boost/property_map/parallel/caching_property_map.hpp

   1 // Copyright 2004 The Trustees of Indiana University.
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  Authors: Douglas Gregor
   8 //           Andrew Lumsdaine
   9 #ifndef BOOST_PARALLEL_CACHING_PROPERTY_MAP_HPP
  10 #define BOOST_PARALLEL_CACHING_PROPERTY_MAP_HPP
  11
  12 #ifndef BOOST_GRAPH_USE_MPI
  13 #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
  14 #endif
  15
  16 #include <boost/property_map/property_map.hpp>
  17
  18 namespace boost {
  19
  20 // This probably doesn't belong here
  21 template<typename Key, typename Value>
  22 inline void local_put(dummy_property_map, const Key&, const Value&) {}
  23
  24 namespace parallel {
  25
  26 /** Property map that caches values placed in it but does not
  27  * broadcast values to remote processors.  This class template is
  28  * meant as an adaptor for @ref distributed_property_map that
  29  * suppresses communication in the event of a remote @c put operation
  30  * by mapping it to a local @c put operation.
  31  *
  32  * @todo Find a better name for @ref caching_property_map
  33  */
  34 template<typename PropertyMap>
  35 class caching_property_map
  36 {
  37 public:
  38   typedef typename property_traits<PropertyMap>::key_type   key_type;
  39   typedef typename property_traits<PropertyMap>::value_type value_type;
  40   typedef typename property_traits<PropertyMap>::reference  reference;
  41   typedef typename property_traits<PropertyMap>::category   category;
  42
  43   explicit caching_property_map(const PropertyMap& property_map)
  44     : property_map(property_map) {}
  45
  46   PropertyMap&        base()       { return property_map; }
  47   const PropertyMap&  base() const { return property_map; }
  48
  49   template<typename Reduce>
  50   void set_reduce(const Reduce& reduce)
  51   { property_map.set_reduce(reduce); }
  52
  53   void reset() { property_map.reset(); }
  54
  55 #if 0
  56   reference operator[](const key_type& key) const
  57   {
  58     return property_map[key];
  59   }
  60 #endif
  61
  62 private:
  63   PropertyMap property_map;
  64 };
  65
  66 template<typename PropertyMap, typename Key>
  67 inline typename caching_property_map<PropertyMap>::value_type
  68 get(const caching_property_map<PropertyMap>& pm, const Key& key)
  69 { return get(pm.base(), key); }
  70
  71 template<typename PropertyMap, typename Key, typename Value>
  72 inline void
  73 local_put(const caching_property_map<PropertyMap>& pm, const Key& key,
  74           const Value& value)
  75 { local_put(pm.base(), key, value); }
  76
  77 template<typename PropertyMap, typename Key, typename Value>
  78 inline void
  79 cache(const caching_property_map<PropertyMap>& pm, const Key& key,
  80       const Value& value)
  81 { cache(pm.base(), key, value); }
  82
  83 template<typename PropertyMap, typename Key, typename Value>
  84 inline void
  85 put(const caching_property_map<PropertyMap>& pm, const Key& key,
  86     const Value& value)
  87 { local_put(pm.base(), key, value); }
  88
  89 template<typename PropertyMap>
  90 inline caching_property_map<PropertyMap>
  91 make_caching_property_map(const PropertyMap& pm)
  92 { return caching_property_map<PropertyMap>(pm); }
  93
  94 } } // end namespace boost::parallel
  95
  96 #endif // BOOST_PARALLEL_CACHING_PROPERTY_MAP_HPP