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Diffstat (limited to 'src/common/settings.h')
-rw-r--r-- | src/common/settings.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/src/common/settings.h b/src/common/settings.h new file mode 100644 index 0000000000..0e9d376e23 --- /dev/null +++ b/src/common/settings.h @@ -0,0 +1,115 @@ +// Copyright (c) 2019-2022 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_COMMON_SETTINGS_H +#define BITCOIN_COMMON_SETTINGS_H + +#include <util/fs.h> + +#include <cstddef> +#include <map> +#include <string> +#include <vector> + +class UniValue; + +namespace common { + +//! Settings value type (string/integer/boolean/null variant). +//! +//! @note UniValue is used here for convenience and because it can be easily +//! serialized in a readable format. But any other variant type that can +//! be assigned strings, int64_t, and bool values and has get_str(), +//! getInt<int64_t>(), get_bool(), isNum(), isBool(), isFalse(), isTrue() and +//! isNull() methods can be substituted if there's a need to move away +//! from UniValue. (An implementation with boost::variant was posted at +//! https://github.com/bitcoin/bitcoin/pull/15934/files#r337691812) +using SettingsValue = UniValue; + +//! Stored settings. This struct combines settings from the command line, a +//! read-only configuration file, and a read-write runtime settings file. +struct Settings { + //! Map of setting name to forced setting value. + std::map<std::string, SettingsValue> forced_settings; + //! Map of setting name to list of command line values. + std::map<std::string, std::vector<SettingsValue>> command_line_options; + //! Map of setting name to read-write file setting value. + std::map<std::string, SettingsValue> rw_settings; + //! Map of config section name and setting name to list of config file values. + std::map<std::string, std::map<std::string, std::vector<SettingsValue>>> ro_config; +}; + +//! Read settings file. +bool ReadSettings(const fs::path& path, + std::map<std::string, SettingsValue>& values, + std::vector<std::string>& errors); + +//! Write settings file. +bool WriteSettings(const fs::path& path, + const std::map<std::string, SettingsValue>& values, + std::vector<std::string>& errors); + +//! Get settings value from combined sources: forced settings, command line +//! arguments, runtime read-write settings, and the read-only config file. +//! +//! @param ignore_default_section_config - ignore values in the default section +//! of the config file (part before any +//! [section] keywords) +//! @param ignore_nonpersistent - ignore non-persistent settings values (forced +//! settings values and values specified on the +//! command line). Only return settings in the +//! read-only config and read-write settings +//! files. +//! @param get_chain_type - enable special backwards compatible behavior +//! for GetChainType +SettingsValue GetSetting(const Settings& settings, + const std::string& section, + const std::string& name, + bool ignore_default_section_config, + bool ignore_nonpersistent, + bool get_chain_type); + +//! Get combined setting value similar to GetSetting(), except if setting was +//! specified multiple times, return a list of all the values specified. +std::vector<SettingsValue> GetSettingsList(const Settings& settings, + const std::string& section, + const std::string& name, + bool ignore_default_section_config); + +//! Return true if a setting is set in the default config file section, and not +//! overridden by a higher priority command-line or network section value. +//! +//! This is used to provide user warnings about values that might be getting +//! ignored unintentionally. +bool OnlyHasDefaultSectionSetting(const Settings& settings, const std::string& section, const std::string& name); + +//! Accessor for list of settings that skips negated values when iterated over. +//! The last boolean `false` value in the list and all earlier values are +//! considered negated. +struct SettingsSpan { + explicit SettingsSpan() = default; + explicit SettingsSpan(const SettingsValue& value) noexcept : SettingsSpan(&value, 1) {} + explicit SettingsSpan(const SettingsValue* data, size_t size) noexcept : data(data), size(size) {} + explicit SettingsSpan(const std::vector<SettingsValue>& vec) noexcept; + const SettingsValue* begin() const; //!< Pointer to first non-negated value. + const SettingsValue* end() const; //!< Pointer to end of values. + bool empty() const; //!< True if there are any non-negated values. + bool last_negated() const; //!< True if the last value is negated. + size_t negated() const; //!< Number of negated values. + + const SettingsValue* data = nullptr; + size_t size = 0; +}; + +//! Map lookup helper. +template <typename Map, typename Key> +auto FindKey(Map&& map, Key&& key) -> decltype(&map.at(key)) +{ + auto it = map.find(key); + return it == map.end() ? nullptr : &it->second; +} + +} // namespace common + +#endif // BITCOIN_COMMON_SETTINGS_H |