From 34fb709f1cc1aee3df246291cc9e7ea9fd54baa6 Mon Sep 17 00:00:00 2001
From: Andrzej Jarmoniuk <gh@jarmoniuk.nl>
Date: Sat, 17 Dec 2022 18:46:22 +0100
Subject: [PATCH] [MENFORCER-435] Added documentation to artifact caches +
 changing the caching operation so the cached objects are already built

---
 .../plugins/enforcer/utils/ArtifactUtils.java | 38 +++++++++++++------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/enforcer-rules/src/main/java/org/apache/maven/plugins/enforcer/utils/ArtifactUtils.java b/enforcer-rules/src/main/java/org/apache/maven/plugins/enforcer/utils/ArtifactUtils.java
index f93546de..3beac7fc 100644
--- a/enforcer-rules/src/main/java/org/apache/maven/plugins/enforcer/utils/ArtifactUtils.java
+++ b/enforcer-rules/src/main/java/org/apache/maven/plugins/enforcer/utils/ArtifactUtils.java
@@ -21,10 +21,10 @@
 import static java.util.Optional.ofNullable;
 
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.maven.RepositoryUtils;
@@ -59,12 +59,21 @@
  * @since 3.0.0
  */
 public final class ArtifactUtils {
-    private static final Map<DependencyNode, Artifact> NODE_ARTIFACT_MAP = new HashMap<>();
-    private static final Map<Artifact, org.eclipse.aether.artifact.Artifact> AETHER_ARTIFACT_MAP = new HashMap<>();
+
+    /**
+     * Caches the results of the {@link #toArtifact(DependencyNode)} method
+     */
+    private static final Map<DependencyNode, Artifact> NODE_ARTIFACT_MAP = new ConcurrentHashMap<>();
+
+    /**
+     * Caches the results of the {@link #toArtifact(Artifact)} method
+     */
+    private static final Map<Artifact, org.eclipse.aether.artifact.Artifact> AETHER_ARTIFACT_MAP =
+            new ConcurrentHashMap<>();
 
     /**
      * Converts {@link DependencyNode} to {@link Artifact}; in comparison
-     * to {@linkpl RepositoryUtils#toArtifact(org.eclipse.aether.artifact.Artifact)}, this method
+     * to {@link RepositoryUtils#toArtifact(org.eclipse.aether.artifact.Artifact)}, this method
      * assigns {@link Artifact#getScope()} and {@link Artifact#isOptional()} based on
      * the dependency information from the node.
      *
@@ -72,10 +81,13 @@ public final class ArtifactUtils {
      * @return target artifact
      */
     public static Artifact toArtifact(DependencyNode node) {
-        Artifact result = NODE_ARTIFACT_MAP.computeIfAbsent(node, n -> RepositoryUtils.toArtifact(n.getArtifact()));
-        ofNullable(node.getDependency()).ifPresent(dependency -> {
-            ofNullable(dependency.getScope()).ifPresent(result::setScope);
-            result.setOptional(dependency.isOptional());
+        Artifact result = NODE_ARTIFACT_MAP.computeIfAbsent(node, n -> {
+            Artifact artifact = RepositoryUtils.toArtifact(n.getArtifact());
+            ofNullable(node.getDependency()).ifPresent(dependency -> {
+                ofNullable(dependency.getScope()).ifPresent(artifact::setScope);
+                artifact.setOptional(dependency.isOptional());
+            });
+            return artifact;
         });
         AETHER_ARTIFACT_MAP.putIfAbsent(result, node.getArtifact());
         return result;
@@ -87,7 +99,11 @@ public static Artifact toArtifact(DependencyNode node) {
      * @return target artifact
      */
     public static org.eclipse.aether.artifact.Artifact toArtifact(Artifact artifact) {
-        return AETHER_ARTIFACT_MAP.computeIfAbsent(artifact, RepositoryUtils::toArtifact);
+        org.eclipse.aether.artifact.Artifact result = RepositoryUtils.toArtifact(artifact);
+        if (artifact != null) {
+            AETHER_ARTIFACT_MAP.putIfAbsent(artifact, result);
+        }
+        return result;
     }
 
     /**
@@ -179,8 +195,8 @@ public static Set<Artifact> filterDependencyArtifacts(Set<Artifact> dependencies
                             .map(p -> p.split(":"))
                             .map(StringUtils::stripAll)
                             .map(arr -> String.join(":", arr))
-                            .flatMap(pattern -> dependencies.stream()
-                                    .filter(artifact -> compareDependency(pattern, artifact)))
+                            .flatMap(pattern ->
+                                    dependencies.stream().filter(artifact -> compareDependency(pattern, artifact)))
                             .collect(Collectors.toSet()))
                     .orElse(null);
         } catch (IllegalArgumentException e) {