k3s/vendor/go.etcd.io/etcd/pkg/v3/ioutil/util.go

44 lines
1.2 KiB
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 ioutil
import (
"io"
"os"
"go.etcd.io/etcd/client/pkg/v3/fileutil"
)
// WriteAndSyncFile behaves just like ioutil.WriteFile in the standard library,
// but calls Sync before closing the file. WriteAndSyncFile guarantees the data
// is synced if there is no error returned.
func WriteAndSyncFile(filename string, data []byte, perm os.FileMode) error {
f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
if err != nil {
return err
}
n, err := f.Write(data)
if err == nil && n < len(data) {
err = io.ErrShortWrite
}
if err == nil {
err = fileutil.Fsync(f)
}
if err1 := f.Close(); err == nil {
err = err1
}
return err
}