From b0de37d09f2303ffcba1584e24ff4074443f1674 Mon Sep 17 00:00:00 2001
From: ymmt <ymmt2005@gmail.com>
Date: Wed, 6 Sep 2023 06:28:56 +0000
Subject: [PATCH] backup: PITR did not work sometimes

A bug in RestoreManager.FindNearestDump caused the bug.
Fixes #563.
---
 backup/restore.go      | 19 +++++++++++++------
 backup/restore_test.go | 10 +++++++++-
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/backup/restore.go b/backup/restore.go
index 9332c9644..f988b3b06 100644
--- a/backup/restore.go
+++ b/backup/restore.go
@@ -138,7 +138,6 @@ func (rm *RestoreManager) Restore(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("failed to list object keys: %w", err)
 	}
-	sort.Strings(keys)
 
 	dumpKey, binlogKey, backupTime := rm.FindNearestDump(keys)
 	if dumpKey == "" {
@@ -195,16 +194,19 @@ func (rm *RestoreManager) Restore(ctx context.Context) error {
 	return nil
 }
 
+// FindNearestDump finds the nearest dump file and binlog file to the restore point.
+// `keys` are object keys for the restoring instance. They need not be sorted.
 func (rm *RestoreManager) FindNearestDump(keys []string) (string, string, time.Time) {
+	sort.Strings(keys)
+
 	var nearest time.Time
 	var nearestDump, nearestBinlog string
 
 	for _, key := range keys {
-		if strings.HasSuffix(key, constants.BinlogFilename) {
-			nearestBinlog = key
-			continue
-		}
-		if !strings.HasSuffix(key, constants.DumpFilename) {
+		isBinlog := strings.HasSuffix(key, constants.BinlogFilename)
+		isDump := strings.HasSuffix(key, constants.DumpFilename)
+		if !isBinlog && !isDump {
+			rm.log.Info("skipping garbage", "key", key)
 			continue
 		}
 
@@ -217,6 +219,11 @@ func (rm *RestoreManager) FindNearestDump(keys []string) (string, string, time.T
 			break
 		}
 
+		if isBinlog {
+			nearestBinlog = key
+			continue
+		}
+
 		nearestDump = key
 		nearest = bkt
 		if path.Dir(nearestDump) != path.Dir(nearestBinlog) {
diff --git a/backup/restore_test.go b/backup/restore_test.go
index d5959bc5b..2b627fc19 100644
--- a/backup/restore_test.go
+++ b/backup/restore_test.go
@@ -15,6 +15,10 @@ func TestFindNearestDump(t *testing.T) {
 		"moco/test/test/garbage",
 		"moco/test/test/20210526000000/dump.tar", // invalid
 		"moco/test/test/20210526-000000/dump.tar",
+		"moco/test/test/20210527-000000/dump.tar",
+		"moco/test/test/20210527-000000/binlog.tar.zst",
+		"moco/test/test/20210528-000000/dump.tar",
+		"moco/test/test/20210528-000000/binlog.tar.zst",
 	}
 
 	testCases := []struct {
@@ -25,7 +29,7 @@ func TestFindNearestDump(t *testing.T) {
 		expectBinlog string
 		expectTime   time.Time
 	}{
-		{"latest", time.Date(2021, time.May, 26, 0, 0, 0, 0, time.UTC),
+		{"exact", time.Date(2021, time.May, 26, 0, 0, 0, 0, time.UTC),
 			"moco/test/test/20210526-000000/dump.tar", "", time.Date(2021, time.May, 26, 0, 0, 0, 0, time.UTC)},
 		{"up-to-date", time.Date(2021, time.May, 26, 1, 0, 0, 0, time.UTC),
 			"moco/test/test/20210526-000000/dump.tar", "", time.Date(2021, time.May, 26, 0, 0, 0, 0, time.UTC)},
@@ -35,6 +39,10 @@ func TestFindNearestDump(t *testing.T) {
 			"moco/test/test/20210525-112233/dump.tar", "moco/test/test/20210525-112233/binlog.tar.zst",
 			time.Date(2021, time.May, 25, 11, 22, 33, 0, time.UTC)},
 		{"not-found", time.Date(2021, time.May, 24, 0, 0, 0, 0, time.UTC), "", "", time.Time{}},
+		{"#563", time.Date(2021, time.May, 27, 12, 0, 0, 0, time.UTC),
+			"moco/test/test/20210527-000000/dump.tar", "moco/test/test/20210527-000000/binlog.tar.zst",
+			time.Date(2021, time.May, 27, 0, 0, 0, 0, time.UTC),
+		},
 	}
 
 	for _, tc := range testCases {