ceph/src/seastar/include/seastar/core/app-template.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright (C) 2014 Cloudius Systems, Ltd.
  20  */
  21 #pragma once
  22
  23 #include <boost/program_options.hpp>
  24 #include <functional>
  25 #include <seastar/core/future.hh>
  26 #include <seastar/core/sstring.hh>
  27 #include <chrono>
  28
  29 namespace seastar {
  30
  31 class app_template {
  32 public:
  33     struct config {
  34         /// The name of the application.
  35         ///
  36         /// Will be used in the --help output to distinguish command line args
  37         /// registered by the application, as opposed to those registered by
  38         /// seastar and its subsystems.
  39         sstring name = "App";
  40         /// The description of the application.
  41         ///
  42         /// Will be printed on the top of the --help output. Lines should be
  43         /// hard-wrapped for 80 chars.
  44         sstring description = "";
  45         std::chrono::duration<double> default_task_quota = std::chrono::microseconds(500);
  46         /// \brief Handle SIGINT/SIGTERM by calling reactor::stop()
  47         ///
  48         /// When true, Seastar will set up signal handlers for SIGINT/SIGTERM that call
  49         /// reactor::stop(). The reactor will then execute callbacks installed by
  50         /// reactor::at_exit().
  51         ///
  52         /// When false, Seastar will not set up signal handlers for SIGINT/SIGTERM
  53         /// automatically. The default behavior (terminate the program) will be kept.
  54         /// You can adjust the behavior of SIGINT/SIGTERM by installing signal handlers
  55         /// via reactor::handle_signal().
  56         bool auto_handle_sigint_sigterm = true;
  57         config() {}
  58     };
  59
  60     using configuration_reader = std::function<void (boost::program_options::variables_map&)>;
  61 private:
  62     config _cfg;
  63     boost::program_options::options_description _opts;
  64     boost::program_options::options_description _opts_conf_file;
  65     boost::program_options::positional_options_description _pos_opts;
  66     std::optional<boost::program_options::variables_map> _configuration;
  67     configuration_reader _conf_reader;
  68
  69     configuration_reader get_default_configuration_reader();
  70 public:
  71     struct positional_option {
  72         const char* name;
  73         const boost::program_options::value_semantic* value_semantic;
  74         const char* help;
  75         int max_count;
  76     };
  77 public:
  78     explicit app_template(config cfg = config());
  79
  80     boost::program_options::options_description& get_options_description();
  81     boost::program_options::options_description& get_conf_file_options_description();
  82     boost::program_options::options_description_easy_init add_options();
  83     void add_positional_options(std::initializer_list<positional_option> options);
  84     boost::program_options::variables_map& configuration();
  85     int run_deprecated(int ac, char ** av, std::function<void ()>&& func);
  86
  87     void set_configuration_reader(configuration_reader conf_reader);
  88
  89     // Runs given function and terminates the application when the future it
  90     // returns resolves. The value with which the future resolves will be
  91     // returned by this function.
  92     int run(int ac, char ** av, std::function<future<int> ()>&& func);
  93
  94     // Like run() which takes std::function<future<int>()>, but returns
  95     // with exit code 0 when the future returned by func resolves
  96     // successfully.
  97     int run(int ac, char ** av, std::function<future<> ()>&& func);
  98 };
  99
 100 }