txn_gorm.go

// Copyright 2022 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"gorm.io/gorm"
)

// TiDBGormBegin start a TiDB and Gorm transaction as a block. If no error is returned, the transaction will be committed. Otherwise, the transaction will be rolled back.
func TiDBGormBegin(db *gorm.DB, pessimistic bool, fc func(tx *gorm.DB) error) (err error) {
	session := db.Session(&gorm.Session{})
	if session.Error != nil {
		return session.Error
	}

	if pessimistic {
		session = session.Exec("set @@tidb_txn_mode=pessimistic")
	} else {
		session = session.Exec("set @@tidb_txn_mode=optimistic")
	}

	if session.Error != nil {
		return session.Error
	}
	return session.Transaction(fc)
}