39 lines
852 B
Go
Vendored
39 lines
852 B
Go
Vendored
// Copyright 2014-2021 Ulrich Kunitz. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package lzma
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
)
|
|
|
|
// breader provides the ReadByte function for a Reader. It doesn't read
|
|
// more data from the reader than absolutely necessary.
|
|
type breader struct {
|
|
io.Reader
|
|
// helper slice to save allocations
|
|
p []byte
|
|
}
|
|
|
|
// ByteReader converts an io.Reader into an io.ByteReader.
|
|
func ByteReader(r io.Reader) io.ByteReader {
|
|
br, ok := r.(io.ByteReader)
|
|
if !ok {
|
|
return &breader{r, make([]byte, 1)}
|
|
}
|
|
return br
|
|
}
|
|
|
|
// ReadByte read byte function.
|
|
func (r *breader) ReadByte() (c byte, err error) {
|
|
n, err := r.Reader.Read(r.p)
|
|
if n < 1 {
|
|
if err == nil {
|
|
err = errors.New("breader.ReadByte: no data")
|
|
}
|
|
return 0, err
|
|
}
|
|
return r.p[0], nil
|
|
}
|