Message.h

Go to the documentation of this file.

//
// Copyright 2014 - 2025 (C). Alex Robenko. All rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 
#pragma once
 
#include "comms/Assert.h"
#include "comms/details/detect.h"
#include "comms/details/field_alias.h"
#include "comms/details/MessageIdTypeRetriever.h"
#include "comms/details/MessageInterfaceBuilder.h"
#include "comms/details/transport_fields_access.h"
#include "comms/ErrorStatus.h"
#include "comms/Field.h"
#include "comms/util/type_traits.h"
 
#include <cstdint>
#include <memory>
#include <type_traits>
 
namespace comms
{
 
template <typename... TOptions>
class Message : public details::MessageInterfaceBuilderT<TOptions...>
{
    using BaseImpl = details::MessageInterfaceBuilderT<TOptions...>;
public:
 
    using InterfaceOptions = details::MessageInterfaceOptionsParser<TOptions...>;
 
    ~Message() noexcept = default;
 
    static constexpr bool hasMsgIdType()
    {
        return InterfaceOptions::HasMsgIdType;
    }
 
    static constexpr bool hasEndian()
    {
        return InterfaceOptions::HasEndian;
    }
 
    static constexpr bool hasGetId()
    {
        return hasMsgIdType() && InterfaceOptions::HasMsgIdInfo;
    }
 
    static constexpr bool hasRead()
    {
        return InterfaceOptions::HasReadIterator;
    }
 
    static constexpr bool hasWrite()
    {
        return InterfaceOptions::HasWriteIterator;
    }
 
    static constexpr bool hasValid()
    {
        return InterfaceOptions::HasValid;
    }
 
    static constexpr bool hasLength()
    {
        return InterfaceOptions::HasLength;
    }
 
    static constexpr bool hasRefresh()
    {
        return InterfaceOptions::HasRefresh;
    }
 
    static constexpr bool hasDispatch()
    {
        return InterfaceOptions::HasHandler;
    }
 
    static constexpr bool hasTransportFields()
    {
        return InterfaceOptions::HasExtraTransportFields;
    }
 
    static constexpr bool hasVersionInTransportFields()
    {
        return InterfaceOptions::HasVersionInExtraTransportFields;
    }
 
    static constexpr std::size_t versionIdxInTransportFields()
    {
        return InterfaceOptions::VersionInExtraTransportFields;
    }
 
    static constexpr bool hasName()
    {
        return InterfaceOptions::HasName;
    }
 
#ifdef FOR_DOXYGEN_DOC_ONLY
    using MsgIdType = typename BaseImpl::MsgIdType;
 
    using MsgIdParamType = typename BaseImpl::MsgIdParamType;
 
    using Endian = typename BaseImpl::Endian;
 
    using Field = BaseImpl::Field;
 
    MsgIdParamType getId() const;
 
    using ReadIterator = TypeProvidedWithOption;
 
    ErrorStatus read(ReadIterator& iter, std::size_t size);
 
    using WriteIterator = TypeProvidedWithOption;
 
    ErrorStatus write(WriteIterator& iter, std::size_t size) const;
 
    bool valid() const;
 
    std::size_t length() const;
 
    bool refresh();
 
    const char* name() const;
 
    using Handler = TypeProvidedWithOption;
 
    using DispatchRetType = typename Handler::RetType;
 
    DispatchRetType dispatch(Handler& handler);
 
    using TransportFields = FieldsProvidedWithOption;
 
    TransportFields& transportFields();
 
    const TransportFields& transportFields() const;
 
    using VersionType = typename BaseImpl::VersionType;
 
    VersionType& version();
 
    const VersionType& version() const;
#endif // #ifdef FOR_DOXYGEN_DOC_ONLY
 
protected:
 
#ifdef FOR_DOXYGEN_DOC_ONLY
    virtual MsgIdParamType getIdImpl() const = 0;
 
    virtual comms::ErrorStatus readImpl(ReadIterator& iter, std::size_t size);
 
    virtual comms::ErrorStatus writeImpl(WriteIterator& iter, std::size_t size) const;
 
    virtual bool validImpl() const;
 
    virtual std::size_t lengthImpl() const;
 
    virtual bool refreshImpl();
 
    virtual DispatchRetType dispatchImpl(Handler& handler);
 
    virtual const char* nameImpl() const = 0;
 
    template <typename T, typename TIter>
    static void writeData(T value, TIter& iter);
 
    template <std::size_t TSize, typename T, typename TIter>
    static void writeData(T value, TIter& iter);
 
    template <typename T, typename TIter>
    static T readData(TIter& iter);
 
    template <typename T, std::size_t TSize, typename TIter>
    static T readData(TIter& iter);
 
#endif // #ifdef FOR_DOXYGEN_DOC_ONLY
};
 
template <typename... TOptions>
inline
Message<TOptions...>& toMessage(Message<TOptions...>& msg)
{
    return msg;
}
 
template <typename... TOptions>
inline
const Message<TOptions...>& toMessage(const Message<TOptions...>& msg)
{
    return msg;
}
 
template <typename T>
constexpr bool isMessage()
{
    return details::hasInterfaceOptions<T>();
}
 
template <typename TMsg, typename TDefaultType = std::intmax_t>
using MessageIdType =
    typename comms::util::LazyDeepConditional<
        TMsg::InterfaceOptions::HasMsgIdType
    >::template Type<
        comms::details::MessageIdTypeRetriever,
        comms::util::AliasType,
        TDefaultType, TMsg
    >;
}  // namespace comms
 
#define COMMS_MSG_TRANSPORT_FIELDS_ACCESS(...) \
    COMMS_EXPAND(COMMS_DEFINE_TRANSPORT_FIELD_ENUM(__VA_ARGS__)) \
    COMMS_MSG_TRANSPORT_FIELDS_ACCESS_FUNC { \
        auto& msgBase = comms::toMessage(*this); \
        using MsgBase = typename std::decay<decltype(msgBase)>::type; \
        static_assert(MsgBase::hasTransportFields(), \
            "Message interface class doesn't define extra transport fields."); \
        using TransportFieldsTuple = typename MsgBase::TransportFields; \
        static_assert(std::tuple_size<TransportFieldsTuple>::value == TransportFieldIdx_numOfValues, \
            "Invalid number of names for transport fields tuple"); \
        return msgBase.transportFields(); \
    } \
    COMMS_MSG_TRANSPORT_FIELDS_ACCESS_CONST_FUNC { \
        return comms::toMessage(*this).transportFields(); \
    } \
    COMMS_EXPAND(COMMS_DO_TRANSPORT_FIELD_ACC_FUNC(TransportFields, transportFields(), __VA_ARGS__))
 
#define COMMS_MSG_TRANSPORT_FIELDS_NAMES(...) \
    COMMS_EXPAND(COMMS_MSG_TRANSPORT_FIELDS_ACCESS(__VA_ARGS__)) \
    COMMS_EXPAND(COMMS_DO_FIELD_TYPEDEF(typename Base::TransportFields, TransportField_, TransportFieldIdx_, __VA_ARGS__))
 
#define COMMS_MSG_TRANSPORT_FIELD_ALIAS_ACCESS(f_, ...) COMMS_EXPAND(COMMS_DO_ALIAS(transportField_, f_, __VA_ARGS__))
 
#define COMMS_MSG_TRANSPORT_FIELD_ALIAS_ACCESS_NOTEMPLATE(f_, ...) COMMS_EXPAND(COMMS_DO_ALIAS_NOTEMPLATE(transportField_, f_, __VA_ARGS__))
 
#define COMMS_MSG_TRANSPORT_FIELD_ALIAS(f_, ...) \
    COMMS_EXPAND(COMMS_MSG_TRANSPORT_FIELD_ALIAS_ACCESS(f_, __VA_ARGS__)) \
    COMMS_EXPAND(COMMS_DO_ALIAS_TYPEDEF(TransportField_, f_, __VA_ARGS__))
 
#define COMMS_MSG_TRANSPORT_FIELD_ALIAS_NOTEMPLATE(f_, ...) \
    COMMS_EXPAND(COMMS_MSG_TRANSPORT_FIELD_ALIAS_ACCESS_NOTEMPLATE(f_, __VA_ARGS__)) \
    COMMS_EXPAND(COMMS_DO_ALIAS_TYPEDEF(TransportField_, f_, __VA_ARGS__))