improve extension binding and added api to query extensions

scm-core/src/main/java/sonia/scm/plugin/ExtensionProcessor.java

@@ -0,0 +1,72 @@
+/**
+ * Copyright (c) 2014, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.inject.Binder;
+
+/**
+ * Process and resolve extensions.
+ *
+ * @author Sebastian Sdorra
+ * @since 2.0.0
+ */
+public interface ExtensionProcessor
+{
+
+  /**
+   * Return extensions
+   *
+   *
+   * @param extensionPoint
+   * @return
+   */
+  public Iterable<Class> byExtensionPoint(Class extensionPoint);
+
+  /**
+   * Method description
+   *
+   *
+   * @param extensionPoint
+   * @return
+   */
+  public Class oneByExtensionPoint(Class extensionPoint);
+
+  /**
+   * Method description
+   *
+   *
+   * @param binder
+   */
+  public void processAutoBindExtensions(Binder binder);
+}

scm-core/src/main/java/sonia/scm/plugin/PluginLoader.java

@@ -35,10 +35,8 @@ package sonia.scm.plugin;
 
 //~--- non-JDK imports --------------------------------------------------------
 
-import com.google.inject.Binder;
 import com.google.inject.Module;
 
-
 //~--- JDK imports ------------------------------------------------------------
 
 import java.util.Collection;
@@ -54,11 +52,9 @@ public interface PluginLoader
    * Method description
    *
    *
-   * @param binder
+   * @return
    */
-  public void processExtensions(Binder binder);
+  public ExtensionProcessor getExtensionProcessor();
-
-  //~--- get methods ----------------------------------------------------------
 
   /**
    * Method description
@@ -90,6 +86,8 @@ public interface PluginLoader
    *
    *
    * @return uber classloader
+   *
+   * @since 2.0.0
    */
   public ClassLoader getUberClassLoader();
 
@@ -99,6 +97,8 @@ public interface PluginLoader
    *
    *
    * @return uber webresourceloader
+   *
+   * @since 2.0.0
    */
   public UberWebResourceLoader getUberWebResourceLoader();
 }

scm-webapp/src/main/java/sonia/scm/ScmContextListener.java

@@ -35,6 +35,7 @@ package sonia.scm;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import com.google.common.base.Stopwatch;
 import com.google.common.collect.Lists;
 import com.google.inject.Guice;
 import com.google.inject.Injector;
@@ -43,11 +44,13 @@ import com.google.inject.servlet.GuiceServletContextListener;
 
 import org.apache.shiro.guice.web.ShiroWebModule;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import sonia.scm.cache.CacheManager;
 import sonia.scm.group.GroupManager;
 import sonia.scm.plugin.DefaultPluginLoader;
 import sonia.scm.plugin.PluginWrapper;
-import sonia.scm.repository.HealthCheckContextListener;
 import sonia.scm.repository.RepositoryManager;
 import sonia.scm.store.StoreFactory;
 import sonia.scm.upgrade.UpgradeManager;
@@ -69,6 +72,14 @@ import javax.servlet.ServletContextEvent;
 public class ScmContextListener extends GuiceServletContextListener
 {
 
+  /**
+   * the logger for ScmContextListener
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ScmContextListener.class);
+
+  //~--- constructors ---------------------------------------------------------
+
   /**
    * Constructs ...
    *
@@ -155,8 +166,6 @@ public class ScmContextListener extends GuiceServletContextListener
       // init servlet context listeners
       globalInjector.getInstance(ServletContextListenerHolder.class)
                     .contextInitialized(servletContextEvent);
-      globalInjector.getInstance(HealthCheckContextListener.class)
-                    .contextInitialized(servletContextEvent);
       //J+
     }
   }
@@ -205,6 +214,7 @@ public class ScmContextListener extends GuiceServletContextListener
    */
   private Injector getDefaultInjector(ServletContext servletCtx)
   {
+    Stopwatch sw = Stopwatch.createStarted();
     DefaultPluginLoader pluginLoader = new DefaultPluginLoader(servletCtx,
                                          parent, plugins);
 
@@ -223,7 +233,12 @@ public class ScmContextListener extends GuiceServletContextListener
 
     SCMContextProvider ctx = SCMContext.getContext();
 
-    return Guice.createInjector(ctx.getStage().getInjectionStage(), moduleList);
+    Injector injector =
+      Guice.createInjector(ctx.getStage().getInjectionStage(), moduleList);
+
+    logger.info("created injector in {}", sw.stop());
+
+    return injector;
   }
 
   /**

scm-webapp/src/main/java/sonia/scm/ScmServletModule.java

@@ -269,7 +269,7 @@ public class ScmServletModule extends JerseyServletModule
     bind(HealthCheckContextListener.class);
 
     // bind extensions
-    pluginLoader.processExtensions(binder());
+    pluginLoader.getExtensionProcessor().processAutoBindExtensions(binder());
 
     // bind security stuff
     bind(PermissionResolver.class, RepositoryPermissionResolver.class);

scm-webapp/src/main/java/sonia/scm/plugin/DefaultExtensionProcessor.java

@@ -0,0 +1,119 @@
+/**
+ * Copyright (c) 2014, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.base.Stopwatch;
+import com.google.inject.Binder;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class DefaultExtensionProcessor implements ExtensionProcessor
+{
+
+  /**
+   * the logger for DefaultExtensionProcessor
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(DefaultExtensionProcessor.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param collector
+   */
+  public DefaultExtensionProcessor(ExtensionCollector collector)
+  {
+    this.collector = collector;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param extensionPoint
+   *
+   * @return
+   */
+  @Override
+  public Iterable<Class> byExtensionPoint(Class extensionPoint)
+  {
+    return collector.byExtensionPoint(extensionPoint);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param extensionPoint
+   *
+   * @return
+   */
+  @Override
+  public Class oneByExtensionPoint(Class extensionPoint)
+  {
+    return collector.oneByExtensionPoint(extensionPoint);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param binder
+   */
+  @Override
+  public void processAutoBindExtensions(Binder binder)
+  {
+    logger.info("start processing extensions");
+
+    Stopwatch sw = Stopwatch.createStarted();
+
+    new ExtensionBinder(binder).bind(collector);
+    logger.info("bound extensions in {}", sw.stop());
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  private final ExtensionCollector collector;
+}

scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java

@@ -39,8 +39,6 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSet.Builder;
 import com.google.common.collect.Iterables;
-import com.google.common.collect.Sets;
-import com.google.inject.Binder;
 import com.google.inject.Module;
 
 import org.slf4j.Logger;
@@ -102,8 +100,8 @@ public class DefaultPluginLoader implements PluginLoader
 
       modules = getInstalled(parent, context, PATH_MODULECONFIG);
 
-      appendExtensions(multiple, single, extensions, modules);
+      collector = new ExtensionCollector(Iterables.concat(modules, unwrap()));
-      appendExtensions(multiple, single, extensions, unwrap());
+      extensionProcessor = new DefaultExtensionProcessor(collector);
     }
     catch (IOException | JAXBException ex)
     {
@@ -111,31 +109,20 @@ public class DefaultPluginLoader implements PluginLoader
     }
   }
 
-  //~--- methods --------------------------------------------------------------
-
-  /**
-   * Method description
-   *
-   *
-   * @param binder
-   */
-  @Override
-  public void processExtensions(Binder binder)
-  {
-    logger.info("start processing extensions");
-
-    if (logger.isInfoEnabled())
-    {
-      logger.info(
-        "found {} extensions for {} multiple and {} single extension points",
-        extensions.size(), multiple.size(), single.size());
-    }
-
-    new ExtensionBinder(binder).bind(multiple, single, extensions);
-  }
-
   //~--- get methods ----------------------------------------------------------
 
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  @Override
+  public ExtensionProcessor getExtensionProcessor()
+  {
+    return extensionProcessor;
+  }
+
   /**
    * Method description
    *
@@ -145,7 +132,7 @@ public class DefaultPluginLoader implements PluginLoader
   @Override
   public Set<Module> getInjectionModules()
   {
-    return ImmutableSet.copyOf(injectionModules);
+    return ImmutableSet.copyOf(collector.getInjectionModules());
   }
 
   /**
@@ -198,56 +185,6 @@ public class DefaultPluginLoader implements PluginLoader
 
   //~--- methods --------------------------------------------------------------
 
-  /**
-   * Method description
-   *
-   *
-   * @param multiple
-   * @param single
-   * @param extensions
-   * @param mods
-   */
-  private void appendExtensions(Set<Class> multiple, Set<Class> single,
-    Set<Class> extensions, Iterable<? extends ScmModule> mods)
-  {
-    for (ScmModule mod : mods)
-    {
-      for (ExtensionPointElement epe : mod.getExtensionPoints())
-      {
-        if (epe.isMultiple())
-        {
-          multiple.add(epe.getClazz());
-        }
-        else
-        {
-          single.add(epe.getClazz());
-        }
-      }
-
-      for (Class extensionClass : mod.getExtensions())
-      {
-        if (Module.class.isAssignableFrom(extensionClass))
-        {
-          try
-          {
-            injectionModules.add((Module) extensionClass.newInstance());
-          }
-          catch (IllegalAccessException | InstantiationException ex)
-          {
-            logger.error("could not create instance of module", ex);
-          }
-        }
-        else
-        {
-          extensions.add(extensionClass);
-        }
-      }
-
-      Iterables.addAll(extensions, mod.getRestProviders());
-      Iterables.addAll(extensions, mod.getRestResources());
-    }
-  }
-
   /**
    * Method description
    *
@@ -296,27 +233,21 @@ public class DefaultPluginLoader implements PluginLoader
 
   //~--- fields ---------------------------------------------------------------
 
+  /** Field description */
+  private final ExtensionCollector collector;
+
+  /** Field description */
+  private final ExtensionProcessor extensionProcessor;
+
+  /** Field description */
+  private final Set<PluginWrapper> installedPlugins;
+
+  /** Field description */
+  private final Set<ScmModule> modules;
+
   /** Field description */
   private final ClassLoader uberClassLoader;
 
   /** Field description */
   private final UberWebResourceLoader uberWebResourceLoader;
-
-  /** Field description */
-  private Set<PluginWrapper> installedPlugins;
-
-  /** Field description */
-  private Set<ScmModule> modules;
-
-  /** Field description */
-  private Set<Class> multiple = Sets.newHashSet();
-
-  /** Field description */
-  private Set<Class> single = Sets.newHashSet();
-
-  /** Field description */
-  private Set<Module> injectionModules = Sets.newHashSet();
-
-  /** Field description */
-  private Set<Class> extensions = Sets.newHashSet();
 }

scm-webapp/src/main/java/sonia/scm/plugin/ExtensionBinder.java

@@ -35,10 +35,8 @@ package sonia.scm.plugin;
 
 //~--- non-JDK imports --------------------------------------------------------
 
-import com.google.common.collect.Iterables;
-import com.google.common.collect.Sets;
 import com.google.inject.Binder;
-import com.google.inject.Scopes;
+import com.google.inject.Singleton;
 import com.google.inject.binder.AnnotatedBindingBuilder;
 import com.google.inject.binder.ScopedBindingBuilder;
 import com.google.inject.multibindings.Multibinder;
@@ -49,12 +47,6 @@ import org.slf4j.LoggerFactory;
 import sonia.scm.EagerSingleton;
 import sonia.scm.util.Util;
 
-//~--- JDK imports ------------------------------------------------------------
-
-import java.util.Set;
-
-import javax.ws.rs.ext.Provider;
-
 /**
  *
  * @author Sebastian Sdorra
@@ -63,6 +55,12 @@ import javax.ws.rs.ext.Provider;
 public final class ExtensionBinder
 {
 
+  /** Field description */
+  private static final String TYPE_LOOSE_EXT = "loose extension";
+
+  /** Field description */
+  private static final String TYPE_REST_RESOURCE = "rest resource";
+
   /**
    * the logger for ExtensionBinder
    */
@@ -88,93 +86,54 @@ public final class ExtensionBinder
    * Method description
    *
    *
-   * @param mutipleExtensionPoints
+   * @param collector
-   * @param singleExtensionPoints
-   * @param extensions
    */
-  public void bind(Set<Class> mutipleExtensionPoints,
+  public void bind(ExtensionCollector collector)
-    Set<Class> singleExtensionPoints, Set<Class> extensions)
   {
-    if (logger.isInfoEnabled())
+    logger.info("bind extensions to extension points");
+
+    for (ExtensionPointElement epe : collector.getExtensionPointElements())
     {
-      logger.info("bind {} extensions to {} extension points",
+      if (epe.isMultiple())
-        extensions.size(),
-        mutipleExtensionPoints.size() + singleExtensionPoints.size());
-    }
-
-    Set<Class> boundClasses = Sets.newHashSet();
-
-    for (Class extensionPointClass : mutipleExtensionPoints)
-    {
-      bindMultiExtensionPoint(boundClasses, extensionPointClass, extensions);
-    }
-
-    for (Class extensionPointClass : singleExtensionPoints)
-    {
-      bindExtensionPoint(boundClasses, extensionPointClass, extensions);
-    }
-
-    Set<Class> extensionsCopy = Sets.newHashSet(extensions);
-
-    Iterables.removeAll(extensionsCopy, boundClasses);
-
-    for (Class extension : extensionsCopy)
-    {
-      AnnotatedBindingBuilder abb = binder.bind(extension);
-
-      if (isProvider(extension))
       {
-        logger.info("bind provider {} as singleton", extension);
+        bindMultiExtensionPoint(epe, collector.byExtensionPoint(epe));
-        abb.in(Scopes.SINGLETON);
-      }
-      else if (isEagerSingleton(extension))
-      {
-
-        logger.info("bind {} as eager singleton, without extensionpoint",
-          extension);
-        abb.asEagerSingleton();
       }
       else
       {
-        logger.info("bind {}, without extensionpoint", extension);
+        Class extension = collector.oneByExtensionPoint(epe);
-        binder.bind(extension);
-      }
-    }
-  }
 
-  /**
+        if (extension != null)
-   * Method description
-   *
-   *
-   *
-   * @param found
-   *
-   * @param boundClasses
-   * @param extensionPointClass
-   * @param extensions
-   */
-  @SuppressWarnings("unchecked")
-  private void bindExtensionPoint(Set<Class> boundClasses,
-    Class extensionPointClass, Set<Class> extensions)
-  {
-    boolean bound = false;
-
-    for (Class extensionClass : extensions)
-    {
-      if (extensionPointClass.isAssignableFrom(extensionClass))
-      {
-        if (bound)
         {
-          throw new IllegalStateException(
+          bindSingleInstance(epe, extension);
-            "extension point ".concat(extensionPointClass.getName()).concat(
+        }
-              " is not multiple and is already bound to another class"));
+        else
+        {
+          logger.warn("could not find extension for extension point {}",
+            epe.getClazz());
         }
-
-        bindSingleInstance(extensionPointClass, extensionClass);
-        boundClasses.add(extensionClass);
-        bound = true;
       }
     }
+
+    logger.info("bind loose extensions");
+    bindLooseExtensions(collector.getLooseExtensions());
+    logger.info("bind rest providers");
+    bindRestProviders(collector.getRestProviders());
+    logger.info("bind rest resources");
+    bindRestResource(collector.getRestResources());
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param extensions
+   */
+  private void bindLooseExtensions(Iterable<Class> extensions)
+  {
+    for (Class extension : extensions)
+    {
+      singleBind(TYPE_LOOSE_EXT, extension);
+    }
   }
 
   /**
@@ -184,14 +143,17 @@ public final class ExtensionBinder
    *
    * @param found
    *
+   * @param extensionPoint
+   *
    * @param boundClasses
    * @param extensionPointClass
    * @param extensions
    */
-  @SuppressWarnings("unchecked")
+  private void bindMultiExtensionPoint(ExtensionPointElement extensionPoint,
-  private void bindMultiExtensionPoint(Set<Class> boundClasses,
+    Iterable<Class> extensions)
-    Class extensionPointClass, Iterable<Class> extensions)
   {
+    Class extensionPointClass = extensionPoint.getClazz();
+
     if (logger.isInfoEnabled())
     {
       logger.info("create multibinder for {}", extensionPointClass.getName());
@@ -202,47 +164,72 @@ public final class ExtensionBinder
 
     for (Class extensionClass : extensions)
     {
-      if (extensionPointClass.isAssignableFrom(extensionClass))
+      boolean eagerSingleton = isEagerSingleton(extensionClass);
+
+      if (logger.isInfoEnabled())
       {
-        boolean eagerSingleton = isEagerSingleton(extensionClass);
+        String as = Util.EMPTY_STRING;
-
-        if (logger.isInfoEnabled())
-        {
-          String as = Util.EMPTY_STRING;
-
-          if (eagerSingleton)
-          {
-            as = " as eager singleton";
-          }
-
-          logger.info("bind {} to multibinder of {}{}",
-            extensionClass.getName(), extensionPointClass.getName(), as);
-        }
-
-        ScopedBindingBuilder sbb = multibinder.addBinding().to(extensionClass);
 
         if (eagerSingleton)
         {
-          sbb.asEagerSingleton();
+          as = " as eager singleton";
-          logger.info("bind {} as eager singleton");
         }
 
-        boundClasses.add(extensionClass);
+        logger.info("bind {} to multibinder of {}{}", extensionClass.getName(),
+          extensionPointClass.getName(), as);
+      }
+
+      ScopedBindingBuilder sbb = multibinder.addBinding().to(extensionClass);
+
+      if (eagerSingleton)
+      {
+        sbb.asEagerSingleton();
       }
     }
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param restProviders
+   */
+  private void bindRestProviders(Iterable<Class> restProviders)
+  {
+    for (Class restProvider : restProviders)
+    {
+      logger.info("bind rest provider {}", restProvider);
+      binder.bind(restProvider).in(Singleton.class);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param restResources
+   */
+  private void bindRestResource(Iterable<Class> restResources)
+  {
+    for (Class restResource : restResources)
+    {
+      singleBind(TYPE_REST_RESOURCE, restResource);
+    }
+  }
+
   /**
    * Method description
    *
    *
    * @param extensionPointClass
+   *
+   * @param extensionPoint
    * @param extensionClass
    */
-  @SuppressWarnings("unchecked")
+  private void bindSingleInstance(ExtensionPointElement extensionPoint,
-  private void bindSingleInstance(Class extensionPointClass,
     Class extensionClass)
   {
+    Class extensionPointClass = extensionPoint.getClazz();
     boolean eagerSingleton = isEagerSingleton(extensionClass);
 
     if (logger.isInfoEnabled())
@@ -267,6 +254,30 @@ public final class ExtensionBinder
     }
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param type
+   * @param extension
+   */
+  private void singleBind(String type, Class extension)
+  {
+    StringBuilder log = new StringBuilder();
+
+    log.append("bind ").append(type).append(" ").append(extension);
+
+    AnnotatedBindingBuilder abb = binder.bind(extension);
+
+    if (isEagerSingleton(extension))
+    {
+      log.append(" as eager singleton");
+      abb.asEagerSingleton();
+    }
+
+    logger.info(log.toString());
+  }
+
   //~--- get methods ----------------------------------------------------------
 
   /**
@@ -282,19 +293,6 @@ public final class ExtensionBinder
     return extensionClass.isAnnotationPresent(EagerSingleton.class);
   }
 
-  /**
-   * Method description
-   *
-   *
-   * @param extensionClass
-   *
-   * @return
-   */
-  private boolean isProvider(Class extensionClass)
-  {
-    return extensionClass.isAnnotationPresent(Provider.class);
-  }
-
   //~--- fields ---------------------------------------------------------------
 
   /** Field description */

scm-webapp/src/main/java/sonia/scm/plugin/ExtensionCollector.java

@@ -0,0 +1,333 @@
+/**
+ * Copyright (c) 2014, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+import com.google.inject.Module;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+@SuppressWarnings("unchecked")
+public final class ExtensionCollector
+{
+
+  /**
+   * the logger for ExtensionCollector
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ExtensionCollector.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param modules
+   */
+  ExtensionCollector(Iterable<ScmModule> modules)
+  {
+    for (ScmModule module : modules)
+    {
+      collectRootElements(module);
+    }
+
+    for (ScmModule module : modules)
+    {
+      collectExtensions(module);
+    }
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param epe
+   *
+   * @return
+   */
+  public Collection<Class> byExtensionPoint(ExtensionPointElement epe)
+  {
+    Collection<Class> collection = extensions.get(epe);
+    if ( collection == null ){
+      collection = Collections.EMPTY_SET;
+    }
+    return collection;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param clazz
+   *
+   * @return
+   */
+  public Collection<Class> byExtensionPoint(Class clazz)
+  {
+    Collection<Class> exts;
+    ExtensionPointElement epe = extensionPointIndex.get(clazz);
+
+    if (epe != null)
+    {
+      exts = byExtensionPoint(epe);
+    }
+    else
+    {
+      exts = Collections.EMPTY_SET;
+    }
+
+    return exts;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param epe
+   *
+   * @return
+   */
+  public Class oneByExtensionPoint(ExtensionPointElement epe)
+  {
+    return Iterables.getFirst(byExtensionPoint(epe), null);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param clazz
+   *
+   * @return
+   */
+  public Class oneByExtensionPoint(Class clazz)
+  {
+    return Iterables.getFirst(byExtensionPoint(clazz), null);
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Iterable<ExtensionPointElement> getExtensionPointElements()
+  {
+    return extensionPointIndex.values();
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Multimap<ExtensionPointElement, Class> getExtensions()
+  {
+    return extensions;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Set<Module> getInjectionModules()
+  {
+    return injectionModules;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Set<Class> getLooseExtensions()
+  {
+    return looseExtensions;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Set<Class> getRestProviders()
+  {
+    return restProviders;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public Set<Class> getRestResources()
+  {
+    return restResources;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param extension
+   */
+  private void appendExtension(Class extension)
+  {
+    boolean found = false;
+
+    for (Entry<Class, ExtensionPointElement> e : extensionPointIndex.entrySet())
+    {
+      if (e.getKey().isAssignableFrom(extension))
+      {
+        extensions.put(e.getValue(), extension);
+        found = true;
+
+        break;
+      }
+    }
+
+    if (!found)
+    {
+      looseExtensions.add(extension);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param extension
+   */
+  private void appendModule(Class extension)
+  {
+    try
+    {
+      injectionModules.add((Module) extension.newInstance());
+    }
+    catch (IllegalAccessException | InstantiationException ex)
+    {
+      logger.error("could not create instance of module", ex);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param module
+   */
+  private void collectExtensions(ScmModule module)
+  {
+    for (Class extension : module.getExtensions())
+    {
+      if (Module.class.isAssignableFrom(extension))
+      {
+        appendModule(extension);
+      }
+      else
+      {
+        appendExtension(extension);
+      }
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param module
+   */
+  private void collectRootElements(ScmModule module)
+  {
+    for (ExtensionPointElement epe : module.getExtensionPoints())
+    {
+      extensionPointIndex.put(epe.getClazz(), epe);
+    }
+    restProviders.addAll(Lists.newArrayList(module.getRestProviders()));
+    restResources.addAll(Lists.newArrayList(module.getRestResources()));
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  private final Set<Class> looseExtensions = Sets.newHashSet();
+
+  /** Field description */
+  private final Set<Module> injectionModules = Sets.newHashSet();
+
+  /** Field description */
+  private final Set<Class> restProviders = Sets.newHashSet();
+
+  /** Field description */
+  private final Set<Class> restResources = Sets.newHashSet();
+
+  /** Field description */
+  private final Multimap<ExtensionPointElement, Class> extensions =
+    HashMultimap.create();
+
+  /** Field description */
+  private final Map<Class, ExtensionPointElement> extensionPointIndex =
+    Maps.newHashMap();
+}