Chris@16: // Copyright Daniel Wallin 2007. Use, modification and distribution is
Chris@16: // subject to the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_SHUFFLED_DISTRIBUTION_070923_HPP
Chris@16: #define BOOST_SHUFFLED_DISTRIBUTION_070923_HPP
Chris@16: 
Chris@16: #ifndef BOOST_GRAPH_USE_MPI
Chris@16: #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
Chris@16: #endif
Chris@16: 
Chris@16: # include <boost/assert.hpp>
Chris@16: # include <boost/iterator/counting_iterator.hpp>
Chris@16: # include <vector>
Chris@16: 
Chris@16: namespace boost { namespace graph { namespace distributed {
Chris@16: 
Chris@16: template <class BaseDistribution>
Chris@16: struct shuffled_distribution : BaseDistribution
Chris@16: {
Chris@16:     typedef std::size_t size_type;
Chris@16: 
Chris@16:     template <class ProcessGroup>
Chris@16:     shuffled_distribution(ProcessGroup const& pg, BaseDistribution const& base)
Chris@16:       : BaseDistribution(base)
Chris@16:       , n(num_processes(pg))
Chris@16:       , mapping_(make_counting_iterator(size_type(0)), make_counting_iterator(n))
Chris@16:       , reverse_mapping(mapping_)
Chris@16:     {}
Chris@16: 
Chris@16:     std::vector<size_type> const& mapping() const
Chris@16:     {
Chris@16:         return mapping_;
Chris@16:     }
Chris@16: 
Chris@16:     template <class InputIterator>
Chris@16:     void assign_mapping(InputIterator first, InputIterator last)
Chris@16:     {
Chris@16:         mapping_.assign(first, last);
Chris@16:         BOOST_ASSERT(mapping_.size() == n);
Chris@16:         reverse_mapping.resize(mapping_.size());
Chris@16: 
Chris@16:         for (std::vector<size_t>::iterator i(mapping_.begin());
Chris@16:             i != mapping_.end(); ++i)
Chris@16:         {
Chris@16:             reverse_mapping[*i] = i - mapping_.begin();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     BaseDistribution& base()
Chris@16:     {
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     BaseDistribution const& base() const
Chris@16:     {
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     template <class ProcessID>
Chris@16:     size_type block_size(ProcessID id, size_type n) const
Chris@16:     {
Chris@16:         return base().block_size(reverse_mapping[id], n);
Chris@16:     }
Chris@16: 
Chris@16:     template <class T>
Chris@16:     size_type operator()(T const& value) const
Chris@16:     {
Chris@16:         return mapping_[base()(value)];
Chris@16:     }
Chris@16: 
Chris@16:     template <class ProcessID>
Chris@16:     size_type start(ProcessID id) const
Chris@16:     {
Chris@16:         return base().start(reverse_mapping[id]);
Chris@16:     }
Chris@16: 
Chris@16:     size_type local(size_type i) const
Chris@16:     {
Chris@16:         return base().local(i);
Chris@16:     }
Chris@16: 
Chris@16:     size_type global(size_type i) const
Chris@16:     {
Chris@16:         return base().global(i);
Chris@16:     }
Chris@16: 
Chris@16:     template <class ProcessID>
Chris@16:     size_type global(ProcessID id, size_type n) const
Chris@16:     {
Chris@16:         return base().global(reverse_mapping[id], n);
Chris@16:     }
Chris@16: 
Chris@16:     template <class Archive>
Chris@16:     void serialize(Archive& ar, unsigned long /*version*/)
Chris@16:     {
Chris@16:         ar & serialization::make_nvp("base", base());
Chris@16:     }
Chris@16: 
Chris@16:     void clear() 
Chris@16:     {
Chris@16:         base().clear();
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     size_type n;
Chris@16:     std::vector<size_type> mapping_;
Chris@16:     std::vector<size_type> reverse_mapping;
Chris@16: };
Chris@16: 
Chris@16: }}} // namespace boost::graph::distributed
Chris@16: 
Chris@16: #endif // BOOST_SHUFFLED_DISTRIBUTION_070923_HPP
Chris@16: