mpi/detail/packed_iprimitive.hpp

0001 // (C) Copyright 2005 Matthias Troyer
0002
0003 // Use, modification and distribution is subject to the Boost Software
0004 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0005 // http://www.boost.org/LICENSE_1_0.txt)
0006
0007 //  Authors: Matthias Troyer
0008
0009 #ifndef BOOST_MPI_PACKED_IPRIMITIVE_HPP
0010 #define BOOST_MPI_PACKED_IPRIMITIVE_HPP
0011
0012 #include <boost/mpi/config.hpp>
0013 #include <cstddef> // size_t
0014 #include <boost/config.hpp>
0015 #include <boost/mpi/datatype.hpp>
0016 #include <boost/mpi/exception.hpp>
0017 #include <boost/mpi/detail/antiques.hpp>
0018 #include <boost/serialization/array.hpp>
0019 #include <vector>
0020 #include <boost/mpi/detail/antiques.hpp>
0021 #include <boost/mpi/allocator.hpp>
0022
0023 namespace boost { namespace mpi {
0024
0025 /// deserialization using MPI_Unpack
0026
0027 class BOOST_MPI_DECL packed_iprimitive
0028 {
0029 public:
0030     /// the type of the buffer from which the data is unpacked upon deserialization
0031     typedef std::vector<char, allocator<char> > buffer_type;
0032
0033     packed_iprimitive(buffer_type & b, MPI_Comm const & comm, int position = 0)
0034          : buffer_(b),
0035            comm(comm),
0036            position(position)
0037         {
0038         }
0039
0040     void* address ()
0041     {
0042       return detail::c_data(buffer_);
0043     }
0044
0045     void const* address () const
0046     {
0047       return detail::c_data(buffer_);
0048     }
0049
0050     const std::size_t& size() const
0051     {
0052       return size_ = buffer_.size();
0053     }
0054
0055     void resize(std::size_t s)
0056     {
0057       buffer_.resize(s);
0058     }
0059
0060     void load_binary(void *address, std::size_t count)
0061         {
0062           load_impl(address,MPI_BYTE,count);
0063         }
0064
0065     // fast saving of arrays of fundamental types
0066     template<class T>
0067     void load_array(serialization::array_wrapper<T> const& x, unsigned int /* file_version */)
0068     {
0069       if (x.count())
0070         load_impl(x.address(), get_mpi_datatype(*x.address()), x.count());
0071     }
0072
0073 /*
0074     template<class T>
0075     void load(serialization::array_wrapper<T> const& x)
0076     {
0077       load_array(x,0u);
0078     }
0079 */
0080
0081     typedef is_mpi_datatype<mpl::_1> use_array_optimization;
0082
0083     // default saving of primitives.
0084     template<class T>
0085     void load( T & t)
0086     {
0087       load_impl(&t, get_mpi_datatype(t), 1);
0088     }
0089
0090     template<class CharType>
0091     void load(std::basic_string<CharType> & s)
0092     {
0093         unsigned int l;
0094         load(l);
0095         s.resize(l);
0096         // note breaking a rule here - could be a problem on some platform
0097         if (l)
0098           load_impl(const_cast<CharType *>(s.data()),
0099                     get_mpi_datatype(CharType()),l);
0100     }
0101
0102 private:
0103
0104     void load_impl(void * p, MPI_Datatype t, int l)
0105     {
0106       BOOST_MPI_CHECK_RESULT(MPI_Unpack,
0107                              (const_cast<char*>(detail::c_data(buffer_)), buffer_.size(), &position, p, l, t, comm));
0108     }
0109
0110     buffer_type & buffer_;
0111     mutable std::size_t size_;
0112     MPI_Comm comm;
0113     int position;
0114 };
0115
0116 } } // end namespace boost::mpi
0117
0118 #endif // BOOST_MPI_PACKED_IPRIMITIVE_HPP