Add `ChainMonitor::archive_fully_resolved_monitor_channels`

[rust-lightning] / lightning / src / chain / chainmonitor.rs

diff --git a/lightning/src/chain/chainmonitor.rs b/lightning/src/chain/chainmonitor.rs
index b71f10f58d455cc0fccff487884dd65f12c8d5cc..efea0cf03f7d9a250675fde8bc6d6ee653edc9c1 100644 (file)
--- a/lightning/src/chain/chainmonitor.rs
+++ b/lightning/src/chain/chainmonitor.rs
@@ -43,7 +43,6 @@ use crate::ln::channelmanager::ChannelDetails;
 
 use crate::prelude::*;
 use crate::sync::{RwLock, RwLockReadGuard, Mutex, MutexGuard};
-use core::iter::FromIterator;
 use core::ops::Deref;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use bitcoin::secp256k1::PublicKey;
@@ -195,6 +194,11 @@ pub trait Persist<ChannelSigner: WriteableEcdsaChannelSigner> {
        ///
        /// [`Writeable::write`]: crate::util::ser::Writeable::write
        fn update_persisted_channel(&self, channel_funding_outpoint: OutPoint, update: Option<&ChannelMonitorUpdate>, data: &ChannelMonitor<ChannelSigner>, update_id: MonitorUpdateId) -> ChannelMonitorUpdateStatus;
+       /// Prevents the channel monitor from being loaded on startup.
+       ///
+       /// Archiving the data in a backup location (rather than deleting it fully) is useful for
+       /// hedging against data loss in case of unexpected failure.
+       fn archive_persisted_channel(&self, channel_funding_outpoint: OutPoint);
 }
 
 struct MonitorHolder<ChannelSigner: WriteableEcdsaChannelSigner> {
@@ -318,7 +322,7 @@ where C::Target: chain::Filter,
                FN: Fn(&ChannelMonitor<ChannelSigner>, &TransactionData) -> Vec<TransactionOutputs>
        {
                let err_str = "ChannelMonitor[Update] persistence failed unrecoverably. This indicates we cannot continue normal operation and must shut down.";
-               let funding_outpoints: HashSet<OutPoint> = HashSet::from_iter(self.monitors.read().unwrap().keys().cloned());
+               let funding_outpoints = hash_set_from_iter(self.monitors.read().unwrap().keys().cloned());
                for funding_outpoint in funding_outpoints.iter() {
                        let monitor_lock = self.monitors.read().unwrap();
                        if let Some(monitor_state) = monitor_lock.get(funding_outpoint) {
@@ -420,7 +424,7 @@ where C::Target: chain::Filter,
        /// transactions relevant to the watched channels.
        pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F, persister: P) -> Self {
                Self {
-                       monitors: RwLock::new(HashMap::new()),
+                       monitors: RwLock::new(new_hash_map()),
                        sync_persistence_id: AtomicCounter::new(),
                        chain_source,
                        broadcaster,
@@ -486,9 +490,9 @@ where C::Target: chain::Filter,
        #[cfg(not(c_bindings))]
        /// Lists the pending updates for each [`ChannelMonitor`] (by `OutPoint` being monitored).
        pub fn list_pending_monitor_updates(&self) -> HashMap<OutPoint, Vec<MonitorUpdateId>> {
-               self.monitors.read().unwrap().iter().map(|(outpoint, holder)| {
+               hash_map_from_iter(self.monitors.read().unwrap().iter().map(|(outpoint, holder)| {
                        (*outpoint, holder.pending_monitor_updates.lock().unwrap().clone())
-               }).collect()
+               }))
        }
 
        #[cfg(c_bindings)]
@@ -636,6 +640,62 @@ where C::Target: chain::Filter,
                        )
                }
        }
+
+       /// Triggers rebroadcasts of pending claims from force-closed channels after a transaction
+       /// signature generation failure.
+       ///
+       /// `monitor_opt` can be used as a filter to only trigger them for a specific channel monitor.
+       pub fn signer_unblocked(&self, monitor_opt: Option<OutPoint>) {
+               let monitors = self.monitors.read().unwrap();
+               if let Some(funding_txo) = monitor_opt {
+                       if let Some(monitor_holder) = monitors.get(&funding_txo) {
+                               monitor_holder.monitor.signer_unblocked(
+                                       &*self.broadcaster, &*self.fee_estimator, &self.logger
+                               )
+                       }
+               } else {
+                       for (_, monitor_holder) in &*monitors {
+                               monitor_holder.monitor.signer_unblocked(
+                                       &*self.broadcaster, &*self.fee_estimator, &self.logger
+                               )
+                       }
+               }
+       }
+
+       /// Archives fully resolved channel monitors by calling [`Persist::archive_persisted_channel`].
+       ///
+       /// This is useful for pruning fully resolved monitors from the monitor set and primary
+       /// storage so they are not kept in memory and reloaded on restart.
+       ///
+       /// Should be called occasionally (once every handful of blocks or on startup).
+       ///
+       /// Depending on the implementation of [`Persist::archive_persisted_channel`] the monitor
+       /// data could be moved to an archive location or removed entirely.
+       pub fn archive_fully_resolved_channel_monitors(&self) {
+               let mut have_monitors_to_prune = false;
+               for (_, monitor_holder) in self.monitors.read().unwrap().iter() {
+                       let logger = WithChannelMonitor::from(&self.logger, &monitor_holder.monitor);
+                       if monitor_holder.monitor.is_fully_resolved(&logger) {
+                               have_monitors_to_prune = true;
+                       }
+               }
+               if have_monitors_to_prune {
+                       let mut monitors = self.monitors.write().unwrap();
+                       monitors.retain(|funding_txo, monitor_holder| {
+                               let logger = WithChannelMonitor::from(&self.logger, &monitor_holder.monitor);
+                               if monitor_holder.monitor.is_fully_resolved(&logger) {
+                                       log_info!(logger,
+                                               "Archiving fully resolved ChannelMonitor for funding txo {}",
+                                               funding_txo
+                                       );
+                                       self.persister.archive_persisted_channel(*funding_txo);
+                                       false
+                               } else {
+                                       true
+                               }
+                       });
+               }
+       }
 }
 
 impl<ChannelSigner: WriteableEcdsaChannelSigner, C: Deref, T: Deref, F: Deref, L: Deref, P: Deref>