[MNG-6698] Lazily compute the ManagedVersionMap

This map is not used by Maven and the computation can be quite heavy, so lazily compute it. In addition, do not clone the map as it's an unmodifiable one already. This closes apache#263
prudhviraj0526 · Jul 6, 2019 · 7ba9700 · 7ba9700
1 parent 84bf187
commit 7ba9700
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Showing 2 changed files with 59 additions and 9 deletions.
diff --git a/maven-core/src/main/java/org/apache/maven/project/DefaultProjectBuilder.java b/maven-core/src/main/java/org/apache/maven/project/DefaultProjectBuilder.java
@@ -21,8 +21,10 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -780,21 +782,69 @@ private void initProject( MavenProject project, Map<String, MavenProject> projec
         Map<String, Artifact> map = null;
         if ( repositorySystem != null )
         {
-            DependencyManagement dependencyManagement = project.getDependencyManagement();
+            final DependencyManagement dependencyManagement = project.getDependencyManagement();
             if ( ( dependencyManagement != null ) && ( ( dependencyManagement.getDependencies() ) != null )
                 && ( dependencyManagement.getDependencies().size() > 0 ) )
             {
-                map = new HashMap<>();
-                for ( Dependency d : dependencyManagement.getDependencies() )
+                map = new AbstractMap<String, Artifact>()
                 {
-                    Artifact artifact = repositorySystem.createDependencyArtifact( d );
+                    HashMap<String, Artifact> delegate;
 
-                    if ( artifact != null )
+                    @Override
+                    public Set<Entry<String, Artifact>> entrySet()
                     {
-                        map.put( d.getManagementKey(), artifact );
+                        return Collections.unmodifiableSet( compute().entrySet() );
                     }
-                }
-                map = Collections.unmodifiableMap( map );
+
+                    @Override
+                    public Set<String> keySet()
+                    {
+                        return Collections.unmodifiableSet( compute().keySet() );
+                    }
+
+                    @Override
+                    public Collection<Artifact> values()
+                    {
+                        return Collections.unmodifiableCollection( compute().values() );
+                    }
+
+                    @Override
+                    public boolean containsValue( Object value )
+                    {
+                        return compute().containsValue( value );
+                    }
+
+                    @Override
+                    public boolean containsKey( Object key )
+                    {
+                        return compute().containsKey( key );
+                    }
+
+                    @Override
+                    public Artifact get( Object key )
+                    {
+                        return compute().get( key );
+                    }
+
+                    HashMap<String, Artifact> compute()
+                    {
+                        if ( delegate == null )
+                        {
+                            delegate = new HashMap<>();
+                            for ( Dependency d : dependencyManagement.getDependencies() )
+                            {
+                                Artifact artifact = repositorySystem.createDependencyArtifact( d );
+
+                                if ( artifact != null )
+                                {
+                                    delegate.put( d.getManagementKey(), artifact );
+                                }
+                            }
+                        }
+
+                        return delegate;
+                    }
+                };
             }
             else
             {

diff --git a/maven-core/src/main/java/org/apache/maven/project/MavenProject.java b/maven-core/src/main/java/org/apache/maven/project/MavenProject.java
@@ -1304,7 +1304,7 @@ private void deepCopy( MavenProject project )
 
         if ( project.getManagedVersionMap() != null )
         {
-            setManagedVersionMap( new HashMap<>( project.getManagedVersionMap() ) );
+            setManagedVersionMap( project.getManagedVersionMap() );
         }
 
         lifecyclePhases.addAll( project.lifecyclePhases );