https://github.com/etcd-io/etcd
Tip revision: e348b1aedd9167360c466ae98f7343d3e22281f8 authored by Gyuho Lee on 28 March 2018, 20:00:06 UTC
version: 3.3.3
version: 3.3.3
Tip revision: e348b1a
db.go
// Copyright 2015 The etcd Authors
//
// 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 snap
import (
"errors"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"github.com/coreos/etcd/pkg/fileutil"
)
var ErrNoDBSnapshot = errors.New("snap: snapshot file doesn't exist")
// SaveDBFrom saves snapshot of the database from the given reader. It
// guarantees the save operation is atomic.
func (s *Snapshotter) SaveDBFrom(r io.Reader, id uint64) (int64, error) {
f, err := ioutil.TempFile(s.dir, "tmp")
if err != nil {
return 0, err
}
var n int64
n, err = io.Copy(f, r)
if err == nil {
err = fileutil.Fsync(f)
}
f.Close()
if err != nil {
os.Remove(f.Name())
return n, err
}
fn := s.dbFilePath(id)
if fileutil.Exist(fn) {
os.Remove(f.Name())
return n, nil
}
err = os.Rename(f.Name(), fn)
if err != nil {
os.Remove(f.Name())
return n, err
}
plog.Infof("saved database snapshot to disk [total bytes: %d]", n)
return n, nil
}
// DBFilePath returns the file path for the snapshot of the database with
// given id. If the snapshot does not exist, it returns error.
func (s *Snapshotter) DBFilePath(id uint64) (string, error) {
if _, err := fileutil.ReadDir(s.dir); err != nil {
return "", err
}
if fn := s.dbFilePath(id); fileutil.Exist(fn) {
return fn, nil
}
return "", ErrNoDBSnapshot
}
func (s *Snapshotter) dbFilePath(id uint64) string {
return filepath.Join(s.dir, fmt.Sprintf("%016x.snap.db", id))
}