GpuBuffer.hpp

/*
  Copyright 2024 SINTEF AS
 
  This file is part of the Open Porous Media project (OPM).
 
  OPM is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
 
  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
 
  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_GPUBUFFER_HEADER_HPP
#define OPM_GPUBUFFER_HEADER_HPP
#include <dune/common/fvector.hh>
#include <dune/istl/bvector.hh>
#include <exception>
#include <fmt/core.h>
#include <opm/common/ErrorMacros.hpp>
#include <opm/simulators/linalg/gpuistl/detail/safe_conversion.hpp>
#include <opm/simulators/linalg/gpuistl/GpuView.hpp>
#include <vector>
#include <string>
#include <cuda_runtime.h>
 
 
namespace Opm::gpuistl
{

template <typename T>
class GpuBuffer
{
public:
    using field_type = T;
    using size_type = size_t;
    using value_type = T;

    GpuBuffer(const GpuBuffer<T>& other);

    explicit GpuBuffer(const std::vector<T>& data);

    GpuBuffer() = default;

    explicit GpuBuffer(const size_t numberOfElements);
 

    GpuBuffer(const T* dataOnHost, const size_t numberOfElements);

    virtual ~GpuBuffer();

    T* data();

    const T* data() const;

    template <int BlockDimension>
    void copyFromHost(const Dune::BlockVector<Dune::FieldVector<T, BlockDimension>>& bvector)
    {
        // TODO: [perf] vector.size() can be replaced by bvector.N() * BlockDimension
        if (m_numberOfElements != bvector.size()) {
            OPM_THROW(std::runtime_error,
                      fmt::format("Given incompatible vector size. GpuBuffer has size {}, \n"
                                  "however, BlockVector has N() = {}, and size = {}.",
                                  m_numberOfElements,
                                  bvector.N(),
                                  bvector.size()));
        }
        const auto dataPointer = static_cast<const T*>(&(bvector[0][0]));
        copyFromHost(dataPointer, m_numberOfElements);
    }

    template <int BlockDimension>
    void copyToHost(Dune::BlockVector<Dune::FieldVector<T, BlockDimension>>& bvector) const
    {
        // TODO: [perf] vector.size() can be replaced by bvector.N() * BlockDimension
        if (m_numberOfElements != bvector.size()) {
            OPM_THROW(std::runtime_error,
                      fmt::format("Given incompatible vector size. GpuBuffer has size {},\n however, the BlockVector "
                                  "has has N() = {}, and size() = {}.",
                                  m_numberOfElements,
                                  bvector.N(),
                                  bvector.size()));
        }
        const auto dataPointer = static_cast<T*>(&(bvector[0][0]));
        copyToHost(dataPointer, m_numberOfElements);
    }

    void copyFromHost(const T* dataPointer, size_t numberOfElements);

    void copyToHost(T* dataPointer, size_t numberOfElements) const;

    void copyFromHost(const std::vector<T>& data);

    void copyToHost(std::vector<T>& data) const;

    size_type size() const;

    void resize(size_t);

    std::vector<T> asStdVector() const;
 
private:
    T* m_dataOnDevice = nullptr;
    size_t m_numberOfElements = 0;
 
    void assertSameSize(const GpuBuffer<T>& other) const;
    void assertSameSize(size_t size) const;
 
    void assertHasElements() const;
};
 
template <class T>
GpuView<T> make_view(GpuBuffer<T>&);
 
template <class T>
GpuView<const T> make_view(const GpuBuffer<T>&);
 
} // namespace Opm::gpuistl
#endif