codeberg-forgejo/modules/util/io.go

43 lines
975 B
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package util
import (
"errors"
"io"
)
// ReadAtMost reads at most len(buf) bytes from r into buf.
// It returns the number of bytes copied. n is only less than len(buf) if r provides fewer bytes.
// If EOF occurs while reading, err will be nil.
func ReadAtMost(r io.Reader, buf []byte) (n int, err error) {
n, err = io.ReadFull(r, buf)
if err == io.EOF || err == io.ErrUnexpectedEOF {
err = nil
}
return n, err
}
// ErrNotEmpty is an error reported when there is a non-empty reader
var ErrNotEmpty = errors.New("not-empty")
// IsEmptyReader reads a reader and ensures it is empty
func IsEmptyReader(r io.Reader) (err error) {
var buf [1]byte
for {
n, err := r.Read(buf[:])
if err != nil {
if err == io.EOF {
return nil
}
return err
}
if n > 0 {
return ErrNotEmpty
}
}
}