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path: root/ber/len.go
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package ber

func UnmarshalLen(b []byte) (i, n int) {
	if b[0]&0x80 == 0 {
		return int(b[0]), 1
	}
	n = int(b[0] & 0x7f)
	for k := n; k > 0; k-- {
		i += int(b[k]) << uint((k-1)*8)
	}
	return i, n + 1
}

func lenLen(i int) (n int) {
	for i > 255 {
		n++
		i >>= 8
	}
	return n + 1
}

func MarshalLen(i int) (b []byte) {
	if i < 0x80 {
		return []byte{byte(i)}
	}
	n := lenLen(i)
	b = append(b, byte(n)|0x80)
	for ; n > 0; n-- {
		b = append(b, byte(i>>uint((n-1)*8)))
	}
	return
}