1 files changed, 73 insertions, 0 deletions
diff --git a/libs/mpi/src/graph_communicator.cpp b/libs/mpi/src/graph_communicator.cpp
new file mode 100644
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+++ b/libs/mpi/src/graph_communicator.cpp
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+// Copyright (C) 2007 Trustees of Indiana University
+
+// Authors: Douglas Gregor
+//          Andrew Lumsdaine
+
+// Use, modification and distribution is subject to the Boost Software
+// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#include <boost/mpi/graph_communicator.hpp>
+
+namespace boost { namespace mpi {
+
+// Incidence Graph requirements
+std::pair<detail::comm_out_edge_iterator, detail::comm_out_edge_iterator>
+out_edges(int vertex, const graph_communicator& comm)
+{
+  int nneighbors = out_degree(vertex, comm);
+  shared_array<int> neighbors(new int[nneighbors]);
+  BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors, 
+                         ((MPI_Comm)comm, vertex, nneighbors, neighbors.get()));
+  return std::make_pair(detail::comm_out_edge_iterator(vertex, neighbors, 0),
+                        detail::comm_out_edge_iterator(vertex, neighbors, 
+                                                       nneighbors));
+}
+
+int out_degree(int vertex, const graph_communicator& comm)
+{
+  int nneighbors;
+  BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors_count, 
+                         ((MPI_Comm)comm, vertex, &nneighbors));
+  return nneighbors;
+}
+
+// Adjacency Graph requirements
+std::pair<detail::comm_adj_iterator, detail::comm_adj_iterator>
+adjacent_vertices(int vertex, const graph_communicator& comm)
+{
+  int nneighbors = out_degree(vertex, comm);
+  shared_array<int> neighbors(new int[nneighbors]);
+  BOOST_MPI_CHECK_RESULT(MPI_Graph_neighbors, 
+                         ((MPI_Comm)comm, vertex, nneighbors, neighbors.get()));
+  return std::make_pair(detail::comm_adj_iterator(neighbors, 0),
+                        detail::comm_adj_iterator(neighbors, nneighbors));
+}
+
+// Edge List Graph requirements
+std::pair<detail::comm_edge_iterator, detail::comm_edge_iterator>
+edges(const graph_communicator& comm);
+
+std::pair<detail::comm_edge_iterator, detail::comm_edge_iterator>
+edges(const graph_communicator& comm)
+{
+  int nnodes, nedges;
+  BOOST_MPI_CHECK_RESULT(MPI_Graphdims_get, ((MPI_Comm)comm, &nnodes, &nedges));
+
+  shared_array<int> indices(new int[nnodes]);
+  shared_array<int> edges(new int[nedges]);
+  BOOST_MPI_CHECK_RESULT(MPI_Graph_get,
+                         ((MPI_Comm)comm, nnodes, nedges, 
+                          indices.get(), edges.get()));
+  return std::make_pair(detail::comm_edge_iterator(indices, edges),
+                        detail::comm_edge_iterator(nedges));
+}
+
+
+int num_edges(const graph_communicator& comm)
+{
+  int nnodes, nedges;
+  BOOST_MPI_CHECK_RESULT(MPI_Graphdims_get, ((MPI_Comm)comm, &nnodes, &nedges));
+  return nedges;
+}
+
+} } // end namespace boost::mpi