boost/mpi/packed_oarchive.hpp

   1 // (C) Copyright 2005 Matthias Troyer
   2 // (C) Copyright 2006 Douglas Gregor <doug.gregor -at- gmail.com>
   3
   4 // Use, modification and distribution is subject to the Boost Software
   5 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7
   8 //  Authors: Matthias Troyer
   9 //           Douglas Gregor
  10
  11 /** @file packed_oarchive.hpp
  12  *
  13  *  This header provides the facilities for unpacking Serializable
  14  *  data types from a buffer using @c MPI_Unpack. The buffers are
  15  *  typically received via MPI and have been packed either by via the
  16  *  facilities in @c packed_iarchive.hpp or @c MPI_Pack.
  17  */
  18 #ifndef BOOST_MPI_PACKED_OARCHIVE_HPP
  19 #define BOOST_MPI_PACKED_OARCHIVE_HPP
  20
  21 #include <boost/mpi/datatype.hpp>
  22 #include <boost/archive/detail/auto_link_archive.hpp>
  23 #include <boost/archive/basic_binary_oarchive.hpp>
  24 #include <boost/mpi/detail/packed_oprimitive.hpp>
  25 #include <boost/mpi/detail/binary_buffer_oprimitive.hpp>
  26
  27 namespace boost { namespace mpi {
  28
  29 #ifdef BOOST_MPI_HOMOGENEOUS
  30   typedef binary_buffer_oprimitive oprimitive;
  31 #else
  32   typedef packed_oprimitive oprimitive;
  33 #endif
  34
  35 /** @brief An archive that unpacks binary data from an MPI buffer.
  36  *
  37  *  The @c packed_oarchive class is an Archiver (as in the
  38  *  Boost.Serialization library) that unpacks binary data from a
  39  *  buffer received via MPI. It can operate on any Serializable data
  40  *  type and will use the @c MPI_Unpack function of the underlying MPI
  41  *  implementation to perform deserialization.
  42  */
  43
  44 class BOOST_MPI_DECL packed_oarchive
  45   : public oprimitive,
  46     public archive::basic_binary_oarchive<packed_oarchive>
  47 {
  48 public:
  49   /**
  50    *  Construct a @c packed_oarchive to receive data over the given
  51    *  MPI communicator and with an initial buffer.
  52    *
  53    *  @param comm The communicator over which this archive will be
  54    *  received.
  55    *
  56    *  @param b A user-defined buffer that contains the binary
  57    *  representation of serialized objects.
  58    *
  59    *  @param flags Control the serialization of the data types. Refer
  60    *  to the Boost.Serialization documentation before changing the
  61    *  default flags.
  62    */
  63   packed_oarchive( MPI_Comm const & comm, buffer_type & b, unsigned int flags = boost::archive::no_header)
  64          : oprimitive(b,comm),
  65            archive::basic_binary_oarchive<packed_oarchive>(flags)
  66         {}
  67
  68   /**
  69    *  Construct a @c packed_oarchive to receive data over the given
  70    *  MPI communicator.
  71    *
  72    *  @param comm The communicator over which this archive will be
  73    *  received.
  74    *
  75    *  @param flags Control the serialization of the data types. Refer
  76    *  to the Boost.Serialization documentation before changing the
  77    *  default flags.
  78    */
  79   packed_oarchive ( MPI_Comm const & comm, unsigned int flags =  boost::archive::no_header)
  80          : oprimitive(internal_buffer_,comm),
  81            archive::basic_binary_oarchive<packed_oarchive>(flags)
  82         {}
  83
  84   // Save everything else in the usual way, forwarding on to the Base class
  85   template<class T>
  86   void save_override(T const& x, int version, mpl::false_)
  87   {
  88     archive::basic_binary_oarchive<packed_oarchive>::save_override(x,version);
  89   }
  90
  91   // Save it directly using the primnivites
  92   template<class T>
  93   void save_override(T const& x, int /*version*/, mpl::true_)
  94   {
  95     oprimitive::save(x);
  96   }
  97
  98   // Save all supported datatypes directly
  99   template<class T>
 100   void save_override(T const& x, int version)
 101   {
 102     typedef typename mpl::apply1<use_array_optimization,T>::type use_optimized;
 103     save_override(x, version, use_optimized());
 104   }
 105
 106 private:
 107   /// An internal buffer to be used when the user does not supply his
 108   /// own buffer.
 109   buffer_type internal_buffer_;
 110 };
 111
 112 } } // end namespace boost::mpi
 113
 114 // required by export
 115 BOOST_SERIALIZATION_REGISTER_ARCHIVE(boost::mpi::packed_oarchive)
 116 BOOST_SERIALIZATION_USE_ARRAY_OPTIMIZATION(boost::mpi::packed_oarchive)
 117
 118
 119
 120 #endif // BOOST_MPI_PACKED_OARCHIVE_HPP