Variable.h

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/*****************************************************************************
 * vim:tw=78
 *
 * Copyright (C) 2021 Richard Hacker (lerichi at gmx dot net),
 *                    Florian Pose (fp at igh dot de),
 *                    Bjarne von Horn (vh at igh dot de).
 *
 * This file is part of the PdCom library.
 *
 * The PdCom library is free software: you can redistribute it and/or modify
 * it under the terms of 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.
 *
 * The PdCom library 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 Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the PdCom library. If not, see <http://www.gnu.org/licenses/>.
 *
 *****************************************************************************/

 
#ifndef PDCOM5_VARIABLE_H
#define PDCOM5_VARIABLE_H
 
#include "DataDeserializer.h"
#include "Future.h"
#include "Selector.h"
#include "SizeTypeInfo.h"
#include "details.h"
 
#include <chrono>
#include <istream>
#include <memory>
#include <ostream>
#include <pdcom5_export.h>
#include <stdint.h>
#include <string>
#include <vector>
 
namespace PdCom {
namespace impl {
class Variable;
}
struct Exception;
class Process;
class VariablePollResult;

class PDCOM5_PUBLIC Variable
{
    friend class impl::Variable;
 
    explicit Variable(std::weak_ptr<const impl::Variable> pimpl) :
        pimpl_(std::move(pimpl))
    {}
 
  public:
    using PollFuture =
            Future<PdCom::Exception const &,
                   VariablePollResult,
                   std::chrono::nanoseconds>;
 
    using SetValueFuture = Future<PdCom::Exception const &>;
 

    Variable() = default;

    template <typename T>
    typename std::enable_if<!std::is_arithmetic<T>::value, SetValueFuture>::type
    setValue(T const &data, const Selector &selector = {nullptr}) const
    {
        static_assert(
                std::is_same<
                        decltype(data[0]),
                        typename std::add_lvalue_reference<
                                const typename T::value_type>::type>::value,
                "Index operator does not return a lvalue reference of an "
                "integral");
        static_assert(
                details::is_contiguous<T>::value,
                "Container must be contiguous");
        return setValue(
                &data[0],
                details::TypeInfoTraits<typename T::value_type>::type_info.type,
                data.size(), selector);
    }

    template <typename T>
    typename std::enable_if<std::is_arithmetic<T>::value, SetValueFuture>::type
    setValue(T const &data, const Selector &selector = {nullptr}) const
    {
        return setValue(
                &data, details::TypeInfoTraits<T>::type_info.type, 1, selector);
    }

    template <typename T, size_t M, size_t N>
    SetValueFuture
    setValue(const T (&data)[M][N], const Selector &selector = {nullptr}) const
    {
        return setValue(
                data, details::TypeInfoTraits<T>::type_info.type, M * N,
                selector);
    }

    SetValueFuture setValue(
            const void *src,
            TypeInfo::DataType src_type,
            size_t count,
            const Selector &selector = {nullptr}) const;

    PdCom::Variable::SetValueFuture setValue(
            const void *src,
            TypeInfo::DataType src_type,
            size_t count,
            size_t offset) const;

    TypeInfo getTypeInfo() const;
    SizeInfo getSizeInfo() const;
    std::string getPath() const;
    std::string getName() const;
    std::string getAlias() const;
    int getTaskId() const;

    bool isWriteable() const;
    std::chrono::duration<double> getSampleTime() const;
 

    bool empty() const noexcept { return (pimpl_.expired()); }

    PollFuture poll() const;

    Process *getProcess() const;
 
  private:
    std::weak_ptr<const impl::Variable> pimpl_;
};

class PDCOM5_PUBLIC VariablePollResult :
    public DataDeserializer<VariablePollResult>
{
    std::vector<char> data_;
    Variable variable_;
 
  public:
    explicit VariablePollResult(Variable var) :
        data_(var.getSizeInfo().totalElements()
              * var.getTypeInfo().element_size),
        variable_(var)
    {}
 
    const void *getData() const noexcept { return data_.data(); }
    void *getData() noexcept { return data_.data(); }
    Variable getVariable() const noexcept { return variable_; }
};
 
}  // namespace PdCom
 
#endif  // PDCOM5_VARIABLE_H