better example

This commit is contained in:
2025-02-06 16:04:51 +01:00
parent f3e98543d7
commit e6a58eb999
13 changed files with 59 additions and 75 deletions

View File

@@ -0,0 +1,278 @@
#pragma once
#include <sp/protocol/Message.h>
#include <sp/protocol/Templates.h>
namespace sp {
namespace option {
// Provide static numeric ID, to facilitate implementation of GetIdImpl()
template <std::intmax_t TId>
struct StaticNumIdImpl {};
// Facilitate implementation of DispatchImpl()
template <typename TActual>
struct DispatchImpl {};
// Provide fields of the message, facilitate implementation of
// ReadImpl(), WriteImpl(), ValidImpl(), etc...
template <typename TFields>
struct FieldsImpl {};
} // namespace option
template <typename... TOptions>
class MessageImplParsedOptions;
template <>
struct MessageImplParsedOptions<> {
static const bool HasStaticNumIdImpl = false;
static const bool HasDispatchImpl = false;
static const bool HasFieldsImpl = false;
};
template <std::intmax_t TId, typename... TOptions>
struct MessageImplParsedOptions<option::StaticNumIdImpl<TId>, TOptions...> : public MessageImplParsedOptions<TOptions...> {
static const bool HasStaticNumIdImpl = true;
static const std::intmax_t MsgId = TId;
};
template <typename TActual, typename... TOptions>
struct MessageImplParsedOptions<option::DispatchImpl<TActual>, TOptions...> : public MessageImplParsedOptions<TOptions...> {
static const bool HasDispatchImpl = true;
using ActualMessage = TActual;
};
template <typename TFields, typename... TOptions>
struct MessageImplParsedOptions<option::FieldsImpl<TFields>, TOptions...> : public MessageImplParsedOptions<TOptions...> {
static const bool HasFieldsImpl = true;
using Fields = TFields;
};
// ID information chunk
template <typename TBase, std::intmax_t TId>
class MessageImplStaticNumIdBase : public TBase {
public:
// Reuse the message ID type defined in the interface
using MsgIdType = typename TBase::MsgIdType;
protected:
virtual MsgIdType GetIdImpl() const override {
return static_cast<MsgIdType>(TId);
}
};
// Dispatch implementation chunk
template <typename TBase, typename TActual>
class MessageImplDispatchBase : public TBase {
public:
// Reuse the Handler type defined in the interface class
using Handler = typename TBase::HandlerType;
protected:
virtual void DispatchImpl(Handler& handler) override {
handler.Handle(static_cast<TActual&>(*this));
}
};
template <typename TBase, typename TFields>
class MessageImplFieldsBase : public TBase {
public:
using AllFields = TFields;
AllFields& GetFields() {
return m_Fields;
}
const AllFields& GetFields() const {
return m_Fields;
}
template<std::size_t FIndex>
auto& GetField() {
return std::get<FIndex>(GetFields()).GetValue();
}
private:
TFields m_Fields;
};
template <typename TBase>
class MessageImplFieldsReadBase : public TBase {
protected:
void ReadImpl(DataBuffer& buffer) override {
//TODO: add endianess
auto& allFields = TBase::GetFields();
tupleForEach(allFields, FieldReader{buffer});
}
};
template <typename TBase>
class MessageImplFieldsWriteBase : public TBase {
protected:
void WriteImpl(DataBuffer& buffer) override {
//TODO: add endianess
auto& allFields = TBase::GetFields();
tupleForEach(allFields, FieldWriter{buffer});
}
};
template <typename TBase>
class MessageImplFieldsValidBase : public TBase {
protected:
bool ValidImpl() const override {
// Access fields via interface provided in previous chunk
// auto& allFields = TBase::GetFields();
//... // validate all the fields
}
};
// id impl
template <typename TBase, typename ParsedImplOptions, bool TImplement>
struct MessageImplProcessStaticNumId;
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessStaticNumId<TBase, ParsedImplOptions, true> {
using Type = MessageImplStaticNumIdBase<TBase, ParsedImplOptions::MsgId>;
};
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessStaticNumId<TBase, ParsedImplOptions, false> {
using Type = TBase;
};
// dispatch impl
template <typename TBase, typename ParsedImplOptions, bool TImplement>
struct MessageImplProcessDispatch;
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessDispatch<TBase, ParsedImplOptions, true> {
using Type = MessageImplDispatchBase<TBase, typename ParsedImplOptions::ActualMessage>;
};
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessDispatch<TBase, ParsedImplOptions, false> {
using Type = TBase;
};
// fields impl
template <typename TBase, typename ParsedImplOptions, bool TImplement>
struct MessageImplProcessFields;
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessFields<TBase, ParsedImplOptions, true> {
using Type = MessageImplFieldsBase<TBase, typename ParsedImplOptions::Fields>;
};
template <typename TBase, typename ParsedImplOptions>
struct MessageImplProcessFields<TBase, ParsedImplOptions, false> {
using Type = TBase;
};
// read impl
template <typename TBase, bool TImplement>
struct MessageImplProcessReadFields;
template <typename TBase>
struct MessageImplProcessReadFields<TBase, true> {
using Type = MessageImplFieldsReadBase<TBase>;
};
template <typename TBase>
struct MessageImplProcessReadFields<TBase, false> {
using Type = TBase;
};
// write impl
template <typename TBase, bool TImplement>
struct MessageImplProcessWriteFields;
template <typename TBase>
struct MessageImplProcessWriteFields<TBase, true> {
using Type = MessageImplFieldsWriteBase<TBase>;
};
template <typename TBase>
struct MessageImplProcessWriteFields<TBase, false> {
using Type = TBase;
};
// valid impl
template <typename TBase, bool TImplement>
struct MessageImplProcessValidFields;
template <typename TBase>
struct MessageImplProcessValidFields<TBase, true> {
using Type = MessageImplFieldsValidBase<TBase>;
};
template <typename TBase>
struct MessageImplProcessValidFields<TBase, false> {
using Type = TBase;
};
// TBase is interface class
// TOptions... are the implementation options
template <typename TBase, typename... TOptions>
struct MessageImplBuilder {
// ParsedOptions class is supposed to be defined in comms::Message class
using InterfaceOptions = typename TBase::ParsedOptions;
// Parse implementation options
using ImplOptions = MessageImplParsedOptions<TOptions...>;
// Provide GetIdImpl() if possible
static const bool HasStaticNumIdImpl = InterfaceOptions::HasMsgIdType && ImplOptions::HasStaticNumIdImpl;
using Base1 = typename MessageImplProcessStaticNumId<TBase, ImplOptions, HasStaticNumIdImpl>::Type;
// Provide DispatchImpl() if possible
static const bool HasDispatchImpl = InterfaceOptions::HasHandler && ImplOptions::HasDispatchImpl;
using Base2 = typename MessageImplProcessDispatch<Base1, ImplOptions, HasDispatchImpl>::Type;
// Provide access to fields if possible
using Base3 = typename MessageImplProcessFields<Base2, ImplOptions, ImplOptions::HasFieldsImpl>::Type;
// Provide ReadImpl() if possible
static const bool HasReadImpl = InterfaceOptions::HasReadOperations && ImplOptions::HasFieldsImpl;
using Base4 = typename MessageImplProcessReadFields<Base3, HasReadImpl>::Type;
// Provide WriteImpl() if possible
static const bool HasWriteImpl = InterfaceOptions::HasWriteOperations && ImplOptions::HasFieldsImpl;
using Base5 = typename MessageImplProcessWriteFields<Base4, HasWriteImpl>::Type;
// Provide ValidImpl() if possible
static const bool HasValidImpl = InterfaceOptions::HasValid && ImplOptions::HasFieldsImpl;
using Base6 = typename MessageImplProcessValidFields<Base5, HasValidImpl>::Type;
// The last BaseN must be taken as final type.
using Type = Base6;
};
template <typename TBase, typename... TOptions>
class MessageBase : public MessageImplBuilder<TBase, TOptions...>::Type {};
} // namespace sp