From b7e3c20383d9d7a4f90cef94d83c0085f4673fd6 Mon Sep 17 00:00:00 2001
From: xinhangzhou <shuangcui@aliyun.com>
Date: Mon, 24 Mar 2025 17:13:47 +0800
Subject: [PATCH] refactor: use maps.Copy for cleaner map handling

Signed-off-by: xinhangzhou <shuangcui@aliyun.com>
---
 accessman.go                               |  5 ++---
 channeldb/invoices.go                      | 13 ++++---------
 docs/release-notes/release-notes-0.19.0.md |  3 +++
 kvdb/prefetch_test.go                      |  5 ++---
 lnwire/custom_records.go                   | 10 +++-------
 rpcserver.go                               |  5 ++---
 watchtower/wtclient/client.go              |  5 ++---
 7 files changed, 18 insertions(+), 28 deletions(-)

diff --git a/accessman.go b/accessman.go
index e1ccc5c34..b11ced72c 100644
--- a/accessman.go
+++ b/accessman.go
@@ -2,6 +2,7 @@ package lnd
 
 import (
 	"fmt"
+	"maps"
 	"sync"
 
 	"github.com/btcsuite/btcd/btcec/v2"
@@ -66,9 +67,7 @@ func newAccessMan(cfg *accessManConfig) (*accessMan, error) {
 	// We'll populate the server's peerCounts map with the counts fetched
 	// via initAccessPerms. Also note that we haven't yet connected to the
 	// peers.
-	for peerPub, count := range counts {
-		a.peerCounts[peerPub] = count
-	}
+	maps.Copy(a.peerCounts, counts)
 
 	return a, nil
 }
diff --git a/channeldb/invoices.go b/channeldb/invoices.go
index 1ef323d9d..13439bf3d 100644
--- a/channeldb/invoices.go
+++ b/channeldb/invoices.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
 	"time"
 
 	"github.com/lightningnetwork/lnd/graph/db/models"
@@ -815,9 +816,7 @@ func (k *kvInvoiceUpdater) UpdateAmpState(setID [32]byte,
 			cancelledHtlcs := k.invoice.HTLCSet(
 				&setID, invpkg.HtlcStateCanceled,
 			)
-			for htlcKey, htlc := range cancelledHtlcs {
-				k.updatedAmpHtlcs[setID][htlcKey] = htlc
-			}
+			maps.Copy(k.updatedAmpHtlcs[setID], cancelledHtlcs)
 
 		case invpkg.HtlcStateSettled:
 			k.updatedAmpHtlcs[setID] = make(
@@ -1438,9 +1437,7 @@ func fetchFilteredAmpInvoices(invoiceBucket kvdb.RBucket, invoiceNum []byte,
 			return nil, err
 		}
 
-		for key, htlc := range htlcsBySetID {
-			htlcs[key] = htlc
-		}
+		maps.Copy(htlcs, htlcsBySetID)
 	}
 
 	return htlcs, nil
@@ -1508,9 +1505,7 @@ func fetchAmpSubInvoices(invoiceBucket kvdb.RBucket, invoiceNum []byte,
 				return err
 			}
 
-			for key, htlc := range htlcsBySetID {
-				htlcs[key] = htlc
-			}
+			maps.Copy(htlcs, htlcsBySetID)
 
 			return nil
 		},
diff --git a/docs/release-notes/release-notes-0.19.0.md b/docs/release-notes/release-notes-0.19.0.md
index e4ce83116..160b3bd33 100644
--- a/docs/release-notes/release-notes-0.19.0.md
+++ b/docs/release-notes/release-notes-0.19.0.md
@@ -433,6 +433,9 @@ The underlying functionality between those two options remain the same.
   inputs spending logic in the sweeper so it can properly handle missing inputs
   and recover from restart.
 
+* A code refactor to [use maps.Copy instead of manually copying map
+   elements](https://github.com/lightningnetwork/lnd/pull/9630).
+
 
 ## Tooling and Documentation
 
diff --git a/kvdb/prefetch_test.go b/kvdb/prefetch_test.go
index 4d9a851a1..1b3aaa810 100644
--- a/kvdb/prefetch_test.go
+++ b/kvdb/prefetch_test.go
@@ -2,6 +2,7 @@ package kvdb
 
 import (
 	"fmt"
+	"maps"
 	"testing"
 
 	"github.com/btcsuite/btcwallet/walletdb"
@@ -77,9 +78,7 @@ func prefetchTest(t *testing.T, db walletdb.DB,
 	}, func() {})
 	require.NoError(t, err)
 
-	for k, v := range put {
-		items[k] = v
-	}
+	maps.Copy(items, put)
 
 	for _, k := range remove {
 		delete(items, k)
diff --git a/lnwire/custom_records.go b/lnwire/custom_records.go
index a63aa5dfb..de5ff4a23 100644
--- a/lnwire/custom_records.go
+++ b/lnwire/custom_records.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"maps"
 	"sort"
 
 	"github.com/lightningnetwork/lnd/fn/v2"
@@ -94,13 +95,8 @@ func (c CustomRecords) Copy() CustomRecords {
 // records will be used.
 func (c CustomRecords) MergedCopy(other CustomRecords) CustomRecords {
 	copiedRecords := make(CustomRecords, len(c))
-	for k, v := range c {
-		copiedRecords[k] = v
-	}
-
-	for k, v := range other {
-		copiedRecords[k] = v
-	}
+	maps.Copy(copiedRecords, c)
+	maps.Copy(copiedRecords, other)
 
 	return copiedRecords
 }
diff --git a/rpcserver.go b/rpcserver.go
index fea7ac30e..cec5823f4 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
 	"math"
 	"net"
 	"net/http"
@@ -3339,9 +3340,7 @@ func (r *rpcServer) GetInfo(_ context.Context,
 		// Add the features to our map of features, allowing over writing of
 		// existing values because features in different sets with the same bit
 		// are duplicated across sets.
-		for bit, feature := range rpcFeatures {
-			features[bit] = feature
-		}
+		maps.Copy(features, rpcFeatures)
 	}
 
 	// TODO(roasbeef): add synced height n stuff
diff --git a/watchtower/wtclient/client.go b/watchtower/wtclient/client.go
index b3e322faa..8d74e9d1f 100644
--- a/watchtower/wtclient/client.go
+++ b/watchtower/wtclient/client.go
@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"errors"
 	"fmt"
+	"maps"
 	"math/big"
 	"net"
 	"sync"
@@ -1252,9 +1253,7 @@ func (c *client) handleNewTower(tower *Tower) error {
 		return fmt.Errorf("unable to determine sessions for tower %x: "+
 			"%v", tower.IdentityKey.SerializeCompressed(), err)
 	}
-	for id, session := range sessions {
-		c.candidateSessions[id] = session
-	}
+	maps.Copy(c.candidateSessions, sessions)
 
 	return nil
 }