x/src/hash.rs

const INITIAL_STATE: u64 = 0xcbf29ce484222325;
const PRIME: u64 = 0x100000001b3;

//noinspection DuplicatedCode
pub const fn hash(bytes: &[u8]) -> u64 {
    let mut hash = INITIAL_STATE;
    let mut i = 0;
    while i < bytes.len() {
        hash = hash ^ bytes[i] as u64;
        hash = hash.wrapping_mul(PRIME);
        i += 1;
    }
    hash
}

//noinspection DuplicatedCode
pub const fn hash32(bytes: &[u32]) -> u64 {
    let mut hash = INITIAL_STATE;
    let mut i = 0;
    while i < bytes.len() {
        hash = hash ^ bytes[i] as u64;
        hash = hash.wrapping_mul(PRIME);
        i += 1;
    }
    hash
}

//noinspection DuplicatedCode
pub const fn hash64(bytes: &[u64]) -> u64 {
    let mut hash = INITIAL_STATE;
    let mut i = 0;
    while i < bytes.len() {
        hash = hash ^ bytes[i];
        hash = hash.wrapping_mul(PRIME);
        i += 1;
    }
    hash
}

//noinspection DuplicatedCode
pub const fn hash_utf8(bytes: &[u8]) -> u64 {
    let mut hash = INITIAL_STATE;
    let mut i = 0;
    while i < bytes.len() {

        let char = match bytes[i] {
            0x40..=0x5A => bytes[i] + 0x20,
            _ => bytes[i],
        } as u64;

        hash = hash ^ (char);
        hash = hash.wrapping_mul(PRIME);
        i += 1;
    }
    hash
}

//noinspection DuplicatedCode
pub const fn hash_utf16(bytes: &[u16]) -> u64 {
    let mut hash = INITIAL_STATE;
    let mut i = 0;
    while i < bytes.len() {

        let char = match bytes[i] {
            0x40..=0x5A => bytes[i] + 0x20,
            _ => bytes[i],
        } as u64;

        hash = hash ^ (char);
        hash = hash.wrapping_mul(PRIME);
        i += 1;
    }
    hash
}