[#3] Remove overrun exception
Remove UlidCreatorException // extremely unlikely to occur overrun Add UlidCreator.toString() // from UUID to crockford base 32 Change DefaultRandomStrategy // no need for thread local SecureRandom Update test cases Update README.md Update javadoc Test coverage: 94.2%
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			@ -3,22 +3,27 @@
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A Java library for generating ULIDs.
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* Generated in lexicographical order;
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* Can be stored as a UUID/GUID;
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* Can be stored as a string of 26 chars;
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* String format is encoded to [Crockford's base32](https://www.crockford.com/base32.html);
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* String format is URL safe, case insensitive and accepts hyphens.
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How to Use
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------------------------------------------------------
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Create a ULID as GUID:
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Create a ULID:
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```java
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UUID ulid = UlidCreator.getUlid();
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UUID ulid = UlidCreator.getUlid(); // 01706d6c-6aad-c795-370c-98d0be881bba
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```
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Create a ULID as string:
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Create a ULID string:
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```java
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String ulid = UlidCreator.getUlidString();
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String ulid = UlidCreator.getUlidString(); // 01E1PPRTMSQ34W7JR5YSND6B8Z
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```
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### Maven dependency
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Add these lines to your `pom.xml`.
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			@ -28,7 +33,7 @@ Add these lines to your `pom.xml`.
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<dependency>
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  <groupId>com.github.f4b6a3</groupId>
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  <artifactId>ulid-creator</artifactId>
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  <version>2.0.2</version>
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  <version>2.1.0</version>
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</dependency>
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```
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See more options in [maven.org](https://search.maven.org/artifact/com.github.f4b6a3/ulid-creator).
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			@ -36,20 +41,20 @@ See more options in [maven.org](https://search.maven.org/artifact/com.github.f4b
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Implementation
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------------------------------------------------------
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### ULID as GUID
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### ULID
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The GUIDs in this library are based on the [ULID specification](https://github.com/ulid/spec). The first 48 bits represent the count of milliseconds since Unix Epoch, 1 January 1970. The remaining 60 bits are generated by a secure random number generator.
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Every time the timestamp changes the random part is reset to a new random value. If the current timestamp is equal to the previous one, the random bits are incremented by 1.
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The default random number generator is a thread safe `java.security.SecureRandom`, but it's possible to use any RNG that extends `java.util.Random`.
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The default random number generator is `java.security.SecureRandom`.
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```java
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// GUID based on ULID spec
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UUID ulid = UlidCreator.getUlid();
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```
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Examples of GUIDs based on ULID spec:
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Sequence of GUIDs based on ULID spec:
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```text
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01706d6c-6aac-80bd-7ff5-f660c2dd58ea
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			@ -74,18 +79,18 @@ Examples of GUIDs based on ULID spec:
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  millisecs        randomness
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```
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### ULID as string
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### ULID string
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The ULID is a 26 char sequence. See the [ULID specification](https://github.com/ulid/spec) for more information.
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The ULID string is a sequence of 26 chars. See the [ULID specification](https://github.com/ulid/spec) for more information.
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See the section on GUIDs to know how the 128 bits are generated in this library.
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```java
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// ULIDs
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// String based on ULID spec
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String ulid = UlidCreator.getUlidString();
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```
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Examples of ULIDs:
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Sequence of Strings based on ULID spec:
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```text
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01E1PPRTMSQ34W7JR5YSND6B8T
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			@ -107,36 +112,35 @@ Examples of ULIDs:
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         ^ look          ^ look
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|---------|--------------|
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   milli     randomness
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 millisecs   randomness
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```
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#### How use the `UlidSpecCreator` directly
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### How use the `UlidSpecCreator` directly
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These are some examples of using the `UlidSpecCreator` to create ULIDs strings:
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These are some examples of using the `UlidSpecCreator` to create ULID strings:
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```java
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// with your custom timestamp strategy
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TimestampStrategy customStrategy = new CustomTimestampStrategy();
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String ulid = UlidCreator.getUlidSpecCreator()
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	.withTimestampStrategy(customStrategy)
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	.createString();
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UlidSpecCreator creator = UlidCreator.getUlidSpecCreator()
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	.withTimestampStrategy(customStrategy);
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String ulid = creator.createString();
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```
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```java
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// with your custom random strategy that wraps any random generator
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RandomStrategy customStrategy = new CustomRandomStrategy();
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String ulid = UlidCreator.getUlidSpecCreator()
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	.withRandomStrategy(customStrategy)
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	.createString();
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UlidSpecCreator creator = UlidCreator.getUlidSpecCreator()
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	.withRandomStrategy(customStrategy);
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String ulid = creator.createString();
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```
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```java
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// with `java.util.Random` number generator
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Random random = new Random();
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String ulid = UlidCreator.getUlidSpecCreator()
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    .withRandomGenerator(random)
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    .createString();
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UlidSpecCreator creator = UlidCreator.getUlidSpecCreator()
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    .withRandomGenerator(random);
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String ulid = creator.createString();
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```
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Benchmark
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------------------------------------------------------
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			@ -150,7 +154,7 @@ Throughput.Java_RandomBased        thrpt    5   2234,199 ±   2,844  ops/ms
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Throughput.UlidCreator_Ulid        thrpt    5  19155,742 ±  22,195  ops/ms
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Throughput.UlidCreator_UlidString  thrpt    5   4946,479 ±  22,800  ops/ms
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---------------------------------------------------------------------------
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Total time: 00:06:41
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Total time: 00:04:01
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---------------------------------------------------------------------------
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```
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			@ -162,7 +166,7 @@ AverageTime.Java_RandomBased        avgt    5  449,641 ± 0,994  ns/op
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AverageTime.UlidCreator_Ulid        avgt    5   52,199 ± 0,185  ns/op
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AverageTime.UlidCreator_UlidString  avgt    5  202,014 ± 2,111  ns/op
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----------------------------------------------------------------------
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Total time: 00:06:41
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Total time: 00:04:01
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----------------------------------------------------------------------
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```
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			@ -27,6 +27,7 @@ package com.github.f4b6a3.ulid;
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import java.util.UUID;
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import com.github.f4b6a3.ulid.creator.UlidSpecCreator;
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import com.github.f4b6a3.ulid.exception.InvalidUlidException;
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import com.github.f4b6a3.ulid.util.UlidConverter;
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/**
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			@ -42,13 +43,31 @@ public final class UlidCreator {
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	/**
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	 * Returns a ULID as GUID from a string.
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	 * 
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	 * The input string must be encoded to Crockford's base32, following the ULID
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	 * specification.
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	 * 
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	 * An exception is thrown if the ULID string is invalid.
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	 * 
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	 * @param ulid a ULID string
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	 * @return a UUID
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	 * @throws InvalidUlidException if invalid
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	 */
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	public static UUID fromString(String ulid) {
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		return UlidConverter.fromString(ulid);
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	}
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	/**
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	 * Convert a UUID to ULID string
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	 * 
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	 * The returning string is encoded to Crockford's base32.
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	 * 
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	 * @param uuid a UUID
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	 * @return a ULID string
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	 */
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	public static String toString(UUID ulid) {
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		return UlidConverter.toString(ulid);
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	}
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	/**
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	 * Returns a ULID as GUID.
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	 * 
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			@ -30,7 +30,6 @@ import java.util.UUID;
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import com.github.f4b6a3.ulid.strategy.RandomStrategy;
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import com.github.f4b6a3.ulid.strategy.random.DefaultRandomStrategy;
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import com.github.f4b6a3.ulid.strategy.random.OtherRandomStrategy;
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import com.github.f4b6a3.ulid.exception.UlidCreatorException;
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import com.github.f4b6a3.ulid.strategy.TimestampStrategy;
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import com.github.f4b6a3.ulid.strategy.timestamp.DefaultTimestampStrategy;
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import com.github.f4b6a3.ulid.util.UlidConverter;
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			@ -120,9 +119,6 @@ public class UlidSpecCreator {
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	 * overflow with less, the generation will fail.
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	 * 
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	 * @return {@link UUID} a GUID value
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	 * 
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	 * @throws UlidCreatorException an overrun exception if too many requests are
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	 *                              made within the same millisecond.
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	 */
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	public synchronized UUID create() {
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			@ -188,18 +184,12 @@ public class UlidSpecCreator {
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	/**
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	 * Increment the random part of the GUID.
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	 * 
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	 * An exception is thrown when more than 2^80 increment operations are made,
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	 * although it's extremely unlikely to occur.
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	 * 
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	 * @throws UlidCreatorException if an overrun happens.
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	 */
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	protected synchronized void increment() {
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		if (++this.random2 >= this.randomMax2) {
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			this.random2 = this.random2 & HALF_RANDOM_COMPONENT;
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			if ((++this.random1 >= this.randomMax1)) {
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				this.reset();
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				throw new UlidCreatorException(OVERRUN_MESSAGE);
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			}
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		}
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	}
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			@ -1,34 +0,0 @@
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/*
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 * MIT License
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 * 
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 * Copyright (c) 2020 Fabio Lima
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 * 
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * of this software and associated documentation files (the "Software"), to deal
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 * in the Software without restriction, including without limitation the rights
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the Software is
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 * furnished to do so, subject to the following conditions:
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 * 
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 * The above copyright notice and this permission notice shall be included in all
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 * copies or substantial portions of the Software.
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 * 
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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 * SOFTWARE.
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 */
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package com.github.f4b6a3.ulid.exception;
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public final class UlidCreatorException extends RuntimeException {
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	private static final long serialVersionUID = 1L;
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	public UlidCreatorException(String message) {
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		super(message);
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	}
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}
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			@ -30,14 +30,14 @@ import java.util.Random;
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import com.github.f4b6a3.ulid.strategy.RandomStrategy;
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/**
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 * It uses a thread local instance of {@link java.security.SecureRandom}.
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 * It uses an instance of {@link java.security.SecureRandom}.
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 */
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public final class DefaultRandomStrategy implements RandomStrategy {
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	protected static final ThreadLocal<Random> THREAD_LOCAL_RANDOM = ThreadLocal.withInitial(SecureRandom::new);
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	private static final Random SECURE_RANDOM = new SecureRandom();
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	@Override
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	public void nextBytes(byte[] bytes) {
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		THREAD_LOCAL_RANDOM.get().nextBytes(bytes);
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		SECURE_RANDOM.nextBytes(bytes);
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	}
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}
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			@ -40,13 +40,13 @@ public final class UlidConverter {
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	 * 
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	 * The returning string is encoded to Crockford's base32.
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	 * 
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	 * @param uuid a UUID
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	 * @param ulid a UUID
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	 * @return a ULID
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	 */
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	public static String toString(UUID uuid) {
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	public static String toString(UUID ulid) {
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		final long msb = uuid.getMostSignificantBits();
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		final long lsb = uuid.getLeastSignificantBits();
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		final long msb = ulid.getMostSignificantBits();
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		final long lsb = ulid.getLeastSignificantBits();
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		final long time = ((msb & 0xffffffffffff0000L) >>> 16);
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		final long random1 = ((msb & 0x000000000000ffffL) << 24) | ((lsb & 0xffffff0000000000L) >>> 40);
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			@ -5,7 +5,6 @@ import java.util.UUID;
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import com.github.f4b6a3.ulid.UlidCreator;
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import com.github.f4b6a3.ulid.creator.UlidSpecCreator;
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import com.github.f4b6a3.ulid.exception.UlidCreatorException;
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import com.github.f4b6a3.ulid.strategy.timestamp.FixedTimestampStretegy;
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/**
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			@ -93,13 +92,7 @@ public class UniquenessTest {
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			for (int i = 0; i < max; i++) {
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				// Request a UUID
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				UUID uuid = null;
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				try {
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					uuid = creator.create();
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				} catch (UlidCreatorException e) {
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					// Ignore the overrun exception and try again
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					uuid = creator.create();
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				}
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				UUID uuid = creator.create();
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				if (verbose) {
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					// Calculate and show progress
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			@ -9,7 +9,6 @@ import java.util.UUID;
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import org.junit.Test;
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import com.github.f4b6a3.ulid.UlidCreator;
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import com.github.f4b6a3.ulid.exception.UlidCreatorException;
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import com.github.f4b6a3.ulid.strategy.timestamp.FixedTimestampStretegy;
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import static org.junit.Assert.*;
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			@ -126,7 +125,7 @@ public class UlidSpecCreatorTest {
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	}
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	@Test
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	public void testShouldThrowOverflowException1() {
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	public void testIncrementRandomComponentMaximum1() {
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		long random1 = 0x000000ffffffffffL;
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		long random2 = 0x000000ffffffffffL;
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| 
						 | 
				
			
			@ -157,16 +156,12 @@ public class UlidSpecCreatorTest {
 | 
			
		|||
		BigInteger bigint2 = new BigInteger(concat2, 16);
 | 
			
		||||
		assertEquals(bigint1.add(BigInteger.valueOf(DEFAULT_LOOP_MAX)), bigint2);
 | 
			
		||||
 | 
			
		||||
		try {
 | 
			
		||||
			uuid = creator.create();
 | 
			
		||||
			fail("It should throw an overflow exception.");
 | 
			
		||||
		} catch (UlidCreatorException e) {
 | 
			
		||||
			// success
 | 
			
		||||
		}
 | 
			
		||||
		// This line resets the random component
 | 
			
		||||
		uuid = creator.create();
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	@Test
 | 
			
		||||
	public void testShouldThrowOverflowException2() {
 | 
			
		||||
	public void testIncrementRandomComponentMaximum2() {
 | 
			
		||||
 | 
			
		||||
		long random1 = (RANDOM.nextLong() & UlidSpecCreatorMock.HALF_RANDOM_COMPONENT);
 | 
			
		||||
		long random2 = (RANDOM.nextLong() & UlidSpecCreatorMock.HALF_RANDOM_COMPONENT);
 | 
			
		||||
| 
						 | 
				
			
			@ -204,13 +199,9 @@ public class UlidSpecCreatorTest {
 | 
			
		|||
		String concat2 = (Long.toHexString(hi2) + Long.toHexString(lo2));
 | 
			
		||||
		BigInteger bigint2 = new BigInteger(concat2, 16);
 | 
			
		||||
		assertEquals(bigint1.add(BigInteger.valueOf(DEFAULT_LOOP_MAX)), bigint2);
 | 
			
		||||
 | 
			
		||||
		try {
 | 
			
		||||
			creator.create();
 | 
			
		||||
			fail("It should throw an overflow exception.");
 | 
			
		||||
		} catch (UlidCreatorException e) {
 | 
			
		||||
			// success
 | 
			
		||||
		}
 | 
			
		||||
		
 | 
			
		||||
		// This line resets the random component
 | 
			
		||||
		creator.create();
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	@Test
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
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		Reference in New Issue