use crate::{decode_inner, encoded_len, Error};
#[cfg(feature = "alloc")]
use crate::{decoded_len, String, Vec};
pub fn decode(src: impl AsRef<[u8]>, dst: &mut [u8]) -> Result<&[u8], Error> {
decode_inner(src.as_ref(), dst, decode_nibble)
}
#[cfg(feature = "alloc")]
pub fn decode_vec(input: impl AsRef<[u8]>) -> Result<Vec<u8>, Error> {
let mut output = vec![0u8; decoded_len(input.as_ref())?];
decode(input, &mut output)?;
Ok(output)
}
pub fn encode<'a>(src: &[u8], dst: &'a mut [u8]) -> Result<&'a [u8], Error> {
let dst = dst
.get_mut(..encoded_len(src))
.ok_or(Error::InvalidLength)?;
for (src, dst) in src.iter().zip(dst.chunks_exact_mut(2)) {
dst[0] = encode_nibble(src >> 4);
dst[1] = encode_nibble(src & 0x0f);
}
Ok(dst)
}
pub fn encode_str<'a>(src: &[u8], dst: &'a mut [u8]) -> Result<&'a str, Error> {
encode(src, dst).map(|r| unsafe { core::str::from_utf8_unchecked(r) })
}
#[cfg(feature = "alloc")]
pub fn encode_string(input: &[u8]) -> String {
let elen = encoded_len(input);
let mut dst = vec![0u8; elen];
let res = encode(input, &mut dst).expect("dst length is correct");
debug_assert_eq!(elen, res.len());
unsafe { crate::String::from_utf8_unchecked(dst) }
}
#[inline(always)]
fn decode_nibble(src: u8) -> u16 {
let byte = src as i16;
let mut ret: i16 = -1;
ret += (((0x2fi16 - byte) & (byte - 0x3a)) >> 8) & (byte - 47);
ret += (((0x40i16 - byte) & (byte - 0x47)) >> 8) & (byte - 54);
ret as u16
}
#[inline(always)]
fn encode_nibble(src: u8) -> u8 {
let mut ret = src as i16 + 0x30;
ret += ((0x39i16 - ret) >> 8) & (0x41i16 - 0x3a);
ret as u8
}