func (buf *fileBuffer) UnmarshalBinary(data []byte) error {
buffer := bytes.NewBuffer(data)
var filename string
var N, L, O int64
_, err := fmt.Fscanln(buffer, &filename)
file, err := os.Open(filename)
if err != nil {
return err
}
buf.file = file
_, err = fmt.Fscanln(buffer, &N, &L, &O)
buf.Wrapper = wrapio.NewWrapper(file, L, O, N)
return nil
}
// NewFile returns a new BufferAt backed by "file" with max-size N.
func NewFile(N int64, file File) BufferAt {
return &fileBuffer{
file: file,
Wrapper: wrapio.NewWrapper(file, 0, 0, N),
}
}