Expose the timelock of transaction packages

Author: TheBlueMatt

lightning/src/chain/package.rs

@@ -387,6 +387,17 @@ impl PackageSolvingData {
 			_ => { panic!("API Error!"); }
 		}
 	}
+	fn absolute_tx_timelock(&self, input_height: u32) -> u32 {
+		let amt = match self {
+			PackageSolvingData::RevokedOutput(_) => input_height + 1,
+			PackageSolvingData::RevokedHTLCOutput(_) => input_height + 1,
+			PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => input_height + 1,
+			PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => std::cmp::max(outp.htlc.cltv_expiry, input_height + 1),
+			PackageSolvingData::HolderHTLCOutput(ref outp) => std::cmp::max(outp.cltv_expiry, input_height + 1),
+			PackageSolvingData::HolderFundingOutput(_) => input_height + 1,
+		};
+		amt
+	}
 }
 
 impl Writeable for PackageSolvingData {
@@ -598,6 +609,13 @@ impl PackageTemplate {
 		}
 		amounts
 	}
+	pub(crate) fn package_timelock(&self) -> u32 {
+		let mut max_locktime = 0;
+		for (_, outp) in self.inputs.iter() {
+			max_locktime = std::cmp::max(max_locktime, outp.absolute_tx_timelock(self.height_original));
+		}
+		max_locktime
+	}
 	pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
 		let mut inputs_weight = 0;
 		let mut witnesses_weight = 2; // count segwit flags