Method CreateObjectData

src/ffi/extra/serialization.cc:197–251

create the data for the object, if the type has a custom data to json function, use it. otherwise, we go over the fields and create the data.

  // create the data for the object, if the type has a custom data to json function,
  // use it. otherwise, we go over the fields and create the data.
  json::Value CreateObjectData(const Any& value) {
    static reflection::TypeAttrColumn data_to_json =
        reflection::TypeAttrColumn(reflection::type_attr::kDataToJson);
    if (data_to_json[value.type_index()] != nullptr) {
      return data_to_json[value.type_index()].cast<Function>()(value);
    }
    // NOTE: invariant: lhs and rhs are already the same type
    const TVMFFITypeInfo* type_info = TVMFFIGetTypeInfo(value.type_index());
    if (!HasCreator(type_info)) {
      TVM_FFI_THROW(TypeError) << "Type `" << String(type_info->type_key)
                               << "` does not support ToJSONGraph "
                               << "(no native creator or __ffi_new__ type attr)";
    }
    const Object* obj = value.cast<const Object*>();
    json::Object data;
    // go over the content and hash the fields
    reflection::ForEachFieldInfo(type_info, [&](const TVMFFIFieldInfo* field_info) {
      // get the field value from both side
      reflection::FieldGetter getter(field_info);
      Any field_value = getter(obj);
      int field_static_type_index = field_info->field_static_type_index;
      String field_name(field_info->name);
      // for static field index that are known, we can directly set the field value.
      switch (field_static_type_index) {
        case TypeIndex::kTVMFFINone: {
          data.Set(field_name, nullptr);
          break;
        }
        case TypeIndex::kTVMFFIBool: {
          data.Set(field_name, details::AnyUnsafe::CopyFromAnyViewAfterCheck<bool>(field_value));
          break;
        }
        case TypeIndex::kTVMFFIInt: {
          data.Set(field_name, details::AnyUnsafe::CopyFromAnyViewAfterCheck<int64_t>(field_value));
          break;
        }
        case TypeIndex::kTVMFFIFloat: {
          data.Set(field_name, details::AnyUnsafe::CopyFromAnyViewAfterCheck<double>(field_value));
          break;
        }
        case TypeIndex::kTVMFFIDataType: {
          DLDataType dtype = details::AnyUnsafe::CopyFromAnyViewAfterCheck<DLDataType>(field_value);
          data.Set(field_name, DLDataTypeToString(dtype));
          break;
        }
        default: {
          // for dynamic field index, we need need to put them onto nodes
          int64_t node_index = GetOrCreateNodeIndex(field_value);
          data.Set(field_name, node_index);
          break;
        }
      }
    });
    return data;
  }

  // maps the original value to the index of the node in the nodes_ array
  std::unordered_map<Any, int64_t, AnyHash, AnyEqual> node_index_map_;