Use a struct to track MPP parts pending claiming

When we started tracking which channels had MPP parts claimed
durably on-disk in their `ChannelMonitor`, we did so with a tuple.
This was fine in that it was only ever accessed in two places, but
as we will start tracking it through to the `ChannelMonitor`s
themselves in the coming commit(s), it is useful to have it in a
struct instead.

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 3b3a0e37e734a781061d889916bfd1ba018d915e..c1750c5af76b6a7d15aba8c1bb2017058804bd6a 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -1062,10 +1062,20 @@ impl_writeable_tlv_based_enum!(EventCompletionAction,
        }
 );
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+/// The source of an HTLC which is being claimed as a part of an incoming payment. Each part is
+/// tracked in [`PendingMPPClaim`].
+struct MPPClaimHTLCSource {
+       counterparty_node_id: PublicKey,
+       funding_txo: OutPoint,
+       channel_id: ChannelId,
+       htlc_id: u64,
+}
+
 #[derive(Debug)]
 pub(crate) struct PendingMPPClaim {
-       channels_without_preimage: Vec<(PublicKey, OutPoint, ChannelId, u64)>,
-       channels_with_preimage: Vec<(PublicKey, OutPoint, ChannelId)>,
+       channels_without_preimage: Vec<MPPClaimHTLCSource>,
+       channels_with_preimage: Vec<MPPClaimHTLCSource>,
 }
 
 #[derive(Clone)]
@@ -6765,8 +6775,12 @@ where
                        let pending_mpp_claim_ptr_opt = if sources.len() > 1 {
                                let channels_without_preimage = sources.iter().filter_map(|htlc| {
                                        if let Some(cp_id) = htlc.prev_hop.counterparty_node_id {
-                                               let prev_hop = &htlc.prev_hop;
-                                               Some((cp_id, prev_hop.outpoint, prev_hop.channel_id, prev_hop.htlc_id))
+                                               Some(MPPClaimHTLCSource {
+                                                       counterparty_node_id: cp_id,
+                                                       funding_txo: htlc.prev_hop.outpoint,
+                                                       channel_id: htlc.prev_hop.channel_id,
+                                                       htlc_id: htlc.prev_hop.htlc_id,
+                                               })
                                        } else {
                                                None
                                        }
@@ -7184,15 +7198,25 @@ where
                                                                                if *pending_claim == claim_ptr {
                                                                                        let mut pending_claim_state_lock = pending_claim.0.lock().unwrap();
                                                                                        let pending_claim_state = &mut *pending_claim_state_lock;
-                                                                                       pending_claim_state.channels_without_preimage.retain(|(cp, outp, cid, hid)| {
-                                                                                               if *cp == counterparty_node_id && *cid == chan_id && *hid == htlc_id {
-                                                                                                       pending_claim_state.channels_with_preimage.push((*cp, *outp, *cid));
+                                                                                       pending_claim_state.channels_without_preimage.retain(|htlc_info| {
+                                                                                               let this_claim =
+                                                                                                       htlc_info.counterparty_node_id == counterparty_node_id
+                                                                                                       && htlc_info.channel_id == chan_id
+                                                                                                       && htlc_info.htlc_id == htlc_id;
+                                                                                               if this_claim {
+                                                                                                       pending_claim_state.channels_with_preimage.push(htlc_info.clone());
                                                                                                        false
                                                                                                } else { true }
                                                                                        });
                                                                                        if pending_claim_state.channels_without_preimage.is_empty() {
-                                                                                               for (cp, outp, cid) in pending_claim_state.channels_with_preimage.iter() {
-                                                                                                       freed_channels.push((*cp, *outp, *cid, blocker.clone()));
+                                                                                               for htlc_info in pending_claim_state.channels_with_preimage.iter() {
+                                                                                                       let freed_chan = (
+                                                                                                               htlc_info.counterparty_node_id,
+                                                                                                               htlc_info.funding_txo,
+                                                                                                               htlc_info.channel_id,
+                                                                                                               blocker.clone()
+                                                                                                       );
+                                                                                                       freed_channels.push(freed_chan);
                                                                                                }
                                                                                        }
                                                                                        !pending_claim_state.channels_without_preimage.is_empty()