Updated UlidBasedGuidCreator

README.md

@@ -18,12 +18,6 @@ Create a ULID as GUID object:
 UUID ulid = UlidCreator.getGuid();
 ```
 
-Create a ULID as byte sequence:
-
-```java
-byte[] ulid = UlidCreator.getBytes();
-```
-
 ### Maven dependency
 
 Add these lines to your `pom.xml`.

src/main/java/com/github/f4b6a3/ulid/UlidCreator.java

@@ -45,7 +45,7 @@ public class UlidCreator {
 	 * @return a GUID
 	 */
 	public static UUID getUlid() {
-		return GuidCreatorLazyHolder.INSTANCE.createGuid();
+		return GuidCreatorLazyHolder.INSTANCE.create();
 	}
 
 	/**
@@ -54,7 +54,7 @@ public class UlidCreator {
 	 * @return a GUID
 	 */
 	public static UUID getFastUlid() {
-		return FastGuidCreatorLazyHolder.INSTANCE.createGuid();
+		return FastGuidCreatorLazyHolder.INSTANCE.create();
 	}
 
 	/**
@@ -86,15 +86,15 @@ public class UlidCreator {
 	 * 
 	 * @return a {@link UlidBasedGuidCreator}
 	 */
-	public static UlidBasedGuidCreator getGuidCreator() {
+	public static UlidBasedGuidCreator getUlidBasedCreator() {
 		return new UlidBasedGuidCreator();
 	}
 
 	private static class GuidCreatorLazyHolder {
-		static final UlidBasedGuidCreator INSTANCE = getGuidCreator();
+		static final UlidBasedGuidCreator INSTANCE = getUlidBasedCreator();
 	}
 
 	private static class FastGuidCreatorLazyHolder {
-		static final UlidBasedGuidCreator INSTANCE = getGuidCreator().withFastRandomGenerator();
+		static final UlidBasedGuidCreator INSTANCE = getUlidBasedCreator().withFastRandomGenerator();
 	}
 }

src/main/java/com/github/f4b6a3/ulid/creator/UlidBasedGuidCreator.java

@@ -124,7 +124,7 @@ public class UlidBasedGuidCreator {
 	 * @throws UlidCreatorException an overrun exception if too many requests are
 	 *                              made within the same millisecond.
 	 */
-	public synchronized UUID createGuid() {
+	public synchronized UUID create() {
 
 		final long timestamp = this.getTimestamp();
 
@@ -143,7 +143,7 @@ public class UlidBasedGuidCreator {
 	 * @return a ULID string
 	 */
 	public synchronized String createString() {
-		UUID guid = createGuid();
+		UUID guid = create();
 		return UlidUtil.fromUuidToUlid(guid);
 	}
 

src/test/java/com/github/f4b6a3/Benchmarks.java

@@ -42,29 +42,29 @@ public class Benchmarks {
 	@Benchmark
 	@BenchmarkMode(Mode.Throughput)
 	@OutputTimeUnit(TimeUnit.MILLISECONDS)
-	public String getUlidThroughput() {
+	public String getUlidStringThroughput() {
-		return UlidCreator.getUlid();
+		return UlidCreator.getUlidString();
 	}
 
 	@Benchmark
 	@BenchmarkMode(Mode.AverageTime)
 	@OutputTimeUnit(TimeUnit.NANOSECONDS)
-	public String getUlidAverage() {
+	public String getUlidStringAverage() {
-		return UlidCreator.getUlid();
+		return UlidCreator.getUlidString();
 	}
 	
 	@Benchmark
 	@BenchmarkMode(Mode.Throughput)
 	@OutputTimeUnit(TimeUnit.MILLISECONDS)
-	public UUID getGuidThroughput() {
+	public UUID getUlidThroughput() {
-		return UlidCreator.getGuid();
+		return UlidCreator.getUlid();
 	}
 
 	@Benchmark
 	@BenchmarkMode(Mode.AverageTime)
 	@OutputTimeUnit(TimeUnit.NANOSECONDS)
-	public UUID getGuidAverage() {
+	public UUID getUlidAverage() {
-		return UlidCreator.getGuid();
+		return UlidCreator.getUlid();
 	}
 
 	@Benchmark

src/test/java/com/github/f4b6a3/UniquenessTest.java

@@ -95,10 +95,10 @@ public class UniquenessTest {
 				// Request a UUID
 				UUID uuid = null;
 				try {
-					uuid = creator.createGuid();
+					uuid = creator.create();
 				} catch (UlidCreatorException e) {
 					// Ignore the overrun exception and try again
-					uuid = creator.createGuid();
+					uuid = creator.create();
 				}
 
 				if (verbose) {
@@ -125,7 +125,7 @@ public class UniquenessTest {
 	}
 
 	public static void execute(boolean verbose, int threadCount, int requestCount) {
-		UlidBasedGuidCreator creator = UlidCreator.getGuidCreator()
+		UlidBasedGuidCreator creator = UlidCreator.getUlidBasedCreator()
 				.withTimestampStrategy(new FixedTimestampStretegy(System.currentTimeMillis()));
 
 		UniquenessTest test = new UniquenessTest(threadCount, requestCount, creator, verbose);

src/test/java/com/github/f4b6a3/ulid/UlidCreatorTest.java

@@ -1,19 +1,36 @@
 package com.github.f4b6a3.ulid;
 
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import com.github.f4b6a3.ulid.UlidCreator;
+import com.github.f4b6a3.ulid.creator.UlidBasedGuidCreator;
 import com.github.f4b6a3.ulid.util.UlidUtil;
 
 import static org.junit.Assert.*;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
 
 public class UlidCreatorTest {
 
+	private static int processors;
+
 	private static final int ULID_LENGTH = 26;
 	private static final int DEFAULT_LOOP_MAX = 100_000;
 
+	private static final String DUPLICATE_UUID_MSG = "A duplicate ULID was created";
+
+	@BeforeClass
+	public static void beforeClass() {
+
+		processors = Runtime.getRuntime().availableProcessors();
+		if (processors < 4) {
+			processors = 4;
+		}
+	}
+
 	@Test
 	public void testGetUlid() {
 		String[] list = new String[DEFAULT_LOOP_MAX];
@@ -73,4 +90,49 @@ public class UlidCreatorTest {
 		}
 	}
 
+	@Test
+	public void testGetUlidBasedGuidParallelGeneratorsShouldCreateUniqueUuids() throws InterruptedException {
+
+		Thread[] threads = new Thread[processors];
+		TestThread.clearHashSet();
+
+		// Instantiate and start many threads
+		for (int i = 0; i < processors; i++) {
+			threads[i] = new TestThread(UlidCreator.getUlidBasedCreator(), DEFAULT_LOOP_MAX);
+			threads[i].start();
+		}
+
+		// Wait all the threads to finish
+		for (Thread thread : threads) {
+			thread.join();
+		}
+
+		// Check if the quantity of unique UUIDs is correct
+		assertTrue(DUPLICATE_UUID_MSG, TestThread.hashSet.size() == (DEFAULT_LOOP_MAX * processors));
+	}
+
+	private static class TestThread extends Thread {
+
+		private static Set<UUID> hashSet = new HashSet<>();
+		private UlidBasedGuidCreator creator;
+		private int loopLimit;
+
+		public TestThread(UlidBasedGuidCreator creator, int loopLimit) {
+			this.creator = creator;
+			this.loopLimit = loopLimit;
+		}
+
+		public static void clearHashSet() {
+			hashSet = new HashSet<>();
+		}
+
+		@Override
+		public void run() {
+			for (int i = 0; i < loopLimit; i++) {
+				synchronized (hashSet) {
+					hashSet.add(creator.create());
+				}
+			}
+		}
+	}
 }

src/test/java/com/github/f4b6a3/ulid/creator/UlidBasedGuidCreatorTest.java

@@ -25,10 +25,10 @@ public class UlidBasedGuidCreatorTest {
 		UlidBasedGuidCreatorMock creator = new UlidBasedGuidCreatorMock(TIMESTAMP);
 		creator.withTimestampStrategy(new FixedTimestampStretegy(TIMESTAMP));
 
-		UUID uuid = creator.createGuid();
+		UUID uuid = creator.create();
 		long firstMsb = creator.extractRandomMsb(uuid);
 		for (int i = 0; i < DEFAULT_LOOP_MAX; i++) {
-			uuid = creator.createGuid();
+			uuid = creator.create();
 
 		}
 
@@ -37,7 +37,7 @@ public class UlidBasedGuidCreatorTest {
 		assertEquals(String.format("The last MSB should be iqual to the first %s.", expectedMsb), expectedMsb, lastMsb);
 
 		creator.withTimestampStrategy(new FixedTimestampStretegy(TIMESTAMP + 1));
-		uuid = creator.createGuid();
+		uuid = creator.create();
 		lastMsb = uuid.getMostSignificantBits();
 		assertNotEquals("The last MSB should be random after timestamp changed.", firstMsb, lastMsb);
 	}
@@ -48,10 +48,10 @@ public class UlidBasedGuidCreatorTest {
 		UlidBasedGuidCreatorMock creator = new UlidBasedGuidCreatorMock(TIMESTAMP);
 		creator.withTimestampStrategy(new FixedTimestampStretegy(TIMESTAMP));
 
-		UUID uuid = creator.createGuid();
+		UUID uuid = creator.create();
 		long firstLsb = creator.extractRandomLsb(uuid);
 		for (int i = 0; i < DEFAULT_LOOP_MAX; i++) {
-			uuid = creator.createGuid();
+			uuid = creator.create();
 		}
 
 		long lastLsb = creator.extractRandomLsb(uuid);
@@ -60,7 +60,7 @@ public class UlidBasedGuidCreatorTest {
 
 		long notExpected = firstLsb + DEFAULT_LOOP_MAX + 1;
 		creator.withTimestampStrategy(new FixedTimestampStretegy(TIMESTAMP + 1));
-		uuid = creator.createGuid();
+		uuid = creator.create();
 		lastLsb = uuid.getLeastSignificantBits();
 		assertNotEquals("The last LSB should be random after timestamp changed.", notExpected, lastLsb);
 	}
@@ -75,7 +75,7 @@ public class UlidBasedGuidCreatorTest {
 
 		UUID uuid = new UUID(0, 0);
 		for (int i = 0; i < DEFAULT_LOOP_MAX; i++) {
-			uuid = creator.createGuid();
+			uuid = creator.create();
 		}
 
 		long expectedLsb = lsb + DEFAULT_LOOP_MAX;
@@ -96,7 +96,7 @@ public class UlidBasedGuidCreatorTest {
 
 		UUID uuid = new UUID(0, 0);
 		for (int i = 0; i < DEFAULT_LOOP_MAX; i++) {
-			uuid = creator.createGuid();
+			uuid = creator.create();
 		}
 
 		long expectedMsb = msb;
@@ -120,11 +120,11 @@ public class UlidBasedGuidCreatorTest {
 		creator.withTimestampStrategy(new FixedTimestampStretegy(TIMESTAMP));
 
 		for (int i = 0; i < DEFAULT_LOOP_MAX - 1; i++) {
-			creator.createGuid();
+			creator.create();
 		}
 
 		try {
-			creator.createGuid();
+			creator.create();
 			fail("It should throw an overflow exception.");
 		} catch (UlidCreatorException e) {
 			// success
@@ -147,7 +147,7 @@ public class UlidBasedGuidCreatorTest {
 
 		UUID uuid = new UUID(0, 0);
 		for (int i = 0; i < DEFAULT_LOOP_MAX - 1; i++) {
-			uuid = creator.createGuid();
+			uuid = creator.create();
 		}
 
 		long expectedLsb = (lsbMax - 1) & UlidBasedGuidCreatorMock.HALF_RANDOM_COMPONENT;
@@ -159,7 +159,7 @@ public class UlidBasedGuidCreatorTest {
 		assertEquals("Incorrect MSB after loop.", expectedMsb, randomMsb);
 
 		try {
-			creator.createGuid();
+			creator.create();
 			fail("It should throw an overflow exception.");
 		} catch (UlidCreatorException e) {
 			// success