f - Move recursion outside nested for-loops

Author: jkczyz

lightning/src/chain/chainmonitor.rs

@@ -93,25 +93,32 @@ where C::Target: chain::Filter,
 	/// [`chain::Watch::release_pending_monitor_events`]: ../trait.Watch.html#tymethod.release_pending_monitor_events
 	/// [`chain::Filter`]: ../trait.Filter.html
 	pub fn block_connected(&self, header: &BlockHeader, txdata: &TransactionDataRef, height: u32) {
+		let mut dependent_txdata = Vec::new();
 		let monitors = self.monitors.read().unwrap();
 		for monitor in monitors.values() {
 			let mut txn_outputs = monitor.block_connected(header, txdata, height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);
 
+			// Register any new outputs with the chain source for filtering, storing any dependent
+			// transactions from within the block that previously had not been included in txdata.
 			if let Some(ref chain_source) = self.chain_source {
 				for (txid, outputs) in txn_outputs.drain(..) {
 					for (idx, output) in outputs.iter() {
-						// Register any new outputs with the chain source for filtering and recurse
-						// if it indicates that there are dependent transactions within the block
-						// that had not been previously included in txdata.
 						let outpoint = OutPoint { txid, index: *idx as u16 };
-						if let Some(txdata) = chain_source.register_output(&outpoint, &output.script_pubkey) {
-							let txdata: Vec<_> = txdata.iter().map(|(index, tx)| (*index, tx)).collect();
-							self.block_connected(header, &txdata, height);
+						if let Some(mut new_txdata) = chain_source.register_output(&outpoint, &output.script_pubkey) {
+							dependent_txdata.append(&mut new_txdata);
 						}
 					}
 				}
 			}
 		}
+
+		// Recursively call for any dependent transactions that were identified by the chain source.
+		if !dependent_txdata.is_empty() {
+			dependent_txdata.sort_unstable_by_key(|(index, _tx)| *index);
+			dependent_txdata.dedup_by_key(|(index, _tx)| *index);
+			let txdata: Vec<_> = dependent_txdata.iter().map(|(index, tx)| (*index, tx)).collect();
+			self.block_connected(header, &txdata, height);
+		}
 	}
 
 	/// Dispatches to per-channel monitors, which are responsible for updating their on-chain view