boost/mpi/detail/packed_oprimitive.hpp
// (C) Copyright 2005 Matthias Troyer
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Authors: Matthias Troyer
#ifndef BOOST_MPI_PACKED_OPRIMITIVE_HPP
#define BOOST_MPI_PACKED_OPRIMITIVE_HPP
#include <boost/mpi/config.hpp>
#include <iostream>
#include <cstddef> // size_t
#include <boost/config.hpp>
#include <boost/mpi/datatype.hpp>
#include <boost/mpi/exception.hpp>
#include <boost/serialization/detail/get_data.hpp>
#include <boost/serialization/array.hpp>
#include <boost/assert.hpp>
#include <vector>
#include <boost/mpi/allocator.hpp>
namespace boost { namespace mpi {
/// serialization using MPI::Pack
class BOOST_MPI_DECL packed_oprimitive
{
public:
/// the type of the buffer into which the data is packed upon serialization
typedef std::vector<char, allocator<char> > buffer_type;
packed_oprimitive(buffer_type & b, MPI_Comm const & comm)
: buffer_(b),
comm(comm)
{
}
void const * address() const
{
return &buffer_[0];
}
const std::size_t& size() const
{
return size_ = buffer_.size();
}
void save_binary(void const *address, std::size_t count)
{
save_impl(address,MPI_BYTE,count);
}
// fast saving of arrays
template<class T>
void save_array(serialization::array<T> const& x, unsigned int /* file_version */)
{
if (x.count())
save_impl(x.address(), get_mpi_datatype(*x.address()), x.count());
}
typedef is_mpi_datatype<mpl::_1> use_array_optimization;
#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
friend class archive::save_access;
protected:
#else
public:
#endif
// default saving of primitives.
template<class T>
void save(const T & t)
{
save_impl(&t, get_mpi_datatype<T>(t), 1);
}
void save(const std::string &s)
{
unsigned int l = static_cast<unsigned int>(s.size());
save(l);
save_impl(s.data(),MPI_CHAR,s.size());
}
private:
void save_impl(void const * p, MPI_Datatype t, int l)
{
// allocate enough memory
int memory_needed;
BOOST_MPI_CHECK_RESULT(MPI_Pack_size,(l,t,comm,&memory_needed));
int position = buffer_.size();
buffer_.resize(position + memory_needed);
// pack the data into the buffer
BOOST_MPI_CHECK_RESULT(MPI_Pack,
(const_cast<void*>(p), l, t, boost::serialization::detail::get_data(buffer_), buffer_.size(), &position, comm));
// reduce the buffer size if needed
BOOST_ASSERT(std::size_t(position) <= buffer_.size());
if (std::size_t(position) < buffer_.size())
buffer_.resize(position);
}
buffer_type& buffer_;
mutable std::size_t size_;
MPI_Comm comm;
};
} } // end namespace boost::mpi
#endif // BOOST_MPI_PACKED_OPRIMITIVE_HPP