handle clock drift #12

Added drift tolerance of 10 seconds to preserve monotonicity when the
system clock is adjusted by NTP after a small clock drift or when the
system clock jumps back by 1 second due to leap second.

The payload component is incremented when the current time:
- is the same as the previous time;
- has moved backwards up to 10 seconds.

The time component is also incremented if the payload component is
exceeded, which is quite rare.

CHANGELOG.md

@@ -6,6 +6,10 @@ All notable changes to this project will be documented in this file.
 
 Nothing unreleaded.
 
+## [3.1.0] - 2022-04-21
+
+Handle clock drift. #12
+
 ## [3.0.0] - 2022-01-30
 
 Implemented KSUID with sub-second precision. #11
@@ -118,7 +122,8 @@ Project created as an alternative Java implementation of [K-Sortable Unique IDen
 -   Added `DefaultRandomGenerator`
 -   Added test cases
 
-[unreleased]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-3.0.0...HEAD
+[unreleased]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-3.1.0...HEAD
+[3.1.0]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-3.0.0...ksuid-creator-3.1.0
 [3.0.0]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-2.3.0...ksuid-creator-3.0.0
 [2.3.0]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-2.2.0...ksuid-creator-2.3.0
 [2.2.0]: https://github.com/f4b6a3/ksuid-creator/compare/ksuid-creator-2.1.2...ksuid-creator-2.2.0

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021 Fabio Lima
+Copyright (c) 2021-2022 Fabio Lima
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -40,7 +40,7 @@ Add these lines to your `pom.xml`.
 <dependency>
   <groupId>com.github.f4b6a3</groupId>
   <artifactId>ksuid-creator</artifactId>
-  <version>3.0.0</version>
+  <version>3.1.0</version>
 </dependency>
 ```
 

src/main/java/com/github/f4b6a3/ksuid/Ksuid.java

@@ -1,7 +1,7 @@
 /*
  * MIT License
  * 
- * Copyright (c) 2021 Fabio Lima
+ * Copyright (c) 2021-2022 Fabio Lima
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -383,6 +383,14 @@ public Ksuid increment() {
 		for (int i = PAYLOAD_BYTES - 1; i >= 0; i--) {
 			if (++ksuid.payload[i] != overflow) {
 				break; // stop if did't overflow
+			} else {
+				if (i == 0) {
+					// If the payload component overflows,
+					// increment the time component by 1.
+					// This event is quite rare to occur.
+					final long time = ksuid.getTime() + 1;
+					ksuid = new Ksuid(time, ksuid.getPayload());
+				}
 			}
 		}
 

src/main/java/com/github/f4b6a3/ksuid/KsuidCreator.java

@@ -1,7 +1,7 @@
 /*
  * MIT License
  * 
- * Copyright (c) 2021 Fabio Lima
+ * Copyright (c) 2021-2022 Fabio Lima
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal