IOTask.hpp

/* Copyright 2017-2025 Fabian Koller, Axel Huebl, Franz Poeschel, Junmin Gu
 *
 * 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 "openPMD/ChunkInfo.hpp"
#include "openPMD/Dataset.hpp"
#include "openPMD/Error.hpp"
#include "openPMD/IterationEncoding.hpp"
#include "openPMD/Streaming.hpp"
#include "openPMD/auxiliary/Export.hpp"
#include "openPMD/auxiliary/Memory.hpp"
#include "openPMD/auxiliary/Variant.hpp"
#include "openPMD/backend/Attribute.hpp"
#include "openPMD/backend/ParsePreference.hpp"
 
#include <any>
#include <cstddef>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <variant>
#include <vector>
 
namespace openPMD
{
class Attributable;
class Writable;
namespace json
{
    class JsonMatcher;
}
 
Writable *getWritable(Attributable *);

OPENPMDAPI_EXPORT_ENUM_CLASS(Operation){
    CREATE_FILE,
    CHECK_FILE,
    OPEN_FILE,
    CLOSE_FILE,
    DELETE_FILE,
 
    CREATE_PATH,
    CLOSE_PATH,
    OPEN_PATH,
    DELETE_PATH,
    LIST_PATHS,
 
    CREATE_DATASET,
    EXTEND_DATASET,
    OPEN_DATASET,
    DELETE_DATASET,
    WRITE_DATASET,
    READ_DATASET,
    LIST_DATASETS,
    GET_BUFFER_VIEW,
 
    DELETE_ATT,
    WRITE_ATT,
    READ_ATT,
    READ_ATT_ALLSTEPS,
    LIST_ATTS,
 
    ADVANCE,
    AVAILABLE_CHUNKS, 
    DEREGISTER, 
    TOUCH, 
    SET_WRITTEN 
}; // note: if you change the enum members here, please update
   // docs/source/dev/design.rst
 
namespace internal
{
    /*
     * The returned strings are compile-time constants, so no worries about
     * pointer validity.
     */
    OPENPMDAPI_EXPORT std::string operationAsString(Operation);
} // namespace internal
 
struct OPENPMDAPI_EXPORT AbstractParameter
{
    virtual ~AbstractParameter() = default;
    AbstractParameter() = default;
 
    virtual std::unique_ptr<AbstractParameter> to_heap() && = 0;

    template <typename TracingJSON>
    static void warnUnusedParameters(
        TracingJSON &,
        std::string const &currentBackendName,
        std::string const &warningMessage);
 
    // Used as a tag in some constructors to make callsites explicitly
    // acknowledge that joined dimensions will not be automatically resolved
    struct I_dont_want_to_use_joined_dimensions_t
    {};
    constexpr static I_dont_want_to_use_joined_dimensions_t
        I_dont_want_to_use_joined_dimensions{};
 
protected:
    // avoid object slicing
    // by allow only child classes to use these things for defining their own
    // copy/move constructors/assignment operators
    AbstractParameter(const AbstractParameter &) = default;
    AbstractParameter &operator=(const AbstractParameter &) = default;
    AbstractParameter(AbstractParameter &&) = default;
    AbstractParameter &operator=(AbstractParameter &&) = default;
};

template <Operation>
struct OPENPMDAPI_EXPORT Parameter : public AbstractParameter
{
    Parameter() = delete;
    Parameter(Parameter const &) = delete;
    Parameter(Parameter &&) = delete;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CREATE_FILE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CREATE_FILE>(std::move(*this)));
    }
 
    std::string name = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CHECK_FILE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CHECK_FILE>(std::move(*this)));
    }
 
    std::string name = "";
    enum class FileExists
    {
        DontKnow,
        Yes,
        No
    };
    std::shared_ptr<FileExists> fileExists =
        std::make_shared<FileExists>(FileExists::DontKnow);
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::OPEN_FILE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::OPEN_FILE>(std::move(*this)));
    }
 
    // Needed for reopening files in file-based Iteration encoding when using
    // R/W-mode in ADIOS2. Files can only be opened for reading XOR writing,
    // so R/W mode in file-based encoding can only operate at the granularity
    // of files in ADIOS2. The frontend needs to tell us if we should reopen
    // a file for continued reading (WasFoundOnDisk) or for continued writing
    // (WasCreatedByUs).
    enum class Reopen
    {
        WasCreatedByUs,
        WasFoundOnDisk,
        NoReopen
    };
 
    std::string name = "";
    Reopen reopen = Reopen::NoReopen;
    using ParsePreference = internal::ParsePreference;
    std::shared_ptr<ParsePreference> out_parsePreference =
        std::make_shared<ParsePreference>(ParsePreference::UpFront);
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CLOSE_FILE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CLOSE_FILE>(std::move(*this)));
    }
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::DELETE_FILE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::DELETE_FILE>(std::move(*this)));
    }
 
    std::string name = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CREATE_PATH> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CREATE_PATH>(std::move(*this)));
    }
 
    std::string path = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CLOSE_PATH> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CLOSE_PATH>(std::move(*this)));
    }
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::OPEN_PATH> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::OPEN_PATH>(std::move(*this)));
    }
 
    std::string path = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::DELETE_PATH> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::DELETE_PATH>(std::move(*this)));
    }
 
    std::string path = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::LIST_PATHS> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::LIST_PATHS>(std::move(*this)));
    }
 
    std::shared_ptr<std::vector<std::string>> paths =
        std::make_shared<std::vector<std::string>>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::CREATE_DATASET> : public AbstractParameter
{
    Parameter(Dataset const &ds)
        : extent(ds.extent)
        , dtype(ds.dtype)
        , options(ds.options)
        , joinedDimension(ds.joinedDimension())
    {}
 
    // default constructor, but callsites need to explicitly acknowledge that
    // joined dimensions will not be automatically configured when using it
    Parameter(I_dont_want_to_use_joined_dimensions_t)
    {}
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::CREATE_DATASET>(std::move(*this)));
    }
 
    std::string name = "";
    Extent extent = {};
    Datatype dtype = Datatype::UNDEFINED;
    std::string options = "{}";
    std::optional<size_t> joinedDimension;
 
    template <typename TracingJSON>
    TracingJSON compileJSONConfig(
        Writable const *writable,
        json::JsonMatcher &,
        std::string const &backendName) const;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::EXTEND_DATASET> : public AbstractParameter
{
    Parameter(Extent e) : joinedDimension(Dataset::joinedDimension(e))
    {
        this->extent = std::move(e);
    }
 
    // default constructor, but callsites need to explicitly acknowledge that
    // joined dimensions will not be automatically configured when using it
    Parameter(I_dont_want_to_use_joined_dimensions_t)
    {}
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::EXTEND_DATASET>(std::move(*this)));
    }
 
    Extent extent = {};
    std::optional<size_t> joinedDimension;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::OPEN_DATASET> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::OPEN_DATASET>(std::move(*this)));
    }
 
    template <typename TracingJSON>
    static TracingJSON compileJSONConfig(
        Writable const *writable,
        json::JsonMatcher &,
        std::string const &backendName);
 
    std::string name = "";
    std::shared_ptr<Datatype> dtype = std::make_shared<Datatype>();
    std::shared_ptr<Extent> extent = std::make_shared<Extent>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::DELETE_DATASET> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::DELETE_DATASET>(std::move(*this)));
    }
 
    std::string name = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::WRITE_DATASET> : public AbstractParameter
{
    Parameter() = default;
 
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = delete;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = delete;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::WRITE_DATASET>(std::move(*this)));
    }
 
    Extent extent = {};
    Offset offset = {};
    Datatype dtype = Datatype::UNDEFINED;
    auxiliary::WriteBuffer data;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::READ_DATASET> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::READ_DATASET>(std::move(*this)));
    }
 
    Extent extent = {};
    Offset offset = {};
    Datatype dtype = Datatype::UNDEFINED;
    std::shared_ptr<void> data = nullptr;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::LIST_DATASETS> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::LIST_DATASETS>(std::move(*this)));
    }
 
    std::shared_ptr<std::vector<std::string>> datasets =
        std::make_shared<std::vector<std::string>>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::GET_BUFFER_VIEW> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::GET_BUFFER_VIEW>(std::move(*this)));
    }
 
    // in parameters
    Offset offset;
    Extent extent;
    Datatype dtype = Datatype::UNDEFINED;
    bool update = false;
    // out parameters
    struct OutParameters
    {
        bool backendManagedBuffer = false;
        unsigned viewIndex = 0;
        void *ptr = nullptr;
    };
    std::shared_ptr<OutParameters> out = std::make_shared<OutParameters>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::DELETE_ATT> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::DELETE_ATT>(std::move(*this)));
    }
 
    std::string name = "";
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::WRITE_ATT> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::WRITE_ATT>(std::move(*this)));
    }
 
    std::string name = "";
    Datatype dtype = Datatype::UNDEFINED;
    /*
     * If true, this attribute changes across IO steps.
     * It should only be written in backends that support IO steps,
     * otherwise writing should be skipped.
     * The frontend is responsible for handling both situations.
     */
    enum class ChangesOverSteps
    {
        No,
        Yes,
        IfPossible
    };
    ChangesOverSteps changesOverSteps = ChangesOverSteps::No;
    // attribute_types
    std::any m_resource;
    template <typename T>
    void setResource(T val);
    template <typename variant_t>
    variant_t const &resource() const;
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::READ_ATT> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::READ_ATT>(std::move(*this)));
    }
 
    std::string name = "";
    std::shared_ptr<Datatype> dtype = std::make_shared<Datatype>();
 
    // attribute_types
    std::shared_ptr<std::any> m_resource = std::make_shared<std::any>();
    template <typename variant_t>
    variant_t const &resource() const;
    template <typename T>
    void setResource(T val);
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::READ_ATT_ALLSTEPS> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::READ_ATT_ALLSTEPS>(std::move(*this)));
    }
 
    std::string name = "";
    std::shared_ptr<Datatype> dtype = std::make_shared<Datatype>();
 
    // vector_of_attributes_type
    std::shared_ptr<std::any> m_resource = std::make_shared<std::any>();
    template <typename variant_t>
    variant_t const &resource() const;
    template <typename variant_t>
    variant_t &resource();
    template <typename T>
    void setResource(std::vector<T> val);
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::LIST_ATTS> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::LIST_ATTS>(std::move(*this)));
    }
 
    std::shared_ptr<std::vector<std::string>> attributes =
        std::make_shared<std::vector<std::string>>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::ADVANCE> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::ADVANCE>(std::move(*this)));
    }
 
    struct StepSelection
    {
        std::optional<size_t> step;
    };
 
    // input parameters
    std::variant<AdvanceMode, StepSelection> mode;
    bool isThisStepMandatory = false;
    // output parameter
    std::shared_ptr<AdvanceStatus> status =
        std::make_shared<AdvanceStatus>(AdvanceStatus::OK);
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::AVAILABLE_CHUNKS> : public AbstractParameter
{
    Parameter() = default;
    Parameter(Parameter &&) = default;
    Parameter(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
    Parameter &operator=(Parameter const &) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::unique_ptr<AbstractParameter>(
            new Parameter<Operation::AVAILABLE_CHUNKS>(std::move(*this)));
    }
 
    // output parameter
    std::shared_ptr<ChunkTable> chunks = std::make_shared<ChunkTable>();
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::DEREGISTER> : public AbstractParameter
{
    Parameter(void const *ptr_in) : former_parent(ptr_in)
    {}
 
    Parameter(Parameter const &) = default;
    Parameter(Parameter &&) = default;
 
    Parameter &operator=(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::make_unique<Parameter<Operation::DEREGISTER>>(
            std::move(*this));
    }
 
    // Just for verbose logging.
    void const *former_parent = nullptr;
};
 
template <>
struct OPENPMDAPI_EXPORT Parameter<Operation::TOUCH> : public AbstractParameter
{
    explicit Parameter() = default;
 
    Parameter(Parameter const &) = default;
    Parameter(Parameter &&) = default;
 
    Parameter &operator=(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::make_unique<Parameter<Operation::TOUCH>>(std::move(*this));
    }
};
 
template <>
struct OPENPMDAPI_EXPORT
    Parameter<Operation::SET_WRITTEN> : public AbstractParameter
{
    explicit Parameter() = default;
 
    Parameter(Parameter const &) = default;
    Parameter(Parameter &&) = default;
 
    Parameter &operator=(Parameter const &) = default;
    Parameter &operator=(Parameter &&) = default;
 
    std::unique_ptr<AbstractParameter> to_heap() && override
    {
        return std::make_unique<Parameter<Operation::SET_WRITTEN>>(
            std::move(*this));
    }
 
    bool target_status = false;
};

class OPENPMDAPI_EXPORT IOTask
{
public:
    template <Operation op>
    explicit IOTask(Writable *w, Parameter<op> p)
        : writable{w}, operation{op}, parameter{std::move(p).to_heap()}
    {}
 
    template <Operation op>
    explicit IOTask(Attributable *a, Parameter<op> p)
        : writable{getWritable(a)}
        , operation{op}
        , parameter{std::move(p).to_heap()}
    {}
 
    IOTask(IOTask const &other);
    IOTask(IOTask &&other) noexcept;
    IOTask &operator=(IOTask const &other);
    IOTask &operator=(IOTask &&other) noexcept;
 
    Writable *writable;
    Operation operation;
    std::shared_ptr<AbstractParameter> parameter;
}; // IOTask
} // namespace openPMD