pub fn encode(set: &Vec<Vec<u8>>) -> Vec<u8> {
if set.is_empty() {
vec![0_u8]
} else {
set
.iter()
.map(|x| {
let len: usize = x.len();
if len == 0 {
vec![0_u8, 0_u8]
} else {
let mut len_buf: Vec<u8> = len.to_le_bytes().to_vec();
while len_buf[len_buf.len() - 1] == 0 {
len_buf.remove(len_buf.len() - 1);
}
len_buf.push(0);
[len_buf, x.to_vec()].concat()
}
})
.fold(vec![], |acc, x| [acc,x].concat())
}
}
pub fn decode(astro: &Vec<u8>) -> Vec<Vec<u8>> {
let mut set: Vec<Vec<u8>> = Vec::new();
if astro != &vec![0_u8] {
let mut i: usize = 0;
let usize_bytes = (usize::BITS/8) as usize;
while i < astro.len() {
if astro[i] == 0 {
set.push(Vec::new());
i += 2
} else {
let mut len_buf: Vec<u8> = Vec::new();
while astro[i] != 0 {
len_buf.push(astro[i]);
i += 1
}
i += 1;
if len_buf.len() > usize_bytes {
break
} else {
while len_buf.len() < usize_bytes {
len_buf.push(0);
}
let len: usize = usize::from_le_bytes(len_buf.try_into().unwrap());
let buf: Vec<u8> = astro[i..(i + len)].to_vec();
i += len;
set.push(buf)
}
}
}
}
set
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn one_bytes() {
let set: Vec<Vec<u8>> = vec![vec![1,2,3]];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
#[test]
fn three_bytes() {
let set: Vec<Vec<u8>> = vec![vec![1,2,3], vec![4,5,6], vec![7,8,9]];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
#[test]
fn empty_set() {
let set: Vec<Vec<u8>> = vec![];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
#[test]
fn one_empty_bytes() {
let set: Vec<Vec<u8>> = vec![vec![]];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
#[test]
fn three_empty_bytes() {
let set: Vec<Vec<u8>> = vec![vec![], vec![], vec![]];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
#[test]
fn two_empty_bytes() {
let set: Vec<Vec<u8>> = vec![vec![1,2,3], vec![], vec![7,8,9]];
let astro = encode(&set);
assert_eq!(set, decode(&astro));
}
}