| // 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" |
| ) |
| |
| // ErrLimit indicates that the limit of the LimitedByteWriter has been |
| // reached. |
| var ErrLimit = errors.New("limit reached") |
| |
| // LimitedByteWriter provides a byte writer that can be written until a |
| // limit is reached. The field N provides the number of remaining |
| // bytes. |
| type LimitedByteWriter struct { |
| BW io.ByteWriter |
| N int64 |
| } |
| |
| // WriteByte writes a single byte to the limited byte writer. It returns |
| // ErrLimit if the limit has been reached. If the byte is successfully |
| // written the field N of the LimitedByteWriter will be decremented by |
| // one. |
| func (l *LimitedByteWriter) WriteByte(c byte) error { |
| if l.N <= 0 { |
| return ErrLimit |
| } |
| if err := l.BW.WriteByte(c); err != nil { |
| return err |
| } |
| l.N-- |
| return nil |
| } |