Senbei/senbei-crypto/src/crc32.rs

const fn build_table() -> [u32; 256] {
    let mut table = [0u32; 256];
    let mut i = 0;
    while i < 256 {
        let mut c = i as u32;
        let mut k = 0;
        while k < 8 {
            c = if c & 1 != 0 {
                0xEDB8_8320 ^ (c >> 1)
            } else {
                c >> 1
            };
            k += 1;
        }
        table[i] = c;
        i += 1;
    }
    table
}

const TABLE: [u32; 256] = build_table();

pub fn append(initial: u32, data: &[u8]) -> u32 {
    let mut crc = !initial;
    for &b in data {
        crc = TABLE[((crc ^ b as u32) & 0xFF) as usize] ^ (crc >> 8);
    }
    !crc
}

pub fn compute(data: &[u8]) -> u32 {
    append(0, data)
}