DatasetFiller.hpp

/* Copyright 2018-2021 Franz Poeschel
 *
 * This file is part of openPMD-api.
 *
 * openPMD-api is free software: you can redistribute it and/or modify
 * it under the terms of of either the GNU General Public License or
 * the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * openPMD-api 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 and the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * and the GNU Lesser General Public License along with openPMD-api.
 * If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
 
#include <memory>
#include "openPMD/Dataset.hpp"
#include <random>
 
 
namespace openPMD
{
    template< typename T >
    class DatasetFiller
    {
    protected:
        Extent::value_type m_numberOfItems;
    public:
        using resultType = T;
 
        explicit DatasetFiller( Extent::value_type numberOfItems = 0 );
 
        virtual ~DatasetFiller() = default;
 
        virtual std::shared_ptr< T > produceData( ) = 0;
 
        virtual void setNumberOfItems( Extent::value_type numberOfItems ) = 0;
    };
 
 
    template< typename T >
    DatasetFiller< T >::DatasetFiller( Extent::value_type numberOfItems ) :
        m_numberOfItems( numberOfItems )
    {}
 
 
    template< typename DF >
    class SimpleDatasetFillerProvider
    {
    public:
        using resultType = typename DF::resultType;
    private:
        std::shared_ptr< DF > m_df;
 
 
        template<
            typename T,
            typename Dummy=void
        >
        struct Helper
        {
            std::shared_ptr< DatasetFiller< T>> operator()( std::shared_ptr<DF> & )
            {
                throw std::runtime_error(
                    "Can only create data of type " +
                    datatypeToString( determineDatatype< resultType >( ) )
                );
            }
        };
 
        template< typename Dummy >
        struct Helper<
            resultType,
            Dummy
        >
        {
            std::shared_ptr< DatasetFiller< resultType>> operator()(std::shared_ptr<DF> &df )
            {
                return df;
            }
        };
 
    public:
 
 
        explicit SimpleDatasetFillerProvider( DF df ) :
            m_df { std::make_shared< DF >( std::move( df ) ) }
        {}
 
 
        template< typename T >
        std::shared_ptr< DatasetFiller< T >> operator()( )
        {
            Helper< T > h;
            return h( m_df );
        }
    };
 
 
}