ceph/src/boost/libs/mpi/src/graph_communicator.cpp

   1 // Copyright (C) 2007 Trustees of Indiana University
   2
   3 // Authors: Douglas Gregor
   4 //          Andrew Lumsdaine
   5
   6 // Use, modification and distribution is subject to the Boost Software
   7 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9 #include <boost/mpi/graph_communicator.hpp>
  10
  11 namespace boost { namespace mpi {
  12
  13 // Incidence Graph requirements
  14 std::pair<detail::comm_out_edge_iterator, detail::comm_out_edge_iterator>
  15 out_edges(int vertex, const graph_communicator& comm)
  16 {
  17   int nneighbors = out_degree(vertex, comm);
  18   shared_array<int> neighbors(new int[nneighbors]);
  19   BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors,
  20                          ((MPI_Comm)comm, vertex, nneighbors, neighbors.get()));
  21   return std::make_pair(detail::comm_out_edge_iterator(vertex, neighbors, 0),
  22                         detail::comm_out_edge_iterator(vertex, neighbors,
  23                                                        nneighbors));
  24 }
  25
  26 int out_degree(int vertex, const graph_communicator& comm)
  27 {
  28   int nneighbors;
  29   BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors_count,
  30                          ((MPI_Comm)comm, vertex, &nneighbors));
  31   return nneighbors;
  32 }
  33
  34 // Adjacency Graph requirements
  35 std::pair<detail::comm_adj_iterator, detail::comm_adj_iterator>
  36 adjacent_vertices(int vertex, const graph_communicator& comm)
  37 {
  38   int nneighbors = out_degree(vertex, comm);
  39   shared_array<int> neighbors(new int[nneighbors]);
  40   BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors,
  41                          ((MPI_Comm)comm, vertex, nneighbors, neighbors.get()));
  42   return std::make_pair(detail::comm_adj_iterator(neighbors, 0),
  43                         detail::comm_adj_iterator(neighbors, nneighbors));
  44 }
  45
  46 // Edge List Graph requirements
  47 std::pair<detail::comm_edge_iterator, detail::comm_edge_iterator>
  48 edges(const graph_communicator& comm);
  49
  50 std::pair<detail::comm_edge_iterator, detail::comm_edge_iterator>
  51 edges(const graph_communicator& comm)
  52 {
  53   int nnodes, nedges;
  54   BOOST_MPI_CHECK_RESULT(MPI_Graphdims_get, ((MPI_Comm)comm, &nnodes, &nedges));
  55
  56   shared_array<int> indices(new int[nnodes]);
  57   shared_array<int> edges(new int[nedges]);
  58   BOOST_MPI_CHECK_RESULT(MPI_Graph_get,
  59                          ((MPI_Comm)comm, nnodes, nedges,
  60                           indices.get(), edges.get()));
  61   return std::make_pair(detail::comm_edge_iterator(indices, edges),
  62                         detail::comm_edge_iterator(nedges));
  63 }
  64
  65
  66 int num_edges(const graph_communicator& comm)
  67 {
  68   int nnodes, nedges;
  69   BOOST_MPI_CHECK_RESULT(MPI_Graphdims_get, ((MPI_Comm)comm, &nnodes, &nedges));
  70   return nedges;
  71 }
  72
  73 } } // end namespace boost::mpi