Function b2a_uu

crates/stdlib/src/binascii.rs:807–846

(
        data: ArgBytesLike,
        BacktickArg { backtick }: BacktickArg,
        vm: &VirtualMachine,
    )

    #[pyfunction]
    fn b2a_uu(
        data: ArgBytesLike,
        BacktickArg { backtick }: BacktickArg,
        vm: &VirtualMachine,
    ) -> PyResult<Vec<u8>> {
        #[inline]
        const fn uu_b2a(num: u8, backtick: bool) -> u8 {
            if backtick && num == 0 {
                0x60
            } else {
                b' ' + num
            }
        }

        data.with_ref(|b| {
            let length = b.len();
            if length > 45 {
                return Err(super::new_binascii_error(
                    "At most 45 bytes at once".to_owned(),
                    vm,
                ));
            }
            let mut res = Vec::<u8>::with_capacity(2 + length.div_ceil(3) * 4);
            res.push(uu_b2a(length as u8, backtick));

            for chunk in b.chunks(3) {
                let char_a = *chunk.first().unwrap();
                let char_b = *chunk.get(1).unwrap_or(&0);
                let char_c = *chunk.get(2).unwrap_or(&0);

                res.push(uu_b2a(char_a >> 2, backtick));
                res.push(uu_b2a(((char_a & 0x3) << 4) | (char_b >> 4), backtick));
                res.push(uu_b2a(((char_b & 0xf) << 2) | (char_c >> 6), backtick));
                res.push(uu_b2a(char_c & 0x3f, backtick));
            }

            res.push(0xau8);
            Ok(res)
        })
    }
}

struct Base64DecodeError(base64::DecodeError);