cereal.hpp

/*
  Copyright (c) 2013, 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 <COPYRIGHT HOLDER> 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_CEREAL_HPP_
#define CEREAL_CEREAL_HPP_

#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <cstddef>
#include <cstdint>

#include <cereal/details/traits.hpp>
#include <cereal/details/helpers.hpp>
#include <cereal/types/base_class.hpp>
#include <cereal/types/common.hpp>

namespace cereal
{

  // ######################################################################
  struct Exception : public std::runtime_error
  {
    using std::runtime_error::runtime_error;
  };

  // ######################################################################

  template <class T> inline
  NameValuePair<T> make_nvp( std::string const & name, T && value )
  {
    return {name.c_str(), std::forward<T>(value)};
  }


  template <class T> inline
  NameValuePair<T> make_nvp( const char * name, T && value )
  {
    return {name, std::forward<T>(value)};
  }


  #define CEREAL_NVP(T) ::cereal::make_nvp(#T, T)

  // ######################################################################

  template <class T> inline
  BinaryData<T> binary_data( T && data, size_t size )
  {
    return {std::forward<T>(data), size};
  }

  // ######################################################################

  template <class T>
  SizeTag<T> make_size_tag( T && sz )
  {
    return {std::forward<T>(sz)};
  }

  // ######################################################################

  template <class Archive, class T>
  void prologue( Archive & /* archive */, T const & /* data */)
  { }

  template <class Archive, class T>
  void epilogue( Archive & /* archive */, T const & /* data */)
  { }

  // ######################################################################

  enum Flags { AllowEmptyClassElision = 1 };

  // ######################################################################

  #define CEREAL_REGISTER_ARCHIVE(Archive)                            \
  namespace cereal { namespace detail {                               \
  template <class T>                                                  \
  typename polymorphic_serialization_support<Archive, T>::type        \
  instantiate_polymorphic_binding( T*, Archive*, adl_tag );           \
  } } // end namespaces


  template<class ArchiveType, std::uint32_t Flags = 0>
  class OutputArchive : public detail::OutputArchiveBase
  {
    public:

      OutputArchive(ArchiveType * const self) : self(self), itsCurrentPointerId(1), itsCurrentPolymorphicTypeId(1)
      { }

      template <class ... Types> inline
      ArchiveType & operator()( Types && ... args )
      {
        self->process( std::forward<Types>( args )... );
        return *self;
      }


      std::uint32_t registerSharedPointer( void const * addr )
      {
        // Handle null pointers by just returning 0
        if(addr == 0) return 0;

        auto id = itsSharedPointerMap.find( addr );
        if( id == itsSharedPointerMap.end() )
        {
          auto ptrId = itsCurrentPointerId++;
          itsSharedPointerMap.insert( {addr, ptrId} );
          return ptrId | detail::msb_32bit; // mask MSB to be 1
        }
        else
          return id->second;
      }


      std::uint32_t registerPolymorphicType( char const * name )
      {
        auto id = itsPolymorphicTypeMap.find( name );
        if( id == itsPolymorphicTypeMap.end() )
        {
          auto polyId = itsCurrentPolymorphicTypeId++;
          itsPolymorphicTypeMap.insert( {name, polyId} );
          return polyId | detail::msb_32bit; // mask MSB to be 1
        }
        else
          return id->second;
      }

    private:
      template <class T> inline
      void process( T && head )
      {
        prologue( *self, head );
        self->processImpl( head );
        epilogue( *self, head );
      }

      template <class T, class ... Other> inline
      void process( T && head, Other && ... tail )
      {
        self->process( std::forward<T>( head ) );
        self->process( std::forward<Other>( tail )... );
      }


      template <class T> inline
      ArchiveType & processImpl(virtual_base_class<T> const & b)
      {
        traits::detail::base_class_id id(b.base_ptr);
        if(itsBaseClassSet.count(id) == 0)
        {
          itsBaseClassSet.insert(id);
          self->processImpl( *b.base_ptr );
        }
        return *self;
      }


      template <class T> inline
      ArchiveType & processImpl(base_class<T> const & b)
      {
        self->processImpl( *b.base_ptr );
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_member_serialize<T, ArchiveType>() ||
                              (traits::is_output_serializable<T, ArchiveType>() && traits::has_member_serialize<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T const & t)
      {
        access::member_serialize(*self, const_cast<T &>(t));
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_non_member_serialize<T, ArchiveType>() ||
                              (traits::is_output_serializable<T, ArchiveType>() && traits::has_non_member_serialize<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T const & t)
      {
        serialize(*self, const_cast<T &>(t));
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_member_save<T, ArchiveType>() ||
                              (traits::is_output_serializable<T, ArchiveType>() && traits::has_member_save<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T const & t)
      {
        access::member_save(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_non_member_save<T, ArchiveType>() ||
                              (traits::is_output_serializable<T, ArchiveType>() && traits::has_non_member_save<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T const & t)
      {
        save(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<(Flags & AllowEmptyClassElision) &&
          !traits::is_output_serializable<T, ArchiveType>() && traits::is_empty_class<T>(), ArchiveType &>::type
      processImpl(T const &)
      {
        return *self;
      }

      template <class T> inline
      typename std::enable_if<!traits::is_specialized<T, ArchiveType>() && !traits::is_output_serializable<T, ArchiveType>() &&
        (!(Flags & AllowEmptyClassElision) || ((Flags & AllowEmptyClassElision) && !traits::is_empty_class<T>())),
        ArchiveType &>::type
      processImpl(T const &)
      {
        static_assert(traits::is_output_serializable<T, ArchiveType>(), "Trying to serialize an unserializable type with an output archive.\n\n"
            "Types must either have a serialize function, or separate save/load functions (but not both).\n"
            "Serialize functions generally have the following signature:\n\n"
            "template<class Archive>\n"
            "  void serialize(Archive & ar)\n"
            "  {\n"
            "    ar( member1, member2, member3 );\n"
            "  }\n\n" );
        return *self;
      }

    private:
      ArchiveType * const self;

      std::unordered_set<traits::detail::base_class_id, traits::detail::base_class_id_hash> itsBaseClassSet;

      std::unordered_map<void const *, std::uint32_t> itsSharedPointerMap;

      std::uint32_t itsCurrentPointerId;

      std::unordered_map<char const *, std::uint32_t> itsPolymorphicTypeMap;

      std::uint32_t itsCurrentPolymorphicTypeId;
  }; // class OutputArchive

  // ######################################################################

  template<class ArchiveType, std::uint32_t Flags = 0>
  class InputArchive : public detail::InputArchiveBase
  {
    public:

      InputArchive(ArchiveType * const self) : self(self) { }

      template <class ... Types> inline
      ArchiveType & operator()( Types && ... args )
      {
        process( std::forward<Types>( args )... );
        return *self;
      }


      std::shared_ptr<void> getSharedPointer(std::uint32_t const id)
      {
        if(id == 0) return std::shared_ptr<void>(nullptr);

        auto ptr = itsSharedPointerMap.find( id );
        if(ptr == itsSharedPointerMap.end())
          throw Exception("Error while trying to deserialize a smart pointer. Could not find id " + std::to_string(id));

        return ptr->second;
      }


      void registerSharedPointer(std::uint32_t const id, std::shared_ptr<void> ptr)
      {
        std::uint32_t const stripped_id = id & ~detail::msb_32bit;
        itsSharedPointerMap.insert( {stripped_id, ptr} );
      }


      std::string getPolymorphicName(std::uint32_t const id)
      {
        auto name = itsPolymorphicTypeMap.find( id );
        if(name == itsPolymorphicTypeMap.end())
        {
          throw Exception("Error while trying to deserialize a polymorphic pointer. Could not find type id " + std::to_string(id));
        }
        return name->second;
      }


      void registerPolymorphicName(std::uint32_t const id, std::string const & name)
      {
        std::uint32_t const stripped_id = id & ~detail::msb_32bit;
        itsPolymorphicTypeMap.insert( {stripped_id, name} );
      }

    private:
      template <class T> inline
      void process( T && head )
      {
        prologue( *self, head );
        self->processImpl( head );
        epilogue( *self, head );
      }

      template <class T, class ... Other> inline
      void process( T && head, Other && ... tail )
      {
        process( std::forward<T>( head ) );
        process( std::forward<Other>( tail )... );
      }


      template <class T> inline
      ArchiveType & processImpl(virtual_base_class<T> & b)
      {
        traits::detail::base_class_id id(b.base_ptr);
        if(itsBaseClassSet.count(id) == 0)
        {
          itsBaseClassSet.insert(id);
          self->processImpl( *b.base_ptr );
        }
        return *self;
      }


      template <class T> inline
      ArchiveType & processImpl(base_class<T> & b)
      {
        self->processImpl( *b.base_ptr );
        return *self;
      }


      template <class T> inline
      typename std::enable_if<traits::is_specialized_member_serialize<T, ArchiveType>() ||
                              (traits::is_input_serializable<T, ArchiveType>() && traits::has_member_serialize<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T & t)
      {
        access::member_serialize(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_non_member_serialize<T, ArchiveType>() ||
                              (traits::is_input_serializable<T, ArchiveType>() && traits::has_non_member_serialize<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T & t)
      {
        serialize(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_member_load<T, ArchiveType>() ||
                              (traits::is_input_serializable<T, ArchiveType>() && traits::has_member_load<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T & t)
      {
        access::member_load(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<traits::is_specialized_non_member_load<T, ArchiveType>() ||
                              (traits::is_input_serializable<T, ArchiveType>() && traits::has_non_member_load<T, ArchiveType>()),
                              ArchiveType &>::type
      processImpl(T & t)
      {
        load(*self, t);
        return *self;
      }

      template <class T> inline
      typename std::enable_if<(Flags & AllowEmptyClassElision) &&
          !traits::is_input_serializable<T, ArchiveType>() && traits::is_empty_class<T>(), ArchiveType &>::type
      processImpl(T const &)
      {
        return *self;
      }

      template <class T> inline
      typename std::enable_if<!traits::is_specialized<T, ArchiveType>() && !traits::is_input_serializable<T, ArchiveType>() &&
        (!(Flags & AllowEmptyClassElision) || ((Flags & AllowEmptyClassElision) && !traits::is_empty_class<T>())),
        ArchiveType &>::type
      processImpl(T const &)
      {
        static_assert(traits::is_output_serializable<T, ArchiveType>(), "Trying to serialize an unserializable type with an output archive.\n\n"
            "Types must either have a serialize function, or separate save/load functions (but not both).\n"
            "Serialize functions generally have the following signature:\n\n"
            "template<class Archive>\n"
            "  void serialize(Archive & ar)\n"
            "  {\n"
            "    ar( member1, member2, member3 );\n"
            "  }\n\n" );
        return *self;
      }

    private:
      ArchiveType * const self;

      std::unordered_set<traits::detail::base_class_id, traits::detail::base_class_id_hash> itsBaseClassSet;

      std::unordered_map<std::uint32_t, std::shared_ptr<void>> itsSharedPointerMap;

      std::unordered_map<std::uint32_t, std::string> itsPolymorphicTypeMap;
  }; // class InputArchive
} // namespace cereal

#endif // CEREAL_CEREAL_HPP_