Line data    Source code

       1             : // Copyright (c) 2019-2022 The Bitcoin Core developers
       2             : // Distributed under the MIT software license, see the accompanying
       3             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4             : 
       5             : #ifndef BITCOIN_COMMON_SETTINGS_H
       6             : #define BITCOIN_COMMON_SETTINGS_H
       7             : 
       8             : #include <util/fs.h>
       9             : 
      10             : #include <cstddef>
      11             : #include <map>
      12             : #include <string>
      13             : #include <vector>
      14             : 
      15             : class UniValue;
      16             : 
      17             : namespace common {
      18             : 
      19             : //! Settings value type (string/integer/boolean/null variant).
      20             : //!
      21             : //! @note UniValue is used here for convenience and because it can be easily
      22             : //!       serialized in a readable format. But any other variant type that can
      23             : //!       be assigned strings, int64_t, and bool values and has get_str(),
      24             : //!       getInt<int64_t>(), get_bool(), isNum(), isBool(), isFalse(), isTrue() and
      25             : //!       isNull() methods can be substituted if there's a need to move away
      26             : //!       from UniValue. (An implementation with boost::variant was posted at
      27             : //!       https://github.com/bitcoin/bitcoin/pull/15934/files#r337691812)
      28             : using SettingsValue = UniValue;
      29             : 
      30             : //! Stored settings. This struct combines settings from the command line, a
      31             : //! read-only configuration file, and a read-write runtime settings file.
      32             : struct Settings {
      33             :     //! Map of setting name to forced setting value.
      34             :     std::map<std::string, SettingsValue> forced_settings;
      35             :     //! Map of setting name to list of command line values.
      36             :     std::map<std::string, std::vector<SettingsValue>> command_line_options;
      37             :     //! Map of setting name to read-write file setting value.
      38             :     std::map<std::string, SettingsValue> rw_settings;
      39             :     //! Map of config section name and setting name to list of config file values.
      40             :     std::map<std::string, std::map<std::string, std::vector<SettingsValue>>> ro_config;
      41             : };
      42             : 
      43             : //! Read settings file.
      44             : bool ReadSettings(const fs::path& path,
      45             :     std::map<std::string, SettingsValue>& values,
      46             :     std::vector<std::string>& errors);
      47             : 
      48             : //! Write settings file.
      49             : bool WriteSettings(const fs::path& path,
      50             :     const std::map<std::string, SettingsValue>& values,
      51             :     std::vector<std::string>& errors);
      52             : 
      53             : //! Get settings value from combined sources: forced settings, command line
      54             : //! arguments, runtime read-write settings, and the read-only config file.
      55             : //!
      56             : //! @param ignore_default_section_config - ignore values in the default section
      57             : //!                                        of the config file (part before any
      58             : //!                                        [section] keywords)
      59             : //! @param ignore_nonpersistent - ignore non-persistent settings values (forced
      60             : //!                               settings values and values specified on the
      61             : //!                               command line). Only return settings in the
      62             : //!                               read-only config and read-write settings
      63             : //!                               files.
      64             : //! @param get_chain_type - enable special backwards compatible behavior
      65             : //!                         for GetChainType
      66             : SettingsValue GetSetting(const Settings& settings,
      67             :     const std::string& section,
      68             :     const std::string& name,
      69             :     bool ignore_default_section_config,
      70             :     bool ignore_nonpersistent,
      71             :     bool get_chain_type);
      72             : 
      73             : //! Get combined setting value similar to GetSetting(), except if setting was
      74             : //! specified multiple times, return a list of all the values specified.
      75             : std::vector<SettingsValue> GetSettingsList(const Settings& settings,
      76             :     const std::string& section,
      77             :     const std::string& name,
      78             :     bool ignore_default_section_config);
      79             : 
      80             : //! Return true if a setting is set in the default config file section, and not
      81             : //! overridden by a higher priority command-line or network section value.
      82             : //!
      83             : //! This is used to provide user warnings about values that might be getting
      84             : //! ignored unintentionally.
      85             : bool OnlyHasDefaultSectionSetting(const Settings& settings, const std::string& section, const std::string& name);
      86             : 
      87             : //! Accessor for list of settings that skips negated values when iterated over.
      88             : //! The last boolean `false` value in the list and all earlier values are
      89             : //! considered negated.
      90             : struct SettingsSpan {
      91             :     explicit SettingsSpan() = default;
      92        3179 :     explicit SettingsSpan(const SettingsValue& value) noexcept : SettingsSpan(&value, 1) {}
      93        3940 :     explicit SettingsSpan(const SettingsValue* data, size_t size) noexcept : data(data), size(size) {}
      94             :     explicit SettingsSpan(const std::vector<SettingsValue>& vec) noexcept;
      95             :     const SettingsValue* begin() const; //!< Pointer to first non-negated value.
      96             :     const SettingsValue* end() const;   //!< Pointer to end of values.
      97             :     bool empty() const;                 //!< True if there are any non-negated values.
      98             :     bool last_negated() const;          //!< True if the last value is negated.
      99             :     size_t negated() const;             //!< Number of negated values.
     100             : 
     101             :     const SettingsValue* data = nullptr;
     102             :     size_t size = 0;
     103             : };
     104             : 
     105             : //! Map lookup helper.
     106             : template <typename Map, typename Key>
     107      679665 : auto FindKey(Map&& map, Key&& key) -> decltype(&map.at(key))
     108             : {
     109      679665 :     auto it = map.find(key);
     110      679665 :     return it == map.end() ? nullptr : &it->second;
     111           0 : }
     112             : 
     113             : } // namespace common
     114             : 
     115             : #endif // BITCOIN_COMMON_SETTINGS_H