core-framework/include/core/ObjectFactory.h

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <string>
#include <memory>
#include <utility>
#include "core/ClassName.h"
#include "minifi-cpp/core/ObjectFactory.h"

namespace org::apache::nifi::minifi::core {

class ObjectFactoryImpl : public ObjectFactory {
 public:
  explicit ObjectFactoryImpl(std::string group) : group_(std::move(group)) {}

  ObjectFactoryImpl() = default;

  std::string getGroupName() const override {
    return group_;
  }

 protected:
  std::string group_;
};

/**
 * Factory that is used as an interface for
 * creating processors from shared objects.
 */
template<class T>
class DefaultObjectFactory : public ObjectFactoryImpl {
 public:
  DefaultObjectFactory()
      : className(core::className<T>()) {
  }

  explicit DefaultObjectFactory(std::string group_name)
      : ObjectFactoryImpl(std::move(group_name)),
      className(core::className<T>()) {
  }

  /**
   * Create a unique pointer to a new processor.
   */
  std::unique_ptr<CoreComponent> create(const std::string &name) override {
    return std::make_unique<T>(name);
  }

  /**
   * Create a unique pointer to a new processor.
   */
  std::unique_ptr<CoreComponent> create(const std::string &name, const utils::Identifier &uuid) override {
    return std::make_unique<T>(name, uuid);
  }

  /**
   * Create a raw pointer to a new processor.
   */
  gsl::owner<CoreComponent*> createRaw(const std::string &name) override {
    const gsl::owner<T*> ptr = new T(name);
    if (const auto converted = dynamic_cast<CoreComponent*>(ptr)) {
      return converted;
    }
    delete ptr;
    return nullptr;
  }

  /**
   * Create a raw pointer to a new processor.
   */
  gsl::owner<CoreComponent*> createRaw(const std::string &name, const utils::Identifier &uuid) override {
    const gsl::owner<T*> ptr = new T(name, uuid);
    if (const auto converted = dynamic_cast<CoreComponent*>(ptr)) {
      return converted;
    }
    delete ptr;
    return nullptr;
  }

  /**
   * Gets the class name for the object
   * @return class name for the processor.
   */
  std::string getClassName() override {
    return className;
  }

 protected:
  std::string className;
};

}  // namespace org::apache::nifi::minifi::core