chore: migrate database in background

* do database migration in background for fast startup time
* the caveat is: for the first time startup, service is not available until the migration is done

model/main.go

@@ -1,14 +1,16 @@
 package model
 
 import (
-	"gorm.io/driver/mysql"
-	"gorm.io/driver/postgres"
-	"gorm.io/driver/sqlite"
-	"gorm.io/gorm"
+	"fmt"
 	"one-api/common"
 	"os"
 	"strings"
 	"time"
+
+	"gorm.io/driver/mysql"
+	"gorm.io/driver/postgres"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
 )
 
 var DB *gorm.DB
@@ -82,7 +84,32 @@ func InitDB() (err error) {
 		if !common.IsMasterNode {
 			return nil
 		}
+
+		// migrate database in the background, to avoid blocking application startup
+		go func() {
+			err = migrateDB(db)
+			if err != nil {
+				common.FatalLog(fmt.Errorf("migrateDB error: %v", err))
+			}
+		}()
+	} else {
+		common.FatalLog(err)
+	}
+	return err
+}
+
+func CloseDB() error {
+	sqlDB, err := DB.DB()
+	if err != nil {
+		return err
+	}
+	err = sqlDB.Close()
+	return err
+}
+
+func migrateDB(db *gorm.DB) error {
 	common.SysLog("database migration started")
+	var err error
 	err = db.AutoMigrate(&Channel{})
 	if err != nil {
 		return err
@@ -114,17 +141,4 @@ func InitDB() (err error) {
 	common.SysLog("database migrated")
 	err = createRootAccountIfNeed()
 	return err
-	} else {
-		common.FatalLog(err)
-	}
-	return err
-}
-
-func CloseDB() error {
-	sqlDB, err := DB.DB()
-	if err != nil {
-		return err
-	}
-	err = sqlDB.Close()
-	return err
 }