From 9c69cfe4c54e38edd2f54303be2f8a53dcf5bad8 Mon Sep 17 00:00:00 2001 From: Russell Yanofsky Date: Sun, 28 Apr 2019 19:08:26 -0400 Subject: Add /settings.json persistent settings storage. Persistent settings are used in followup PRs #15936 to unify gui settings between bitcoin-qt and bitcoind, and #15937 to add a load_on_startup flag to the loadwallet RPC and maintain a dynamic list of wallets that should be loaded on startup that also can be shared between bitcoind and bitcoin-qt. --- src/util/settings.cpp | 7 ++++- src/util/settings.h | 8 +++-- src/util/system.cpp | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/util/system.h | 34 +++++++++++++++++++++ 4 files changed, 127 insertions(+), 4 deletions(-) (limited to 'src/util') diff --git a/src/util/settings.cpp b/src/util/settings.cpp index 34894e994e..b92b1d30c3 100644 --- a/src/util/settings.cpp +++ b/src/util/settings.cpp @@ -13,12 +13,13 @@ namespace { enum class Source { FORCED, COMMAND_LINE, + RW_SETTINGS, CONFIG_FILE_NETWORK_SECTION, CONFIG_FILE_DEFAULT_SECTION }; //! Merge settings from multiple sources in precedence order: -//! Forced config > command line > config file network-specific section > config file default section +//! Forced config > command line > read-write settings file > config file network-specific section > config file default section //! //! This function is provided with a callback function fn that contains //! specific logic for how to merge the sources. @@ -33,6 +34,10 @@ static void MergeSettings(const Settings& settings, const std::string& section, if (auto* values = FindKey(settings.command_line_options, name)) { fn(SettingsSpan(*values), Source::COMMAND_LINE); } + // Merge in the read-write settings + if (const SettingsValue* value = FindKey(settings.rw_settings, name)) { + fn(SettingsSpan(*value), Source::RW_SETTINGS); + } // Merge in the network-specific section of the config file if (!section.empty()) { if (auto* map = FindKey(settings.ro_config, section)) { diff --git a/src/util/settings.h b/src/util/settings.h index ee160e1ac8..ed36349232 100644 --- a/src/util/settings.h +++ b/src/util/settings.h @@ -26,13 +26,15 @@ namespace util { //! https://github.com/bitcoin/bitcoin/pull/15934/files#r337691812) using SettingsValue = UniValue; -//! Stored bitcoin settings. This struct combines settings from the command line -//! and a read-only configuration file. +//! 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 forced_settings; //! Map of setting name to list of command line values. std::map> command_line_options; + //! Map of setting name to read-write file setting value. + std::map rw_settings; //! Map of config section name and setting name to list of config file values. std::map>> ro_config; }; @@ -48,7 +50,7 @@ bool WriteSettings(const fs::path& path, std::vector& errors); //! Get settings value from combined sources: forced settings, command line -//! arguments and the read-only config file. +//! 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 diff --git a/src/util/system.cpp b/src/util/system.cpp index 7e7ba840cd..8164e884b1 100644 --- a/src/util/system.cpp +++ b/src/util/system.cpp @@ -73,6 +73,7 @@ const int64_t nStartupTime = GetTime(); const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf"; +const char * const BITCOIN_SETTINGS_FILENAME = "settings.json"; ArgsManager gArgs; @@ -372,6 +373,84 @@ bool ArgsManager::IsArgSet(const std::string& strArg) const return !GetSetting(strArg).isNull(); } +bool ArgsManager::InitSettings(std::string& error) +{ + if (!GetSettingsPath()) { + return true; // Do nothing if settings file disabled. + } + + std::vector errors; + if (!ReadSettingsFile(&errors)) { + error = strprintf("Failed loading settings file:\n- %s\n", Join(errors, "\n- ")); + return false; + } + if (!WriteSettingsFile(&errors)) { + error = strprintf("Failed saving settings file:\n- %s\n", Join(errors, "\n- ")); + return false; + } + return true; +} + +bool ArgsManager::GetSettingsPath(fs::path* filepath, bool temp) const +{ + if (IsArgNegated("-settings")) { + return false; + } + if (filepath) { + std::string settings = GetArg("-settings", BITCOIN_SETTINGS_FILENAME); + *filepath = fs::absolute(temp ? settings + ".tmp" : settings, GetDataDir(/* net_specific= */ true)); + } + return true; +} + +static void SaveErrors(const std::vector errors, std::vector* error_out) +{ + for (const auto& error : errors) { + if (error_out) { + error_out->emplace_back(error); + } else { + LogPrintf("%s\n", error); + } + } +} + +bool ArgsManager::ReadSettingsFile(std::vector* errors) +{ + fs::path path; + if (!GetSettingsPath(&path, /* temp= */ false)) { + return true; // Do nothing if settings file disabled. + } + + LOCK(cs_args); + m_settings.rw_settings.clear(); + std::vector read_errors; + if (!util::ReadSettings(path, m_settings.rw_settings, read_errors)) { + SaveErrors(read_errors, errors); + return false; + } + return true; +} + +bool ArgsManager::WriteSettingsFile(std::vector* errors) const +{ + fs::path path, path_tmp; + if (!GetSettingsPath(&path, /* temp= */ false) || !GetSettingsPath(&path_tmp, /* temp= */ true)) { + throw std::logic_error("Attempt to write settings file when dynamic settings are disabled."); + } + + LOCK(cs_args); + std::vector write_errors; + if (!util::WriteSettings(path_tmp, m_settings.rw_settings, write_errors)) { + SaveErrors(write_errors, errors); + return false; + } + if (!RenameOver(path_tmp, path)) { + SaveErrors({strprintf("Failed renaming settings file %s to %s\n", path_tmp.string(), path.string())}, errors); + return false; + } + return true; +} + bool ArgsManager::IsArgNegated(const std::string& strArg) const { return GetSetting(strArg).isFalse(); @@ -893,6 +972,9 @@ void ArgsManager::LogArgs() const for (const auto& section : m_settings.ro_config) { logArgsPrefix("Config file arg:", section.first, section.second); } + for (const auto& setting : m_settings.rw_settings) { + LogPrintf("Setting file arg: %s = %s\n", setting.first, setting.second.write()); + } logArgsPrefix("Command-line arg:", "", m_settings.command_line_options); } diff --git a/src/util/system.h b/src/util/system.h index a5eea5dfab..0bd14cc9ea 100644 --- a/src/util/system.h +++ b/src/util/system.h @@ -41,6 +41,7 @@ int64_t GetStartupTime(); extern const char * const BITCOIN_CONF_FILENAME; +extern const char * const BITCOIN_SETTINGS_FILENAME; void SetupEnvironment(); bool SetupNetworking(); @@ -333,6 +334,39 @@ public: */ Optional GetArgFlags(const std::string& name) const; + /** + * Read and update settings file with saved settings. This needs to be + * called after SelectParams() because the settings file location is + * network-specific. + */ + bool InitSettings(std::string& error); + + /** + * Get settings file path, or return false if read-write settings were + * disabled with -nosettings. + */ + bool GetSettingsPath(fs::path* filepath = nullptr, bool temp = false) const; + + /** + * Read settings file. Push errors to vector, or log them if null. + */ + bool ReadSettingsFile(std::vector* errors = nullptr); + + /** + * Write settings file. Push errors to vector, or log them if null. + */ + bool WriteSettingsFile(std::vector* errors = nullptr) const; + + /** + * Access settings with lock held. + */ + template + void LockSettings(Fn&& fn) + { + LOCK(cs_args); + fn(m_settings); + } + /** * Log the config file options and the command line arguments, * useful for troubleshooting. -- cgit v1.2.3