fnv1_32 and fnv1a_32 in rust

fnv1_32.rs

// see libhashkit/fnv_32.cc from memcached

// Just using this as excuse to test out the Rust lang
// be warned on correctness, completeness, etc

// Should match libhashkit
// should also match https://www.nitrxgen.net/hashgen/


// FNV hash'es lifted from Dustin Sallings work
const FNV_32_INIT: u32 = 2166136261;
const FNV_32_PRIME: u32 = 16777619;


fn main() 
{
    gut_check();
}

fn hashkit_fnv1a_32(key: &Vec<u8>) -> u32 
{
    let mut hash = FNV_32_INIT;
    
    for byte in key.iter() {
        let val = *byte as u32;
        hash ^= val;
        hash = hash.wrapping_mul(FNV_32_PRIME);
    }
    
    return hash;
}



fn hashkit_fnv1_32(key: &Vec<u8>) -> u32 
{
    let mut hash = FNV_32_INIT;
    
    for byte in key.iter() {
        let val = *byte as u32;
        hash = hash.wrapping_mul(FNV_32_PRIME);
        hash ^= val;
    }
    
    return hash;
}


fn gut_check() {
    assert_eq!( hashkit_fnv1a_32( &String::from("helloworld").into_bytes() ), 0x3B9F5C61 );
    assert_eq!( hashkit_fnv1_32 ( &String::from("helloworld").into_bytes() ), 0x944d07a1 );

    
    assert_eq!( hashkit_fnv1a_32( &String::from("rollmostar").into_bytes() ), 0xdbdccafa );
    assert_eq!( hashkit_fnv1_32 ( &String::from("rollmostar").into_bytes() ), 0x32220158 );
}