40 lines
852 B
Go
40 lines
852 B
Go
// Copyright 2014-2019 Ulrich Kunitz. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package lzma
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import (
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"errors"
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"io"
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)
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// breader provides the ReadByte function for a Reader. It doesn't read
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// more data from the reader than absolutely necessary.
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type breader struct {
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io.Reader
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// helper slice to save allocations
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p []byte
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}
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// ByteReader converts an io.Reader into an io.ByteReader.
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func ByteReader(r io.Reader) io.ByteReader {
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br, ok := r.(io.ByteReader)
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if !ok {
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return &breader{r, make([]byte, 1)}
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}
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return br
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}
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// ReadByte read byte function.
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func (r *breader) ReadByte() (c byte, err error) {
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n, err := r.Reader.Read(r.p)
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if n < 1 {
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if err == nil {
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err = errors.New("breader.ReadByte: no data")
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}
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return 0, err
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}
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return r.p[0], nil
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}
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