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mod consts;
pub fn encode(input: &[u8]) -> String {
if input.len() == 0 {
return String::new();
}
if input.len() == 1 {
return String::from(consts::SUFFIXES[input[0] as usize]);
}
let should_pad = input.len() % 2 != 0;
let length = input.len() + should_pad as usize;
let dashes = if input.len() > 2 { length / 2 - 1 } else { 0 };
let capacity = length * 3 + dashes;
let mut output = String::with_capacity(capacity);
if should_pad {
output.push_str(consts::PREFIXES[0]);
}
let mut dashes_placed = 0;
let iter = input.rchunks_exact(2);
let remainder = iter.remainder();
if remainder.len() != 0 {
output.push_str(consts::SUFFIXES[remainder[0] as usize]);
if dashes_placed != dashes {
output.push('-');
dashes_placed += 1;
}
}
for pair in iter.rev() {
output.push_str(consts::PREFIXES[pair[0] as usize]);
output.push_str(consts::SUFFIXES[pair[1] as usize]);
if dashes_placed != dashes {
output.push('-');
dashes_placed += 1;
}
}
output
}
pub fn decode(input: &str) -> Option<Vec<u8>> {
if !input.is_ascii() {
return None;
}
let stripped_input = input.replace(&['-', ' '][..], "");
if stripped_input.len() == 3 {
return Some(vec![*consts::SUFFIXES_MAP.get(&stripped_input[..])?]);
}
if stripped_input.len() % 3 != 0 {
return None;
}
let capacity = stripped_input.len() / 3;
let mut output: Vec<u8> = Vec::with_capacity(capacity);
for i in (0..stripped_input.len()).step_by(6) {
output.push(*consts::PREFIXES_MAP.get(&stripped_input[i..i + 3])?);
if stripped_input.len() >= i + 6 {
output.push(*consts::SUFFIXES_MAP.get(&stripped_input[i + 3..i + 6])?);
}
}
Some(output)
}