public void testAltIndexIsReversible() throws Exception {
final long max = Long.MAX_VALUE - 1L; // must be even!
final long incr = 1000000L;
final Random random = new Random(1L);
final byte[] fingerprint = new byte[1];
for (long index = 0; index != next(index, incr, max); index = next(index, incr, max)) {
random.nextBytes(fingerprint);
int f = (random.nextInt(126) + 1) * (random.nextBoolean() ? 1 : -1);
final long altIndex = MURMUR128_BEALDUPRAS_32.altIndex(index, f, max);
final long altAltIndex = MURMUR128_BEALDUPRAS_32.altIndex(altIndex, f, max);
assertEquals("index should equal altIndex(altIndex(index)):" + f, index, altAltIndex);
}
}
public void testIndexIsModuloM() throws Exception {
final int min = Integer.MIN_VALUE;
final int max = Integer.MAX_VALUE;
final int incr = 100000;
final long m = 0x1DEAL;
for (int hash = min; hash != next(hash, incr, max); hash = next(hash, incr, max)) {
final long index = MURMUR128_BEALDUPRAS_32.index(hash, m);
assertThat(index).isLessThan(m);
assertThat(index).isGreaterThan(-1L);
}
}
public void testFingerprintBoundaries() throws Exception {
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0x80000000, 1)).isEqualTo(0x01);
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0xC0000000, 2)).isEqualTo(0x03);
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0xE0000000, 3)).isEqualTo(0x04);
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0xE0000000, 8)).isEqualTo(0xE0);
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0xE0000000, 16)).isEqualTo(0xE000);
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0x80000000, Integer.SIZE)).isEqualTo(0x80000000);
for (int f = 1; f < Integer.SIZE; f++) {
assertThat(MURMUR128_BEALDUPRAS_32.fingerprint(0x00, f)).isNotEqualTo(0x00);
}
}