tidb db_writer 代码
文件路径：/store/mockstore/unistore/tikv/mvcc/db_writer.go
/ Copyright 2019-present 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 mvcc
import (
"sync"
"github.com/pingcap/badger"
"github.com/pingcap/kvproto/pkg/kvrpcpb"
"github.com/pingcap/tidb/store/mockstore/unistore/lockstore"
)
/ DBWriter is the interface to persistent data.
type DBWriter interface {
Open()
Close()
Write(batch WriteBatch) error
DeleteRange(start, end []byte, latchHandle LatchHandle) error
NewWriteBatch(startTS, commitTS uint64, ctx *kvrpcpb.Context) WriteBatch
}
/ LatchHandle is the interface for handling latches.
type LatchHandle interface {
AcquireLatches(hashVals []uint64)
ReleaseLatches(hashVals []uint64)
}
/ WriteBatch is the interface to batch write.
type WriteBatch interface {
Prewrite(key []byte, lock *Lock)
Commit(key []byte, lock *Lock)
Rollback(key []byte, deleleLock bool)
PessimisticLock(key []byte, lock *Lock)
PessimisticRollback(key []byte)
}
/ DBBundle represents the db bundle.
type DBBundle struct {
DB *badger.DB
LockStore *lockstore.MemStore
MemStoreMu sync.Mutex
StateTS uint64
}
/ DBSnapshot represents the db snapshot.
type DBSnapshot struct {
Txn *badger.Txn
LockStore *lockstore.MemStore
}
/ NewDBSnapshot returns a new db snapshot.
func NewDBSnapshot(db *DBBundle) *DBSnapshot {
return &DBSnapshot{
Txn: db.DB.NewTransaction(false),
LockStore: db.LockStore,
}
}