Use HashMaps as, well, HashMaps (don't iter for key match)

Author: dunxen

lightning/src/ln/interactivetxs.rs

@@ -177,23 +177,27 @@ impl NegotiationContext {
 		} else {
 			return Err(AbortReason::PrevTxOutInvalid);
 		};
-		if self.inputs.iter().any(|(serial_id, _)| *serial_id == msg.serial_id) {
-			// The receiving node:
-			//  - MUST fail the negotiation if:
-			//    - the `serial_id` is already included in the transaction
-			return Err(AbortReason::DuplicateSerialId);
-		}
-		let prev_outpoint = OutPoint { txid, vout: msg.prevtx_out };
-		self.inputs.entry(msg.serial_id).or_insert_with(|| TxInputWithPrevOutput {
-			input: TxIn {
-				previous_output: prev_outpoint.clone(),
-				sequence: Sequence(msg.sequence),
-				..Default::default()
+		match self.inputs.entry(msg.serial_id) {
+			hash_map::Entry::Occupied(_) => {
+				// The receiving node:
+				//  - MUST fail the negotiation if:
+				//    - the `serial_id` is already included in the transaction
+				Err(AbortReason::DuplicateSerialId)
 			},
-			prev_output: prev_out,
-		});
-		self.prevtx_outpoints.insert(prev_outpoint);
-		Ok(())
+			hash_map::Entry::Vacant(entry) => {
+				let prev_outpoint = OutPoint { txid, vout: msg.prevtx_out };
+				entry.insert(TxInputWithPrevOutput {
+					input: TxIn {
+						previous_output: prev_outpoint.clone(),
+						sequence: Sequence(msg.sequence),
+						..Default::default()
+					},
+					prev_output: prev_out,
+				});
+				self.prevtx_outpoints.insert(prev_outpoint);
+				Ok(())
+			},
+		}
 	}
 
 	fn received_tx_remove_input(&mut self, msg: &msgs::TxRemoveInput) -> Result<(), AbortReason> {
@@ -263,16 +267,18 @@ impl NegotiationContext {
 			return Err(AbortReason::InvalidOutputScript);
 		}
 
-		if self.outputs.iter().any(|(serial_id, _)| *serial_id == msg.serial_id) {
-			// The receiving node:
-			//  - MUST fail the negotiation if:
-			//    - the `serial_id` is already included in the transaction
-			return Err(AbortReason::DuplicateSerialId);
+		match self.outputs.entry(msg.serial_id) {
+			hash_map::Entry::Occupied(_) => {
+				// The receiving node:
+				//  - MUST fail the negotiation if:
+				//    - the `serial_id` is already included in the transaction
+				Err(AbortReason::DuplicateSerialId)
+			},
+			hash_map::Entry::Vacant(entry) => {
+				entry.insert(TxOut { value: msg.sats, script_pubkey: msg.script.clone() });
+				Ok(())
+			},
 		}
-
-		let output = TxOut { value: msg.sats, script_pubkey: msg.script.clone() };
-		self.outputs.entry(msg.serial_id).or_insert(output);
-		Ok(())
 	}
 
 	fn received_tx_remove_output(&mut self, msg: &msgs::TxRemoveOutput) -> Result<(), AbortReason> {