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bitsery/include/bitsery/details/serialization_common.h
2019-03-12 14:54:04 +02:00

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//MIT License
//
//Copyright (c) 2017 Mindaugas Vinkelis
//
//Permission is hereby granted, free of charge, to any person obtaining a copy
//of this software and associated documentation files (the "Software"), to deal
//in the Software without restriction, including without limitation the rights
//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the Software is
//furnished to do so, subject to the following conditions:
//
//The above copyright notice and this permission notice shall be included in all
//copies or substantial portions of the Software.
//
//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//SOFTWARE.
#ifndef BITSERY_DETAILS_SERIALIZATION_COMMON_H
#define BITSERY_DETAILS_SERIALIZATION_COMMON_H
#include <type_traits>
#include <utility>
#include <tuple>
#include "adapter_utils.h"
#include "../traits/core/traits.h"
namespace bitsery {
//this allows to call private serialize method, and construct instance (if no default constructor is provided) for your type
//just make friend it in your class
class Access {
public:
template<typename S, typename T>
static auto serialize(S &s, T &obj) -> decltype(obj.serialize(s)) {
obj.serialize(s);
}
template <typename T>
static T create() {
//if you get an error here, please create default constructor
return T{};
}
template <typename T>
static T* createInHeap() {
return new T{};
}
};
//when call to serialize function is ambiguous (member and non-member serialize function exists for a type)
//specialize this class by inheriting from either UseNonMemberFnc or UseMemberFnc
//e.g.
//template <> struct SelectSerializeFnc<MyDerivedClass>:UseMemberFnc {};
template<typename T>
struct SelectSerializeFnc : std::integral_constant<int, 0> {
};
//types you need to inherit from when specializing SelectSerializeFnc class
struct UseNonMemberFnc : std::integral_constant<int, 1> {
};
struct UseMemberFnc : std::integral_constant<int, 2> {
};
//serializer/deserializer, does not have public interface to get underlying writer/reader
//to prevent users from using writer/reader directly, because they have different interface
//and they cannot be used describing serialization flows.: use extensions for this reason.
//this class allows to get underlying adapter writer/reader, and only should be used outside serialization functions.
struct AdapterAccess {
template<typename Serializer>
static typename Serializer::TWriter &getWriter(Serializer &s) {
return s._writer;
}
template<typename Deserializer>
static typename Deserializer::TReader &getReader(Deserializer &s) {
return s._reader;
}
};
namespace details {
//helper types for error handling
template<typename T>
struct IsContainerTraitsDefined : public IsDefined<typename traits::ContainerTraits<T>::TValue> {
};
template<typename T>
struct IsTextTraitsDefined : public IsDefined<typename traits::TextTraits<T>::TValue> {
};
template<typename Ext, typename T>
struct IsExtensionTraitsDefined : public IsDefined<typename traits::ExtensionTraits<Ext, T>::TValue> {
};
#ifdef _MSC_VER
//helper types for HasSerializeFunction
template <typename S, typename T>
using TrySerializeFunction = decltype(serialize(std::declval<S &>(), std::declval<T &>()));
template <typename S, typename T>
struct HasSerializeFunctionHelper {
template <typename Q, typename R, typename = TrySerializeFunction<Q, R>>
static std::true_type tester(Q&&, R&&);
static std::false_type tester(...);
using type = decltype(tester(std::declval<S>(), std::declval<T>()));
};
template <typename S, typename T>
struct HasSerializeFunction :HasSerializeFunctionHelper<S, T>::type {};
//helper types for HasSerializeMethod
template <typename S, typename T>
using TrySerializeMethod = decltype(Access::serialize(std::declval<S &>(), std::declval<T &>()));
template <typename S, typename T>
struct HasSerializeMethodHelper {
template <typename Q, typename R, typename = TrySerializeMethod<Q, R>>
static std::true_type tester(Q&&, R&&);
static std::false_type tester(...);
using type = decltype(tester(std::declval<S>(), std::declval<T>()));
};
template <typename S, typename T>
struct HasSerializeMethod :HasSerializeMethodHelper<S, T>::type {};
//helper types for IsFlexibleIncluded
template <typename S, typename T>
using TryArchiveProcess = decltype(archiveProcess(std::declval<S &>(), std::declval<T &&>()));
template <typename S, typename T>
struct IsFlexibleIncludedHelper {
template <typename Q, typename R, typename = TryArchiveProcess<Q, R>>
static std::true_type tester(Q&&, R&&);
static std::false_type tester(...);
using type = decltype(tester(std::declval<S>(), std::declval<T>()));
};
template <typename S, typename T>
struct IsFlexibleIncluded :IsFlexibleIncludedHelper<S, T>::type {};
#else
//helper metafunction, that is added to c++17
template<typename... Ts>
struct make_void {
typedef void type;
};
template<typename... Ts>
using void_t = typename make_void<Ts...>::type;
template<typename, typename, typename = void>
struct HasSerializeFunction : std::false_type {
};
template<typename S, typename T>
struct HasSerializeFunction<S, T,
void_t<decltype(serialize(std::declval<S &>(), std::declval<T &>()))>
> : std::true_type {
};
template<typename, typename, typename = void>
struct HasSerializeMethod : std::false_type {
};
template<typename S, typename T>
struct HasSerializeMethod<S, T,
void_t<decltype(Access::serialize(std::declval<S &>(), std::declval<T &>()))>
> : std::true_type {
};
//this solution doesn't work with visual studio, but is more elegant
template<typename, typename, typename = void>
struct IsFlexibleIncluded : std::false_type {
};
template<typename S, typename T>
struct IsFlexibleIncluded<S, T,
void_t<decltype(archiveProcess(std::declval<S &>(), std::declval<T &&>()))>
> : std::true_type {
};
#endif
//used for extensions when extension TValue = void
struct DummyType {
};
/*
* this includes all integral types, floats and enums(except bool)
*/
template<typename T>
struct IsFundamentalType : std::integral_constant<bool,
std::is_enum<T>::value
|| std::is_floating_point<T>::value
|| std::is_integral<T>::value> {
};
template<typename T, typename Integral = void>
struct IntegralFromFundamental {
using TValue = T;
};
template<typename T>
struct IntegralFromFundamental<T, typename std::enable_if<std::is_enum<T>::value>::type> {
using TValue = typename std::underlying_type<T>::type;
};
template<typename T>
struct IntegralFromFundamental<T, typename std::enable_if<std::is_floating_point<T>::value>::type> {
using TValue = typename std::conditional<std::is_same<T, float>::value, uint32_t, uint64_t>::type;
};
template<typename T>
struct UnsignedFromFundamental {
using type = typename std::make_unsigned<typename IntegralFromFundamental<T>::TValue>::type;
};
template<typename T>
using SameSizeUnsigned = typename UnsignedFromFundamental<T>::type;
/*
* functions for object serialization
*/
template<typename S, typename T>
struct SerializeFunction {
static void invoke(S &s, T &v) {
static_assert(HasSerializeFunction<S, T>::value || HasSerializeMethod<S, T>::value,
"\nPlease define 'serialize' function for your type (inside or outside of class):\n"
" template<typename S>\n"
" void serialize(S& s)\n"
" {\n"
" ...\n"
" }\n");
using TDecayed = typename std::decay<T>::type;
selectSerializeFnc(s, v, SelectSerializeFnc<TDecayed>{});
}
static constexpr bool isDefined() {
return HasSerializeFunction<S, T>::value || HasSerializeMethod<S, T>::value;
}
private:
static void selectSerializeFnc(S &s, T &v, std::integral_constant<int, 0>) {
static_assert(!(HasSerializeFunction<S, T>::value && HasSerializeMethod<S, T>::value),
"\nPlease define only one 'serialize' function (member OR free).\n"
"If serialization function is inherited from base class, then explicitly select correct function for your type e.g.:\n"
" template <>\n"
" struct SelectSerializeFnc<DerivedClass>:UseMemberFnc {};\n");
selectSerializeFnc(s, v, std::integral_constant<int,
HasSerializeFunction<S, T>::value ? 1 : 2>{});
}
static void selectSerializeFnc(S &s, T &v, std::integral_constant<int, 1>) {
serialize(s, v);
}
static void selectSerializeFnc(S &s, T &v, std::integral_constant<int, 2>) {
Access::serialize(s, v);
}
};
/*
* functions for object serialization
*/
template<typename S, typename T, typename Enabled = void>
struct ArchiveFunction {
static void invoke(S &s, T &&obj) {
static_assert(IsFlexibleIncluded<S, T>::value,
"\nPlease include '<bitsery/flexible.h>' to use 'archive' function:\n");
archiveProcess(s, std::forward<T>(obj));
}
};
/*
* helper function for getting context from serializer/deserializer
*/
template<typename T, template<typename...> class Template>
struct IsSpecializationOf : std::false_type {
};
template<template<typename...> class Template, typename... Args>
struct IsSpecializationOf<Template<Args...>, Template> : std::true_type {
};
//helper types for better error messages
template<typename Find, typename ... TList>
struct GetTypeIndex : std::integral_constant<size_t, 0> {
};
//found it
template<typename Find, typename ... Tail>
struct GetTypeIndex<Find, Find, Tail...> : std::integral_constant<size_t, 0> {
};
//iteratates over types
template<typename Find, typename Head, typename ... Tail>
struct GetTypeIndex<Find, Head, Tail...> : std::integral_constant<size_t,
1 + GetTypeIndex<Find, Tail...>::value> {
};
template<typename Find, typename ... TList>
struct HasType : std::integral_constant<bool, (GetTypeIndex<Find, TList...>::value<(sizeof ... (TList)))> {
};
template<typename TCast, typename Tuple>
struct HasContext : std::is_same<TCast, Tuple> {
};
template<typename TCast, typename ... Args>
struct HasContext<TCast, std::tuple<Args...>> : HasType<TCast, Args...> {
};
/*
* get context, and static assert if type doesn't exists
*/
template<typename TCast, typename ... Args>
TCast *getContextImpl(std::tuple<Args...> *ctx, std::true_type) {
using TCastIndex = GetTypeIndex<TCast, Args...>;
static_assert(HasType<TCast, Args...>::value, "Invalid context cast. Context type doesn't exists.\nSome functionality requires (de)seserializer to have specific context.");
return std::addressof(std::get<TCastIndex::value>(*ctx));
}
template<typename TCast, typename TContext>
TCast *getContextImpl(TContext *ctx, std::false_type) {
static_assert(std::is_convertible<TContext *, TCast *>::value, "Invalid context cast. Context type doesn't exists.\nSome functionality requires (de)seserializer to have specific context.");
return static_cast<TCast *>(ctx);
}
//get local ctx
template<typename TCast, typename TContext, typename TInternalContext>
TCast *chooseInternalOrExternalContext(TContext *, TInternalContext &internalCtx, std::true_type) {
return getContextImpl<TCast>(&internalCtx, std::true_type{});
}
//get external ctx
template<typename TCast, typename TContext, typename TInternalContext>
TCast *chooseInternalOrExternalContext(TContext *ctx, TInternalContext &, std::false_type) {
return ctx
? getContextImpl<TCast>(ctx, IsSpecializationOf<TContext, std::tuple>{})
: nullptr;
}
template<typename TCast, typename TContext, typename TInternalContext>
TCast *getContext(TContext *ctx, TInternalContext &internalCtx) {
return chooseInternalOrExternalContext<TCast>(ctx, internalCtx, HasContext<TCast, TInternalContext>{});
}
/*
* get context, if type doesn't exists then do not static_assert but return null instead
*/
template<typename TCast, typename TContext>
TCast *getContextFromTypeIfExists(TContext *ctx, std::true_type) {
return static_cast<TCast *>(ctx);
}
template<typename TCast, typename TContext>
TCast *getContextFromTypeIfExists(TContext *, std::false_type) {
return nullptr;
}
template<typename TCast, typename TContext>
TCast *getContextImplIfExists(TContext *ctx, std::false_type) {
return getContextFromTypeIfExists<TCast>(ctx, std::is_convertible<TContext *, TCast *>{});
}
template<typename TCast, typename TContext>
TCast *getContextFromTupleIfExists(TContext *ctx, std::true_type tmp) {
return getContextImpl<TCast>(ctx, tmp);
}
template<typename TCast, typename TContext>
TCast *getContextFromTupleIfExists(TContext *, std::false_type) {
return nullptr;
}
template<typename TCast, typename TContext>
TCast *getContextImplIfExists(TContext *ctx, std::true_type) {
return getContextFromTupleIfExists<TCast>(ctx, HasContext<TCast, TContext>{});
}
//get local ctx
template<typename TCast, typename TContext, typename TInternalContext>
TCast *chooseInternalOrExternalContextIfExists(TContext *, TInternalContext &internalCtx, std::true_type) {
return getContextImplIfExists<TCast>(&internalCtx, std::true_type{});
}
//get external ctx
template<typename TCast, typename TContext, typename TInternalContext>
TCast *chooseInternalOrExternalContextIfExists(TContext *ctx, TInternalContext &, std::false_type) {
return ctx
? getContextImplIfExists<TCast>(ctx, IsSpecializationOf<TContext, std::tuple>{})
: nullptr;
}
template<typename TCast, typename TContext, typename TInternalContext>
TCast *getContextIfTypeExists(TContext *ctx, TInternalContext &internalCtx) {
return chooseInternalOrExternalContextIfExists<TCast>(ctx, internalCtx, HasContext<TCast, TInternalContext>{});
}
}
}
#endif //BITSERY_DETAILS_SERIALIZATION_COMMON_H