public int hashLong(long input) {
        int low = (int) input;
        int high = (int) (input >>> 32);

        int k1 = mixK1(low);
        int h1 = mixH1(seed, k1);

        k1 = mixK1(high);
        h1 = mixH1(h1, k1);

        return fmix(h1, 8);
    }
32-bit Murmur3 hasher.  This is based on Guava's Murmur3_32HashFunction.
indexr-common/src/main/java/io/indexr/util/Hasher32.java