boost/compute/iterator/constant_buffer_iterator.hpp
//---------------------------------------------------------------------------//
// Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
//
// Distributed under 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
//
// See http://boostorg.github.com/compute for more information.
//---------------------------------------------------------------------------//
#ifndef BOOST_COMPUTE_ITERATOR_CONSTANT_BUFFER_ITERATOR_HPP
#define BOOST_COMPUTE_ITERATOR_CONSTANT_BUFFER_ITERATOR_HPP
#include <cstddef>
#include <iterator>
#include <boost/iterator/iterator_facade.hpp>
#include <boost/compute/buffer.hpp>
#include <boost/compute/iterator/buffer_iterator.hpp>
#include <boost/compute/type_traits/is_device_iterator.hpp>
namespace boost {
namespace compute {
// forward declaration for constant_buffer_iterator<T>
template<class T> class constant_buffer_iterator;
namespace detail {
// helper class which defines the iterator_facade super-class
// type for constant_buffer_iterator<T>
template<class T>
class constant_buffer_iterator_base
{
public:
typedef ::boost::iterator_facade<
::boost::compute::constant_buffer_iterator<T>,
T,
::std::random_access_iterator_tag,
::boost::compute::detail::buffer_value<T>
> type;
};
} // end detail namespace
/// \class constant_buffer_iterator
/// \brief An iterator for a buffer in the \c constant memory space.
///
/// The constant_buffer_iterator class provides an iterator for values in a
/// buffer in the \c constant memory space.
///
/// For iterating over values in the \c global memory space (the most common
/// case), use the buffer_iterator class.
///
/// \see buffer_iterator
template<class T>
class constant_buffer_iterator :
public detail::constant_buffer_iterator_base<T>::type
{
public:
typedef typename detail::constant_buffer_iterator_base<T>::type super_type;
typedef typename super_type::reference reference;
typedef typename super_type::difference_type difference_type;
constant_buffer_iterator()
: m_buffer(0),
m_index(0)
{
}
constant_buffer_iterator(const buffer &buffer, size_t index)
: m_buffer(&buffer),
m_index(index)
{
}
constant_buffer_iterator(const constant_buffer_iterator<T> &other)
: m_buffer(other.m_buffer),
m_index(other.m_index)
{
}
constant_buffer_iterator<T>& operator=(const constant_buffer_iterator<T> &other)
{
if(this != &other){
m_buffer = other.m_buffer;
m_index = other.m_index;
}
return *this;
}
~constant_buffer_iterator()
{
}
const buffer& get_buffer() const
{
return *m_buffer;
}
size_t get_index() const
{
return m_index;
}
T read(command_queue &queue) const
{
BOOST_ASSERT(m_buffer && m_buffer->get());
BOOST_ASSERT(m_index < m_buffer->size() / sizeof(T));
return detail::read_single_value<T>(m_buffer, m_index, queue);
}
void write(const T &value, command_queue &queue)
{
BOOST_ASSERT(m_buffer && m_buffer->get());
BOOST_ASSERT(m_index < m_buffer->size() / sizeof(T));
detail::write_single_value<T>(m_buffer, m_index, queue);
}
template<class Expr>
detail::buffer_iterator_index_expr<T, Expr>
operator[](const Expr &expr) const
{
BOOST_ASSERT(m_buffer);
BOOST_ASSERT(m_buffer->get());
return detail::buffer_iterator_index_expr<T, Expr>(
*m_buffer, m_index, memory_object::constant_memory, expr
);
}
private:
friend class ::boost::iterator_core_access;
reference dereference() const
{
return detail::buffer_value<T>(*m_buffer, m_index);
}
bool equal(const constant_buffer_iterator<T> &other) const
{
return m_buffer == other.m_buffer && m_index == other.m_index;
}
void increment()
{
m_index++;
}
void decrement()
{
m_index--;
}
void advance(difference_type n)
{
m_index = static_cast<size_t>(static_cast<difference_type>(m_index) + n);
}
difference_type distance_to(const constant_buffer_iterator<T> &other) const
{
return static_cast<difference_type>(other.m_index - m_index);
}
private:
const buffer *m_buffer;
size_t m_index;
};
/// Creates a new constant_buffer_iterator for \p buffer at \p index.
///
/// \param buffer the \ref buffer object
/// \param index the index in the buffer
///
/// \return a \c constant_buffer_iterator for \p buffer at \p index
template<class T>
inline constant_buffer_iterator<T>
make_constant_buffer_iterator(const buffer &buffer, size_t index = 0)
{
return constant_buffer_iterator<T>(buffer, index);
}
/// \internal_ (is_device_iterator specialization for constant_buffer_iterator)
template<class T>
struct is_device_iterator<constant_buffer_iterator<T> > : boost::true_type {};
namespace detail {
// is_buffer_iterator specialization for constant_buffer_iterator
template<class Iterator>
struct is_buffer_iterator<
Iterator,
typename boost::enable_if<
boost::is_same<
constant_buffer_iterator<typename Iterator::value_type>,
typename boost::remove_const<Iterator>::type
>
>::type
> : public boost::true_type {};
} // end detail namespace
} // end compute namespace
} // end boost namespace
#endif // BOOST_COMPUTE_ITERATOR_CONSTANT_BUFFER_ITERATOR_HPP