xmvn/0001-Fix-installer-plugin-loading.patch

From 0fd7b0d19bd96456292585e883e3ba2ebbaf579b Mon Sep 17 00:00:00 2001
From: Mikolaj Izdebski <mizdebsk@redhat.com>
Date: Wed, 21 Jun 2017 10:21:10 +0200
Subject: [PATCH] Fix installer plugin loading

---
 .../install/impl/ArtifactInstallerFactory.java     |  97 ++++++--
 .../tools/install/impl/IsolatedClassRealm.java     | 245 +++++++++++++++++++++
 2 files changed, 320 insertions(+), 22 deletions(-)
 create mode 100644 xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/IsolatedClassRealm.java

diff --git a/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/ArtifactInstallerFactory.java b/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/ArtifactInstallerFactory.java
index 7a80571..e6a9a2d 100644
--- a/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/ArtifactInstallerFactory.java
+++ b/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/ArtifactInstallerFactory.java
@@ -15,8 +15,17 @@
  */
 package org.fedoraproject.xmvn.tools.install.impl;
 
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.Arrays;
-import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 import org.slf4j.Logger;
@@ -35,49 +44,93 @@ class ArtifactInstallerFactory
 
     private final ArtifactInstaller defaultArtifactInstaller;
 
-    private final ArtifactInstaller eclipseArtifactInstaller;
+    private final IsolatedClassRealm pluginRealm;
 
-    private static ArtifactInstaller loadPlugin( String className )
+    private final Map<String, ArtifactInstaller> cachedPluginsByType = new LinkedHashMap<>();
+
+    private final Map<String, ArtifactInstaller> cachedPluginsByImplClass = new LinkedHashMap<>();
+
+    private ArtifactInstaller tryLoadPlugin( String type )
     {
+        if ( cachedPluginsByType.containsKey( type ) )
+            return cachedPluginsByType.get( type );
+
         try
         {
-            return (ArtifactInstaller) ArtifactInstallerFactory.class.getClassLoader().loadClass( className ).newInstance();
+            String resourceName = ArtifactInstaller.class.getCanonicalName() + "/" + type;
+            InputStream resourceStream = pluginRealm != null ? pluginRealm.getResourceAsStream( resourceName ) : null;
+            if ( resourceStream == null )
+            {
+                logger.debug( "No XMvn Installer plugin found for packaging type {}", type );
+                cachedPluginsByType.put( type, null );
+                return null;
+            }
+
+            String pluginImplClass;
+            try ( BufferedReader resourceReader = new BufferedReader( new InputStreamReader( resourceStream ) ) )
+            {
+                pluginImplClass = resourceReader.readLine();
+            }
+
+            ArtifactInstaller pluggedInInstaller = cachedPluginsByImplClass.get( pluginImplClass );
+            if ( pluggedInInstaller == null )
+            {
+                pluggedInInstaller = (ArtifactInstaller) pluginRealm.loadClass( pluginImplClass ).newInstance();
+                cachedPluginsByImplClass.put( pluginImplClass, pluggedInInstaller );
+            }
+
+            cachedPluginsByType.put( type, pluggedInInstaller );
+            return pluggedInInstaller;
         }
-        catch ( ReflectiveOperationException e )
+        catch ( IOException | ReflectiveOperationException e )
         {
-            return null;
+            throw new RuntimeException( "Unable to load XMvn Installer plugin for packaging type " + type, e );
         }
     }
 
     public ArtifactInstallerFactory( Configurator configurator )
     {
         defaultArtifactInstaller = new DefaultArtifactInstaller( configurator );
-        // FIXME Don't hardcode plugin class name
-        eclipseArtifactInstaller = loadPlugin( "org.fedoraproject.p2.xmvn.EclipseArtifactInstaller" );
+
+        Path pluginDir = Paths.get( "/usr/share/xmvn/lib/installer" );
+        if ( Files.isDirectory( pluginDir ) )
+        {
+            ClassLoader parentClassLoader = ArtifactInstallerFactory.class.getClassLoader();
+            pluginRealm = new IsolatedClassRealm( parentClassLoader );
+            pluginRealm.addJarDirectory( pluginDir );
+            PLUGIN_IMPORTS.forEach( pluginRealm::importPackage );
+        }
+        else
+        {
+            pluginRealm = null;
+        }
     }
 
     /**
-     * List of Tycho pacgkaging types.
+     * List of packages imported from XMvn Installer class loader to plug-in realms.
      */
-    private static final Collection<String> ECLIPSE_PACKAGING_TYPES = Arrays.asList( "eclipse-plugin", //
-                                                                                     "eclipse-test-plugin", //
-                                                                                     "eclipse-feature", //
-                                                                                     "eclipse-repository", //
-                                                                                     "eclipse-application", //
-                                                                                     "eclipse-update-site", //
-                                                                                     "eclipse-target-definition" );
+    private static final List<String> PLUGIN_IMPORTS = Arrays.asList( // XMvn API
+                                                                      "org.fedoraproject.xmvn.artifact", //
+                                                                      "org.fedoraproject.xmvn.config", //
+                                                                      "org.fedoraproject.xmvn.deployer", //
+                                                                      "org.fedoraproject.xmvn.locator", //
+                                                                      "org.fedoraproject.xmvn.metadata", //
+                                                                      "org.fedoraproject.xmvn.resolver", //
+                                                                      // XMvn Installer SPI
+                                                                      "org.fedoraproject.xmvn.tools.install", //
+                                                                      // SLF4J API
+                                                                      "org.slf4j" //
+    );
 
     @SuppressWarnings( "unused" )
     public ArtifactInstaller getInstallerFor( Artifact artifact, Properties properties )
     {
         String type = properties.getProperty( "type" );
-        if ( type != null && ECLIPSE_PACKAGING_TYPES.contains( type ) )
+        if ( type != null )
         {
-            if ( eclipseArtifactInstaller != null )
-                return eclipseArtifactInstaller;
-
-            logger.error( "Unable to load XMvn P2 plugin, Eclipse artifact installation will be impossible" );
-            throw new RuntimeException( "Unable to load XMvn P2 plugin" );
+            ArtifactInstaller pluggedInInstaller = tryLoadPlugin( type );
+            if ( pluggedInInstaller != null )
+                return pluggedInInstaller;
         }
 
         return defaultArtifactInstaller;
diff --git a/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/IsolatedClassRealm.java b/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/IsolatedClassRealm.java
new file mode 100644
index 0000000..3324604
--- /dev/null
+++ b/xmvn-tools/xmvn-install/src/main/java/org/fedoraproject/xmvn/tools/install/impl/IsolatedClassRealm.java
@@ -0,0 +1,245 @@
+/*-
+ * Copyright (c) 2014-2017 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.fedoraproject.xmvn.tools.install.impl;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+/**
+ * A generic, isolated class loader.
+ * <p>
+ * This class loader has its own classpath, separate from the primary Java classpath. It has a parent class loader, to
+ * which it delegates loading a set of imported classes. All other classes are loaded from its own classpath.
+ * 
+ * @author Mikolaj Izdebski
+ */
+class IsolatedClassRealm
+    extends URLClassLoader
+{
+    static
+    {
+        registerAsParallelCapable();
+    }
+
+    private final ClassLoader parent;
+
+    private final Set<String> imports = new HashSet<>();
+
+    private final Set<String> importsAll = new HashSet<>();
+
+    public IsolatedClassRealm( ClassLoader parent )
+    {
+        super( new URL[0], null );
+        this.parent = parent;
+    }
+
+    public void addJar( Path jar )
+    {
+        try
+        {
+            addURL( jar.toUri().toURL() );
+        }
+        catch ( MalformedURLException e )
+        {
+            throw new RuntimeException( e );
+        }
+    }
+
+    public void addJarDirectory( Path dir )
+    {
+        try ( DirectoryStream<Path> stream = Files.newDirectoryStream( dir, "*.jar" ) )
+        {
+            for ( Path path : stream )
+            {
+                addJar( path );
+            }
+        }
+        catch ( IOException e )
+        {
+            throw new RuntimeException( e );
+        }
+    }
+
+    public void importPackage( String packageName )
+    {
+        imports.add( packageName );
+    }
+
+    public void importAllPackages( String packageName )
+    {
+        importsAll.add( packageName );
+    }
+
+    boolean isImported( String name )
+    {
+        int index = name.lastIndexOf( '/' );
+
+        if ( index >= 0 )
+        {
+            name = name.replace( '/', '.' );
+        }
+        else
+        {
+            index = Math.max( name.lastIndexOf( '.' ), 0 );
+        }
+
+        String namespace = name.substring( 0, index );
+
+        if ( imports.contains( namespace ) )
+            return true;
+
+        while ( !namespace.isEmpty() )
+        {
+            if ( importsAll.contains( namespace ) )
+                return true;
+
+            namespace = namespace.substring( 0, Math.max( namespace.lastIndexOf( '.' ), 0 ) );
+        }
+
+        return false;
+    }
+
+    @Override
+    public Class<?> loadClass( String name )
+        throws ClassNotFoundException
+    {
+        return loadClass( name, false );
+    }
+
+    @Override
+    protected Class<?> loadClass( String name, boolean resolve )
+        throws ClassNotFoundException
+    {
+        if ( isImported( name ) )
+        {
+            try
+            {
+                return parent.loadClass( name );
+            }
+            catch ( ClassNotFoundException e )
+            {
+            }
+        }
+
+        try
+        {
+            return super.loadClass( name, resolve );
+        }
+        catch ( ClassNotFoundException e )
+        {
+        }
+
+        synchronized ( getClassLoadingLock( name ) )
+        {
+            Class<?> clazz = findLoadedClass( name );
+            if ( clazz != null )
+            {
+                return clazz;
+            }
+
+            try
+            {
+                return super.findClass( name );
+            }
+            catch ( ClassNotFoundException e )
+            {
+            }
+        }
+
+        throw new ClassNotFoundException( name );
+    }
+
+    @Override
+    protected Class<?> findClass( String name )
+        throws ClassNotFoundException
+    {
+        throw new ClassNotFoundException( name );
+    }
+
+    @Override
+    public URL getResource( String name )
+    {
+        if ( isImported( name ) )
+        {
+            URL resource = parent.getResource( name );
+            if ( resource != null )
+            {
+                return resource;
+            }
+        }
+
+        URL resource = super.getResource( name );
+        if ( resource != null )
+        {
+            return resource;
+        }
+
+        resource = super.findResource( name );
+        if ( resource != null )
+        {
+            return resource;
+        }
+
+        return null;
+    }
+
+    @Override
+    public Enumeration<URL> getResources( String name )
+        throws IOException
+    {
+        Collection<URL> resources = new LinkedHashSet<>();
+
+        if ( isImported( name ) )
+        {
+            try
+            {
+                resources.addAll( Collections.list( parent.getResources( name ) ) );
+            }
+            catch ( IOException e )
+            {
+            }
+        }
+
+        try
+        {
+            resources.addAll( Collections.list( super.getResources( name ) ) );
+        }
+        catch ( IOException e )
+        {
+        }
+
+        try
+        {
+            resources.addAll( Collections.list( super.findResources( name ) ) );
+        }
+        catch ( IOException e )
+        {
+        }
+
+        return Collections.enumeration( resources );
+    }
+}
-- 
2.9.3