// Copyright 2004 The Trustees of Indiana University. | |
// 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) | |
// Authors: Douglas Gregor | |
// Andrew Lumsdaine | |
#ifndef BOOST_GRAPH_PARALLEL_PROPERTIES_HPP | |
#define BOOST_GRAPH_PARALLEL_PROPERTIES_HPP | |
#ifndef BOOST_GRAPH_USE_MPI | |
#error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included" | |
#endif | |
#include <boost/graph/properties.hpp> | |
#include <boost/property_map/parallel/distributed_property_map.hpp> | |
namespace boost { | |
/*************************************************************************** | |
* Property map reduction operations | |
***************************************************************************/ | |
/** | |
* Metafunction that produces a reduction operation for the given | |
* property. The default behavior merely forwards to @ref | |
* basic_reduce, but it is expected that this class template will be | |
* specified for important properties. | |
*/ | |
template<typename Property> | |
struct property_reduce | |
{ | |
template<typename Value> | |
class apply : public parallel::basic_reduce<Value> {}; | |
}; | |
/** | |
* Reduction of vertex colors can only darken, not lighten, the | |
* color. Black cannot turn black, grey can only turn black, and | |
* white can be changed to either color. The default color is white. | |
*/ | |
template<> | |
struct property_reduce<vertex_color_t> | |
{ | |
template<typename Color> | |
class apply | |
{ | |
typedef color_traits<Color> traits; | |
public: | |
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true); | |
template<typename Key> | |
Color operator()(const Key&) const { return traits::white(); } | |
template<typename Key> | |
Color operator()(const Key&, Color local, Color remote) const { | |
if (local == traits::white()) return remote; | |
else if (remote == traits::black()) return remote; | |
else return local; | |
} | |
}; | |
}; | |
/** | |
* Reduction of a distance always takes the shorter distance. The | |
* default distance value is the maximum value for the data type. | |
*/ | |
template<> | |
struct property_reduce<vertex_distance_t> | |
{ | |
template<typename T> | |
class apply | |
{ | |
public: | |
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true); | |
template<typename Key> | |
T operator()(const Key&) const { return (std::numeric_limits<T>::max)(); } | |
template<typename Key> | |
T operator()(const Key&, T x, T y) const { return x < y? x : y; } | |
}; | |
}; | |
template<> | |
struct property_reduce<vertex_predecessor_t> | |
{ | |
template<typename T> | |
class apply | |
{ | |
public: | |
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true); | |
T operator()(T key) const { return key; } | |
T operator()(T key, T, T y) const { return y; } | |
}; | |
}; | |
template<typename Property, typename PropertyMap> | |
inline void set_property_map_role(Property p, PropertyMap pm) | |
{ | |
typedef typename property_traits<PropertyMap>::value_type value_type; | |
typedef property_reduce<Property> property_red; | |
typedef typename property_red::template apply<value_type> reduce; | |
pm.set_reduce(reduce()); | |
} | |
} // end namespace boost | |
#endif // BOOST_GRAPH_PARALLEL_PROPERTIES_HPP |