k3s/vendor/go.etcd.io/etcd/pkg/ioutil/readcloser.go

67 lines
1.6 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 (
"fmt"
"io"
)
// ReaderAndCloser implements io.ReadCloser interface by combining
// reader and closer together.
type ReaderAndCloser struct {
io.Reader
io.Closer
}
var (
ErrShortRead = fmt.Errorf("ioutil: short read")
ErrExpectEOF = fmt.Errorf("ioutil: expect EOF")
)
// NewExactReadCloser returns a ReadCloser that returns errors if the underlying
// reader does not read back exactly the requested number of bytes.
func NewExactReadCloser(rc io.ReadCloser, totalBytes int64) io.ReadCloser {
return &exactReadCloser{rc: rc, totalBytes: totalBytes}
}
type exactReadCloser struct {
rc io.ReadCloser
br int64
totalBytes int64
}
func (e *exactReadCloser) Read(p []byte) (int, error) {
n, err := e.rc.Read(p)
e.br += int64(n)
if e.br > e.totalBytes {
return 0, ErrExpectEOF
}
if e.br < e.totalBytes && n == 0 {
return 0, ErrShortRead
}
return n, err
}
func (e *exactReadCloser) Close() error {
if err := e.rc.Close(); err != nil {
return err
}
if e.br < e.totalBytes {
return ErrShortRead
}
return nil
}