Prune and persist network graph on startup

Previously, we'd initially prune/persist after 60 seconds, which may be
too long or too short. Now we prune/persist as soon as we can on startup,
whether that be immediately for normal P2P gossip, or after the first
RGS update.

Author: alecchendev

lightning-background-processor/src/lib.rs

@@ -111,11 +111,6 @@ const SCORER_PERSIST_TIMER: u64 = 30;
 #[cfg(test)]
 const SCORER_PERSIST_TIMER: u64 = 1;
 
-#[cfg(not(test))]
-const FIRST_NETWORK_PRUNE_TIMER: u64 = 60;
-#[cfg(test)]
-const FIRST_NETWORK_PRUNE_TIMER: u64 = 1;
-
 #[cfg(not(test))]
 const REBROADCAST_TIMER: u64 = 30;
 #[cfg(test)]
@@ -126,7 +121,7 @@ const REBROADCAST_TIMER: u64 = 1;
 const fn min_u64(a: u64, b: u64) -> u64 { if a < b { a } else { b } }
 #[cfg(feature = "futures")]
 const FASTEST_TIMER: u64 = min_u64(min_u64(FRESHNESS_TIMER, PING_TIMER),
-	min_u64(SCORER_PERSIST_TIMER, min_u64(FIRST_NETWORK_PRUNE_TIMER, REBROADCAST_TIMER)));
+	min_u64(SCORER_PERSIST_TIMER, REBROADCAST_TIMER));
 
 /// Either [`P2PGossipSync`] or [`RapidGossipSync`].
 pub enum GossipSync<
@@ -275,7 +270,7 @@ macro_rules! define_run_body {
 
 		let mut last_freshness_call = $get_timer(FRESHNESS_TIMER);
 		let mut last_ping_call = $get_timer(PING_TIMER);
-		let mut last_prune_call = $get_timer(FIRST_NETWORK_PRUNE_TIMER);
+		let mut last_prune_call = $get_timer(NETWORK_PRUNE_TIMER);
 		let mut last_scorer_persist_call = $get_timer(SCORER_PERSIST_TIMER);
 		let mut last_rebroadcast_call = $get_timer(REBROADCAST_TIMER);
 		let mut have_pruned = false;
@@ -352,8 +347,7 @@ macro_rules! define_run_body {
 			// falling back to our usual hourly prunes. This avoids short-lived clients never
 			// pruning their network graph. We run once 60 seconds after startup before
 			// continuing our normal cadence.
-			let prune_timer = if have_pruned { NETWORK_PRUNE_TIMER } else { FIRST_NETWORK_PRUNE_TIMER };
-			if $timer_elapsed(&mut last_prune_call, prune_timer) {
+			if !have_pruned || $timer_elapsed(&mut last_prune_call, NETWORK_PRUNE_TIMER) {
 				// The network graph must not be pruned while rapid sync completion is pending
 				if let Some(network_graph) = $gossip_sync.prunable_network_graph() {
 					#[cfg(feature = "std")] {
@@ -371,8 +365,7 @@ macro_rules! define_run_body {
 
 					have_pruned = true;
 				}
-				let prune_timer = if have_pruned { NETWORK_PRUNE_TIMER } else { FIRST_NETWORK_PRUNE_TIMER };
-				last_prune_call = $get_timer(prune_timer);
+				last_prune_call = $get_timer(NETWORK_PRUNE_TIMER);
 			}
 
 			if $timer_elapsed(&mut last_scorer_persist_call, SCORER_PERSIST_TIMER) {
@@ -1557,7 +1550,7 @@ mod tests {
 		let background_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].rapid_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
 
 		do_test_not_pruning_network_graph_until_graph_sync_completion!(nodes,
-			receiver.recv_timeout(Duration::from_secs(super::FIRST_NETWORK_PRUNE_TIMER * 5)),
+			receiver.recv_timeout(Duration::from_secs(5)),
 			std::thread::sleep(Duration::from_millis(1)));
 
 		background_processor.stop().unwrap();
@@ -1592,7 +1585,7 @@ mod tests {
 			do_test_not_pruning_network_graph_until_graph_sync_completion!(nodes, {
 				let mut i = 0;
 				loop {
-					tokio::time::sleep(Duration::from_secs(super::FIRST_NETWORK_PRUNE_TIMER)).await;
+					tokio::time::sleep(Duration::from_secs(1)).await;
 					if let Ok(()) = receiver.try_recv() { break Ok::<(), ()>(()); }
 					assert!(i < 5);
 					i += 1;