xml.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_ARCHIVES_XML_HPP_
#define CEREAL_ARCHIVES_XML_HPP_
#include <cereal/cereal.hpp>
#include <cereal/details/util.hpp>

#include <cereal/external/rapidxml/rapidxml.hpp>
#include <cereal/external/rapidxml/rapidxml_print.hpp>
#include <cereal/external/base64.hpp>

#include <sstream>
#include <stack>
#include <vector>
#include <limits>
#include <string>
#include <cstring>
#include <cmath>

namespace cereal
{
  namespace xml_detail
  {
    #ifndef CEREAL_XML_STRING_VALUE

    #define CEREAL_XML_STRING_VALUE "cereal"
    #endif // CEREAL_XML_STRING_VALUE

    static const char * CEREAL_XML_STRING = CEREAL_XML_STRING_VALUE;

    inline bool isWhitespace( char c )
    {
      return c == ' ' || c == '\t' || c == '\n' || c == '\r';
    }
  }

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

  class XMLOutputArchive : public OutputArchive<XMLOutputArchive>, public traits::TextArchive
  {
    public:

      class Options
      {
        public:
          static Options Default(){ return Options(); }

          static Options NoIndent(){ return Options( std::numeric_limits<double>::max_digits10, false ); }


          explicit Options( int precision = std::numeric_limits<double>::max_digits10,
                            bool indent = true,
                            bool outputType = false ) :
            itsPrecision( precision ),
            itsIndent( indent ),
            itsOutputType( outputType ) { }

        private:
          friend class XMLOutputArchive;
          int itsPrecision;
          bool itsIndent;
          bool itsOutputType;
      };


      XMLOutputArchive( std::ostream & stream, Options const & options = Options::Default() ) :
        OutputArchive<XMLOutputArchive>(this),
        itsStream(stream),
        itsOutputType( options.itsOutputType ),
        itsIndent( options.itsIndent )
      {
        // rapidxml will delete all allocations when xml_document is cleared
        auto node = itsXML.allocate_node( rapidxml::node_declaration );
        node->append_attribute( itsXML.allocate_attribute( "version", "1.0" ) );
        node->append_attribute( itsXML.allocate_attribute( "encoding", "utf-8" ) );
        itsXML.append_node( node );

        // allocate root node
        auto root = itsXML.allocate_node( rapidxml::node_element, xml_detail::CEREAL_XML_STRING );
        itsXML.append_node( root );
        itsNodes.emplace( root );

        // set attributes on the streams
        itsStream << std::boolalpha;
        itsStream.precision( options.itsPrecision );
        itsOS << std::boolalpha;
        itsOS.precision( options.itsPrecision );
      }

      ~XMLOutputArchive()
      {
        const int flags = itsIndent ? 0x0 : rapidxml::print_no_indenting;
        rapidxml::print( itsStream, itsXML, flags );
        itsXML.clear();
      }


      void saveBinaryValue( const void * data, size_t size, const char * name = nullptr )
      {
        itsNodes.top().name = name;

        startNode();

        auto base64string = base64::encode( reinterpret_cast<const unsigned char *>( data ), size );
        saveValue( base64string );

        if( itsOutputType )
          itsNodes.top().node->append_attribute( itsXML.allocate_attribute( "type", "cereal binary data" ) );

        finishNode();
      };




      void startNode()
      {
        // generate a name for this new node
        const auto nameString = itsNodes.top().getValueName();

        // allocate strings for all of the data in the XML object
        auto namePtr = itsXML.allocate_string( nameString.data(), nameString.length() + 1 );

        // insert into the XML
        auto node = itsXML.allocate_node( rapidxml::node_element, namePtr, nullptr, nameString.size() );
        itsNodes.top().node->append_node( node );
        itsNodes.emplace( node );
      }

      void finishNode()
      {
        itsNodes.pop();
      }

      void setNextName( const char * name )
      {
        itsNodes.top().name = name;
      }


      template <class T> inline
      void saveValue( T const & value )
      {
        itsOS.clear(); itsOS.seekp( 0, std::ios::beg );
        itsOS << value << std::ends;

        const auto strValue = itsOS.str();

        // If the first or last character is a whitespace, add xml:space attribute
        // the string always contains a '\0' added by std::ends, so the last character is at len-2 and an 'empty' 
        // string has a length of 1 or lower
        const auto len = strValue.length();
        if ( len > 1 && ( xml_detail::isWhitespace( strValue[0] ) || xml_detail::isWhitespace( strValue[len - 2] ) ) )
        {
          itsNodes.top().node->append_attribute( itsXML.allocate_attribute( "xml:space", "preserve" ) );
        }

        // allocate strings for all of the data in the XML object
        auto dataPtr = itsXML.allocate_string( itsOS.str().c_str(), itsOS.str().length() + 1 );

        // insert into the XML
        itsNodes.top().node->append_node( itsXML.allocate_node( rapidxml::node_data, nullptr, dataPtr ) );
      }

      void saveValue( uint8_t const & value )
      {
        saveValue( static_cast<uint32_t>( value ) );
      }

      void saveValue( int8_t const & value )
      {
        saveValue( static_cast<int32_t>( value ) );
      }

      template <class T> inline
      void insertType()
      {
        if( !itsOutputType )
          return;

        // generate a name for this new node
        const auto nameString = util::demangledName<T>();

        // allocate strings for all of the data in the XML object
        auto namePtr = itsXML.allocate_string( nameString.data(), nameString.length() + 1 );

        itsNodes.top().node->append_attribute( itsXML.allocate_attribute( "type", namePtr ) );
      }

      void appendAttribute( const char * name, const char * value )
      {
        auto namePtr =  itsXML.allocate_string( name );
        auto valuePtr = itsXML.allocate_string( value );
        itsNodes.top().node->append_attribute( itsXML.allocate_attribute( namePtr, valuePtr ) );
      }

    protected:
      struct NodeInfo
      {
        NodeInfo( rapidxml::xml_node<> * n = nullptr,
                  const char * nm = nullptr ) :
          node( n ),
          counter( 0 ),
          name( nm )
        { }

        rapidxml::xml_node<> * node; 
        size_t counter;              
        const char * name;           


        std::string getValueName()
        {
          if( name )
          {
            auto n = name;
            name = nullptr;
            return {n};
          }
          else
            return "value" + std::to_string( counter++ ) + "\0";
        }
      }; // NodeInfo


    private:
      std::ostream & itsStream;        
      rapidxml::xml_document<> itsXML; 
      std::stack<NodeInfo> itsNodes;   
      std::ostringstream itsOS;        
      bool itsOutputType;              
      bool itsIndent;                  
  }; // XMLOutputArchive

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

  class XMLInputArchive : public InputArchive<XMLInputArchive>, public traits::TextArchive
  {
    public:


      XMLInputArchive( std::istream & stream ) :
        InputArchive<XMLInputArchive>( this ),
        itsData( std::istreambuf_iterator<char>( stream ), std::istreambuf_iterator<char>() )
      {
        try
        {
          itsData.push_back('\0'); // rapidxml will do terrible things without the data being null terminated
          itsXML.parse<rapidxml::parse_trim_whitespace | rapidxml::parse_no_data_nodes | rapidxml::parse_declaration_node>( reinterpret_cast<char *>( itsData.data() ) );
        }
        catch( rapidxml::parse_error const & )
        {
          //std::cerr << "-----Original-----" << std::endl;
          //stream.seekg(0);
          //std::cout << std::string( std::istreambuf_iterator<char>( stream ), std::istreambuf_iterator<char>() ) << std::endl;

          //std::cerr << "-----Error-----" << std::endl;
          //std::cerr << e.what() << std::endl;
          //std::cerr << e.where<char>() << std::endl;
          throw Exception("XML Parsing failed - likely due to invalid characters or invalid naming");
        }

        // Parse the root
        auto root = itsXML.first_node( xml_detail::CEREAL_XML_STRING );
        if( root == nullptr )
          throw Exception("Could not detect cereal root node - likely due to empty or invalid input");
        else
          itsNodes.emplace( root );
      }


      void loadBinaryValue( void * data, size_t size, const char * name = nullptr )
      {
        setNextName( name );
        startNode();

        std::string encoded;
        loadValue( encoded );

        auto decoded = base64::decode( encoded );

        if( size != decoded.size() )
          throw Exception("Decoded binary data size does not match specified size");

        std::memcpy( data, decoded.data(), decoded.size() );

        finishNode();
      };




      void startNode()
      {
        auto next = itsNodes.top().child; // By default we would move to the next child node
        auto const expectedName = itsNodes.top().name; // this is the expected name from the NVP, if provided

        // If we were given an NVP name, look for it in the current level of the document.
        //    We only need to do this if either we have exhausted the siblings of the current level or
        //    the NVP name does not match the name of the node we would normally read next
        if( expectedName && ( next == nullptr || std::strcmp( next->name(), expectedName ) != 0 ) )
        {
          next = itsNodes.top().search( expectedName );

          if( next == nullptr )
            throw Exception("XML Parsing failed - provided NVP not found");
        }

        itsNodes.emplace( next );
      }

      void finishNode()
      {
        // remove current
        itsNodes.pop();

        // advance parent
        itsNodes.top().advance();

        // Reset name
        itsNodes.top().name = nullptr;
      }

      const char * getNodeName() const
      {
        return itsNodes.top().node->name();
      }

      void setNextName( const char * name )
      {
        itsNodes.top().name = name;
      }

      template <class T, traits::EnableIf<std::is_unsigned<T>::value,
                                          std::is_same<T, bool>::value> = traits::sfinae> inline
      void loadValue( T & value )
      {
        std::istringstream is( itsNodes.top().node->value() );
        is.setf( std::ios::boolalpha );
        is >> value;
      }

      template <class T, traits::EnableIf<std::is_integral<T>::value,
                                          !std::is_same<T, bool>::value,
                                          sizeof(T) == sizeof(char)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = *reinterpret_cast<T*>( itsNodes.top().node->value() );
      }

      void loadValue( int8_t & value )
      {
        int32_t val; loadValue( val ); value = static_cast<int8_t>( val );
      }

      void loadValue( uint8_t & value )
      {
        uint32_t val; loadValue( val ); value = static_cast<uint8_t>( val );
      }

      template <class T, traits::EnableIf<std::is_unsigned<T>::value,
                                          !std::is_same<T, bool>::value,
                                          !std::is_same<T, unsigned char>::value,
                                          sizeof(T) < sizeof(long long)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = static_cast<T>( std::stoul( itsNodes.top().node->value() ) );
      }

      template <class T, traits::EnableIf<std::is_unsigned<T>::value,
                                          !std::is_same<T, bool>::value,
                                          sizeof(T) >= sizeof(long long)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = static_cast<T>( std::stoull( itsNodes.top().node->value() ) );
      }

      template <class T, traits::EnableIf<std::is_signed<T>::value,
                                          !std::is_same<T, char>::value,
                                          sizeof(T) <= sizeof(int)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = static_cast<T>( std::stoi( itsNodes.top().node->value() ) );
      }

      template <class T, traits::EnableIf<std::is_signed<T>::value,
                                          (sizeof(T) > sizeof(int)),
                                          sizeof(T) <= sizeof(long)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = static_cast<T>( std::stol( itsNodes.top().node->value() ) );
      }

      template <class T, traits::EnableIf<std::is_signed<T>::value,
                                          (sizeof(T) > sizeof(long)),
                                          sizeof(T) <= sizeof(long long)> = traits::sfinae> inline
      void loadValue( T & value )
      {
        value = static_cast<T>( std::stoll( itsNodes.top().node->value() ) );
      }

      void loadValue( float & value )
      {
        try
        {
          value = std::stof( itsNodes.top().node->value() );
        }
        catch( std::out_of_range const & )
        {
          // special case for denormalized values
          std::istringstream is( itsNodes.top().node->value() );
          is >> value;
          if( std::fpclassify( value ) != FP_SUBNORMAL )
            throw;
        }
      }

      void loadValue( double & value )
      {
        try
        {
          value = std::stod( itsNodes.top().node->value() );
        }
        catch( std::out_of_range const & )
        {
          // special case for denormalized values
          std::istringstream is( itsNodes.top().node->value() );
          is >> value;
          if( std::fpclassify( value ) != FP_SUBNORMAL )
            throw;
        }
      }

      void loadValue( long double & value )
      {
        try
        {
          value = std::stold( itsNodes.top().node->value() );
        }
        catch( std::out_of_range const & )
        {
          // special case for denormalized values
          std::istringstream is( itsNodes.top().node->value() );
          is >> value;
          if( std::fpclassify( value ) != FP_SUBNORMAL )
            throw;
        }
      }

      template<class CharT, class Traits, class Alloc> inline
      void loadValue( std::basic_string<CharT, Traits, Alloc> & str )
      {
        std::basic_istringstream<CharT, Traits> is( itsNodes.top().node->value() );

        str.assign( std::istreambuf_iterator<CharT, Traits>( is ),
                    std::istreambuf_iterator<CharT, Traits>() );
      }

      template <class T> inline
      void loadSize( T & value )
      {
        value = getNumChildren( itsNodes.top().node );
      }

    protected:
      static size_t getNumChildren( rapidxml::xml_node<> * node )
      {
        size_t size = 0;
        node = node->first_node(); // get first child

        while( node != nullptr )
        {
          ++size;
          node = node->next_sibling();
        }

        return size;
      }


      struct NodeInfo
      {
        NodeInfo( rapidxml::xml_node<> * n = nullptr ) :
          node( n ),
          child( n->first_node() ),
          size( XMLInputArchive::getNumChildren( n ) ),
          name( nullptr )
        { }


        void advance()
        {
          if( size > 0 )
          {
            --size;
            child = child->next_sibling();
          }
        }


        rapidxml::xml_node<> * search( const char * searchName )
        {
          if( searchName )
          {
            size_t new_size = XMLInputArchive::getNumChildren( node );
            const size_t name_size = rapidxml::internal::measure( searchName );

            for( auto new_child = node->first_node(); new_child != nullptr; new_child = new_child->next_sibling() )
            {
              if( rapidxml::internal::compare( new_child->name(), new_child->name_size(), searchName, name_size, true ) )
              {
                size = new_size;
                child = new_child;

                return new_child;
              }
              --new_size;
            }
          }

          return nullptr;
        }

        rapidxml::xml_node<> * node;  
        rapidxml::xml_node<> * child; 
        size_t size;                  
        const char * name;            
      }; // NodeInfo


    private:
      std::vector<char> itsData;       
      rapidxml::xml_document<> itsXML; 
      std::stack<NodeInfo> itsNodes;   
  };

  // ######################################################################
  // XMLArchive prologue and epilogue functions
  // ######################################################################

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

  template <class T> inline
  void prologue( XMLOutputArchive &, NameValuePair<T> const & )
  { }

  template <class T> inline
  void prologue( XMLInputArchive &, NameValuePair<T> const & )
  { }

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

  template <class T> inline
  void epilogue( XMLOutputArchive &, NameValuePair<T> const & )
  { }

  template <class T> inline
  void epilogue( XMLInputArchive &, NameValuePair<T> const & )
  { }

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

  template <class T> inline
  void prologue( XMLOutputArchive & ar, SizeTag<T> const & )
  {
    ar.appendAttribute( "size", "dynamic" );
  }

  template <class T> inline
  void prologue( XMLInputArchive &, SizeTag<T> const & )
  { }


  template <class T> inline
  void epilogue( XMLOutputArchive &, SizeTag<T> const & )
  { }

  template <class T> inline
  void epilogue( XMLInputArchive &, SizeTag<T> const & )
  { }

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

  template <class T, traits::DisableIf<traits::has_minimal_base_class_serialization<T, traits::has_minimal_output_serialization, XMLOutputArchive>::value ||
                                       traits::has_minimal_output_serialization<T, XMLOutputArchive>::value> = traits::sfinae> inline
  void prologue( XMLOutputArchive & ar, T const & )
  {
    ar.startNode();
    ar.insertType<T>();
  }

  template <class T, traits::DisableIf<traits::has_minimal_base_class_serialization<T, traits::has_minimal_input_serialization, XMLInputArchive>::value ||
                                       traits::has_minimal_input_serialization<T, XMLInputArchive>::value> = traits::sfinae> inline
  void prologue( XMLInputArchive & ar, T const & )
  {
    ar.startNode();
  }

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

  template <class T, traits::DisableIf<traits::has_minimal_base_class_serialization<T, traits::has_minimal_output_serialization, XMLOutputArchive>::value ||
                                       traits::has_minimal_output_serialization<T, XMLOutputArchive>::value> = traits::sfinae> inline
  void epilogue( XMLOutputArchive & ar, T const & )
  {
    ar.finishNode();
  }

  template <class T, traits::DisableIf<traits::has_minimal_base_class_serialization<T, traits::has_minimal_input_serialization, XMLInputArchive>::value ||
                                       traits::has_minimal_input_serialization<T, XMLInputArchive>::value> = traits::sfinae> inline
  void epilogue( XMLInputArchive & ar, T const & )
  {
    ar.finishNode();
  }

  // ######################################################################
  // Common XMLArchive serialization functions
  // ######################################################################

  template <class T> inline
  void CEREAL_SAVE_FUNCTION_NAME( XMLOutputArchive & ar, NameValuePair<T> const & t )
  {
    ar.setNextName( t.name );
    ar( t.value );
  }

  template <class T> inline
  void CEREAL_LOAD_FUNCTION_NAME( XMLInputArchive & ar, NameValuePair<T> & t )
  {
    ar.setNextName( t.name );
    ar( t.value );
  }

  // ######################################################################
  template <class T> inline
  void CEREAL_SAVE_FUNCTION_NAME( XMLOutputArchive &, SizeTag<T> const & )
  { }

  template <class T> inline
  void CEREAL_LOAD_FUNCTION_NAME( XMLInputArchive & ar, SizeTag<T> & st )
  {
    ar.loadSize( st.size );
  }

  // ######################################################################
  template <class T, traits::EnableIf<std::is_arithmetic<T>::value> = traits::sfinae> inline
  void CEREAL_SAVE_FUNCTION_NAME(XMLOutputArchive & ar, T const & t)
  {
    ar.saveValue( t );
  }

  template <class T, traits::EnableIf<std::is_arithmetic<T>::value> = traits::sfinae> inline
  void CEREAL_LOAD_FUNCTION_NAME(XMLInputArchive & ar, T & t)
  {
    ar.loadValue( t );
  }

  // ######################################################################
  template<class CharT, class Traits, class Alloc> inline
  void CEREAL_SAVE_FUNCTION_NAME(XMLOutputArchive & ar, std::basic_string<CharT, Traits, Alloc> const & str)
  {
    ar.saveValue( str );
  }

  template<class CharT, class Traits, class Alloc> inline
  void CEREAL_LOAD_FUNCTION_NAME(XMLInputArchive & ar, std::basic_string<CharT, Traits, Alloc> & str)
  {
    ar.loadValue( str );
  }
} // namespace cereal

// register archives for polymorphic support
CEREAL_REGISTER_ARCHIVE(cereal::XMLOutputArchive)
CEREAL_REGISTER_ARCHIVE(cereal::XMLInputArchive)

// tie input and output archives together
CEREAL_SETUP_ARCHIVE_TRAITS(cereal::XMLInputArchive, cereal::XMLOutputArchive)

#endif // CEREAL_ARCHIVES_XML_HPP_