From 38aaa4d07a903661c36f35efbbde8f5f20a4247e Mon Sep 17 00:00:00 2001
From: Boris Nagaev <bnagaev@gmail.com>
Date: Mon, 23 Jun 2025 00:56:58 -0300
Subject: [PATCH] staticaddr: recover withdrawals in parallel

Use errgroup to publish each transaction in a separate goroutine.
Publishing a transaction can take a while in neutrino mode.
---
 go.mod                         |  7 ++--
 staticaddr/withdraw/manager.go | 58 +++++++++++++++++++++-------------
 2 files changed, 39 insertions(+), 26 deletions(-)

diff --git a/go.mod b/go.mod
index 5cd43d6c..a609a47b 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ require (
 	github.com/btcsuite/btcd/btcutil v1.1.5
 	github.com/btcsuite/btcd/btcutil/psbt v1.1.10
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0
-	github.com/btcsuite/btclog v0.0.0-20241003133417-09c4e92e319c // indirect
+	github.com/btcsuite/btclog/v2 v2.0.1-0.20250110154127-3ae4bf1cb318
 	github.com/btcsuite/btcwallet v0.16.13
 	github.com/btcsuite/btcwallet/wtxmgr v1.5.6
 	github.com/davecgh/go-spew v1.1.1
@@ -36,6 +36,7 @@ require (
 	github.com/urfave/cli v1.22.14
 	go.etcd.io/bbolt v1.3.11
 	golang.org/x/net v0.38.0
+	golang.org/x/sync v0.12.0
 	google.golang.org/grpc v1.64.1
 	google.golang.org/protobuf v1.34.2
 	gopkg.in/macaroon-bakery.v2 v2.3.0
@@ -43,8 +44,6 @@ require (
 	modernc.org/sqlite v1.34.5
 )
 
-require github.com/btcsuite/btclog/v2 v2.0.1-0.20250110154127-3ae4bf1cb318
-
 require (
 	dario.cat/mergo v1.0.1 // indirect
 	github.com/Azure/go-ansiterm v0.0.0-20230124172434-306776ec8161 // indirect
@@ -56,6 +55,7 @@ require (
 	github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da // indirect
 	github.com/aead/siphash v1.0.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/btcsuite/btclog v0.0.0-20241003133417-09c4e92e319c // indirect
 	github.com/btcsuite/btcwallet/wallet/txauthor v1.3.5 // indirect
 	github.com/btcsuite/btcwallet/wallet/txrules v1.2.2 // indirect
 	github.com/btcsuite/btcwallet/wallet/txsizes v1.2.5 // indirect
@@ -185,7 +185,6 @@ require (
 	golang.org/x/crypto v0.36.0 // indirect
 	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8 // indirect
 	golang.org/x/mod v0.21.0 // indirect
-	golang.org/x/sync v0.12.0 // indirect
 	golang.org/x/sys v0.31.0 // indirect
 	golang.org/x/term v0.30.0 // indirect
 	golang.org/x/text v0.23.0 // indirect
diff --git a/staticaddr/withdraw/manager.go b/staticaddr/withdraw/manager.go
index 7d12709b..2914d518 100644
--- a/staticaddr/withdraw/manager.go
+++ b/staticaddr/withdraw/manager.go
@@ -26,6 +26,7 @@ import (
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
+	"golang.org/x/sync/errgroup"
 )
 
 var (
@@ -238,32 +239,45 @@ func (m *Manager) recoverWithdrawals(ctx context.Context) error {
 		)
 	}
 
+	// Publishing a transaction can take a while in neutrino mode, so
+	// do it in parallel.
+	eg := &errgroup.Group{}
+
 	// We can now reinstate each cluster of deposits for a withdrawal.
-	for finalizedWithdrawalTx, deposits := range depositsByWithdrawalTx {
-		tx := finalizedWithdrawalTx
-		err = m.cfg.DepositManager.TransitionDeposits(
-			ctx, deposits, deposit.OnWithdrawInitiated,
-			deposit.Withdrawing,
-		)
-		if err != nil {
-			return err
-		}
+	for tx, deposits := range depositsByWithdrawalTx {
+		eg.Go(func() error {
+			err := m.cfg.DepositManager.TransitionDeposits(
+				ctx, deposits, deposit.OnWithdrawInitiated,
+				deposit.Withdrawing,
+			)
+			if err != nil {
+				return err
+			}
 
-		_, err = m.publishFinalizedWithdrawalTx(ctx, tx)
-		if err != nil {
-			return err
-		}
+			_, err = m.publishFinalizedWithdrawalTx(ctx, tx)
+			if err != nil {
+				return err
+			}
 
-		err = m.handleWithdrawal(
-			ctx, deposits, tx.TxHash(), tx.TxOut[0].PkScript,
-		)
-		if err != nil {
-			return err
-		}
+			err = m.handleWithdrawal(
+				ctx, deposits, tx.TxHash(),
+				tx.TxOut[0].PkScript,
+			)
+			if err != nil {
+				return err
+			}
 
-		m.mu.Lock()
-		m.finalizedWithdrawalTxns[tx.TxHash()] = tx
-		m.mu.Unlock()
+			m.mu.Lock()
+			m.finalizedWithdrawalTxns[tx.TxHash()] = tx
+			m.mu.Unlock()
+
+			return nil
+		})
+	}
+
+	// Wait for all goroutines to report back.
+	if err := eg.Wait(); err != nil {
+		return fmt.Errorf("error recovering withdrawals: %w", err)
 	}
 
 	return nil