ArrayPolicies.hpp

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///////////////////////////////////////////////////////////////////////////////
//
// File: ArrayPolicies.hpp
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Scientific Computing and Imaging Institute,
// University of Utah (USA) and Department of Aeronautics, Imperial
// College London (UK).
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description: Implementations of the array creation and destruction policies.
//
///////////////////////////////////////////////////////////////////////////////
 
#ifndef NEKTAR_LIB_UTILITIES_BASIC_UTILS_ARRAY_POLICIES_HPP
#define NEKTAR_LIB_UTILITIES_BASIC_UTILS_ARRAY_POLICIES_HPP
 
#include <memory>
#include <type_traits>
 
#include <LibUtilities/BasicConst/NektarUnivTypeDefs.hpp>
#include <LibUtilities/Memory/NekMemoryManager.hpp>
#include <boost/core/ignore_unused.hpp>
#include <boost/multi_array.hpp>
 
namespace Nektar
{
template <typename ObjectType, typename enabled = void>
class ArrayInitializationPolicy;
 
/// \internal
/// \brief Does nothing.
template <typename ObjectType>
class ArrayInitializationPolicy<
    ObjectType,
    typename std::enable_if<std::is_fundamental<ObjectType>::value>::type>
{
public:
    static void Initialize(ObjectType *data, size_t itemsToCreate)
    {
        boost::ignore_unused(data, itemsToCreate);
    }
 
    static void Initialize(ObjectType *data, size_t itemsToCreate,
                           const ObjectType &initValue)
    {
        std::fill_n(data, itemsToCreate, initValue);
    }
 
    static void Initialize(ObjectType *data, size_t itemsToCreate,
                           const ObjectType *initValue)
    {
        std::copy(initValue, initValue + itemsToCreate, data);
    }
};
 
/// \internal
/// \brief Default initializes all elements.
///
/// \internal
/// The user calls Initialize, which immediately calls DoInitialization.  There
/// reason for this separation is because the code for creating an array of
/// default initialized elements and an array of copy constructed elements is
/// identical except for the actual call to placement new.
///
///
template <typename ObjectType>
class ArrayInitializationPolicy<
    ObjectType,
    typename std::enable_if<!std::is_fundamental<ObjectType>::value>::type>
{
public:
    /// \brief Initalize each element in the array with ObjectType's default
    /// constructor. \param data The array of values to populate. \param
    /// itemsToCreate The size of data.
    static void Initialize(ObjectType *data, size_t itemsToCreate)
    {
        DoInitialization(data, itemsToCreate,
                         [](ObjectType *element) { new (element) ObjectType; });
    }
 
    /// \brief Initalize each element in the array with ObjectType's copy
    /// constructor. \param data The array of values to populate. \param
    /// itemsToCreate The size of data. \param initValue The inital value each
    /// element in data will have.
    static void Initialize(ObjectType *data, size_t itemsToCreate,
                           const ObjectType &initValue)
    {
        DoInitialization(data, itemsToCreate, [&](ObjectType *element) {
            new (element) ObjectType(initValue);
        });
    }
 
    static void Initialize(ObjectType *data, size_t itemsToCreate,
                           const ObjectType *initValue)
    {
        DoInitialization(data, itemsToCreate, [&](ObjectType *element) {
            new (element) ObjectType(*initValue);
            initValue++;
        });
    }
 
private:
    template <typename CreateType>
    static void DoInitialization(ObjectType *data, size_t itemsToCreate,
                                 const CreateType &f)
    {
        size_t nextObjectToCreate = 0;
        try
        {
            for (size_t i = 0; i < itemsToCreate; ++i)
            {
                ObjectType *memLocation = &data[i];
                f(memLocation);
                ++nextObjectToCreate;
            }
        }
        catch (...)
        {
            for (size_t i = 0; i < nextObjectToCreate; ++i)
            {
                ObjectType *memLocation = &data[nextObjectToCreate - i - 1];
                memLocation->~ObjectType();
            }
            throw;
        }
    }
};
 
template <typename ObjectType, typename enabled = void>
class ArrayDestructionPolicy;
 
template <typename ObjectType>
class ArrayDestructionPolicy<
    ObjectType,
    typename std::enable_if<std::is_fundamental<ObjectType>::value>::type>
{
public:
    static void Destroy(ObjectType *data, size_t itemsToDestroy)
    {
        boost::ignore_unused(data, itemsToDestroy);
    }
};
 
template <typename ObjectType>
class ArrayDestructionPolicy<
    ObjectType,
    typename std::enable_if<!std::is_fundamental<ObjectType>::value>::type>
{
public:
    static void Destroy(ObjectType *data, size_t itemsToDestroy)
    {
        for (size_t i = 0; i < itemsToDestroy; ++i)
        {
            ObjectType *memLocation = &data[itemsToDestroy - i - 1];
            memLocation->~ObjectType();
        }
    }
};
 
template <typename Dim, typename DataType, typename ExtentListType>
std::shared_ptr<boost::multi_array_ref<DataType, Dim::Value>> CreateStorage(
    const ExtentListType &extent)
{
    typedef boost::multi_array_ref<DataType, Dim::Value> ArrayType;
    size_t size       = std::accumulate(extent.begin(), extent.end(), 1,
                                  std::multiplies<size_t>());
    DataType *storage = MemoryManager<DataType>::RawAllocate(size);
    return MemoryManager<ArrayType>::AllocateSharedPtrD(
        [=](boost::multi_array_ref<DataType, Dim::Value> *ptr) {
            boost::ignore_unused(ptr);
            ArrayDestructionPolicy<DataType>::Destroy(storage, size);
            MemoryManager<DataType>::RawDeallocate(storage, size);
        },
        storage, extent);
}
 
template <typename DataType>
std::shared_ptr<boost::multi_array_ref<DataType, 1>> CreateStorage(size_t d1)
{
    std::vector<size_t> extents = {d1};
    return CreateStorage<OneD, DataType>(extents);
}
 
template <typename DataType>
std::shared_ptr<boost::multi_array_ref<DataType, 2>> CreateStorage(size_t d1,
                                                                   size_t d2)
{
    std::vector<size_t> extents = {d1, d2};
    return CreateStorage<TwoD, DataType>(extents);
}
 
template <typename DataType>
std::shared_ptr<boost::multi_array_ref<DataType, 3>> CreateStorage(size_t d1,
                                                                   size_t d2,
                                                                   size_t d3)
{
    std::vector<size_t> extents = {d1, d2, d3};
    return CreateStorage<ThreeD, DataType>(extents);
}
} // namespace Nektar
 
#endif // NEKTAR_LIB_UTILITIES_BASIC_UTILS_ARRAY_POLICIES_HPP