndex(fileIndex);
         _steps[step]->setTime(dt);

Post/PViewIO.cpp

@@ -210,7 +210,7 @@ bool PView::readMSH(const std::string &fileName, int fileIndex)
         if(p) d = dynamic_cast<PViewDataGModel*>(p->getData());
         bool create = d ? false : true;
         if(create) d = new PViewDataGModel(type);
-        if(!d->readMSH(fileName, fileIndex, fp, binary, swap, timeStep,
+        if(!d->readMSH(viewName, fileName, fileIndex, fp, binary, swap, timeStep,
                        time, partition, numComp, numEnt, interpolationScheme)){
           Msg::Error("Could not read data in msh file");
           if(create) delete d;