1 // Copyright (c) 2019-2020 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_UTIL_SETTINGS_H 6 #define BITCOIN_UTIL_SETTINGS_H 7 8 #include <fs.h> 9 10 #include <map> 11 #include <string> 12 #include <vector> 13 14 class UniValue; 15 16 namespace util { 17 18 //! Settings value type (string/integer/boolean/null variant). 19 //! 20 //! @note UniValue is used here for convenience and because it can be easily 21 //! serialized in a readable format. But any other variant type that can 22 //! be assigned strings, int64_t, and bool values and has get_str(), 23 //! get_int64(), get_bool(), isNum(), isBool(), isFalse(), isTrue() and 24 //! isNull() methods can be substituted if there's a need to move away 25 //! from UniValue. (An implementation with boost::variant was posted at 26 //! https://github.com/bitcoin/bitcoin/pull/15934/files#r337691812) 27 using SettingsValue = UniValue; 28 29 //! Stored settings. This struct combines settings from the command line, a 30 //! read-only configuration file, and a read-write runtime settings file. 31 struct Settings { 32 //! Map of setting name to forced setting value. 33 std::map<std::string, SettingsValue> forced_settings; 34 //! Map of setting name to list of command line values. 35 std::map<std::string, std::vector<SettingsValue>> command_line_options; 36 //! Map of setting name to read-write file setting value. 37 std::map<std::string, SettingsValue> rw_settings; 38 //! Map of config section name and setting name to list of config file values. 39 std::map<std::string, std::map<std::string, std::vector<SettingsValue>>> ro_config; 40 }; 41 42 //! Read settings file. 43 bool ReadSettings(const fs::path& path, 44 std::map<std::string, SettingsValue>& values, 45 std::vector<std::string>& errors); 46 47 //! Write settings file. 48 bool WriteSettings(const fs::path& path, 49 const std::map<std::string, SettingsValue>& values, 50 std::vector<std::string>& errors); 51 52 //! Get settings value from combined sources: forced settings, command line 53 //! arguments, runtime read-write settings, and the read-only config file. 54 //! 55 //! @param ignore_default_section_config - ignore values in the default section 56 //! of the config file (part before any 57 //! [section] keywords) 58 //! @param get_chain_name - enable special backwards compatible behavior 59 //! for GetChainName 60 SettingsValue GetSetting(const Settings& settings, 61 const std::string& section, 62 const std::string& name, 63 bool ignore_default_section_config, 64 bool get_chain_name); 65 66 //! Get combined setting value similar to GetSetting(), except if setting was 67 //! specified multiple times, return a list of all the values specified. 68 std::vector<SettingsValue> GetSettingsList(const Settings& settings, 69 const std::string& section, 70 const std::string& name, 71 bool ignore_default_section_config); 72 73 //! Return true if a setting is set in the default config file section, and not 74 //! overridden by a higher priority command-line or network section value. 75 //! 76 //! This is used to provide user warnings about values that might be getting 77 //! ignored unintentionally. 78 bool OnlyHasDefaultSectionSetting(const Settings& settings, const std::string& section, const std::string& name); 79 80 //! Accessor for list of settings that skips negated values when iterated over. 81 //! The last boolean `false` value in the list and all earlier values are 82 //! considered negated. 83 struct SettingsSpan { 84 explicit SettingsSpan() = default; SettingsSpanSettingsSpan85 explicit SettingsSpan(const SettingsValue& value) noexcept : SettingsSpan(&value, 1) {} SettingsSpanSettingsSpan86 explicit SettingsSpan(const SettingsValue* data, size_t size) noexcept : data(data), size(size) {} 87 explicit SettingsSpan(const std::vector<SettingsValue>& vec) noexcept; 88 const SettingsValue* begin() const; //!< Pointer to first non-negated value. 89 const SettingsValue* end() const; //!< Pointer to end of values. 90 bool empty() const; //!< True if there are any non-negated values. 91 bool last_negated() const; //!< True if the last value is negated. 92 size_t negated() const; //!< Number of negated values. 93 94 const SettingsValue* data = nullptr; 95 size_t size = 0; 96 }; 97 98 //! Map lookup helper. 99 template <typename Map, typename Key> 100 auto FindKey(Map&& map, Key&& key) -> decltype(&map.at(key)) 101 { 102 auto it = map.find(key); 103 return it == map.end() ? nullptr : &it->second; 104 } 105 106 } // namespace util 107 108 #endif // BITCOIN_UTIL_SETTINGS_H 109