polymorphic.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_POLYMORPHIC_HPP_
#define CEREAL_TYPES_POLYMORPHIC_HPP_

#include <cereal/cereal.hpp>
#include <cereal/types/memory.hpp>

#include <cereal/details/util.hpp>
#include <cereal/details/helpers.hpp>
#include <cereal/details/traits.hpp>
#include <cereal/details/polymorphic_impl.hpp>

#ifdef _MSC_VER
#define CEREAL_STATIC_CONSTEXPR static
#else
#define CEREAL_STATIC_CONSTEXPR static constexpr
#endif


#define CEREAL_REGISTER_TYPE(...)                                        \
  namespace cereal {                                                     \
  namespace detail {                                                     \
  template <>                                                            \
  struct binding_name<__VA_ARGS__>                                       \
  {                                                                      \
    CEREAL_STATIC_CONSTEXPR char const * name() { return #__VA_ARGS__; } \
  };                                                                     \
  } } /* end namespaces */                                               \
  CEREAL_BIND_TO_ARCHIVES(__VA_ARGS__)


#define CEREAL_REGISTER_TYPE_WITH_NAME(T, Name)                     \
  namespace cereal {                                                \
  namespace detail {                                                \
  template <>                                                       \
  struct binding_name<T>                                            \
  { CEREAL_STATIC_CONSTEXPR char const * name() { return Name; } }; \
  } } /* end namespaces */                                          \
  CEREAL_BIND_TO_ARCHIVES(T)


#define CEREAL_REGISTER_POLYMORPHIC_RELATION(Base, Derived)                     \
  namespace cereal {                                                            \
  namespace detail {                                                            \
  template <>                                                                   \
  struct PolymorphicRelation<Base, Derived>                                     \
  { static void bind() { RegisterPolymorphicCaster<Base, Derived>::bind(); } }; \
  } } /* end namespaces */


#define CEREAL_REGISTER_DYNAMIC_INIT(LibName)                \
  namespace cereal {                                         \
  namespace detail {                                         \
    void CEREAL_DLL_EXPORT dynamic_init_dummy_##LibName() {} \
  } } /* end namespaces */


#define CEREAL_FORCE_DYNAMIC_INIT(LibName)              \
  namespace cereal {                                    \
  namespace detail {                                    \
    void dynamic_init_dummy_##LibName();                \
  } /* end detail */                                    \
  namespace {                                           \
    void dynamic_init_##LibName()                       \
    {                                                   \
      ::cereal::detail::dynamic_init_dummy_##LibName(); \
    }                                                   \
  } } /* end namespaces */

namespace cereal
{
  namespace polymorphic_detail
  {

    #define UNREGISTERED_POLYMORPHIC_EXCEPTION(LoadSave, Name)                                                                                      \
      throw cereal::Exception("Trying to " #LoadSave " an unregistered polymorphic type (" + Name + ").\n"                                          \
                              "Make sure your type is registered with CEREAL_REGISTER_TYPE and that the archive "                                   \
                              "you are using was included (and registered with CEREAL_REGISTER_ARCHIVE) prior to calling CEREAL_REGISTER_TYPE.\n"   \
                              "If your type is already registered and you still see this error, you may need to use CEREAL_REGISTER_DYNAMIC_INIT.");


    template<class Archive> inline
    typename ::cereal::detail::InputBindingMap<Archive>::Serializers getInputBinding(Archive & ar, std::uint32_t const nameid)
    {
      // If the nameid is zero, we serialized a null pointer
      if(nameid == 0)
      {
        typename ::cereal::detail::InputBindingMap<Archive>::Serializers emptySerializers;
        emptySerializers.shared_ptr = [](void*, std::shared_ptr<void> & ptr, std::type_info const &) { ptr.reset(); };
        emptySerializers.unique_ptr = [](void*, std::unique_ptr<void, ::cereal::detail::EmptyDeleter<void>> & ptr, std::type_info const &) { ptr.reset( nullptr ); };
        return emptySerializers;
      }

      std::string name;
      if(nameid & detail::msb_32bit)
      {
        ar( CEREAL_NVP_("polymorphic_name", detail::make_polymorphic_key_tag(name)) );
        ar.registerPolymorphicName(nameid, name);
      }
      else
        name = ar.getPolymorphicName(nameid);

      auto const & bindingMap = detail::StaticObject<detail::InputBindingMap<Archive>>::getInstance().map;

      auto binding = bindingMap.find(name);
      if(binding == bindingMap.end())
        UNREGISTERED_POLYMORPHIC_EXCEPTION(load, name)
      return binding->second;
    }

    template <class Archive> inline
    bool hasPolymorphicBinding(const std::string& name) {
      auto const & bindingMap = detail::StaticObject<detail::InputBindingMap<Archive>>::getInstance().map;
      return bindingMap.end() != bindingMap.find(name);
    }


    template<class Archive, class T> inline
    typename std::enable_if<(traits::is_default_constructible<T>::value
                             || traits::has_load_and_construct<T, Archive>::value)
                             && !std::is_abstract<T>::value, bool>::type
    serialize_wrapper(Archive & ar, std::shared_ptr<T> & ptr, std::uint32_t const nameid)
    {
      if(nameid & detail::msb2_32bit)
      {
        ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper(ptr)) );
        return true;
      }
      return false;
    }


    template<class Archive, class T, class D> inline
    typename std::enable_if<(traits::is_default_constructible<T>::value
                             || traits::has_load_and_construct<T, Archive>::value)
                             && !std::is_abstract<T>::value, bool>::type
    serialize_wrapper(Archive & ar, std::unique_ptr<T, D> & ptr, std::uint32_t const nameid)
    {
      if(nameid & detail::msb2_32bit)
      {
        ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper(ptr)) );
        return true;
      }
      return false;
    }


    template<class Archive, class T> inline
    typename std::enable_if<(!traits::is_default_constructible<T>::value
                             && !traits::has_load_and_construct<T, Archive>::value)
                             || std::is_abstract<T>::value, bool>::type
    serialize_wrapper(Archive &, std::shared_ptr<T> &, std::uint32_t const nameid)
    {
      if(nameid & detail::msb2_32bit)
        throw cereal::Exception("Cannot load a polymorphic type that is not default constructable and does not have a load_and_construct function");
      return false;
    }


    template<class Archive, class T, class D> inline
     typename std::enable_if<(!traits::is_default_constructible<T>::value
                               && !traits::has_load_and_construct<T, Archive>::value)
                               || std::is_abstract<T>::value, bool>::type
    serialize_wrapper(Archive &, std::unique_ptr<T, D> &, std::uint32_t const nameid)
    {
      if(nameid & detail::msb2_32bit)
        throw cereal::Exception("Cannot load a polymorphic type that is not default constructable and does not have a load_and_construct function");
      return false;
    }
  } // polymorphic_detail

  // ######################################################################
  // Pointer serialization for polymorphic types

  template <class Archive, class T> inline
  typename std::enable_if<std::is_polymorphic<T>::value && std::is_abstract<T>::value, void>::type
  CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::shared_ptr<T> const & ptr )
  {
    if(!ptr)
    {
      // same behavior as nullptr in memory implementation
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(std::uint32_t(0))) );
      return;
    }

    std::type_info const & ptrinfo = typeid(*ptr.get());
    static std::type_info const & tinfo = typeid(T);
    // ptrinfo can never be equal to T info since we can't have an instance
    // of an abstract object
    //  this implies we need to do the lookup

    auto const & bindingMap = detail::StaticObject<detail::OutputBindingMap<Archive>>::getInstance().map;

    auto binding = bindingMap.find(std::type_index(ptrinfo));
    if(binding == bindingMap.end())
      UNREGISTERED_POLYMORPHIC_EXCEPTION(save, cereal::util::demangle(ptrinfo.name()))

    binding->second.shared_ptr(&ar, ptr.get(), tinfo);
  }

  template <class Archive, class T> inline
  typename std::enable_if<std::is_polymorphic<T>::value && !std::is_abstract<T>::value, void>::type
  CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::shared_ptr<T> const & ptr )
  {
    if(!ptr)
    {
      // same behavior as nullptr in memory implementation
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(std::uint32_t(0))) );
      return;
    }

    std::type_info const & ptrinfo = typeid(*ptr.get());
    static std::type_info const & tinfo = typeid(T);

    if(ptrinfo == tinfo)
    {
      // The 2nd msb signals that the following pointer does not need to be
      // cast with our polymorphic machinery
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(detail::msb2_32bit)) );

      ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper(ptr)) );

      return;
    }

    auto const & bindingMap = detail::StaticObject<detail::OutputBindingMap<Archive>>::getInstance().map;

    auto binding = bindingMap.find(std::type_index(ptrinfo));
    if(binding == bindingMap.end())
      UNREGISTERED_POLYMORPHIC_EXCEPTION(save, cereal::util::demangle(ptrinfo.name()))

    binding->second.shared_ptr(&ar, ptr.get(), tinfo);
  }

  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 )
  {
    std::uint32_t nameid;
    ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(nameid)) );

    // Check to see if we can skip all of this polymorphism business
    if(polymorphic_detail::serialize_wrapper(ar, ptr, nameid))
      return;

    auto binding = polymorphic_detail::getInputBinding(ar, nameid);
    std::shared_ptr<void> result;
    binding.shared_ptr(&ar, result, typeid(T));
    ptr = std::static_pointer_cast<T>(result);
  }

  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_("locked_ptr", 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_("locked_ptr", sptr) );
    ptr = sptr;
  }

  template <class Archive, class T, class D> inline
  typename std::enable_if<std::is_polymorphic<T>::value && std::is_abstract<T>::value, void>::type
  CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::unique_ptr<T, D> const & ptr )
  {
    if(!ptr)
    {
      // same behavior as nullptr in memory implementation
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(std::uint32_t(0))) );
      return;
    }

    std::type_info const & ptrinfo = typeid(*ptr.get());
    static std::type_info const & tinfo = typeid(T);
    // ptrinfo can never be equal to T info since we can't have an instance
    // of an abstract object
    //  this implies we need to do the lookup

    auto const & bindingMap = detail::StaticObject<detail::OutputBindingMap<Archive>>::getInstance().map;

    auto binding = bindingMap.find(std::type_index(ptrinfo));
    if(binding == bindingMap.end())
      UNREGISTERED_POLYMORPHIC_EXCEPTION(save, cereal::util::demangle(ptrinfo.name()))

    binding->second.unique_ptr(&ar, ptr.get(), tinfo);
  }

  template <class Archive, class T, class D> inline
  typename std::enable_if<std::is_polymorphic<T>::value && !std::is_abstract<T>::value, void>::type
  CEREAL_SAVE_FUNCTION_NAME( Archive & ar, std::unique_ptr<T, D> const & ptr )
  {
    if(!ptr)
    {
      // same behavior as nullptr in memory implementation
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(std::uint32_t(0))) );
      return;
    }

    std::type_info const & ptrinfo = typeid(*ptr.get());
    static std::type_info const & tinfo = typeid(T);

    if(ptrinfo == tinfo)
    {
      // The 2nd msb signals that the following pointer does not need to be
      // cast with our polymorphic machinery
      ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(detail::msb2_32bit)) );

      ar( CEREAL_NVP_("ptr_wrapper", memory_detail::make_ptr_wrapper(ptr)) );

      return;
    }

    auto const & bindingMap = detail::StaticObject<detail::OutputBindingMap<Archive>>::getInstance().map;

    auto binding = bindingMap.find(std::type_index(ptrinfo));
    if(binding == bindingMap.end())
      UNREGISTERED_POLYMORPHIC_EXCEPTION(save, cereal::util::demangle(ptrinfo.name()))

    binding->second.unique_ptr(&ar, ptr.get(), tinfo);
  }

  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 )
  {
    std::uint32_t nameid;
    ar( CEREAL_NVP_("polymorphic_id", detail::make_polymorphic_id_tag(nameid)) );

    // Check to see if we can skip all of this polymorphism business
    if(polymorphic_detail::serialize_wrapper(ar, ptr, nameid))
      return;

    auto binding = polymorphic_detail::getInputBinding(ar, nameid);
    std::unique_ptr<void, ::cereal::detail::EmptyDeleter<void>> result;
    binding.unique_ptr(&ar, result, typeid(T));
    ptr.reset(static_cast<T*>(result.release()));
  }

  #undef UNREGISTERED_POLYMORPHIC_EXCEPTION
} // namespace cereal
#endif // CEREAL_TYPES_POLYMORPHIC_HPP_