Repository: bitcoin/bitcoin
File: src/init.cpp (C++)

Code before:
    const auto signetChainParams = CreateChainParams(argsman, ChainType::SIGNET);
    const auto regtestChainParams = CreateChainParams(argsman, ChainType::REGTEST);

    // Hidden Options
    std::vector<std::string> hidden_args = {
        "-dbcrashratio", "-forcecompactdb",
        // GUI args. These will be overwritten by SetupUIArgs for the GUI
        "-choosedatadir", "-lang=<lang>", "-min", "-resetguisettings", "-splash", "-uiplatform"};

    argsman.AddArg("-version", "Print version and exit", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#if HAVE_SYSTEM
    argsman.AddArg("-alertnotify=<cmd>", "Execute command when an alert is raised (%s in cmd is replaced by message)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif
    argsman.AddArg("-assumevalid=<hex>", strprintf("If this block is in the chain assume that it and its ancestors are valid and potentially skip their script verification (0 to verify all, default: %s, testnet: %s, signet: %s)", defaultChainParams->GetConsensus().defaultAssumeValid.GetHex(), testnetChainParams->GetConsensus().defaultAssumeValid.GetHex(), signetChainParams->GetConsensus().defaultAssumeValid.GetHex()), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-blocksdir=<dir>", "Specify directory to hold blocks subdirectory for *.dat files (default: <datadir>)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-fastprune", "Use smaller block files and lower minimum prune height for testing purposes", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
#if HAVE_SYSTEM
    argsman.AddArg("-blocknotify=<cmd>", "Execute command when the best block changes (%s in cmd is replaced by block hash)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif
    argsman.AddArg("-blockreconstructionextratxn=<n>", strprintf("Extra transactions to keep in memory for compact block reconstructions (default: %u)", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-blocksonly", strprintf("Whether to reject transactions from network peers. Automatic broadcast and rebroadcast of any transactions from inbound peers is disabled, unless the peer has the 'forcerelay' permission. RPC transactions are not affected. (default: %u)", DEFAULT_BLOCKSONLY), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-coinstatsindex", strprintf("Maintain coinstats index used by the gettxoutsetinfo RPC (default: %u)", DEFAULT_COINSTATSINDEX), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-conf=<file>", strprintf("Specify path to read-only configuration file. Relative paths will be prefixed by datadir location (only useable from command line, not configuration file) (default: %s)", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-datadir=<dir>", "Specify data directory", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-dbbatchsize", strprintf("Maximum database write batch size in bytes (default: %u)", nDefaultDbBatchSize), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::OPTIONS);
    argsman.AddArg("-dbcache=<n>", strprintf("Maximum database cache size <n> MiB (%d to %d, default: %d). Make sure you have enough RAM. In addition, unused mempool memory is shared for this cache (see -maxmempool).", nMinDbCache, nMaxDbCache, nDefaultDbCache), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-includeconf=<file>", "Specify additional configuration file, relative to the -datadir path (only useable from configuration file, not command line)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-allowignoredconf", strprintf("For backwards compatibility, treat an unused %s file in the datadir as a warning, not an error.", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-loadblock=<file>", "Imports blocks from external file on startup", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-maxmempool=<n>", strprintf("Keep the transaction memory pool below <n> megabytes (default: %u)", DEFAULT_MAX_MEMPOOL_SIZE_MB), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-maxorphantx=<n>", strprintf("Keep at most <n> unconnectable transactions in memory (default: %u)", DEFAULT_MAX_ORPHAN_TRANSACTIONS), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-mempoolexpiry=<n>", strprintf("Do not keep transactions in the mempool longer than <n> hours (default: %u)", DEFAULT_MEMPOOL_EXPIRY_HOURS), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-minimumchainwork=<hex>", strprintf("Minimum work assumed to exist on a valid chain in hex (default: %s, testnet: %s, signet: %s)", defaultChainParams->GetConsensus().nMinimumChainWork.GetHex(), testnetChainParams->GetConsensus().nMinimumChainWork.GetHex(), signetChainParams->GetConsensus().nMinimumChainWork.GetHex()), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::OPTIONS);
    argsman.AddArg("-par=<n>", strprintf("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)",
        -GetNumCores(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-persistmempool", strprintf("Whether to save the mempool on shutdown and load on restart (default: %u)", DEFAULT_PERSIST_MEMPOOL), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-pid=<file>", strprintf("Specify pid file. Relative paths will be prefixed by a net-specific datadir location. (default: %s)", BITCOIN_PID_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-prune=<n>", strprintf("Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex. "
            "Warning: Reverting this setting requires re-downloading the entire blockchain. "
            "(default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >=%u = automatically prune block files to stay under the specified target size in MiB)", MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-reindex", "Rebuild chain state and block index from the blk*.dat files on disk. This will also rebuild active optional indexes.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-reindex-chainstate", "Rebuild chain state from the currently indexed blocks. When in pruning mode or if blocks on disk might be corrupted, use full -reindex instead.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-settings=<file>", strprintf("Specify path to dynamic settings data file. Can be disabled with -nosettings. File is written at runtime and not meant to be edited by users (use %s instead for custom settings). Relative paths will be prefixed by datadir location. (default: %s)", BITCOIN_CONF_FILENAME, BITCOIN_SETTINGS_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#if HAVE_SYSTEM
    argsman.AddArg("-startupnotify=<cmd>", "Execute command on startup.", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-shutdownnotify=<cmd>", "Execute command immediately before beginning shutdown. The need for shutdown may be urgent, so be careful not to delay it long (if the command doesn't require interaction with the server, consider having it fork into the background).", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif
    argsman.AddArg("-txindex", strprintf("Maintain a full transaction index, used by the getrawtransaction rpc call (default: %u)", DEFAULT_TXINDEX), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-blockfilterindex=<type>",
                 strprintf("Maintain an index of compact filters by block (default: %s, values: %s).", DEFAULT_BLOCKFILTERINDEX, ListBlockFilterTypes()) +
                 " If <type> is not supplied or if <type> = 1, indexes for all known types are enabled.",

Review comment (performance):
While touching this help, I think the following would be much clearer (particularly `s/for/with`).

```suggestion
    argsman.AddArg("-dbcache=<n>", strprintf("Maximum database cache size <n> MiB (%d to %d, default: %d). Make sure you have enough RAM. In addition, unused memory allocated to the mempool is shared with this cache (see -maxmempool).", nMinDbCache, nMaxDbCache, nDefaultDbCache), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
```


Code after:

static boost::signals2::connection rpc_notify_block_change_connection;
static void OnRPCStarted()
{
    rpc_notify_block_change_connection = uiInterface.NotifyBlockTip_connect(std::bind(RPCNotifyBlockChange, std::placeholders::_2));
}

static void OnRPCStopped()
{
    rpc_notify_block_change_connection.disconnect();
    RPCNotifyBlockChange(nullptr);
    g_best_block_cv.notify_all();
    LogPrint(BCLog::RPC, "RPC stopped.\n");
}

void SetupServerArgs(ArgsManager& argsman)
{
    SetupHelpOptions(argsman);
    argsman.AddArg("-help-debug", "Print help message with debugging options and exit", ArgsManager::ALLOW_ANY, OptionsCategory::DEBUG_TEST); // server-only for now

    init::AddLoggingArgs(argsman);

    const auto defaultBaseParams = CreateBaseChainParams(ChainType::MAIN);
    const auto testnetBaseParams = CreateBaseChainParams(ChainType::TESTNET);
    const auto signetBaseParams = CreateBaseChainParams(ChainType::SIGNET);
    const auto regtestBaseParams = CreateBaseChainParams(ChainType::REGTEST);
    const auto defaultChainParams = CreateChainParams(argsman, ChainType::MAIN);
    const auto testnetChainParams = CreateChainParams(argsman, ChainType::TESTNET);
    const auto signetChainParams = CreateChainParams(argsman, ChainType::SIGNET);
    const auto regtestChainParams = CreateChainParams(argsman, ChainType::REGTEST);

    // Hidden Options
    std::vector<std::string> hidden_args = {
        "-dbcrashratio", "-forcecompactdb",
        // GUI args. These will be overwritten by SetupUIArgs for the GUI
        "-choosedatadir", "-lang=<lang>", "-min", "-resetguisettings", "-splash", "-uiplatform"};

    argsman.AddArg("-version", "Print version and exit", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#if HAVE_SYSTEM
    argsman.AddArg("-alertnotify=<cmd>", "Execute command when an alert is raised (%s in cmd is replaced by message)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif
    argsman.AddArg("-assumevalid=<hex>", strprintf("If this block is in the chain assume that it and its ancestors are valid and potentially skip their script verification (0 to verify all, default: %s, testnet: %s, signet: %s)", defaultChainParams->GetConsensus().defaultAssumeValid.GetHex(), testnetChainParams->GetConsensus().defaultAssumeValid.GetHex(), signetChainParams->GetConsensus().defaultAssumeValid.GetHex()), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-blocksdir=<dir>", "Specify directory to hold blocks subdirectory for *.dat files (default: <datadir>)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-fastprune", "Use smaller block files and lower minimum prune height for testing purposes", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
#if HAVE_SYSTEM
    argsman.AddArg("-blocknotify=<cmd>", "Execute command when the best block changes (%s in cmd is replaced by block hash)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
#endif
    argsman.AddArg("-blockreconstructionextratxn=<n>", strprintf("Extra transactions to keep in memory for compact block reconstructions (default: %u)", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-blocksonly", strprintf("Whether to reject transactions from network peers. Disables automatic broadcast and rebroadcast of transactions, unless the source peer has the 'forcerelay' permission. RPC transactions are not affected. (default: %u)", DEFAULT_BLOCKSONLY), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-coinstatsindex", strprintf("Maintain coinstats index used by the gettxoutsetinfo RPC (default: %u)", DEFAULT_COINSTATSINDEX), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
    argsman.AddArg("-conf=<file>", strprintf("Specify path to read-only configuration file. Relative paths will be prefixed by datadir location (only useable from command line, not configuration file) (default: %s)", BITCOIN_CONF_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);