src/MEDSPLITTER/MEDSPLITTER_SCOTCHGraph.cxx

   1 #include <cstdio>
   2 extern "C" {
   3 #define restrict
   4 #include "bin/scotch.h"
   5 }
   6 #include "MEDSPLITTER_Graph.hxx"
   7 #include "MEDSPLITTER_SCOTCHGraph.hxx"
   8
   9 using namespace MEDSPLITTER;
  10
  11 SCOTCHGraph::SCOTCHGraph():Graph()
  12 {
  13 }
  14
  15 SCOTCHGraph::SCOTCHGraph(const MEDMEM::MEDSKYLINEARRAY* graph, int* edgeweight):Graph(graph,edgeweight)
  16 {
  17 }
  18
  19 SCOTCHGraph::~SCOTCHGraph()
  20 {
  21         if (m_partition!=0) {delete m_partition; m_partition=0;}
  22         if (m_graph!=0) {delete m_graph; m_graph=0;}
  23 }
  24
  25 void SCOTCHGraph::partGraph(int ndomain, const string& options_string)
  26 {
  27         // number of graph vertices
  28         int n = m_graph->getNumberOf();
  29
  30         //graph
  31         int * xadj=const_cast<int*>(m_graph->getIndex());
  32         int * adjncy = const_cast<int*>(m_graph->getValue());
  33
  34         //ndomain
  35         int nparts = ndomain;
  36
  37         // output parameters
  38         int* partition = new int[n+1];
  39
  40         SCOTCH_Graph scotch_graph;
  41
  42         SCOTCH_graphInit(&scotch_graph);
  43
  44
  45         SCOTCH_graphBuild(&scotch_graph,
  46                           1, //premier indice 1
  47                           n, // nb of graph nodes
  48                           xadj,
  49                           0,
  50                           m_cellweight, //graph vertices loads
  51                           0,
  52                           xadj[n], // number of edges
  53                           adjncy,
  54                           m_edgeweight);
  55
  56         SCOTCH_Strat scotch_strategy;
  57         SCOTCH_stratInit(&scotch_strategy);
  58
  59         //!user-defined options for the strategy
  60         if (options_string!="")
  61           SCOTCH_stratGraphMap(&scotch_strategy,options_string.c_str());
  62
  63
  64         if (nparts>1)
  65                 SCOTCH_graphPart(&scotch_graph,nparts,&scotch_strategy,partition);
  66         else
  67           // partition for 1 subdomain
  68                 for (int i=0; i<n+1; i++)
  69                         partition[i]=1;
  70
  71         SCOTCH_stratExit(&scotch_strategy);
  72         SCOTCH_graphExit(&scotch_graph);
  73
  74         int* index=new int [n+1];
  75         index[0]=1;
  76         for (int i=0; i<n; i++)
  77         {
  78                 index[i+1]=index[i]+1;
  79         }
  80
  81         //creating a skylinearray with no copy of the index and partition array
  82         // the fifth argument true specifies that only the pointers are passed
  83         //to the object
  84         m_partition = new MEDMEM::MEDSKYLINEARRAY(n,n, index, partition, true);
  85 }