Make the `P2PGossipSync` `UtxoLookup` exchangable without &mut self

Because a `UtxoLookup` implementation is likely to need a reference
to the `PeerManager` which contains a reference to the
`P2PGossipSync`, it is likely to be impossible to get a mutable
reference to the `P2PGossipSync` by the time we want to add a
`UtxoLookup` without a ton of boilerplate and trait wrapping.

Instead, we simply place the `UtxoLookup` in a `RwLock`, allowing
us to modify it without a mutable self reference.

The lifetime bounds updates in tests required in this commit are
entirely unclear to me, but do allow tests to continue building, so
somehow make rustc happier.

diff --git a/lightning/src/ln/functional_test_utils.rs b/lightning/src/ln/functional_test_utils.rs
index 84bc1a1b3f0656476aa1d00771f0368d97003cd0..5ce40f0578a39d9028506877092802c649149515 100644 (file)
--- a/lightning/src/ln/functional_test_utils.rs
+++ b/lightning/src/ln/functional_test_utils.rs
@@ -561,11 +561,11 @@ impl<'a, 'b, 'c> Drop for Node<'a, 'b, 'c> {
        }
 }
 
-pub fn create_chan_between_nodes<'a, 'b, 'c, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>) -> (msgs::ChannelAnnouncement, msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
+pub fn create_chan_between_nodes<'a, 'b, 'c: 'd, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>) -> (msgs::ChannelAnnouncement, msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
        create_chan_between_nodes_with_value(node_a, node_b, 100000, 10001)
 }
 
-pub fn create_chan_between_nodes_with_value<'a, 'b, 'c, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, channel_value: u64, push_msat: u64) -> (msgs::ChannelAnnouncement, msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
+pub fn create_chan_between_nodes_with_value<'a, 'b, 'c: 'd, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, channel_value: u64, push_msat: u64) -> (msgs::ChannelAnnouncement, msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
        let (channel_ready, channel_id, tx) = create_chan_between_nodes_with_value_a(node_a, node_b, channel_value, push_msat);
        let (announcement, as_update, bs_update) = create_chan_between_nodes_with_value_b(node_a, node_b, &channel_ready);
        (announcement, as_update, bs_update, channel_id, tx)
@@ -1169,7 +1169,7 @@ pub fn create_chan_between_nodes_with_value_confirm_second<'a, 'b, 'c>(node_recv
        }), channel_id)
 }
 
-pub fn create_chan_between_nodes_with_value_confirm<'a, 'b, 'c, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, tx: &Transaction) -> ((msgs::ChannelReady, msgs::AnnouncementSignatures), [u8; 32]) {
+pub fn create_chan_between_nodes_with_value_confirm<'a, 'b, 'c: 'd, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, tx: &Transaction) -> ((msgs::ChannelReady, msgs::AnnouncementSignatures), [u8; 32]) {
        let conf_height = core::cmp::max(node_a.best_block_info().1 + 1, node_b.best_block_info().1 + 1);
        create_chan_between_nodes_with_value_confirm_first(node_a, node_b, tx, conf_height);
        confirm_transaction_at(node_a, tx, conf_height);
@@ -1178,7 +1178,7 @@ pub fn create_chan_between_nodes_with_value_confirm<'a, 'b, 'c, 'd>(node_a: &'a
        create_chan_between_nodes_with_value_confirm_second(node_b, node_a)
 }
 
-pub fn create_chan_between_nodes_with_value_a<'a, 'b, 'c, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, channel_value: u64, push_msat: u64) -> ((msgs::ChannelReady, msgs::AnnouncementSignatures), [u8; 32], Transaction) {
+pub fn create_chan_between_nodes_with_value_a<'a, 'b, 'c: 'd, 'd>(node_a: &'a Node<'b, 'c, 'd>, node_b: &'a Node<'b, 'c, 'd>, channel_value: u64, push_msat: u64) -> ((msgs::ChannelReady, msgs::AnnouncementSignatures), [u8; 32], Transaction) {
        let tx = create_chan_between_nodes_with_value_init(node_a, node_b, channel_value, push_msat);
        let (msgs, chan_id) = create_chan_between_nodes_with_value_confirm(node_a, node_b, &tx);
        (msgs, chan_id, tx)
@@ -1218,11 +1218,11 @@ pub fn create_chan_between_nodes_with_value_b<'a, 'b, 'c>(node_a: &Node<'a, 'b,
        ((*announcement).clone(), as_update, bs_update)
 }
 
-pub fn create_announced_chan_between_nodes<'a, 'b, 'c, 'd>(nodes: &'a Vec<Node<'b, 'c, 'd>>, a: usize, b: usize) -> (msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
+pub fn create_announced_chan_between_nodes<'a, 'b, 'c: 'd, 'd>(nodes: &'a Vec<Node<'b, 'c, 'd>>, a: usize, b: usize) -> (msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
        create_announced_chan_between_nodes_with_value(nodes, a, b, 100000, 10001)
 }
 
-pub fn create_announced_chan_between_nodes_with_value<'a, 'b, 'c, 'd>(nodes: &'a Vec<Node<'b, 'c, 'd>>, a: usize, b: usize, channel_value: u64, push_msat: u64) -> (msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
+pub fn create_announced_chan_between_nodes_with_value<'a, 'b, 'c: 'd, 'd>(nodes: &'a Vec<Node<'b, 'c, 'd>>, a: usize, b: usize, channel_value: u64, push_msat: u64) -> (msgs::ChannelUpdate, msgs::ChannelUpdate, [u8; 32], Transaction) {
        let chan_announcement = create_chan_between_nodes_with_value(&nodes[a], &nodes[b], channel_value, push_msat);
        update_nodes_with_chan_announce(nodes, a, b, &chan_announcement.0, &chan_announcement.1, &chan_announcement.2);
        (chan_announcement.1, chan_announcement.2, chan_announcement.3, chan_announcement.4)

diff --git a/lightning/src/routing/gossip.rs b/lightning/src/routing/gossip.rs
index b9b70e0a03165e49f71f7f8c9bf185fd0388d7a2..90b7bb0eddc6b00977f7c087f1935ab42d636e85 100644 (file)
--- a/lightning/src/routing/gossip.rs
+++ b/lightning/src/routing/gossip.rs
@@ -254,7 +254,7 @@ pub struct P2PGossipSync<G: Deref<Target=NetworkGraph<L>>, U: Deref, L: Deref>
 where U::Target: UtxoLookup, L::Target: Logger
 {
        network_graph: G,
-       utxo_lookup: Option<U>,
+       utxo_lookup: RwLock<Option<U>>,
        #[cfg(feature = "std")]
        full_syncs_requested: AtomicUsize,
        pending_events: Mutex<Vec<MessageSendEvent>>,
@@ -273,7 +273,7 @@ where U::Target: UtxoLookup, L::Target: Logger
                        network_graph,
                        #[cfg(feature = "std")]
                        full_syncs_requested: AtomicUsize::new(0),
-                       utxo_lookup,
+                       utxo_lookup: RwLock::new(utxo_lookup),
                        pending_events: Mutex::new(vec![]),
                        logger,
                }
@@ -282,8 +282,8 @@ where U::Target: UtxoLookup, L::Target: Logger
        /// Adds a provider used to check new announcements. Does not affect
        /// existing announcements unless they are updated.
        /// Add, update or remove the provider would replace the current one.
-       pub fn add_utxo_lookup(&mut self, utxo_lookup: Option<U>) {
-               self.utxo_lookup = utxo_lookup;
+       pub fn add_utxo_lookup(&self, utxo_lookup: Option<U>) {
+               *self.utxo_lookup.write().unwrap() = utxo_lookup;
        }
 
        /// Gets a reference to the underlying [`NetworkGraph`] which was provided in
@@ -443,7 +443,7 @@ where U::Target: UtxoLookup, L::Target: Logger
        }
 
        fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, LightningError> {
-               self.network_graph.update_channel_from_announcement(msg, &self.utxo_lookup)?;
+               self.network_graph.update_channel_from_announcement(msg, &*self.utxo_lookup.read().unwrap())?;
                Ok(msg.contents.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY)
        }
 

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 3419f122e7ddfa907ffde3b44c2ee89f47ca6518..7abca061f3b480cfd9d011b9bd70cdbc53778b76 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -3897,7 +3897,7 @@ mod tests {
        fn available_amount_while_routing_test() {
                // Tests whether we choose the correct available channel amount while routing.
 
-               let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
+               let (secp_ctx, network_graph, gossip_sync, chain_monitor, logger) = build_graph();
                let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);