Tx-Sync: Track spent WatchedOutputs and re-add if unconfirmed

[tnull]

Fixes#2734.

• Previously, we would track a spending transaction but wouldn't account for it being reorged out of the chain, in which case we wouldn't monitor the WatchedOutputs until they'd be reloaded on restart.
  In the first commit, we keep any WatchedOutputs around until their spends are sufficiently confirmed and only prune them after ANTI_REORG_DELAY.

• Moreover, we dedup any ConfirmedTxs entries before handing them to Confirm::transactions_confirmed. Previously, we would just push to the confirmed_txsVec, leading to redundant Confirm::transactions_confirmed calls, especially now that we re-confirm previously disconnected spends.
  In the second commit, we ensure that we don't push additional ConfirmedTx entries if already one with matching Txid is present. This not only gets rid of the spurious transactions_confirmed calls (which are harmless), but
  more importantly saves us from issuing unnecessary network calls, which improves latency.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.01%. Comparing base (2c9dbb9) to head (b71c6e2).
Report is 27 commits behind head on main.

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Additional details and impacted files

@@ Coverage Diff @@## main #2946 +/- ##
==========================================
+ Coverage 89.18% 90.01% +0.83% 
==========================================
Files 117 117 Lines 95541 99416 +3875 Branches 95541 99416 +3875 ==========================================
+ Hits 85205 89489 +4284 + Misses 7840 7714 -126 + Partials 2496 2213 -283 

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[TheBlueMatt]

One nit, otherwise LGTM.

[jkczyz]

Looks good modulo the comments.

[jkczyz]

LGTM. Feel free to squash.

[jkczyz]

nit: may as well pass txid by value

[tnull]

Done.

[tnull]

Squashed commits and included the following changes:

> git diff-tree -U2 d7dafc94 b71c6e2f6diff --git a/lightning-transaction-sync/src/esplora.rs b/lightning-transaction-sync/src/esplora.rs
index e7952d6c2..538918ada 100644
--- a/lightning-transaction-sync/src/esplora.rs+++ b/lightning-transaction-sync/src/esplora.rs@@ -274,5 +274,5 @@ where
continue;
}
- if let Some(confirmed_tx) = maybe_await!(self.get_confirmed_tx(&txid, None, None))? {+ if let Some(confirmed_tx) = maybe_await!(self.get_confirmed_tx(*txid, None, None))? {
confirmed_txs.push(confirmed_tx);
}
@@ -297,5 +297,5 @@ where
if let Some(confirmed_tx) = maybe_await!(self
.get_confirmed_tx(
- &spending_txid,+ spending_txid,
spending_tx_status.block_hash,
spending_tx_status.block_height,
@@ -320,5 +320,5 @@ where
#[maybe_async]
fn get_confirmed_tx(
- &self, txid: &Txid, expected_block_hash: Option<BlockHash>, known_block_height: Option<u32>,+ &self, txid: Txid, expected_block_hash: Option<BlockHash>, known_block_height: Option<u32>,
) -> Result<Option<ConfirmedTx>, InternalError> {
if let Some(merkle_block) = maybe_await!(self.client.get_merkle_block(&txid))? {
@@ -335,5 +335,5 @@ where
let mut indexes = Vec::new();
let _ = merkle_block.txn.extract_matches(&mut matches, &mut indexes);
- if indexes.len() != 1 || matches.len() != 1 || matches[0] != *txid {+ if indexes.len() != 1 || matches.len() != 1 || matches[0] != txid {
log_error!(self.logger, "Retrieved Merkle block for txid {} doesn't match expectations. This should not happen. Please verify server integrity.", txid);
return Err(InternalError::Failed);
@@ -343,5 +343,5 @@ where
let pos = *indexes.first().unwrap() as usize;
if let Some(tx) = maybe_await!(self.client.get_tx(&txid))? {
- if tx.txid() != *txid {+ if tx.txid() != txid {
log_error!(self.logger, "Retrieved transaction for txid {} doesn't match expectations. This should not happen. Please verify server integrity.", txid);
return Err(InternalError::Failed);
@@ -350,10 +350,10 @@ where
if let Some(block_height) = known_block_height {
// We can take a shortcut here if a previous call already gave us the height.
- return Ok(Some(ConfirmedTx { tx, txid: *txid, block_header, pos, block_height }));+ return Ok(Some(ConfirmedTx { tx, txid, block_header, pos, block_height }));
}
let block_status = maybe_await!(self.client.get_block_status(&block_hash))?;
if let Some(block_height) = block_status.height {
- return Ok(Some(ConfirmedTx { tx, txid: *txid, block_header, pos, block_height }));+ return Ok(Some(ConfirmedTx { tx, txid, block_header, pos, block_height }));
} else {
// If any previously-confirmed block suddenly is no longer confirmed, we found