text: /**
   * 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 <utility>
  
  #include "utils/OptionalUtils.h"
  
  namespace org {
  namespace apache {
  namespace nifi {
  namespace minifi {
  namespace utils {
  
  class ChecksumCalculator {
   public:
    static constexpr const char* CHECKSUM_TYPE = "SHA256";
    static constexpr size_t LENGTH_OF_HASH_IN_BYTES = 32;
  
    void setFileLocation(const std::string& file_location);
    std::string getFileName() const;
    std::string getChecksum();
    void invalidateChecksum();
  
   private:
    static std::string computeChecksum(const std::string& file_location);
  
    utils::optional<std::string> file_location_;
    utils::optional<std::string> file_name_;
    utils::optional<std::string> checksum_;
  };
  
  inline void ChecksumCalculator::invalidateChecksum() {
    checksum_.reset();
  }
  
  }  // namespace utils
  }  // namespace minifi
  }  // namespace nifi
  }  // namespace apache
  }  // namespace org
  