memory.hpp
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/*
Copyright (c) 2014, Randolph Voorhies, Shane Grant
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of cereal nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL RANDOLPH VOORHIES OR SHANE GRANT BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CEREAL_TYPES_SHARED_PTR_HPP_
#define CEREAL_TYPES_SHARED_PTR_HPP_
#include <cereal/cereal.hpp>
#include <memory>
#include <cstring>
namespace cereal
{
namespace memory_detail
{
template<class T>
struct PtrWrapper
{
PtrWrapper(T && p) : ptr(std::forward<T>(p)) {}
T & ptr;
PtrWrapper & operator=( PtrWrapper const & ) = delete;
};
template<class T> inline
PtrWrapper<T> make_ptr_wrapper(T && t)
{
return {std::forward<T>(t)};
}
template <class Archive, class T>
struct LoadAndConstructLoadWrapper
{
LoadAndConstructLoadWrapper( T * ptr ) :
construct( ptr )
{ }
inline void CEREAL_SERIALIZE_FUNCTION_NAME( Archive & ar )
{
::cereal::detail::Construct<T, Archive>::load_andor_construct( ar, construct );
}
::cereal::construct<T> construct;
};
template <class T>
class EnableSharedStateHelper
{
// typedefs for parent type and storage type
using BaseType = typename ::cereal::traits::get_shared_from_this_base<T>::type;
using ParentType = std::enable_shared_from_this<BaseType>;
using StorageType = typename std::aligned_storage<sizeof(ParentType)>::type;
public:
inline EnableSharedStateHelper( T * ptr ) :
itsPtr( static_cast<ParentType *>( ptr ) ),
itsState()
{
std::memcpy( &itsState, itsPtr, sizeof(ParentType) );
}
inline ~EnableSharedStateHelper()
{
std::memcpy( itsPtr, &itsState, sizeof(ParentType) );
}
private:
ParentType * itsPtr;
StorageType itsState;
}; // end EnableSharedStateHelper
template <class Archive, class T> inline
void loadAndConstructSharedPtr( Archive & ar, T * ptr, std::true_type /* has_shared_from_this */ )
{
memory_detail::LoadAndConstructLoadWrapper<Archive, T> loadWrapper( ptr );
memory_detail::EnableSharedStateHelper<T> state( ptr );
// let the user perform their initialization
ar( CEREAL_NVP_("data", loadWrapper) );
}
template <class Archive, class T> inline
void loadAndConstructSharedPtr( Archive & ar, T * ptr, std::false_type /* has_shared_from_this */ )
{
memory_detail::LoadAndConstructLoadWrapper<Archive, T> loadWrapper( ptr );
ar( CEREAL_NVP_("data", loadWrapper) );
}
} // end namespace memory_detail
template <class Archive, class T> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::shared_ptr<T> const & ptr )
{
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( ptr )) );
}
template <class Archive, class T> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, std::shared_ptr<T> & ptr )
{
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( ptr )) );
}
template <class Archive, class T> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::weak_ptr<T> const & ptr )
{
auto const sptr = ptr.lock();
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( sptr )) );
}
template <class Archive, class T> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, std::weak_ptr<T> & ptr )
{
std::shared_ptr<T> sptr;
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( sptr )) );
ptr = sptr;
}
template <class Archive, class T, class D> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::unique_ptr<T, D> const & ptr )
{
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( ptr )) );
}
template <class Archive, class T, class D> inline
typename std::enable_if<!std::is_polymorphic<T>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, std::unique_ptr<T, D> & ptr )
{
ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper( ptr )) );
}
// ######################################################################
// Pointer wrapper implementations follow below
template <class Archive, class T> inline
void CEREAL_SAVE_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::shared_ptr<T> const &> const & wrapper )
{
auto & ptr = wrapper.ptr;
uint32_t id = ar.registerSharedPointer( ptr.get() );
ar( CEREAL_NVP_("id", id) );
if( id & detail::msb_32bit )
{
ar( CEREAL_NVP_("data", *ptr) );
}
}
template <class Archive, class T> inline
typename std::enable_if<traits::has_load_and_construct<T, Archive>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::shared_ptr<T> &> & wrapper )
{
auto & ptr = wrapper.ptr;
uint32_t id;
ar( CEREAL_NVP_("id", id) );
if( id & detail::msb_32bit )
{
// Storage type for the pointer - since we can't default construct this type,
// we'll allocate it using std::aligned_storage and use a custom deleter
using ST = typename std::aligned_storage<sizeof(T)>::type;
// Valid flag - set to true once construction finishes
// This prevents us from calling the destructor on
// uninitialized data.
auto valid = std::make_shared<bool>( false );
// Allocate our storage, which we will treat as
// uninitialized until initialized with placement new
ptr.reset( reinterpret_cast<T *>( new ST() ),
[=]( T * t )
{
if( valid )
t->~T();
delete reinterpret_cast<ST *>( t );
} );
// Register the pointer
ar.registerSharedPointer( id, ptr );
// Perform the actual loading and allocation
memory_detail::loadAndConstructSharedPtr( ar, ptr.get(), typename ::cereal::traits::has_shared_from_this<T>::type() );
// Mark pointer as valid (initialized)
*valid = true;
}
else
ptr = std::static_pointer_cast<T>(ar.getSharedPointer(id));
}
template <class Archive, class T> inline
typename std::enable_if<!traits::has_load_and_construct<T, Archive>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::shared_ptr<T> &> & wrapper )
{
auto & ptr = wrapper.ptr;
uint32_t id;
ar( CEREAL_NVP_("id", id) );
if( id & detail::msb_32bit )
{
ptr.reset( detail::Construct<T, Archive>::load_andor_construct() );
ar.registerSharedPointer( id, ptr );
ar( CEREAL_NVP_("data", *ptr) );
}
else
ptr = std::static_pointer_cast<T>(ar.getSharedPointer(id));
}
template <class Archive, class T, class D> inline
void CEREAL_SAVE_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::unique_ptr<T, D> const &> const & wrapper )
{
auto & ptr = wrapper.ptr;
// unique_ptr get one byte of metadata which signifies whether they were a nullptr
// 0 == nullptr
// 1 == not null
if( !ptr )
ar( CEREAL_NVP_("valid", uint8_t(0)) );
else
{
ar( CEREAL_NVP_("valid", uint8_t(1)) );
ar( CEREAL_NVP_("data", *ptr) );
}
}
template <class Archive, class T, class D> inline
typename std::enable_if<traits::has_load_and_construct<T, Archive>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::unique_ptr<T, D> &> & wrapper )
{
uint8_t isValid;
ar( CEREAL_NVP_("valid", isValid) );
auto & ptr = wrapper.ptr;
if( isValid )
{
// Storage type for the pointer - since we can't default construct this type,
// we'll allocate it using std::aligned_storage
using ST = typename std::aligned_storage<sizeof(T)>::type;
// Allocate storage - note the ST type so that deleter is correct if
// an exception is thrown before we are initialized
std::unique_ptr<ST> stPtr( new ST() );
// Use wrapper to enter into "data" nvp of ptr_wrapper
memory_detail::LoadAndConstructLoadWrapper<Archive, T> loadWrapper( reinterpret_cast<T *>( stPtr.get() ) );
// Initialize storage
ar( CEREAL_NVP_("data", loadWrapper) );
// Transfer ownership to correct unique_ptr type
ptr.reset( reinterpret_cast<T *>( stPtr.release() ) );
}
else
ptr.reset( nullptr );
}
template <class Archive, class T, class D> inline
typename std::enable_if<!traits::has_load_and_construct<T, Archive>::value, void>::type
CEREAL_LOAD_FUNCTION_NAME( Archive & ar, memory_detail::PtrWrapper<std::unique_ptr<T, D> &> & wrapper )
{
uint8_t isValid;
ar( CEREAL_NVP_("valid", isValid) );
auto & ptr = wrapper.ptr;
if( isValid )
{
ptr.reset( detail::Construct<T, Archive>::load_andor_construct() );
ar( CEREAL_NVP_( "data", *ptr ) );
}
else
{
ptr.reset( nullptr );
}
}
} // namespace cereal
#endif // CEREAL_TYPES_SHARED_PTR_HPP_
CEREAL_NVP_
#define CEREAL_NVP_(name, value)
Convenience for creating a templated NVP.
Definition: helpers.hpp:197
cereal::memory_detail::loadAndConstructSharedPtr
void loadAndConstructSharedPtr(Archive &ar, T *ptr, std::true_type)
Definition: memory.hpp:151
cereal::construct
Used to construct types with no default constructor.
Definition: access.hpp:151
CEREAL_SERIALIZE_FUNCTION_NAME
#define CEREAL_SERIALIZE_FUNCTION_NAME
The serialization/deserialization function name to search for.
Definition: macros.hpp:51
cereal::memory_detail::LoadAndConstructLoadWrapper
A struct that acts as a wrapper around calling load_andor_construct.
Definition: memory.hpp:66
cereal::memory_detail::EnableSharedStateHelper
Definition: memory.hpp:117
cereal::memory_detail::EnableSharedStateHelper::EnableSharedStateHelper
EnableSharedStateHelper(T *ptr)
Saves the state of some type inheriting from enable_shared_from_this.
Definition: memory.hpp:127
cereal
Definition: access.hpp:39
cereal::memory_detail::PtrWrapper
A wrapper class to notify cereal that it is ok to serialize the contained pointer.
Definition: memory.hpp:45
cereal.hpp
Main cereal functionality.
cereal::memory_detail::EnableSharedStateHelper::~EnableSharedStateHelper
~EnableSharedStateHelper()
Restores the state of the held pointer.
Definition: memory.hpp:135
CEREAL_LOAD_FUNCTION_NAME
#define CEREAL_LOAD_FUNCTION_NAME
The deserialization (load) function name to search for.
Definition: macros.hpp:58
cereal::memory_detail::make_ptr_wrapper
PtrWrapper< T > make_ptr_wrapper(T &&t)
Make a PtrWrapper.
Definition: memory.hpp:56
CEREAL_SAVE_FUNCTION_NAME
#define CEREAL_SAVE_FUNCTION_NAME
The serialization (save) function name to search for.
Definition: macros.hpp:65
cereal::detail::Construct
Definition: traits.hpp:1279