X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Frouting%2Frouter.rs;h=cffd9ddb0a581ea2e26a53ee3f305a8c7f81bbf7;hb=49c9f1885dd7a564c0c78ad5f73ea4792c0171a8;hp=9e31d9ea5e734a3746486b07d5a27415bfccd7b0;hpb=81afc2f1729b2abf5eaa54c5da12f517349486a7;p=rust-lightning

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 9e31d9ea..cffd9ddb 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -29,6 +29,49 @@ use alloc::collections::BinaryHeap;
 use core::cmp;
 use core::ops::Deref;
 
+/// A trait defining behavior for routing a payment.
+pub trait Router {
+	/// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
+	fn find_route(
+		&self, payer: &PublicKey, route_params: &RouteParameters,
+		first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
+	) -> Result<Route, LightningError>;
+}
+
+/// A map with liquidity value (in msat) keyed by a short channel id and the direction the HTLC
+/// is traveling in. The direction boolean is determined by checking if the HTLC source's public
+/// key is less than its destination. See [`InFlightHtlcs::used_liquidity_msat`] for more
+/// details.
+#[cfg(not(any(test, feature = "_test_utils")))]
+pub struct InFlightHtlcs(HashMap<(u64, bool), u64>);
+#[cfg(any(test, feature = "_test_utils"))]
+pub struct InFlightHtlcs(pub HashMap<(u64, bool), u64>);
+
+impl InFlightHtlcs {
+	/// Create a new `InFlightHtlcs` via a mapping from:
+	/// (short_channel_id, source_pubkey < target_pubkey) -> used_liquidity_msat
+	pub fn new(inflight_map: HashMap<(u64, bool), u64>) -> Self {
+		InFlightHtlcs(inflight_map)
+	}
+
+	/// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
+	/// id.
+	pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
+		self.0.get(&(channel_scid, source < target)).map(|v| *v)
+	}
+}
+
+impl Writeable for InFlightHtlcs {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
+}
+
+impl Readable for InFlightHtlcs {
+	fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+		let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
+		Ok(Self(infight_map))
+	}
+}
+
 /// A hop in a route
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct RouteHop {
@@ -185,8 +228,7 @@ pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
 
 // During routing, we only consider paths shorter than our maximum length estimate.
-// In the legacy onion format, the maximum number of hops used to be a fixed value of 20.
-// However, in the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
+// In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
 //
@@ -494,10 +536,8 @@ fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_po
 		EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
 		EffectiveCapacity::MaximumHTLC { amount_msat } =>
 			amount_msat.checked_shr(saturation_shift).unwrap_or(0),
-		EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat: None } =>
-			capacity_msat.checked_shr(saturation_shift).unwrap_or(0),
-		EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat: Some(htlc_max) } =>
-			cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_max),
+		EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
+			cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
 	}
 }
 
@@ -5391,7 +5431,7 @@ mod tests {
 		let usage = ChannelUsage {
 			amount_msat: 0,
 			inflight_htlc_msat: 0,
-			effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_000) },
+			effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
 		};
 		scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
 		scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);