39 lines
748 B
Go
39 lines
748 B
Go
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package bencode
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import (
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"errors"
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"io"
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)
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// Implements io.ByteScanner over io.Reader, for use in Decoder, to ensure
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// that as little as the undecoded input Reader is consumed as possible.
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type scanner struct {
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r io.Reader
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b [1]byte // Buffer for ReadByte
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unread bool // True if b has been unread, and so should be returned next
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}
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func (me *scanner) Read(b []byte) (int, error) {
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return me.r.Read(b)
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}
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func (me *scanner) ReadByte() (byte, error) {
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if me.unread {
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me.unread = false
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return me.b[0], nil
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}
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n, err := me.r.Read(me.b[:])
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if n == 1 {
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err = nil
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}
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return me.b[0], err
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}
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func (me *scanner) UnreadByte() error {
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if me.unread {
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return errors.New("byte already unread")
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}
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me.unread = true
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return nil
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}
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