From 29f65824f9037cb12e716593ad676e717fc1b0a1 Mon Sep 17 00:00:00 2001
From: Athurg Feng <athurg@gooth.org>
Date: Mon, 13 Nov 2023 19:19:51 +0800
Subject: [PATCH] Add support for rotate backup files

---
 server/server.go                | 12 +++++++---
 server/service/backup/backup.go | 39 ++++++++++++++++++++++++++++-----
 2 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/server/server.go b/server/server.go
index 080d3f7415df4..c0e8fe853471a 100644
--- a/server/server.go
+++ b/server/server.go
@@ -52,8 +52,11 @@ func NewServer(ctx context.Context, profile *profile.Profile, store *store.Store
 		Profile: profile,
 
 		// Asynchronous runners.
-		backupRunner: backup.NewBackupRunner(store),
-		telegramBot:  telegram.NewBotWithHandler(integration.NewTelegramHandler(store)),
+		telegramBot: telegram.NewBotWithHandler(integration.NewTelegramHandler(store)),
+	}
+
+	if profile.Driver == "sqlite" {
+		s.backupRunner = backup.NewBackupRunner(store)
 	}
 
 	e.Use(middleware.LoggerWithConfig(middleware.LoggerConfig{
@@ -112,7 +115,10 @@ func NewServer(ctx context.Context, profile *profile.Profile, store *store.Store
 func (s *Server) Start(ctx context.Context) error {
 	go versionchecker.NewVersionChecker(s.Store, s.Profile).Start(ctx)
 	go s.telegramBot.Start(ctx)
-	go s.backupRunner.Run(ctx)
+
+	if s.backupRunner != nil {
+		go s.backupRunner.Run(ctx)
+	}
 
 	metric.Enqueue("server start")
 	return s.e.Start(fmt.Sprintf("%s:%d", s.Profile.Addr, s.Profile.Port))
diff --git a/server/service/backup/backup.go b/server/service/backup/backup.go
index 399d586dd79f3..b979aa38ec850 100644
--- a/server/service/backup/backup.go
+++ b/server/service/backup/backup.go
@@ -3,6 +3,7 @@ package backup
 import (
 	"context"
 	"fmt"
+	"os"
 	"strconv"
 	"time"
 
@@ -24,6 +25,8 @@ func NewBackupRunner(store *store.Store) *BackupRunner {
 	}
 }
 
+const MaxBackupFiles = 5
+
 func (r *BackupRunner) Run(ctx context.Context) {
 	intervalStr := r.Store.GetSystemSettingValueWithDefault(ctx, apiv1.SystemSettingAutoBackupIntervalName.String(), "")
 	if intervalStr == "" {
@@ -46,20 +49,46 @@ func (r *BackupRunner) Run(ctx context.Context) {
 	ticker := time.NewTicker(time.Duration(interval) * time.Second)
 	defer ticker.Stop()
 
-	var t time.Time
 	for {
 		select {
 		case <-ctx.Done():
 			log.Info("stop auto backup graceful.")
 			return
-		case t = <-ticker.C:
+		case <-ticker.C:
+		}
+
+		filename := r.Store.Profile.DSN + ".bak"
+
+		if err := rotateFiles(filename, MaxBackupFiles); err != nil {
+			log.Error("fail to rotate backup files", zap.Error(err))
+			continue
 		}
 
-		filename := r.Store.Profile.DSN + t.Format("-20060102-150405.bak")
 		log.Info(fmt.Sprintf("create backup to %s", filename))
-		err := r.Store.BackupTo(ctx, filename)
-		if err != nil {
+		if err := r.Store.BackupTo(ctx, filename); err != nil {
 			log.Error("fail to create backup", zap.Error(err))
 		}
 	}
 }
+
+func rotateFiles(filename string, cnt int) error {
+	// Generate suffix slices of history files like "",".1",".2",".3"...
+	ss := make([]string, cnt-1)
+	for i := 1; i < len(ss); i++ {
+		ss[i] = fmt.Sprintf(".%d", i)
+	}
+
+	// Iterate through the suffix slices and rename the files
+	for i := len(ss) - 1; i >= 0; i-- {
+		from := filename + ss[i]
+		to := filename + "." + strconv.Itoa(i+1)
+
+		log.Info("rotate file", zap.String("from", from), zap.String("to", to))
+		err := os.Rename(from, to)
+		if err != nil && !os.IsNotExist(err) {
+			return err
+		}
+	}
+
+	return nil
+}