[vtk-developers] [VTK 0013851]: Serious performance issue in vtkGraphs when removing vertices

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
====================================================================== 
http://www.vtk.org/Bug/view.php?id=13851 
====================================================================== 
Reported By:                Matthias Schneider
Assigned To:                
====================================================================== 
Project:                    VTK
Issue ID:                   13851
Category:                   (No Category)
Reproducibility:            have not tried
Severity:                   minor
Priority:                   normal
Status:                     backlog
Project:                    TBD 
Type:                       performance 
Resolution:                 open
Fixed in Version:           
====================================================================== 
Date Submitted:             2013-02-01 12:21 EST
Last Modified:              2013-02-01 12:21 EST
====================================================================== 
Summary:                    Serious performance issue in vtkGraphs when removing
vertices
Description: 
vtkGraph seems to have a serious bottleneck when removing vertices from the
graph structure.

vtkGraph::RemoveVerticesInternal() internally calls
vtkGraph::RemoveVertexInternal() which recomputes the edge list structure in
every call:

vtkGraph.cxx:1458ff

this->ForceOwnership();
this->BuildEdgeList();  // This function assumes the edge list is created.

I am not totally sure abut the additional comment concerning the assumption.
I could not find any reason for an unconditional update of the edge list so far.
Therefore, I'd suggest to add the following condition:

this->ForceOwnership();
if (!this->EdgeList) {
  this->BuildEdgeList();
}

Other functions seem to call BuildEdgeList() with exactly the same condition.
====================================================================== 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2013-02-01 12:21 Matthias SchneiderNew Issue                                    
======================================================================