[geos-devel] [GEOS] #383: error occur when buffer

[GEOS]

#383: error occur when buffer
------------------------+---------------------------------------------------
 Reporter:  atubar      |       Owner:  geos-devel@…              
     Type:  defect      |      Status:  new                       
 Priority:  major       |   Milestone:  3.2.1                     
Component:  Default     |     Version:  3.2.0                     
 Severity:  Unassigned  |    Keywords:                            
------------------------+---------------------------------------------------
 we debug the source code, and find that this function cause huge memory
 cost, especially of the 'for' circulation.

 void SegmentNodeList::addSplitEdges(std::vector<SegmentString*>& edgeList)
 {

         // testingOnly
 #if GEOS_DEBUG
         std::cerr<<__FUNCTION__<<" entered"<<std::endl;
         std::vector<SegmentString*> testingSplitEdges;
 #endif

         // ensure that the list has entries for the first and last
         // point of the edge
         addEndpoints();
         addCollapsedNodes();

         // there should always be at least two entries in the list
         // since the endpoints are nodes
         iterator it=begin();
         SegmentNode *eiPrev=*it;
         assert(eiPrev);
         it++;

         //problem occurs here
         for(iterator itEnd=end(); it!=itEnd; ++it)
         {
         //&&&&This circulation consumes lots of memory so as to run out of
 the memory,then the program collapse
                 SegmentNode *ei=*it;
                 assert(ei);

                 if ( ! ei->compareTo(*eiPrev) ) continue;

                 SegmentString *newEdge=createSplitEdge(eiPrev, ei);
                 edgeList.push_back(newEdge);
 #if GEOS_DEBUG
                 testingSplitEdges.push_back(newEdge);
 #endif
                 eiPrev = ei;
         }

 #if GEOS_DEBUG
         std::cerr<<__FUNCTION__<<" finished, now checking
 correctness"<<std::endl;
         checkSplitEdgesCorrectness(testingSplitEdges);
 #endif
 }

-- 
Ticket URL: <http://trac.osgeo.org/geos/ticket/383>
GEOS <http://geos.refractions.net/>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).