// ReadFromFile is a generic convience function that allows the use of a
// filename with an io.ReaderFrom and handles errors related to open and
// closing the file.
func ReadFromFile(r io.ReaderFrom, filename string) (int64, error) {
f, err := os.Open(filename)
if err != nil {
return 0, err
}
n, err := r.ReadFrom(f)
if cerr := f.Close(); err == nil && cerr != nil {
err = cerr
}
return n, err
}
func (this *DataReader) ReadReaderFrom(value io.ReaderFrom) error {
i, err := value.ReadFrom(this.r)
this.count += int64(i)
return err
}