ceph/src/boost/libs/mpi/include/boost/mpi/detail/packed_iprimitive.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_IPRIMITIVE_HPP
  10 #define BOOST_MPI_PACKED_IPRIMITIVE_HPP
  11
  12 #include <boost/mpi/config.hpp>
  13 #include <cstddef> // size_t
  14 #include <boost/config.hpp>
  15 #include <boost/mpi/datatype.hpp>
  16 #include <boost/mpi/exception.hpp>
  17 #include <boost/assert.hpp>
  18 #include <boost/serialization/array.hpp>
  19 #include <boost/serialization/detail/get_data.hpp>
  20 #include <vector>
  21 #include <boost/mpi/allocator.hpp>
  22
  23 namespace boost { namespace mpi {
  24
  25 /// deserialization using MPI_Unpack
  26
  27 class BOOST_MPI_DECL packed_iprimitive
  28 {
  29 public:
  30     /// the type of the buffer from which the data is unpacked upon deserialization
  31     typedef std::vector<char, allocator<char> > buffer_type;
  32
  33     packed_iprimitive(buffer_type & b, MPI_Comm const & comm, int position = 0)
  34          : buffer_(b),
  35            comm(comm),
  36            position(position)
  37         {
  38         }
  39
  40     void* address ()
  41     {
  42       return &buffer_[0];
  43     }
  44
  45     void const* address () const
  46     {
  47       return &buffer_[0];
  48     }
  49
  50     const std::size_t& size() const
  51     {
  52       return size_ = buffer_.size();
  53     }
  54
  55     void resize(std::size_t s)
  56     {
  57       buffer_.resize(s);
  58     }
  59
  60     void load_binary(void *address, std::size_t count)
  61         {
  62           load_impl(address,MPI_BYTE,count);
  63         }
  64
  65     // fast saving of arrays of fundamental types
  66     template<class T>
  67     void load_array(serialization::array_wrapper<T> const& x, unsigned int /* file_version */)
  68     {
  69       if (x.count())
  70         load_impl(x.address(), get_mpi_datatype(*x.address()), x.count());
  71     }
  72
  73 /*
  74     template<class T>
  75     void load(serialization::array_wrapper<T> const& x)
  76     {
  77       load_array(x,0u);
  78     }
  79 */
  80
  81     typedef is_mpi_datatype<mpl::_1> use_array_optimization;
  82
  83     // default saving of primitives.
  84     template<class T>
  85     void load( T & t)
  86     {
  87       load_impl(&t, get_mpi_datatype(t), 1);
  88     }
  89
  90     template<class CharType>
  91     void load(std::basic_string<CharType> & s)
  92     {
  93         unsigned int l;
  94         load(l);
  95         s.resize(l);
  96         // note breaking a rule here - could be a problem on some platform
  97         if (l)
  98           load_impl(const_cast<CharType *>(s.data()),
  99                     get_mpi_datatype(CharType()),l);
 100     }
 101
 102 private:
 103
 104     void load_impl(void * p, MPI_Datatype t, int l)
 105     {
 106       BOOST_MPI_CHECK_RESULT(MPI_Unpack,
 107         (const_cast<char*>(boost::serialization::detail::get_data(buffer_)), buffer_.size(), &position, p, l, t, comm));
 108     }
 109
 110     buffer_type & buffer_;
 111     mutable std::size_t size_;
 112     MPI_Comm comm;
 113     int position;
 114 };
 115
 116 } } // end namespace boost::mpi
 117
 118 #endif // BOOST_MPI_PACKED_IPRIMITIVE_HPP