From cd31cdb6b174b1e8d6abcf46b33b4f39c96a7254 Mon Sep 17 00:00:00 2001 From: Steven Roose Date: Thu, 5 Dec 2019 20:29:16 +0000 Subject: [PATCH] Document the default values of configs --- lightning/src/util/config.rs | 57 +++++++++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 14 deletions(-) diff --git a/lightning/src/util/config.rs b/lightning/src/util/config.rs index 70ba6ae80..3c4ab77c1 100644 --- a/lightning/src/util/config.rs +++ b/lightning/src/util/config.rs @@ -4,6 +4,9 @@ use ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT}; /// Top-level config which holds ChannelHandshakeLimits and ChannelConfig. +/// +/// Default::default() provides sane defaults for most configurations +/// (but currently with 0 relay fees!) #[derive(Clone, Debug)] pub struct UserConfig { /// Channel config that we propose to our counterparty. @@ -15,7 +18,6 @@ pub struct UserConfig { } impl Default for UserConfig { - /// Provides sane defaults for most configurations (but with 0 relay fees!) fn default() -> Self { UserConfig { own_channel_config: ChannelHandshakeConfig::default(), @@ -26,28 +28,32 @@ impl Default for UserConfig { } /// Configuration we set when applicable. +/// +/// Default::default() provides sane defaults. #[derive(Clone, Debug)] pub struct ChannelHandshakeConfig { /// Confirmations we will wait for before considering the channel locked in. /// Applied only for inbound channels (see ChannelHandshakeLimits::max_minimum_depth for the /// equivalent limit applied to outbound channels). + /// + /// Default value: 6. pub minimum_depth: u32, /// Set to the amount of time we require our counterparty to wait to claim their money. /// /// It's one of the main parameter of our security model. We (or one of our watchtowers) MUST /// be online to check for peer having broadcast a revoked transaction to steal our funds /// at least once every our_to_self_delay blocks. - /// Default is BREAKDOWN_TIMEOUT, we enforce it as a minimum at channel opening so you can - /// tweak config to ask for more security, not less. /// /// Meanwhile, asking for a too high delay, we bother peer to freeze funds for nothing in /// case of an honest unilateral channel close, which implicitly decrease the economic value of /// our channel. + /// + /// Default value: BREAKDOWN_TIMEOUT (currently 144), we enforce it as a minimum at channel + /// opening so you can tweak config to ask for more security, not less. pub our_to_self_delay: u16, } impl Default for ChannelHandshakeConfig { - /// Provides sane defaults for `ChannelHandshakeConfig` fn default() -> ChannelHandshakeConfig { ChannelHandshakeConfig { minimum_depth: 6, @@ -61,23 +67,39 @@ impl Default for ChannelHandshakeConfig { /// These limits are only applied to our counterparty's limits, not our own. /// /// Use 0/::max_value() as appropriate to skip checking. +/// +/// Provides sane defaults for most configurations. +/// +/// Most additional limits are disabled except those with which specify a default in individual +/// field documentation. Note that this may result in barely-usable channels, but since they +/// are applied mostly only to incoming channels that's not much of a problem. #[derive(Copy, Clone, Debug)] pub struct ChannelHandshakeLimits { /// Minimum allowed satoshis when a channel is funded, this is supplied by the sender and so /// only applies to inbound channels. + /// + /// Default value: 0. pub min_funding_satoshis: u64, /// The remote node sets a limit on the minimum size of HTLCs we can send to them. This allows /// you to limit the maximum minimum-size they can require. + /// + /// Default value: u64::max_value. pub max_htlc_minimum_msat: u64, /// The remote node sets a limit on the maximum value of pending HTLCs to them at any given /// time to limit their funds exposure to HTLCs. This allows you to set a minimum such value. + /// + /// Default value: 0. pub min_max_htlc_value_in_flight_msat: u64, /// The remote node will require we keep a certain amount in direct payment to ourselves at all /// time, ensuring that we are able to be punished if we broadcast an old state. This allows to /// you limit the amount which we will have to keep to ourselves (and cannot use for HTLCs). + /// + /// Default value: u64::max_value. pub max_channel_reserve_satoshis: u64, /// The remote node sets a limit on the maximum number of pending HTLCs to them at any given /// time. This allows you to set a minimum such value. + /// + /// Default value: 0. pub min_max_accepted_htlcs: u16, /// Outputs below a certain value will not be added to on-chain transactions. The dust value is /// required to always be higher than this value so this only applies to HTLC outputs (and @@ -86,38 +108,39 @@ pub struct ChannelHandshakeLimits { /// This setting allows you to set a minimum dust limit for their commitment transactions, /// reflecting the reality that tiny outputs are not considered standard transactions and will /// not propagate through the Bitcoin network. - /// Defaults to 546, or the current dust limit on the Bitcoin network. + /// + /// Default value: 546, the current dust limit on the Bitcoin network. pub min_dust_limit_satoshis: u64, /// Maximum allowed threshold above which outputs will not be generated in their commitment /// transactions. /// HTLCs below this amount plus HTLC transaction fees are not enforceable on-chain. + /// + /// Default value: u64::max_value. pub max_dust_limit_satoshis: u64, /// Before a channel is usable the funding transaction will need to be confirmed by at least a /// certain number of blocks, specified by the node which is not the funder (as the funder can /// assume they aren't going to double-spend themselves). - /// This config allows you to set a limit on the maximum amount of time to wait. Defaults to - /// 144 blocks or roughly one day and only applies to outbound channels. + /// This config allows you to set a limit on the maximum amount of time to wait. + /// + /// Default value: 144, or roughly one day and only applies to outbound channels. pub max_minimum_depth: u32, /// Set to force the incoming channel to match our announced channel preference in /// ChannelConfig. - /// Defaults to true to make the default that no announced channels are possible (which is + /// + /// Default value: true, to make the default that no announced channels are possible (which is /// appropriate for any nodes which are not online very reliably). pub force_announced_channel_preference: bool, /// Set to the amount of time we're willing to wait to claim money back to us. /// /// Not checking this value would be a security issue, as our peer would be able to set it to /// max relative lock-time (a year) and we would "lose" money as it would be locked for a long time. - /// Default is MAX_LOCAL_BREAKDOWN_TIMEOUT, which we also enforce as a maximum value + /// + /// Default value: MAX_LOCAL_BREAKDOWN_TIMEOUT (1008), which we also enforce as a maximum value /// so you can tweak config to reduce the loss of having useless locked funds (if your peer accepts) pub their_to_self_delay: u16 } impl Default for ChannelHandshakeLimits { - /// Provides sane defaults for most configurations. - /// - /// Most additional limits are disabled except those with which specify a default in individual - /// field documentation. Note that this may result in barely-usable channels, but since they - /// are applied mostly only to incoming channels that's not much of a problem. fn default() -> Self { ChannelHandshakeLimits { min_funding_satoshis: 0, @@ -141,6 +164,8 @@ pub struct ChannelConfig { /// Amount (in millionths of a satoshi) the channel will charge per transferred satoshi. /// This may be allowed to change at runtime in a later update, however doing so must result in /// update messages sent to notify all nodes of our updated relay fee. + /// + /// Default value: 0. pub fee_proportional_millionths: u32, /// Set to announce the channel publicly and notify all nodes that they can route via this /// channel. @@ -151,6 +176,8 @@ pub struct ChannelConfig { /// channels unless ChannelHandshakeLimits::force_announced_channel_preferences is set. /// /// This cannot be changed after the initial channel handshake. + /// + /// Default value: false. pub announced_channel: bool, /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty /// supports it, they will then enforce the mutual-close output to us matches what we provided @@ -161,6 +188,8 @@ pub struct ChannelConfig { /// lightning payments, so we never require that our counterparties support this option. /// /// This cannot be changed after a channel has been initialized. + /// + /// Default value: true. pub commit_upfront_shutdown_pubkey: bool } -- 2.39.5