Change InFlightHtlcs to a tuple struct

Author: jurvis

lightning-invoice/src/payment.rs

@@ -740,25 +740,22 @@ where
 	}
 }
 
-/// Data structure used to track information about inflight HTLCs.
-pub struct InFlightHtlcs {
-	/// 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.
-	pub map: HashMap<(u64, bool), u64>
-}
+/// 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.
+pub struct InFlightHtlcs(HashMap<(u64, bool), u64>);
 
 impl InFlightHtlcs {
 	/// Creates a new instance with an optional map of liquidity information.
-	pub fn new(map: Option<HashMap<(u64, bool), u64>>) -> Self {
-		InFlightHtlcs { map: map.unwrap_or(HashMap::new()) }
+	pub fn new(used_liquidity_msat: Option<HashMap<(u64, bool), u64>>) -> Self {
+		InFlightHtlcs(used_liquidity_msat.unwrap_or(HashMap::new()))
 	}
 
 	/// 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.map.get(&(channel_scid, source < target))
+		self.0.get(&(channel_scid, source < target))
 	}
 }