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package binutil
import (
"io"
"os"
)
type SizedReader interface {
io.Reader
Size() int64
}
type SizedFile struct {
f *os.File
s *io.SectionReader // helper, for Size()
}
func (r *SizedFile) Read(p []byte) (n int, err error) { return r.s.Read(p) }
func (r *SizedFile) Size() int64 { return r.s.Size() }
func (r *SizedFile) Close() error { return r.f.Close() }
func SizedOpen(filename string) (*SizedFile, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
info, err := f.Stat()
if err != nil {
return nil, err
}
return &SizedFile{
f: f,
s: io.NewSectionReader(f, 0, info.Size()),
}, nil
}
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