ceph/src/boost/boost/mpi/detail/packed_oprimitive.hpp

   1 // (C) Copyright 2005 Matthias Troyer
   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: Matthias Troyer
   8
   9 #ifndef BOOST_MPI_PACKED_OPRIMITIVE_HPP
  10 #define BOOST_MPI_PACKED_OPRIMITIVE_HPP
  11
  12 #include <boost/mpi/config.hpp>
  13 #include <cstddef> // size_t
  14 #include <boost/config.hpp>
  15
  16 #include <boost/mpi/datatype.hpp>
  17 #include <boost/mpi/exception.hpp>
  18 #include <boost/mpi/detail/antiques.hpp>
  19 #include <boost/serialization/array.hpp>
  20 #include <boost/assert.hpp>
  21 #include <vector>
  22 #include <boost/mpi/allocator.hpp>
  23
  24 namespace boost { namespace mpi {
  25
  26 /// serialization using MPI::Pack
  27
  28 class BOOST_MPI_DECL packed_oprimitive
  29 {
  30 public:
  31     /// the type of the buffer into which the data is packed upon serialization
  32     typedef std::vector<char, allocator<char> > buffer_type;
  33
  34     packed_oprimitive(buffer_type & b, MPI_Comm const & comm)
  35          : buffer_(b),
  36            comm(comm)
  37         {
  38         }
  39
  40     void const * address() const
  41     {
  42       return &buffer_[0];
  43     }
  44
  45     const std::size_t& size() const
  46     {
  47       return size_ = buffer_.size();
  48     }
  49
  50     void save_binary(void const *address, std::size_t count)
  51         {
  52           save_impl(address,MPI_BYTE,count);
  53         }
  54
  55     // fast saving of arrays
  56     template<class T>
  57     void save_array(serialization::array_wrapper<T> const& x, unsigned int /* file_version */)
  58     {
  59         if (x.count())
  60           save_impl(x.address(), get_mpi_datatype(*x.address()), x.count());
  61     }
  62
  63     typedef is_mpi_datatype<mpl::_1> use_array_optimization;
  64
  65 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
  66     friend class archive::save_access;
  67 protected:
  68 #else
  69 public:
  70 #endif
  71
  72     // default saving of primitives.
  73     template<class T>
  74     void save(const T & t)
  75     {
  76       save_impl(&t, get_mpi_datatype<T>(t), 1);
  77     }
  78
  79     template<class CharType>
  80     void save(const std::basic_string<CharType> &s)
  81     {
  82       unsigned int l = static_cast<unsigned int>(s.size());
  83       save(l);
  84       if (l)
  85         save_impl(s.data(),get_mpi_datatype(CharType()),s.size());
  86     }
  87
  88 private:
  89
  90     void save_impl(void const * p, MPI_Datatype t, int l)
  91     {
  92       // allocate enough memory
  93       int memory_needed;
  94       BOOST_MPI_CHECK_RESULT(MPI_Pack_size,(l,t,comm,&memory_needed));
  95
  96       int position = buffer_.size();
  97       buffer_.resize(position + memory_needed);
  98
  99       // pack the data into the buffer
 100       BOOST_MPI_CHECK_RESULT(MPI_Pack,
 101                              (const_cast<void*>(p),l,t,
 102                               detail::c_data(buffer_),
 103                               buffer_.size(),
 104                               &position,comm));
 105       // reduce the buffer size if needed
 106       BOOST_ASSERT(std::size_t(position) <= buffer_.size());
 107       if (std::size_t(position) < buffer_.size())
 108           buffer_.resize(position);
 109     }
 110
 111   buffer_type& buffer_;
 112   mutable std::size_t size_;
 113   MPI_Comm comm;
 114 };
 115
 116 } } // end namespace boost::mpi
 117
 118 #endif // BOOST_MPI_PACKED_OPRIMITIVE_HPP