/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.driver.core.utils;
import com.datastax.driver.core.ProtocolVersion;
import com.datastax.driver.core.TypeCodec;
import org.testng.annotations.Test;
import java.nio.ByteBuffer;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.ConcurrentSkipListSet;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertTrue;
public class UUIDsTest {
@Test(groups = "unit")
public void conformanceTest() {
// The UUIDs class does some computation at class initialization, which
// may screw up our assumption below that UUIDs.timeBased() takes less
// than 10ms, so force class loading now.
UUIDs.random();
long now = System.currentTimeMillis();
UUID uuid = UUIDs.timeBased();
assertEquals(uuid.version(), 1);
assertEquals(uuid.variant(), 2);
long tstamp = UUIDs.unixTimestamp(uuid);
// Check now and the uuid timestamp are within 10 millisseconds.
assert now <= tstamp && now >= tstamp - 10 : String.format("now = %d, tstamp = %d", now, tstamp);
}
@Test(groups = "unit")
public void uniquenessTest() {
// Generate 1M uuid and check we never have twice the same one
int nbGenerated = 1000000;
Set<UUID> generated = new HashSet<UUID>(nbGenerated);
for (int i = 0; i < nbGenerated; ++i)
generated.add(UUIDs.timeBased());
assertEquals(generated.size(), nbGenerated);
}
@Test(groups = "unit")
public void multiThreadUniquenessTest() throws Exception {
int nbThread = 10;
int nbGenerated = 10000;
Set<UUID> generated = new ConcurrentSkipListSet<UUID>();
UUIDGenerator[] generators = new UUIDGenerator[nbThread];
for (int i = 0; i < nbThread; i++)
generators[i] = new UUIDGenerator(nbGenerated, generated);
for (int i = 0; i < nbThread; i++)
generators[i].start();
for (int i = 0; i < nbThread; i++)
generators[i].join();
assertEquals(generated.size(), nbThread * nbGenerated);
}
@Test(groups = "unit")
public void timestampIncreasingTest() {
// Generate 1M uuid and check timestamp are always increasing
int nbGenerated = 1000000;
long previous = 0;
for (int i = 0; i < nbGenerated; ++i) {
long current = UUIDs.timeBased().timestamp();
assert previous < current : String.format("previous = %d >= %d = current", previous, current);
}
}
@Test(groups = "unit")
public void startEndOfTest() {
Random random = new Random(System.currentTimeMillis());
int nbTstamp = 10;
int nbPerTstamp = 10;
for (int i = 0; i < nbTstamp; i++) {
long tstamp = (long) random.nextInt();
for (int j = 0; j < nbPerTstamp; j++) {
assertWithin(new UUID(UUIDs.makeMSB(UUIDs.fromUnixTimestamp(tstamp)), random.nextLong()), UUIDs.startOf(tstamp), UUIDs.endOf(tstamp));
}
}
}
private static void assertWithin(UUID uuid, UUID lowerBound, UUID upperBound) {
ByteBuffer uuidBytes = TypeCodec.uuid().serialize(uuid, ProtocolVersion.V1);
ByteBuffer lb = TypeCodec.uuid().serialize(lowerBound, ProtocolVersion.V1);
ByteBuffer ub = TypeCodec.uuid().serialize(upperBound, ProtocolVersion.V1);
assertTrue(compareTimestampBytes(lb, uuidBytes) <= 0);
assertTrue(compareTimestampBytes(ub, uuidBytes) >= 0);
}
private static int compareTimestampBytes(ByteBuffer o1, ByteBuffer o2) {
int o1Pos = o1.position();
int o2Pos = o2.position();
int d = (o1.get(o1Pos + 6) & 0xF) - (o2.get(o2Pos + 6) & 0xF);
if (d != 0) return d;
d = (o1.get(o1Pos + 7) & 0xFF) - (o2.get(o2Pos + 7) & 0xFF);
if (d != 0) return d;
d = (o1.get(o1Pos + 4) & 0xFF) - (o2.get(o2Pos + 4) & 0xFF);
if (d != 0) return d;
d = (o1.get(o1Pos + 5) & 0xFF) - (o2.get(o2Pos + 5) & 0xFF);
if (d != 0) return d;
d = (o1.get(o1Pos) & 0xFF) - (o2.get(o2Pos) & 0xFF);
if (d != 0) return d;
d = (o1.get(o1Pos + 1) & 0xFF) - (o2.get(o2Pos + 1) & 0xFF);
if (d != 0) return d;
d = (o1.get(o1Pos + 2) & 0xFF) - (o2.get(o2Pos + 2) & 0xFF);
if (d != 0) return d;
return (o1.get(o1Pos + 3) & 0xFF) - (o2.get(o2Pos + 3) & 0xFF);
}
private static class UUIDGenerator extends Thread {
private final int toGenerate;
private final Set<UUID> generated;
UUIDGenerator(int toGenerate, Set<UUID> generated) {
this.toGenerate = toGenerate;
this.generated = generated;
}
@Override
public void run() {
for (int i = 0; i < toGenerate; ++i)
generated.add(UUIDs.timeBased());
}
}
}