metrohash 1.0.2

use super::{MetroHash128, MetroHash64};
use std::mem::{self, size_of};
use std::fmt::Write;
use std::hash::Hasher;

const TEST_KEY_63: &'static [u8] = b"012345678901234567890123456789012345678901234567890123456789012";

fn hexlify<T>(value: &T) -> String {
    let mut result = String::with_capacity(size_of::<T>());
    unsafe {
        let value_bytes: *const u8 = mem::transmute(value);
        for i in 0..result.capacity() {
            write!(result, "{:02X}", *value_bytes.offset(i as isize)).unwrap();
        }
    }
    result
}

macro_rules! impl_test {
	($test_fn: ident, $test_hasher: ident, $seed: expr, $expected: expr) => (
		#[test]
		fn $test_fn() {
			let mut hasher = $test_hasher::with_seed($seed);
			hasher.write(TEST_KEY_63);
			let hash = hasher.finish();
			assert_eq!(hexlify(&hash), hexlify(&$expected));
		}
	)
}

// seed = 0
impl_test!(
    test_metrohash64_0,
    MetroHash64,
    0,
    [0x6Bu8, 0x75, 0x3D, 0xAE, 0x06, 0x70, 0x4B, 0xAD]
);
// seed = 1
impl_test!(
    test_metrohash64_1,
    MetroHash64,
    1,
    [0x3Bu8, 0x0D, 0x48, 0x1C, 0xF4, 0xB9, 0xB8, 0xDF]
);
// seed = 0
impl_test!(
    test_metrohash128_0,
    MetroHash128,
    0,
    [
        0xC7u8,
        0x7C,
        0xE2,
        0xBF,
        0xA4,
        0xED,
        0x9F,
        0x9B /*0x05, 0x48, 0xB2, 0xAC, 0x50, 0x74, 0xA2, 0x97*/
    ]
);
// seed = 1
impl_test!(
    test_metrohash128_1,
    MetroHash128,
    1,
    [
        0x45u8,
        0xA3,
        0xCD,
        0xB8,
        0x38,
        0x19,
        0x9D,
        0x7F /*0xBD, 0xD6, 0x8D, 0x86, 0x7A, 0x14, 0xEC, 0xEF*/
    ]
);