YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

// Copyright (c) YugaByte, Inc.

//

// Licensed 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.

//

#ifndef YB_TOOLS_TOOL_ARGUMENTS_H

#define YB_TOOLS_TOOL_ARGUMENTS_H

#include <boost/preprocessor/seq/for_each.hpp>

#include <boost/program_options.hpp>

#include "yb/util/result.h"

// Framework for creating command line tool with multiple subcommands.

// Usage:

// 1) Define actions list for this tool:

// #define MY_TOOL_ACTIONS (Help)(Action1)(Action2)

// 2) Create enum for actions:

// YB_DEFINE_ENUM(MyToolAction, MY_TOOL_ACTIONS);

// 3) For each action define required types and functions:

// 3a) Action arguments:

// struct ActionArguments {

//   int arg1;

//   std::vector<std::string> arg2;

// };

// 3b) Action arguments options:

// const std::string kAction1Description = "Here goes description for action1";

// std::unique_ptr<OptionsDescription> Action1Options() {

//   auto result = std::make_unique<OptionsDescriptionImpl<Action1Arguments>>(

//       kAction1Description);

//   result->desc.add_options()

//       ("arg1", boost::program_options::value(&result->args.arg1)->required(),

//        "Required argument")

//       ("arg2", boost::program_options::value(&result->args.arg2), "Repeatable argument");

//   return result;

// }

// 3c) Action implementation:

// CHECKED_STATUS ApplyPatchExecute(const ApplyPatchArguments& args) {

//   ApplyPatch apply_patch;

//   return apply_patch.Execute(args);

// }

// 4) Bind actions with framework: YB_TOOL_ARGUMENTS(MyToolAction, MY_TOOL_ACTIONS);

// 5) Run framework from main function:

// return yb::tools::ExecuteTool<yb::tools::MyToolAction>(argc, argv);

namespace yb {

namespace tools {

template <class Action>

std::string OptionName(Action action) {

  auto name = ToString(action);

  std::string result;

  for (char ch : name) {

    if (std::isupper(ch)) {

      if (!result.empty()) {

        result += '-';

      }

      result += std::tolower(ch);

    } else {

      result += ch;

    }

  }

  return result;

}

template <class Action>

Result<Action> ActionByName(const std::string& name) {

  for (auto action : List(static_cast<Action*>(nullptr))) {

    if (OptionName(action) == name) {

      return action;

    }

  }

  return STATUS_FORMAT(InvalidArgument, "Unknown command: $0", name);

}

template <class Action>

void ShowHelp(Action action) {

  auto options = CreateOptionsDescription(action);

  std::cout << options->desc << std::endl;

}

template <class Action>

void ShowCommands() {

  std::cout << "Commands:" << std::endl;

  size_t max_name_len = 0;

  for (auto action : List(static_cast<Action*>(nullptr))) {

    max_name_len = std::max(max_name_len, OptionName(action).size());

  }

  max_name_len += 3;

  for (auto action : List(static_cast<Action*>(nullptr))) {

    auto current_name = OptionName(action);

    std::cout << "  " << current_name << std::string(max_name_len - current_name.length(), ' ')

              << Description(action) << std::endl;

  }

}

struct OptionsDescription {

  boost::program_options::positional_options_description positional;

  boost::program_options::options_description desc;

  boost::program_options::options_description hidden;

  explicit OptionsDescription(const std::string& caption) : desc(caption) {}

  virtual ~OptionsDescription() = default;

};

template<class Arguments>

struct OptionsDescriptionImpl : OptionsDescription {

  Arguments args;

  explicit OptionsDescriptionImpl(const std::string& caption) : OptionsDescription(caption) {}

Unexecuted instantiation: _ZN2yb5tools22OptionsDescriptionImplINS0_13HelpArgumentsEEC2ERKNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEE

Unexecuted instantiation: _ZN2yb5tools22OptionsDescriptionImplINS0_19ChangeTimeArgumentsEEC2ERKNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEE

Unexecuted instantiation: _ZN2yb5tools22OptionsDescriptionImplINS0_19ApplyPatchArgumentsEEC2ERKNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEE

};

#define YB_TOOL_ARGUMENTS_DESCRIPTION(x, enum_name, elem) \

  case enum_name::elem: return BOOST_PP_CAT(k, BOOST_PP_CAT(elem, Description));

#define YB_TOOL_ARGUMENTS_CREATE_OPTIONS(x, enum_name, elem) \

  case enum_name::elem: return BOOST_PP_CAT(elem, Options)();

#define YB_TOOL_ARGUMENTS_EXECUTE(x, enum_name, elem) \

  case enum_name::elem: \

    return BOOST_PP_CAT(elem, Execute)( \

        static_cast<const OptionsDescriptionImpl<BOOST_PP_CAT(elem, Arguments)>&>( \

            description).args);

#define YB_TOOL_ARGUMENTS(enum_name, actions) \

  const std::string& Description(enum_name action) { \

    switch (action) { \

      BOOST_PP_SEQ_FOR_EACH(YB_TOOL_ARGUMENTS_DESCRIPTION, enum_name, actions); \

    } \

    FATAL_INVALID_ENUM_VALUE(enum_name, action); \

  } \

  std::unique_ptr<OptionsDescription> CreateOptionsDescription(enum_name action) { \

    switch (action) { \

      BOOST_PP_SEQ_FOR_EACH(YB_TOOL_ARGUMENTS_CREATE_OPTIONS, enum_name, actions); \

    } \

    FATAL_INVALID_ENUM_VALUE(enum_name, action); \

  } \

  CHECKED_STATUS Execute(enum_name action, const OptionsDescription& description) { \

    switch (action) { \

      BOOST_PP_SEQ_FOR_EACH(YB_TOOL_ARGUMENTS_EXECUTE, enum_name, actions); \

    } \

    FATAL_INVALID_ENUM_VALUE(enum_name, action); \

  }

inline std::string GetCommand(int argc, char** argv) {

  return argc < 2 ? "" : argv[1];

}

template <class Action>

int ExecuteTool(int argc, char** argv) {

  std::string cmd = GetCommand(argc, argv);

  if (cmd.empty()) {

    ShowCommands<Action>();

    return 0;

  }

  auto action = ActionByName<Action>(cmd);

  if (!action.ok()) {

    std::cerr << action.status().message().ToBuffer() << std::endl;

    return 1;

  }

  try {

    auto options = CreateOptionsDescription(*action);

    boost::program_options::command_line_parser parser(argc - 1, argv + 1);

    boost::program_options::options_description descriptions;

    descriptions.add(options->desc);

    descriptions.add(options->hidden);

    parser.options(descriptions).positional(options->positional);

    auto parsed = parser.run();

    boost::program_options::variables_map variables_map;

    boost::program_options::store(parsed, variables_map);

    boost::program_options::notify(variables_map);

    auto status = Execute(*action, *options);

    if (!status.ok()) {

      std::cerr << status.message().ToBuffer() << std::endl;

      return 1;

    }

    return 0;

  } catch (std::exception& exc) {

    std::cerr << exc.what() << std::endl;

    ShowHelp(*action);

    return 1;

  }

  return 0;

}

} // namespace tools

} // namespace yb

#endif // YB_TOOLS_TOOL_ARGUMENTS_H