multi_array_ref_base_openfpm.hpp

/*
 * multi_array_ref_openfpm_base.hpp
 *
 *  Created on: Jun 30, 2018
 *      Author: i-bird
 */
 
#ifndef MULTI_ARRAY_REF_OPENFPM_BASE_HPP_
#define MULTI_ARRAY_REF_OPENFPM_BASE_HPP_
 
#include "types.hpp"
#include <boost/mpl/size_t.hpp>
#include "boost/iterator/reverse_iterator.hpp"
#include "storage_order.hpp"
#include <boost/mpl/at.hpp>
#include <boost/mpl/size.hpp>
#include <boost/mpl/pop_front.hpp>
#include <boost/mpl/for_each.hpp>
#include <boost/mpl/range_c.hpp>
#include <boost/type.hpp>
 
namespace openfpm
{
 
// class declarations
 
//template<typename T, std::size_t NumDims, typename Allocator = std::allocator<T> >
//class multi_array_openfpm;
 
template <typename T, int NumDims, typename vector, typename StorageOrder=typename ofp_storage_order<NumDims>::value>
class multi_array_ref_openfpm;
 
// This is a public interface for use by end users!
namespace multi_array_types
{
    typedef openfpm::detail::multi_array::size_type size_type;
    typedef std::ptrdiff_t difference_type;
    typedef openfpm::detail::multi_array::index index;
}
 
 
namespace detail {
namespace multi_array {
 
template <typename T, std::size_t NumDims, typename vector>
class sub_array_openfpm;
 
template <typename T, std::size_t NumDims, typename vector, typename TPtr = const T*>
class const_sub_array_openfpm;
 
  template <typename T, typename TPtr, typename NumDims, typename vector, typename Reference,
            typename IteratorCategory>
class array_iterator_openfpm;
 
template <typename T, std::size_t NumDims, typename TPtr = const T*>
class const_multi_array_view_openfpm;
 
template <typename T, std::size_t NumDims>
class multi_array_view_openfpm;
 
 
// class interfaces
 
class multi_array_base_openfpm
{
public:
    typedef multi_array_types::size_type size_type;
    typedef multi_array_types::difference_type difference_type;
    typedef multi_array_types::index index;
};
 
//
// value_accessor_n
//  contains the routines for accessing elements from
//  N-dimensional views.
//
template<typename T, std::size_t NumDims, typename vector>
class value_accessor_n_openfpm : public multi_array_base_openfpm
{
    typedef multi_array_base_openfpm super_type;
public:
    typedef typename super_type::index index;
 
    //
    // public typedefs used by classes that inherit from this base
    //
    typedef T element;
    typedef openfpm::multi_array_ref_openfpm<T,NumDims-1,typename boost::mpl::pop_front<vector>::type> value_type;
    typedef sub_array_openfpm<T,NumDims-1,typename boost::mpl::pop_front<vector>::type> reference;
    typedef const_sub_array_openfpm<T,NumDims-1,typename boost::mpl::pop_front<vector>::type> const_reference;
 
protected:
 
    // used by array operator[] and iterators to get reference types.
    template <typename Reference, typename TPtr>
    __device__ __host__ inline Reference access(boost::type<Reference>,
                                         index idx,
                                         const index* strides,
                                         TPtr base) const
    {
        TPtr newbase = base + idx * strides[0];
        return Reference(newbase,strides+1);
    }
 
    __device__ __host__ value_accessor_n_openfpm() { }
    __device__ __host__ ~value_accessor_n_openfpm() { }
};
 
template <class T> inline __device__ __host__ void ignore_unused_variable_warning_ofp(T const&) {}
 
//
// value_accessor_one
//  contains the routines for accessing reference elements from
//  1-dimensional views.
//
template<typename T, typename vector>
class value_accessor_one_openfpm : public multi_array_base_openfpm
{
    typedef multi_array_base_openfpm super_type;
public:
    typedef typename super_type::index index;
    //
    // public typedefs for use by classes that inherit it.
    //
    typedef T element;
    typedef T value_type;
    typedef T& reference;
    typedef T const& const_reference;
 
protected:
 
    // used by array operator[] and iterators to get reference types.
    template <typename Reference, typename TPtr>
    inline __device__ __host__ Reference access(boost::type<Reference>,index idx,
                   const index* strides,
                   TPtr base) const
    {
        return *(base + idx * strides[0]);
    }
 
    // used by array operator[] and iterators to get reference types.
    template <typename Reference, typename TPtr>
    inline __device__ __host__ Reference access(boost::type<Reference>,index idx,TPtr base, const index* strides) const
    {
        BOOST_ASSERT(size_type(idx < boost::mpl::at<vector,boost::mpl::int_<0>>::type::value));
        return *(base + idx * strides[0]);
    }
 
    __device__ __host__ value_accessor_one_openfpm() { }
    __device__ __host__ ~value_accessor_one_openfpm() { }
};
 
 
// choose value accessor begins
//
 
template <typename T, std::size_t NumDims,typename vector>
struct choose_value_accessor_n_openfpm
{
    typedef value_accessor_n_openfpm<T,NumDims,vector> type;
};
 
template <typename T,typename vector>
struct choose_value_accessor_one_openfpm
{
    typedef value_accessor_one_openfpm<T,vector> type;
};
 
template <typename T, typename NumDims, typename vector>
struct value_accessor_generator_openfpm
{
    BOOST_STATIC_CONSTANT(std::size_t, dimensionality = NumDims::value);
 
    typedef typename
            boost::mpl::eval_if_c<(dimensionality == 1),
                  choose_value_accessor_one_openfpm<T,vector>,
                  choose_value_accessor_n_openfpm<T,dimensionality,vector>
            >::type type;
};
 
 
template <class T, class NumDims, typename vector>
struct associated_types_openfpm: value_accessor_generator_openfpm<T,NumDims,vector>::type
{};
 
//
// choose value accessor ends
 
// Due to some imprecision in the C++ Standard,
// MSVC 2010 is broken in debug mode: it requires
// that an Output Iterator have output_iterator_tag in its iterator_category if
// that iterator is not bidirectional_iterator or random_access_iterator.
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
struct mutable_iterator_tag
 : boost::random_access_traversal_tag, std::input_iterator_tag
{
  operator std::output_iterator_tag() const {
    return std::output_iterator_tag();
  }
};
#endif
 
 
// multi_array_base
template <typename T, std::size_t NumDims, typename vector>
class multi_array_impl_base_openfpm: public value_accessor_generator_openfpm<T,boost::mpl::size_t<NumDims>,vector>::type
{
    typedef associated_types_openfpm<T,boost::mpl::size_t<NumDims>,vector > types;
public:
 
    typedef typename types::index index;
    typedef typename types::size_type size_type;
    typedef typename types::element element;
    typedef typename types::value_type value_type;
    typedef typename types::reference reference;
    typedef typename types::const_reference const_reference;
 
    template <std::size_t NDims>
    struct subarray
    {
        typedef openfpm::detail::multi_array::sub_array_openfpm<T,NDims,vector> type;
    };
 
    template <std::size_t NDims>
    struct const_subarray
    {
        typedef openfpm::detail::multi_array::const_sub_array_openfpm<T,NDims,vector> type;
    };
 
    template <std::size_t NDims>
    struct array_view_openfpm
    {
        typedef openfpm::detail::multi_array::multi_array_view_openfpm<T,NDims> type;
    };
 
    template <std::size_t NDims>
    struct const_array_view_openfpm
    {
        public:
            typedef openfpm::detail::multi_array::const_multi_array_view_openfpm<T,NDims> type;
    };
 
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
    // Deal with VC 2010 output_iterator_tag requirement
    typedef array_iterator_openfpm<T,T*,mpl::size_t<NumDims>,vector,reference,
                         mutable_iterator_tag> iterator;
#else
    typedef array_iterator_openfpm<T,T*,boost::mpl::size_t<NumDims>, vector,reference,
                         boost::random_access_traversal_tag> iterator;
#endif
    typedef array_iterator_openfpm<T,T const*,boost::mpl::size_t<NumDims>,vector,const_reference,
                                   boost::random_access_traversal_tag> const_iterator;
 
    typedef ::boost::reverse_iterator<iterator> reverse_iterator;
    typedef ::boost::reverse_iterator<const_iterator> const_reverse_iterator;
 
    BOOST_STATIC_CONSTANT(std::size_t, dimensionality = NumDims);
 
protected:
 
    __device__ __host__ multi_array_impl_base_openfpm() { }
    __device__ __host__ ~multi_array_impl_base_openfpm() { }
 
  template <typename StorageOrder, typename Stride_list, typename Extent_type>
  void compute_strides(Stride_list& stride_list, Extent_type& extent)
  {
      // invariant: stride = the stride for dimension n
      index stride = 1;
 
      boost::mpl::for_each<boost::mpl::range_c<int,0,NumDims>>([&](auto i) {
            constexpr int ordering = boost::mpl::at<StorageOrder,boost::mpl::int_<i> >::type::value;
            constexpr int extent_i = boost::mpl::int_<boost::mpl::at<vector,boost::mpl::int_<ordering>>::type::value>::value;
 
          // The stride for this dimension is the product of the
          // lengths of the ranks minor to it.
          stride_list[ordering] = stride;
 
          if (ordering == 0)
              stride *= extent;
          else
              stride *= extent_i;
    });
  }
 
    // Used by operator() in our array classes
    template <typename Reference, typename IndexList, typename TPtr>
    Reference access_element(boost::type<Reference>,
                           const IndexList& indices,
                           TPtr base,
                           const size_type* extents,
                           const index* strides,
                           const index* index_bases) const
    {
        boost::function_requires<
            boost::CollectionConcept<IndexList> >();
        ignore_unused_variable_warning(index_bases);
        ignore_unused_variable_warning(extents);
#ifdef SE_CLASS1
        for (size_type i = 0; i != NumDims; ++i)
        {
            BOOST_ASSERT(indices[i] - index_bases[i] >= 0);
            BOOST_ASSERT(size_type(indices[i] - index_bases[i]) < extents[i]);
        }
#endif
 
        index offset = 0;
        {
            typename IndexList::const_iterator i = indices.begin();
            size_type n = 0;
            while (n != NumDims)
            {
                offset += (*i) * strides[n];
                ++n;
                ++i;
            }
        }
        return base[offset];
    }
};
 
} // namespace multi_array
} // namespace detail
 
} // namespace openfpm
 
 
#endif /* MULTI_ARRAY_REF_OPENFPM_BASE_HPP_ */