From: Jeffrey Czyz Date: Wed, 29 Dec 2021 15:56:54 +0000 (-0600) Subject: Effective channel capacity for router and scoring X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=0a9c2af336b6d4c98b0bfb1c8febe74f0d23abd3;p=rust-lightning Effective channel capacity for router and scoring A channel's capacity may be inferred or learned and is used to make routing decisions, including as a parameter to channel scoring. Define an EffectiveCapacity for this purpose. Score::channel_penalty_msat takes the effective capacity (less in-flight HTLCs for the same payment), and never None. Thus, for hops given in an invoice, the effective capacity is now considered (near) infinite if over a private channel or based on learned information if over a public channel. If a Score implementations needs the effective capacity when updating a channel's score, i.e. in payment_path_failed or payment_path_successful, it can access the channel's EffectiveCapacity via the NetworkGraph by first looking up the channel and then specifying which direction is desired using ChannelInfo::as_directed. --- diff --git a/lightning/src/routing/network_graph.rs b/lightning/src/routing/network_graph.rs index ae597d303..5246a2636 100644 --- a/lightning/src/routing/network_graph.rs +++ b/lightning/src/routing/network_graph.rs @@ -649,6 +649,48 @@ pub struct ChannelInfo { announcement_received_time: u64, } +impl ChannelInfo { + /// Returns a [`DirectedChannelInfo`] for the channel from `source` to `target`. + /// + /// # Panics + /// + /// Panics if `source` and `target` are not the channel's counterparties. + pub fn as_directed(&self, source: &NodeId, target: &NodeId) -> DirectedChannelInfo { + let (direction, source, target) = { + if source == &self.node_one && target == &self.node_two { + (self.one_to_two.as_ref(), &self.node_one, &self.node_two) + } else if source == &self.node_two && target == &self.node_one { + (self.two_to_one.as_ref(), &self.node_two, &self.node_one) + } else if source != &self.node_one && source != &self.node_two { + panic!("Unknown source node: {:?}", source) + } else if target != &self.node_one && target != &self.node_two { + panic!("Unknown target node: {:?}", target) + } else { + unreachable!() + } + }; + DirectedChannelInfo { channel: self, direction, source, target } + } + + /// Returns a [`DirectedChannelInfo`] for the channel directed to the given `target`. + /// + /// # Panics + /// + /// Panics if `target` is not one of the channel's counterparties. + pub fn directed_to(&self, target: &NodeId) -> DirectedChannelInfo { + let (direction, source, target) = { + if target == &self.node_one { + (self.two_to_one.as_ref(), &self.node_two, &self.node_one) + } else if target == &self.node_two { + (self.one_to_two.as_ref(), &self.node_one, &self.node_two) + } else { + panic!("Unknown target node: {:?}", target) + } + }; + DirectedChannelInfo { channel: self, direction, source, target } + } +} + impl fmt::Display for ChannelInfo { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { write!(f, "features: {}, node_one: {}, one_to_two: {:?}, node_two: {}, two_to_one: {:?}", @@ -668,6 +710,105 @@ impl_writeable_tlv_based!(ChannelInfo, { (12, announcement_message, required), }); +/// A wrapper around [`ChannelInfo`] representing information about the channel as directed from a +/// source node to a target node. +pub struct DirectedChannelInfo<'a: 'b, 'b> { + channel: &'a ChannelInfo, + direction: Option<&'b DirectionalChannelInfo>, + source: &'b NodeId, + target: &'b NodeId, +} + +impl<'a: 'b, 'b> DirectedChannelInfo<'a, 'b> { + /// Returns the node id for the source. + pub fn source(&self) -> &'b NodeId { self.source } + + /// Returns the node id for the target. + pub fn target(&self) -> &'b NodeId { self.target } + + /// Consumes the [`DirectedChannelInfo`], returning the wrapped parts. + pub fn into_parts(self) -> (&'a ChannelInfo, Option<&'b DirectionalChannelInfo>) { + (self.channel, self.direction) + } + + /// Returns the [`EffectiveCapacity`] of the channel in a specific direction. + /// + /// This is either the total capacity from the funding transaction, if known, or the + /// `htlc_maximum_msat` for the direction as advertised by the gossip network, if known, + /// whichever is smaller. + pub fn effective_capacity(&self) -> EffectiveCapacity { + Self::effective_capacity_from_parts(self.channel, self.direction) + } + + /// Returns the [`EffectiveCapacity`] of the channel in the given direction. + /// + /// See [`Self::effective_capacity`] for details. + pub fn effective_capacity_from_parts( + channel: &ChannelInfo, direction: Option<&DirectionalChannelInfo> + ) -> EffectiveCapacity { + let capacity_msat = channel.capacity_sats.map(|capacity_sats| capacity_sats * 1000); + direction + .and_then(|direction| direction.htlc_maximum_msat) + .map(|max_htlc_msat| { + let capacity_msat = capacity_msat.unwrap_or(u64::max_value()); + if max_htlc_msat < capacity_msat { + EffectiveCapacity::MaximumHTLC { amount_msat: max_htlc_msat } + } else { + EffectiveCapacity::Total { capacity_msat } + } + }) + .or_else(|| capacity_msat.map(|capacity_msat| + EffectiveCapacity::Total { capacity_msat })) + .unwrap_or(EffectiveCapacity::Unknown) + } +} + +/// The effective capacity of a channel for routing purposes. +/// +/// While this may be smaller than the actual channel capacity, amounts greater than +/// [`Self::as_msat`] should not be routed through the channel. +pub enum EffectiveCapacity { + /// The available liquidity in the channel known from being a channel counterparty, and thus a + /// direct hop. + ExactLiquidity { + /// Either the inbound or outbound liquidity depending on the direction, denominated in + /// millisatoshi. + liquidity_msast: u64, + }, + /// The maximum HTLC amount in one direction as advertised on the gossip network. + MaximumHTLC { + /// The maximum HTLC amount denominated in millisatoshi. + amount_msat: u64, + }, + /// The total capacity of the channel as determined by the funding transaction. + Total { + /// The funding amount denominated in millisatoshi. + capacity_msat: u64, + }, + /// A capacity sufficient to route any payment, typically used for private channels provided by + /// an invoice, though may not be the case for zero-amount invoices. + Infinite, + /// A capacity that is unknown possibly because either the chain state is unavailable to know + /// the total capacity or the `htlc_maximum_msat` was not advertised on the gossip network. + Unknown, +} + +/// The presumed channel capacity denominated in millisatoshi for [`EffectiveCapacity::Unknown`] to +/// use when making routing decisions. +pub const UNKNOWN_CHANNEL_CAPACITY_MSAT: u64 = 250_000 * 1000; + +impl EffectiveCapacity { + /// Returns the effective capacity denominated in millisatoshi. + pub fn as_msat(&self) -> u64 { + match self { + EffectiveCapacity::ExactLiquidity { liquidity_msast } => *liquidity_msast, + EffectiveCapacity::MaximumHTLC { amount_msat } => *amount_msat, + EffectiveCapacity::Total { capacity_msat } => *capacity_msat, + EffectiveCapacity::Infinite => u64::max_value(), + EffectiveCapacity::Unknown => UNKNOWN_CHANNEL_CAPACITY_MSAT, + } + } +} /// Fees for routing via a given channel or a node #[derive(Eq, PartialEq, Copy, Clone, Debug, Hash)] diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs index e49844383..14844171e 100644 --- a/lightning/src/routing/router.rs +++ b/lightning/src/routing/router.rs @@ -18,7 +18,7 @@ use ln::channelmanager::ChannelDetails; use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures}; use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT}; use routing::scoring::Score; -use routing::network_graph::{NetworkGraph, NodeId, RoutingFees}; +use routing::network_graph::{ChannelInfo, DirectedChannelInfo, DirectionalChannelInfo, EffectiveCapacity, NetworkGraph, NodeId, RoutingFees}; use util::ser::{Writeable, Readable}; use util::logger::{Level, Logger}; @@ -328,11 +328,80 @@ impl cmp::PartialOrd for RouteGraphNode { } } -struct DummyDirectionalChannelInfo { - cltv_expiry_delta: u32, - htlc_minimum_msat: u64, - htlc_maximum_msat: Option, - fees: RoutingFees, +/// A wrapper around the various hop representations. +/// +/// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`]. +enum CandidateRouteHop<'a> { + /// A hop from the payer to the next hop to the payee, where the outbound liquidity is known. + FirstHop { + details: &'a ChannelDetails, + }, + /// A hop found in the [`NetworkGraph`], where the channel capacity may or may not be known. + PublicHop { + short_channel_id: u64, + channel: &'a ChannelInfo, + direction: &'a DirectionalChannelInfo, + }, + /// A hop to the payee found in the payment invoice, though not necessarily a direct channel. + PrivateHop { + hint: &'a RouteHintHop, + } +} + +impl<'a> CandidateRouteHop<'a> { + fn short_channel_id(&self) -> u64 { + match self { + CandidateRouteHop::FirstHop { details } => details.short_channel_id.unwrap(), + CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id, + CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id, + } + } + + fn features(&self) -> ChannelFeatures { + match self { + CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(), + CandidateRouteHop::PublicHop { channel, .. } => channel.features.clone(), + CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(), + } + } + + fn cltv_expiry_delta(&self) -> u32 { + match self { + CandidateRouteHop::FirstHop { .. } => 0, + CandidateRouteHop::PublicHop { direction, .. } => direction.cltv_expiry_delta as u32, + CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32, + } + } + + fn htlc_minimum_msat(&self) -> u64 { + match self { + CandidateRouteHop::FirstHop { .. } => 0, + CandidateRouteHop::PublicHop { direction, .. } => direction.htlc_minimum_msat, + CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0), + } + } + + fn fees(&self) -> RoutingFees { + match self { + CandidateRouteHop::FirstHop { .. } => RoutingFees { + base_msat: 0, proportional_millionths: 0, + }, + CandidateRouteHop::PublicHop { direction, .. } => direction.fees, + CandidateRouteHop::PrivateHop { hint } => hint.fees, + } + } + + fn effective_capacity(&self) -> EffectiveCapacity { + match self { + CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity { + liquidity_msast: details.outbound_capacity_msat, + }, + CandidateRouteHop::PublicHop { channel, direction, .. } => { + DirectedChannelInfo::effective_capacity_from_parts(channel, Some(direction)) + }, + CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite, + } + } } /// It's useful to keep track of the hops associated with the fees required to use them, @@ -340,12 +409,12 @@ struct DummyDirectionalChannelInfo { /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees. /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer". #[derive(Clone, Debug)] -struct PathBuildingHop<'a> { +struct PathBuildingHop { // The RouteHintHop fields which will eventually be used if this hop is used in a final Route. // Note that node_features is calculated separately after our initial graph walk. node_id: NodeId, short_channel_id: u64, - channel_features: &'a ChannelFeatures, + channel_features: ChannelFeatures, fee_msat: u64, cltv_expiry_delta: u32, @@ -390,11 +459,11 @@ struct PathBuildingHop<'a> { // Instantiated with a list of hops with correct data in them collected during path finding, // an instance of this struct should be further modified only via given methods. #[derive(Clone)] -struct PaymentPath<'a> { - hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>, +struct PaymentPath { + hops: Vec<(PathBuildingHop, NodeFeatures)>, } -impl<'a> PaymentPath<'a> { +impl PaymentPath { // TODO: Add a value_msat field to PaymentPath and use it instead of this function. fn get_value_msat(&self) -> u64 { self.hops.last().unwrap().0.fee_msat @@ -632,15 +701,6 @@ where L::Target: Logger { let network_graph = network.read_only(); let network_channels = network_graph.channels(); let network_nodes = network_graph.nodes(); - let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes - cltv_expiry_delta: 0, - htlc_minimum_msat: 0, - htlc_maximum_msat: None, - fees: RoutingFees { - base_msat: 0, - proportional_millionths: 0, - } - }; // Allow MPP only if we have a features set from somewhere that indicates the payee supports // it. If the payee supports it they're supposed to include it in the invoice, so that should @@ -659,24 +719,26 @@ where L::Target: Logger { // Prepare the data we'll use for payee-to-payer search by // inserting first hops suggested by the caller as targets. // Our search will then attempt to reach them while traversing from the payee node. - let mut first_hop_targets: HashMap<_, Vec<(_, ChannelFeatures, _, NodeFeatures)>> = + let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> = HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 }); if let Some(hops) = first_hops { for chan in hops { - let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones"); + if chan.short_channel_id.is_none() { + panic!("first_hops should be filled in with usable channels, not pending ones"); + } if chan.counterparty.node_id == *our_node_pubkey { return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError}); } - first_hop_targets.entry(NodeId::from_pubkey(&chan.counterparty.node_id)).or_insert(Vec::new()) - .push((short_channel_id, chan.counterparty.features.to_context(), chan.outbound_capacity_msat, chan.counterparty.features.to_context())); + first_hop_targets + .entry(NodeId::from_pubkey(&chan.counterparty.node_id)) + .or_insert(Vec::new()) + .push(chan); } if first_hop_targets.is_empty() { return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError}); } } - let empty_channel_features = ChannelFeatures::empty(); - // The main heap containing all candidate next-hops sorted by their score (max(A* fee, // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of // adding duplicate entries when we find a better path to a given node. @@ -715,13 +777,11 @@ where L::Target: Logger { log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee.pubkey, our_node_pubkey, final_value_msat); macro_rules! add_entry { - // Adds entry which goes from $src_node_id to $dest_node_id - // over the channel with id $chan_id with fees described in - // $directional_info. + // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop. // $next_hops_fee_msat represents the fees paid for using all the channel *after* this one, // since that value has to be transferred over this channel. // Returns whether this channel caused an update to `targets`. - ( $chan_id: expr, $src_node_id: expr, $dest_node_id: expr, $directional_info: expr, $capacity_sats: expr, $chan_features: expr, $next_hops_fee_msat: expr, + ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr ) => { { // We "return" whether we updated the path at the end, via this: let mut did_add_update_path_to_src_node = false; @@ -729,28 +789,11 @@ where L::Target: Logger { // practice these cases should be caught earlier: // - for regular channels at channel announcement (TODO) // - for first and last hops early in get_route - if $src_node_id != $dest_node_id.clone() { - let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| { - let mut initial_liquidity_available_msat = None; - if let Some(capacity_sats) = $capacity_sats { - initial_liquidity_available_msat = Some(capacity_sats * 1000); - } - - if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat { - if let Some(available_msat) = initial_liquidity_available_msat { - initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat)); - } else { - initial_liquidity_available_msat = Some(htlc_maximum_msat); - } - } - - match initial_liquidity_available_msat { - Some(available_msat) => available_msat, - // We assume channels with unknown balance have - // a capacity of 0.0025 BTC (or 250_000 sats). - None => 250_000 * 1000 - } - }); + if $src_node_id != $dest_node_id { + let short_channel_id = $candidate.short_channel_id(); + let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat + .entry(short_channel_id) + .or_insert_with(|| $candidate.effective_capacity().as_msat()); // It is tricky to substract $next_hops_fee_msat from available liquidity here. // It may be misleading because we might later choose to reduce the value transferred @@ -792,7 +835,7 @@ where L::Target: Logger { None => unreachable!(), }; #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains - let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat && + let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() && amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat; // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't @@ -807,16 +850,16 @@ where L::Target: Logger { // might violate htlc_minimum_msat on the hops which are next along the // payment path (upstream to the payee). To avoid that, we recompute path // path fees knowing the final path contribution after constructing it. - let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees) + let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees()) .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat)) - .map(|fee_msat| cmp::max(fee_msat, $directional_info.htlc_minimum_msat)) + .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat())) .unwrap_or_else(|| u64::max_value()); let hm_entry = dist.entry($src_node_id); let old_entry = hm_entry.or_insert_with(|| { - // If there was previously no known way to access - // the source node (recall it goes payee-to-payer) of $chan_id, first add - // a semi-dummy record just to compute the fees to reach the source node. - // This will affect our decision on selecting $chan_id + // If there was previously no known way to access the source node + // (recall it goes payee-to-payer) of short_channel_id, first add a + // semi-dummy record just to compute the fees to reach the source node. + // This will affect our decision on selecting short_channel_id // as a way to reach the $dest_node_id. let mut fee_base_msat = u32::max_value(); let mut fee_proportional_millionths = u32::max_value(); @@ -827,18 +870,18 @@ where L::Target: Logger { PathBuildingHop { node_id: $dest_node_id.clone(), short_channel_id: 0, - channel_features: $chan_features, + channel_features: $candidate.features(), fee_msat: 0, cltv_expiry_delta: 0, src_lowest_inbound_fees: RoutingFees { base_msat: fee_base_msat, proportional_millionths: fee_proportional_millionths, }, - channel_fees: $directional_info.fees, + channel_fees: $candidate.fees(), next_hops_fee_msat: u64::max_value(), hop_use_fee_msat: u64::max_value(), total_fee_msat: u64::max_value(), - htlc_minimum_msat: $directional_info.htlc_minimum_msat, + htlc_minimum_msat: $candidate.htlc_minimum_msat(), path_htlc_minimum_msat, path_penalty_msat: u64::max_value(), was_processed: false, @@ -863,7 +906,7 @@ where L::Target: Logger { // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us // will have the same effective-fee if $src_node_id != our_node_id { - match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) { + match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) { // max_value means we'll always fail // the old_entry.total_fee_msat > total_fee_msat check None => total_fee_msat = u64::max_value(), @@ -893,7 +936,7 @@ where L::Target: Logger { } let path_penalty_msat = $next_hops_path_penalty_msat.checked_add( - scorer.channel_penalty_msat($chan_id.clone(), amount_to_transfer_over_msat, Some(*available_liquidity_msat), + scorer.channel_penalty_msat(short_channel_id, amount_to_transfer_over_msat, *available_liquidity_msat, &$src_node_id, &$dest_node_id)).unwrap_or_else(|| u64::max_value()); let new_graph_node = RouteGraphNode { node_id: $src_node_id, @@ -904,7 +947,7 @@ where L::Target: Logger { path_penalty_msat, }; - // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id), + // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id), // if this way is cheaper than the already known // (considering the cost to "reach" this channel from the route destination, // the cost of using this channel, @@ -933,12 +976,12 @@ where L::Target: Logger { old_entry.hop_use_fee_msat = hop_use_fee_msat; old_entry.total_fee_msat = total_fee_msat; old_entry.node_id = $dest_node_id.clone(); - old_entry.short_channel_id = $chan_id.clone(); - old_entry.channel_features = $chan_features; + old_entry.short_channel_id = short_channel_id; + old_entry.channel_features = $candidate.features(); old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel - old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32; - old_entry.channel_fees = $directional_info.fees; - old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat; + old_entry.cltv_expiry_delta = $candidate.cltv_expiry_delta(); + old_entry.channel_fees = $candidate.fees(); + old_entry.htlc_minimum_msat = $candidate.htlc_minimum_msat(); old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat; old_entry.path_penalty_msat = path_penalty_msat; #[cfg(any(test, feature = "fuzztarget"))] @@ -1005,8 +1048,9 @@ where L::Target: Logger { if !skip_node { if let Some(first_channels) = first_hop_targets.get(&$node_id) { - for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels { - add_entry!(first_hop, our_node_id, $node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat); + for details in first_channels { + let candidate = CandidateRouteHop::FirstHop { details }; + add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat); } } @@ -1020,21 +1064,19 @@ where L::Target: Logger { for chan_id in $node.channels.iter() { let chan = network_channels.get(chan_id).unwrap(); if !chan.features.requires_unknown_bits() { - if chan.node_one == $node_id { - // ie $node is one, ie next hop in A* is two, via the two_to_one channel - if first_hops.is_none() || chan.node_two != our_node_id { - if let Some(two_to_one) = chan.two_to_one.as_ref() { - if two_to_one.enabled { - add_entry!(chan_id, chan.node_two, chan.node_one, two_to_one, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat); - } - } - } - } else { - if first_hops.is_none() || chan.node_one != our_node_id{ - if let Some(one_to_two) = chan.one_to_two.as_ref() { - if one_to_two.enabled { - add_entry!(chan_id, chan.node_one, chan.node_two, one_to_two, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat); - } + let directed_channel = chan.directed_to(&$node_id); + let source = directed_channel.source(); + let target = directed_channel.target(); + if first_hops.is_none() || *source != our_node_id { + let (channel, direction) = directed_channel.into_parts(); + if let Some(direction) = direction { + if direction.enabled { + let candidate = CandidateRouteHop::PublicHop { + short_channel_id: *chan_id, + channel, + direction, + }; + add_entry!(candidate, *source, *target, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat); } } } @@ -1059,9 +1101,10 @@ where L::Target: Logger { // If first hop is a private channel and the only way to reach the payee, this is the only // place where it could be added. if let Some(first_channels) = first_hop_targets.get(&payee_node_id) { - for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels { - let added = add_entry!(first_hop, our_node_id, payee_node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0, 0u64); - log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, first_hop); + for details in first_channels { + let candidate = CandidateRouteHop::FirstHop { details }; + let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64); + log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id()); } } @@ -1102,39 +1145,26 @@ where L::Target: Logger { let mut aggregate_next_hops_path_penalty_msat: u64 = 0; for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() { - // BOLT 11 doesn't allow inclusion of features for the last hop hints, which - // really sucks, cause we're gonna need that eventually. - let hop_htlc_minimum_msat: u64 = hop.htlc_minimum_msat.unwrap_or(0); - - let directional_info = DummyDirectionalChannelInfo { - cltv_expiry_delta: hop.cltv_expiry_delta as u32, - htlc_minimum_msat: hop_htlc_minimum_msat, - htlc_maximum_msat: hop.htlc_maximum_msat, - fees: hop.fees, - }; - - // We want a value of final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR but we - // need it to increment at each hop by the fee charged at later hops. Further, - // we need to ensure we round up when we divide to get satoshis. - let channel_cap_msat = final_value_msat - .checked_mul(ROUTE_CAPACITY_PROVISION_FACTOR).and_then(|v| v.checked_add(aggregate_next_hops_fee_msat)) - .unwrap_or(u64::max_value()); - let channel_cap_sat = match channel_cap_msat.checked_add(999) { - None => break, // We overflowed above, just ignore this route hint - Some(val) => Some(val / 1000), - }; - - let src_node_id = NodeId::from_pubkey(&hop.src_node_id); - let dest_node_id = NodeId::from_pubkey(&prev_hop_id); + let source = NodeId::from_pubkey(&hop.src_node_id); + let target = NodeId::from_pubkey(&prev_hop_id); + let candidate = network_channels + .get(&hop.short_channel_id) + .map(|channel| channel.as_directed(&source, &target).into_parts()) + .and_then(|(channel, direction)| { + direction.map(|direction| + CandidateRouteHop::PublicHop { + short_channel_id: hop.short_channel_id, + channel, + direction, + }) + }) + .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop }); + let capacity_msat = candidate.effective_capacity().as_msat(); aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat - .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, None, &src_node_id, &dest_node_id)) + .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, capacity_msat, &source, &target)) .unwrap_or_else(|| u64::max_value()); - // We assume that the recipient only included route hints for routes which had - // sufficient value to route `final_value_msat`. Note that in the case of "0-value" - // invoices where the invoice does not specify value this may not be the case, but - // better to include the hints than not. - if !add_entry!(hop.short_channel_id, src_node_id, dest_node_id, directional_info, channel_cap_sat, &empty_channel_features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat) { + if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat) { // If this hop was not used then there is no use checking the preceding hops // in the RouteHint. We can break by just searching for a direct channel between // last checked hop and first_hop_targets @@ -1143,8 +1173,9 @@ where L::Target: Logger { // Searching for a direct channel between last checked hop and first_hop_targets if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) { - for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels { - add_entry!(first_hop, our_node_id , NodeId::from_pubkey(&prev_hop_id), dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat); + for details in first_channels { + let candidate = CandidateRouteHop::FirstHop { details }; + add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat); } } @@ -1161,6 +1192,7 @@ where L::Target: Logger { .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat)); aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; }; + let hop_htlc_minimum_msat = candidate.htlc_minimum_msat(); let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; }; let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat .checked_add(hop_htlc_minimum_msat_inc); @@ -1177,8 +1209,9 @@ where L::Target: Logger { // always assumes that the third argument is a node to which we have a // path. if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) { - for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels { - add_entry!(first_hop, our_node_id , NodeId::from_pubkey(&hop.src_node_id), dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat); + for details in first_channels { + let candidate = CandidateRouteHop::FirstHop { details }; + add_entry!(candidate, our_node_id, NodeId::from_pubkey(&hop.src_node_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat); } } } @@ -1212,9 +1245,9 @@ where L::Target: Logger { 'path_walk: loop { let mut features_set = false; if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) { - for (scid, _, _, ref features) in first_channels { - if *scid == ordered_hops.last().unwrap().0.short_channel_id { - ordered_hops.last_mut().unwrap().1 = features.clone(); + for details in first_channels { + if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.short_channel_id { + ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context(); features_set = true; break; } @@ -2814,7 +2847,7 @@ mod tests { // If we have a peer in the node map, we'll use their features here since we don't have // a way of figuring out their features from the invoice: assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4)); - assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::::new()); + assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11)); assert_eq!(route.paths[0][4].pubkey, nodes[6]); assert_eq!(route.paths[0][4].short_channel_id, 8); @@ -4661,7 +4694,7 @@ mod tests { fn write(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() } } impl Score for BadChannelScorer { - fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _chan_amt: Option, _source: &NodeId, _target: &NodeId) -> u64 { + fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, _target: &NodeId) -> u64 { if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 } } @@ -4679,7 +4712,7 @@ mod tests { } impl Score for BadNodeScorer { - fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option, _source: &NodeId, target: &NodeId) -> u64 { + fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, target: &NodeId) -> u64 { if *target == self.node_id { u64::max_value() } else { 0 } } diff --git a/lightning/src/routing/scoring.rs b/lightning/src/routing/scoring.rs index 20a8afcab..b0b348b80 100644 --- a/lightning/src/routing/scoring.rs +++ b/lightning/src/routing/scoring.rs @@ -91,7 +91,7 @@ pub trait Score $(: $supertrait)* { /// cases it is set to `Some`, even if we're guessing at the channel value. /// /// Your code should be overflow-safe through a `channel_capacity_msat` of 21 million BTC. - fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option, source: &NodeId, target: &NodeId) -> u64; + fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, capacity_msat: u64, source: &NodeId, target: &NodeId) -> u64; /// Handles updating channel penalties after failing to route through a channel. fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64); @@ -101,8 +101,8 @@ pub trait Score $(: $supertrait)* { } impl $(+ $supertrait)*> Score for T { - fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option, source: &NodeId, target: &NodeId) -> u64 { - self.deref().channel_penalty_msat(short_channel_id, send_amt_msat, channel_capacity_msat, source, target) + fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, capacity_msat: u64, source: &NodeId, target: &NodeId) -> u64 { + self.deref().channel_penalty_msat(short_channel_id, send_amt_msat, capacity_msat, source, target) } fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) { @@ -369,23 +369,19 @@ impl Default for ScoringParameters { impl Score for ScorerUsingTime { fn channel_penalty_msat( - &self, short_channel_id: u64, send_amt_msat: u64, chan_capacity_opt: Option, _source: &NodeId, _target: &NodeId + &self, short_channel_id: u64, send_amt_msat: u64, capacity_msat: u64, _source: &NodeId, _target: &NodeId ) -> u64 { let failure_penalty_msat = self.channel_failures .get(&short_channel_id) .map_or(0, |value| value.decayed_penalty_msat(self.params.failure_penalty_half_life)); let mut penalty_msat = self.params.base_penalty_msat + failure_penalty_msat; - - if let Some(chan_capacity_msat) = chan_capacity_opt { - let send_1024ths = send_amt_msat.checked_mul(1024).unwrap_or(u64::max_value()) / chan_capacity_msat; - - if send_1024ths > self.params.overuse_penalty_start_1024th as u64 { - penalty_msat = penalty_msat.checked_add( - (send_1024ths - self.params.overuse_penalty_start_1024th as u64) - .checked_mul(self.params.overuse_penalty_msat_per_1024th).unwrap_or(u64::max_value())) - .unwrap_or(u64::max_value()); - } + let send_1024ths = send_amt_msat.checked_mul(1024).unwrap_or(u64::max_value()) / capacity_msat; + if send_1024ths > self.params.overuse_penalty_start_1024th as u64 { + penalty_msat = penalty_msat.checked_add( + (send_1024ths - self.params.overuse_penalty_start_1024th as u64) + .checked_mul(self.params.overuse_penalty_msat_per_1024th).unwrap_or(u64::max_value())) + .unwrap_or(u64::max_value()); } penalty_msat @@ -622,10 +618,10 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); SinceEpoch::advance(Duration::from_secs(1)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); } #[test] @@ -639,16 +635,16 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_064); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_064); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_128); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_128); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_192); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_192); } #[test] @@ -662,25 +658,25 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); SinceEpoch::advance(Duration::from_secs(9)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); SinceEpoch::advance(Duration::from_secs(1)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); SinceEpoch::advance(Duration::from_secs(10 * 8)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_001); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_001); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); } #[test] @@ -694,18 +690,18 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); // An unchecked right shift 64 bits or more in ChannelFailure::decayed_penalty_msat would // cause an overflow. SinceEpoch::advance(Duration::from_secs(10 * 64)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); } #[test] @@ -719,19 +715,19 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_768); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_768); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_384); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_384); } #[test] @@ -745,13 +741,13 @@ mod tests { }); let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_000); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); let hop = RouteHop { pubkey: PublicKey::from_slice(target.as_slice()).unwrap(), @@ -762,10 +758,10 @@ mod tests { cltv_expiry_delta: 18, }; scorer.payment_path_successful(&[&hop]); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_128); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_128); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_064); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_064); } #[test] @@ -781,20 +777,20 @@ mod tests { let target = target_node_id(); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); scorer.payment_path_failed(&[], 43); - assert_eq!(scorer.channel_penalty_msat(43, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(43, 1, 1, &source, &target), 1_512); let mut serialized_scorer = Vec::new(); scorer.write(&mut serialized_scorer).unwrap(); let deserialized_scorer = ::read(&mut io::Cursor::new(&serialized_scorer)).unwrap(); - assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); - assert_eq!(deserialized_scorer.channel_penalty_msat(43, 1, Some(1), &source, &target), 1_512); + assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); + assert_eq!(deserialized_scorer.channel_penalty_msat(43, 1, 1, &source, &target), 1_512); } #[test] @@ -810,7 +806,7 @@ mod tests { let target = target_node_id(); scorer.payment_path_failed(&[], 42); - assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512); + assert_eq!(scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_512); let mut serialized_scorer = Vec::new(); scorer.write(&mut serialized_scorer).unwrap(); @@ -818,10 +814,10 @@ mod tests { SinceEpoch::advance(Duration::from_secs(10)); let deserialized_scorer = ::read(&mut io::Cursor::new(&serialized_scorer)).unwrap(); - assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256); + assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_256); SinceEpoch::advance(Duration::from_secs(10)); - assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_128); + assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, 1, &source, &target), 1_128); } #[test] @@ -836,11 +832,10 @@ mod tests { let source = source_node_id(); let target = target_node_id(); - assert_eq!(scorer.channel_penalty_msat(42, 1_000, None, &source, &target), 0); - assert_eq!(scorer.channel_penalty_msat(42, 1_000, Some(1_024_000), &source, &target), 0); - assert_eq!(scorer.channel_penalty_msat(42, 256_999, Some(1_024_000), &source, &target), 0); - assert_eq!(scorer.channel_penalty_msat(42, 257_000, Some(1_024_000), &source, &target), 100); - assert_eq!(scorer.channel_penalty_msat(42, 258_000, Some(1_024_000), &source, &target), 200); - assert_eq!(scorer.channel_penalty_msat(42, 512_000, Some(1_024_000), &source, &target), 256 * 100); + assert_eq!(scorer.channel_penalty_msat(42, 1_000, 1_024_000, &source, &target), 0); + assert_eq!(scorer.channel_penalty_msat(42, 256_999, 1_024_000, &source, &target), 0); + assert_eq!(scorer.channel_penalty_msat(42, 257_000, 1_024_000, &source, &target), 100); + assert_eq!(scorer.channel_penalty_msat(42, 258_000, 1_024_000, &source, &target), 200); + assert_eq!(scorer.channel_penalty_msat(42, 512_000, 1_024_000, &source, &target), 256 * 100); } }