Add a simple cache for ComparableVersions

TobiX · slawekjaranowski · commit 2bed457bdefd · 2022-12-21T18:23:16.000+01:00
This can improve performance in pathetic corner cases by up to 50%.
diff --git a/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/BoundArtifactVersion.java b/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/BoundArtifactVersion.java
@@ -56,7 +56,7 @@ public int compareTo(ArtifactVersion other) {
             return -1;
         }
 
-        return comparator.compareTo(new ComparableVersion(other.toString()));
+        return comparator.compareTo(ComparableVersion.of(other.toString()));
     }
 
     @Override
diff --git a/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/ComparableVersion.java b/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/ComparableVersion.java
@@ -26,8 +26,10 @@
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Properties;
 import java.util.Stack;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Generic implementation of version comparison.
@@ -37,6 +39,8 @@
  * Note: The implementation of the maven core should be used.
  */
 public class ComparableVersion implements Comparable<ComparableVersion> {
+    private static final Map<String, ComparableVersion> CACHE = new ConcurrentHashMap<>();
+
     private String value;
 
     private String canonical;
@@ -283,7 +287,17 @@ public String toString() {
         }
     }
 
-    public ComparableVersion(String version) {
+    /**
+     * Get a ComparableVersion representing the version in a string.
+     */
+    public static ComparableVersion of(String version) {
+        return CACHE.computeIfAbsent(version, ComparableVersion::new);
+    }
+
+    /**
+     * Create a ComparableVersion from a string. Try to avoid using this and instead use the cache by calling {@link #of(String)}
+     */
+    protected ComparableVersion(String version) {
         parseVersion(version);
     }
 
diff --git a/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/MavenVersionComparator.java b/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/MavenVersionComparator.java
@@ -39,7 +39,7 @@ public int compare(ArtifactVersion o1, ArtifactVersion o2) {
         if (o1 instanceof BoundArtifactVersion) {
             return o1.compareTo(o2);
         }
-        return new ComparableVersion(o1.toString()).compareTo(new ComparableVersion(o2.toString()));
+        return ComparableVersion.of(o1.toString()).compareTo(ComparableVersion.of(o2.toString()));
     }
 
     /**
diff --git a/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/MercuryVersionComparator.java b/versions-common/src/main/java/org/codehaus/mojo/versions/ordering/MercuryVersionComparator.java
@@ -40,7 +40,7 @@ public class MercuryVersionComparator extends AbstractVersionComparator {
      * {@inheritDoc}
      */
     public int compare(ArtifactVersion o1, ArtifactVersion o2) {
-        return new ComparableVersion(o1.toString()).compareTo(new ComparableVersion(o2.toString()));
+        return ComparableVersion.of(o1.toString()).compareTo(ComparableVersion.of(o2.toString()));
     }
 
     protected int innerGetSegmentCount(ArtifactVersion v) {

Original file line number	Diff line number	Diff line change
`@@ -56,7 +56,7 @@ public int compareTo(ArtifactVersion other) {`
`56`	`56`	`return -1;`
`57`	`57`	`}`
`58`	`58`
`59`		`- return comparator.compareTo(new ComparableVersion(other.toString()));`
	`59`	`+ return comparator.compareTo(ComparableVersion.of(other.toString()));`
`60`	`60`	`}`
`61`	`61`
`62`	`62`	`@Override`
Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@ public int compare(ArtifactVersion o1, ArtifactVersion o2) {`
`39`	`39`	`if (o1 instanceof BoundArtifactVersion) {`
`40`	`40`	`return o1.compareTo(o2);`
`41`	`41`	`}`
`42`		`- return new ComparableVersion(o1.toString()).compareTo(new ComparableVersion(o2.toString()));`
	`42`	`+ return ComparableVersion.of(o1.toString()).compareTo(ComparableVersion.of(o2.toString()));`
`43`	`43`	`}`
`44`	`44`
`45`	`45`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -40,7 +40,7 @@ public class MercuryVersionComparator extends AbstractVersionComparator {`
`40`	`40`	`* {@inheritDoc}`
`41`	`41`	`*/`
`42`	`42`	`public int compare(ArtifactVersion o1, ArtifactVersion o2) {`
`43`		`- return new ComparableVersion(o1.toString()).compareTo(new ComparableVersion(o2.toString()));`
	`43`	`+ return ComparableVersion.of(o1.toString()).compareTo(ComparableVersion.of(o2.toString()));`
`44`	`44`	`}`
`45`	`45`
`46`	`46`	`protected int innerGetSegmentCount(ArtifactVersion v) {`