text: /*
      Copyright (c) 2016, Taiga Nomi
      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 the tiny-dnn 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.
  */
  #pragma once
  
  #include <cereal/archives/json.hpp>
  #include <cereal/types/memory.hpp>
  #include <functional>
  #include <map>
  #include <memory>
  #include <string>
  #include <typeindex>
  
  #include "tiny_dnn/layers/layers.h"
  #include "tiny_dnn/util/macro.h"
  #include "tiny_dnn/util/nn_error.h"
  #include "tiny_dnn/util/serialization_functions.h"
  #include "tiny_dnn/util/serialization_layer_list.h"
  
  namespace tiny_dnn {
  
  template <typename OutputArchive>
  class serialization_helper {
   public:
    void register_saver(
      const std::string &name,
      std::function<void(OutputArchive &, const layer *)> func) {
      savers_[name] = [=](void *ar, const layer *l) {
        return func(*reinterpret_cast<OutputArchive *>(ar), l);
      };
    }
  
    template <typename T>
    void register_type(const std::string &name) {
      type_names_[typeid(T)] = name;
    }
  
    void save(const std::string &layer_name, OutputArchive &ar, const layer *l) {
      check_if_enabled();
  
      if (savers_.find(layer_name) == savers_.end()) {
        throw nn_error("Failed to save layer. Saver for " + layer_name +
                       " is not found.\n"
                       "Please use CNN_REGISTER_LAYER macro to register "
                       "appropriate saver.");
      }
  
      savers_[layer_name](reinterpret_cast<void *>(&ar), l);
    }
  
    const std::string &type_name(std::type_index index) const {
      if (type_names_.find(index) == type_names_.end()) {
        throw nn_error("Typename is not registered");
      }
      return type_names_.at(index);
    }
  
    static serialization_helper &get_instance() {
      static serialization_helper instance;
      return instance;
    }
  
   private:
    void check_if_enabled() const {
  #ifdef CNN_NO_SERIALIZATION
      static_assert(
        sizeof(OutputArchive) == 0,
        "You are using save functions, but serialization function is "
        "disabled "
        "in current configuration.\n\n"
        "You need to undef CNN_NO_SERIALIZATION to enable these functions.\n"
        "If you are using cmake, you can use -DUSE_SERIALIZER=ON "
        "option.\n\n");
  #endif
    }
  
    /** layer-type -> generator  */
    std::map<std::string, std::function<void(void *, const layer *)>> savers_;
  
    std::map<std::type_index, std::string> type_names_;
  
    template <typename T>
    static void save_layer_impl(OutputArchive &oa, const layer *layer);
  
    template <typename T>
    friend void register_layers(T *h);
  
    template <typename T>
    void register_layer(const char *layer_name) {
      register_type<T>(layer_name);
      register_saver(layer_name, save_layer_impl<T>);
    }
  
    serialization_helper() { register_layers(this); }
  
  };  // class serialization_helper
  
  template <typename OutputArchive>
  template <typename T>
  void serialization_helper<OutputArchive>::save_layer_impl(OutputArchive &oa,
                                                            const layer *layer) {
    oa(cereal::make_nvp(
      serialization_helper<OutputArchive>::get_instance().type_name(typeid(T)),
      *dynamic_cast<const T *>(layer)));
  }
  
  template <typename OutputArchive>
  void layer::save_layer(OutputArchive &oa, const layer &l) {
    const std::string &name =
      serialization_helper<OutputArchive>::get_instance().type_name(typeid(l));
    serialization_helper<OutputArchive>::get_instance().save(name, oa, &l);
  }
  
  template <class Archive>
  void layer::serialize_prolog(Archive &ar) {
    ar(cereal::make_nvp(
      "type",
      serialization_helper<Archive>::get_instance().type_name(typeid(*this))));
  }
  
  }  // namespace tiny_dnn
  