RepositoryBrowser is updated to support auto registration.

Refactored the ConcurrentHashMap double-if putIfAbsent idiom into the Memoizer class.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15653 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/DescriptorExtensionList.java

@@ -26,12 +26,12 @@ package hudson;
 import hudson.model.Descriptor;
 import hudson.model.Describable;
 import hudson.model.Hudson;
+import hudson.util.Memoizer;
 
 import java.util.List;
 import java.util.ArrayList;
 import java.util.logging.Logger;
 import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.ConcurrentHashMap;
 import java.lang.reflect.Type;
 import java.lang.reflect.ParameterizedType;
 
@@ -52,7 +52,7 @@ public final class DescriptorExtensionList<T extends Describable<T>> extends Ext
     private final Class<T> describableType;
 
     public DescriptorExtensionList(Hudson hudson, Class<T> describableType) {
-        super(hudson, (Class)Descriptor.class,allocateLegacyInstanceStore(describableType));
+        super(hudson, (Class)Descriptor.class, legacyDescriptors.get(describableType));
         this.describableType = describableType;
     }
 
@@ -78,19 +78,17 @@ public final class DescriptorExtensionList<T extends Describable<T>> extends Ext
      * Obtain the statically-scoped storage to store manulaly registered {@link Descriptor}s.
      */
     private static List allocateLegacyInstanceStore(Class describableType) {
-        List r = legacyDescriptors.get(describableType);
-        if(r!=null)     return r;
-
-        r = new CopyOnWriteArrayList();
-        List x = legacyDescriptors.putIfAbsent(describableType, r);
-        if(x==null) return r;
-        return x;
+        return legacyDescriptors.get(describableType);
     }
 
     /**
      * Stores manually registered Descriptor instances.
      */
-    private static final ConcurrentHashMap<Class,List> legacyDescriptors = new ConcurrentHashMap<Class,List>();
+    private static final Memoizer<Class,List> legacyDescriptors = new Memoizer<Class,List>() {
+        public List compute(Class key) {
+            return new CopyOnWriteArrayList();
+        }
+    };
 
     private static final Logger LOGGER = Logger.getLogger(DescriptorExtensionList.class.getName());
 }

core/src/main/java/hudson/ExtensionList.java

@@ -25,6 +25,8 @@ package hudson;
 
 import hudson.model.Hudson;
 import hudson.util.DescriptorList;
+import hudson.util.Memoizer;
+import hudson.ExtensionPoint.LegacyInstancesAreScopedToHudson;
 
 import java.util.AbstractList;
 import java.util.ArrayList;
@@ -33,6 +35,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Vector;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Retains the known extension instances for the given type 'T'.
@@ -174,6 +177,19 @@ public class ExtensionList<T> extends AbstractList<T> {
                     return Collections.singleton(new ExtensionFinder.Sezpoz());
                 }
             };
+        if(type.getAnnotation(LegacyInstancesAreScopedToHudson.class)!=null)
             return new ExtensionList<T>(hudson,type);
+        else {
+            return new ExtensionList<T>(hudson,type,staticLegacyInstances.get(type));
         }
+    }
+
+    /**
+     * Places to store static-scope legacy instances.
+     */
+    private static final Memoizer<Class,List> staticLegacyInstances = new Memoizer<Class,List>() {
+        public List compute(Class key) {
+            return new CopyOnWriteArrayList();
+        }
+    };
 }

core/src/main/java/hudson/ExtensionPoint.java

@@ -23,6 +23,13 @@
  */
 package hudson;
 
+import hudson.model.Hudson;
+
+import static java.lang.annotation.ElementType.TYPE;
+import java.lang.annotation.Retention;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import java.lang.annotation.Target;
+
 /**
  * Marker interface that designates extensible components
  * in Hudson that can be implemented by plugins.
@@ -41,4 +48,12 @@ package hudson;
  * @see Extension
  */
 public interface ExtensionPoint {
+    /**
+     * Used by designers of extension points (direct subtypes of {@link ExtensionPoint}) to indicate that
+     * the legacy instances are scoped to {@link Hudson} instance. By default, legacy instances are
+     * static scope.  
+     */
+    @Target(TYPE)
+    @Retention(RUNTIME)
+    public @interface LegacyInstancesAreScopedToHudson {}
 }

core/src/main/java/hudson/model/AdministrativeMonitor.java

@@ -26,6 +26,7 @@ package hudson.model;
 import hudson.ExtensionPoint;
 import hudson.ExtensionList;
 import hudson.Extension;
+import hudson.ExtensionPoint.LegacyInstancesAreScopedToHudson;
 import hudson.triggers.SCMTrigger;
 import hudson.triggers.TimerTrigger;
 
@@ -72,6 +73,7 @@ import org.kohsuke.stapler.StaplerResponse;
  * @since 1.273
  * @see Hudson#administrativeMonitors
  */
+@LegacyInstancesAreScopedToHudson
 public abstract class AdministrativeMonitor extends AbstractModelObject implements ExtensionPoint {
     /**
      * Human-readable ID of this monitor, which needs to be unique within the system.

core/src/main/java/hudson/model/Hudson.java

@@ -106,6 +106,7 @@ import hudson.util.XStream2;
 import hudson.util.HudsonIsRestarting;
 import hudson.util.DescribableList;
 import hudson.util.Futures;
+import hudson.util.Memoizer;
 import hudson.widgets.Widget;
 import net.sf.json.JSONObject;
 import org.acegisecurity.*;
@@ -281,12 +282,20 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
     /**
      * All {@link ExtensionList} keyed by their {@link ExtensionList#extensionType}.
      */
-    private transient final ConcurrentHashMap<Class,ExtensionList> extensionLists = new ConcurrentHashMap<Class,ExtensionList>();
+    private transient final Memoizer<Class,ExtensionList> extensionLists = new Memoizer<Class,ExtensionList>() {
+        public ExtensionList compute(Class key) {
+            return ExtensionList.create(Hudson.this,key);
+        }
+    };
 
     /**
      * All {@link DescriptorExtensionList} keyed by their {@link DescriptorExtensionList#describableType}.
      */
-    private transient final ConcurrentHashMap<Class, DescriptorExtensionList> descriptorLists = new ConcurrentHashMap<Class, DescriptorExtensionList>();
+    private transient final Memoizer<Class,DescriptorExtensionList> descriptorLists = new Memoizer<Class,DescriptorExtensionList>() {
+        public DescriptorExtensionList compute(Class key) {
+            return new DescriptorExtensionList(Hudson.this,key);
+        }
+    };
 
     /**
      * Active {@link Cloud}s.
@@ -631,7 +640,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * Gets the repository browser descriptor by name. Primarily used for making them web-visible.
      */
     public Descriptor<RepositoryBrowser<?>> getRepositoryBrowser(String shortClassName) {
-        return findDescriptor(shortClassName,RepositoryBrowsers.LIST);
+        return findDescriptor(shortClassName,RepositoryBrowser.all());
     }
 
     /**
@@ -1468,15 +1477,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      */
     @SuppressWarnings({"unchecked"})
     public <T> ExtensionList<T> getExtensionList(Class<T> extensionType) {
-        // by far the common case is where we find an instance already created.
-        ExtensionList<T> r = extensionLists.get(extensionType);
-        if(r!=null) return r;
-
-        // if we have to create a new one, make sure we don't create two at the same time.
-        r = ExtensionList.create(this,extensionType);
-        ExtensionList<T> x = extensionLists.putIfAbsent(extensionType, r);
-        if(x==null) return r;
-        else        return x;
+        return extensionLists.get(extensionType);
     }
 
     /**
@@ -1488,15 +1489,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      */
     @SuppressWarnings({"unchecked"})
     public <T extends Describable<T>> DescriptorExtensionList<T> getDescriptorList(Class<T> type) {
-        // by far the common case is where we find an instance already created.
-        DescriptorExtensionList r = descriptorLists.get(type);
-        if(r!=null) return r;
-
-        // if we have to create a new one, make sure we don't create two at the same time.
-        r = new DescriptorExtensionList(this,type);
-        DescriptorExtensionList x = descriptorLists.putIfAbsent(type, r);
-        if(x==null) return r;
-        else        return x;
+        return descriptorLists.get(type);
     }
 
     /**

core/src/main/java/hudson/scm/RepositoryBrowser.java

@@ -24,7 +24,12 @@
 package hudson.scm;
 
 import hudson.ExtensionPoint;
+import hudson.DescriptorExtensionList;
+import hudson.Extension;
+import hudson.tasks.BuildWrapper;
 import hudson.model.Describable;
+import hudson.model.Descriptor;
+import hudson.model.Hudson;
 
 import java.io.IOException;
 import java.io.Serializable;
@@ -44,8 +49,7 @@ import java.net.MalformedURLException;
  * {@link RepositoryBrowser} is persisted with {@link SCM}.
  *
  * <p>
- * To have Hudson recognize {@link RepositoryBrowser}, add the descriptor
- * to {@link RepositoryBrowsers#LIST}.
+ * To have Hudson recognize {@link RepositoryBrowser}, put {@link Extension} on your {@link Descriptor}.
  *
  * @author Kohsuke Kawaguchi
  * @since 1.89
@@ -90,5 +94,16 @@ public abstract class RepositoryBrowser<E extends ChangeLogSet.Entry> implements
         }
     }
 
+    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
+        return Hudson.getInstance().getDescriptor(getClass());
+    }
+
+    /**
+     * Returns all the registered {@link RepositoryBrowser} descriptors.
+     */
+    public static DescriptorExtensionList<RepositoryBrowser<?>> all() {
+        return (DescriptorExtensionList)Hudson.getInstance().getDescriptorList(RepositoryBrowser.class);
+    }
+
     private static final long serialVersionUID = 1L;
 }

core/src/main/java/hudson/scm/RepositoryBrowsers.java

@@ -24,8 +24,11 @@
 package hudson.scm;
 
 import hudson.model.Descriptor;
+import hudson.model.Hudson;
 import hudson.model.Descriptor.FormException;
 import hudson.scm.browsers.*;
+import hudson.util.DescriptorList;
+import hudson.Extension;
 import org.kohsuke.stapler.StaplerRequest;
 
 import java.util.ArrayList;
@@ -42,23 +45,18 @@ import net.sf.json.JSONArray;
 public class RepositoryBrowsers {
     /**
      * List of all installed {@link RepositoryBrowsers}.
+     *
+     * @deprecated as of 1.286.
+     *      Use {@link RepositoryBrowser#all()} for read access and {@link Extension} for registration.
      */
-    public static final List<Descriptor<RepositoryBrowser<?>>> LIST = Descriptor.toList(
-        ViewCVS.DESCRIPTOR,
-        ViewSVN.DescriptorImpl.INSTANCE,
-        FishEyeSVN.DESCRIPTOR,
-        FishEyeCVS.DESCRIPTOR,
-        WebSVN.DESCRIPTOR,
-        Sventon.DESCRIPTOR,
-        CollabNetSVN.DESCRIPTOR
-    );
+    public static final List<Descriptor<RepositoryBrowser<?>>> LIST = new DescriptorList<RepositoryBrowser<?>>((Class)RepositoryBrowser.class);
 
     /**
      * Only returns those {@link RepositoryBrowser} descriptors that extend from the given type.
      */
     public static List<Descriptor<RepositoryBrowser<?>>> filter(Class<? extends RepositoryBrowser> t) {
         List<Descriptor<RepositoryBrowser<?>>> r = new ArrayList<Descriptor<RepositoryBrowser<?>>>();
-        for (Descriptor<RepositoryBrowser<?>> d : LIST)
+        for (Descriptor<RepositoryBrowser<?>> d : RepositoryBrowser.all())
             if(t.isAssignableFrom(d.clazz))
                 r.add(d);
         return r;

core/src/main/java/hudson/scm/browsers/CollabNetSVN.java

@@ -24,10 +24,13 @@
 package hudson.scm.browsers;
 
 import hudson.model.Descriptor;
+import hudson.model.Descriptor.FormException;
 import hudson.scm.EditType;
 import hudson.scm.RepositoryBrowser;
 import hudson.scm.SubversionChangeLogSet;
 import hudson.scm.SubversionRepositoryBrowser;
+import hudson.Extension;
+
 import java.io.IOException;
 import java.net.URL;
 import net.sf.json.JSONObject;
@@ -42,19 +45,17 @@ import org.kohsuke.stapler.StaplerRequest;
  */
 public class CollabNetSVN extends SubversionRepositoryBrowser
 {
-    public static final Descriptor<RepositoryBrowser<?>> DESCRIPTOR
-        = new Descriptor<RepositoryBrowser<?>>() {
+    @Extension
+    public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         public String getDisplayName() {
             return "CollabNet";
         }
 
-
         @Override
-        public RepositoryBrowser<?> newInstance(StaplerRequest req,
-                                                JSONObject formData) throws FormException {
+        public RepositoryBrowser<?> newInstance(StaplerRequest req, JSONObject formData) throws FormException {
             return req.bindParameters(CollabNetSVN.class, "collabnet.svn.");
         }
-    };
+    }
 
 
     public final URL url;
@@ -110,12 +111,4 @@ public class CollabNetSVN extends SubversionRepositoryBrowser
         query.add("view=rev");
         return new URL(url, query.toString());
     }
-
-
-    /**
-     * {@inheritDoc}
-     */    
-    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
-        return DESCRIPTOR;
-    }
 }

core/src/main/java/hudson/scm/browsers/FishEyeCVS.java

@@ -24,6 +24,7 @@
 package hudson.scm.browsers;
 
 import hudson.Util;
+import hudson.Extension;
 import hudson.model.Descriptor;
 import hudson.model.Hudson;
 import hudson.scm.CVSChangeLogSet;
@@ -76,12 +77,7 @@ public final class FishEyeCVS extends CVSRepositoryBrowser {
         return null;
     }
 
-    public DescriptorImpl getDescriptor() {
-        return DESCRIPTOR;
-    }
-
-    public static final DescriptorImpl DESCRIPTOR = new DescriptorImpl();
-
+    @Extension
     public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         @Override
         public String getDisplayName() {

core/src/main/java/hudson/scm/browsers/FishEyeSVN.java

@@ -32,6 +32,7 @@ import hudson.scm.SubversionChangeLogSet.Path;
 import hudson.scm.SubversionRepositoryBrowser;
 import hudson.scm.EditType;
 import hudson.util.FormFieldValidator;
+import hudson.Extension;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
 import org.kohsuke.stapler.DataBoundConstructor;
@@ -121,12 +122,7 @@ public class FishEyeSVN extends SubversionRepositoryBrowser {
         return new URL(url,"../../changelog/"+getProjectName()+"/?cs="+changeSet.getRevision());
     }
 
-    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
-        return DESCRIPTOR;
-    }
-
-    public static final Descriptor<RepositoryBrowser<?>> DESCRIPTOR = new DescriptorImpl();
-
+    @Extension
     public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         public String getDisplayName() {
             return "FishEye";

core/src/main/java/hudson/scm/browsers/Sventon.java

@@ -31,6 +31,7 @@ import hudson.scm.SubversionChangeLogSet.Path;
 import hudson.scm.SubversionRepositoryBrowser;
 import hudson.scm.EditType;
 import hudson.util.FormFieldValidator;
+import hudson.Extension;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
 import org.kohsuke.stapler.DataBoundConstructor;
@@ -121,12 +122,7 @@ public class Sventon extends SubversionRepositoryBrowser {
                 repositoryInstance,changeSet.getRevision()));
     }
 
-    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
-        return DESCRIPTOR;
-    }
-
-    public static final Descriptor<RepositoryBrowser<?>> DESCRIPTOR = new DescriptorImpl();
-
+    @Extension
     public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         public String getDisplayName() {
             return "Sventon";

core/src/main/java/hudson/scm/browsers/ViewCVS.java

@@ -29,6 +29,7 @@ import hudson.scm.CVSChangeLogSet.File;
 import hudson.scm.CVSChangeLogSet.Revision;
 import hudson.scm.CVSRepositoryBrowser;
 import hudson.scm.RepositoryBrowser;
+import hudson.Extension;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.DataBoundConstructor;
 
@@ -79,15 +80,12 @@ public final class ViewCVS extends CVSRepositoryBrowser {
         return new QueryBuilder(url.getQuery());
     }
 
-    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
-        return DESCRIPTOR;
-    }
-
-    public static final Descriptor<RepositoryBrowser<?>> DESCRIPTOR = new Descriptor<RepositoryBrowser<?>>() {
+    @Extension
+    public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         public String getDisplayName() {
             return "ViewCVS";
         }
-    };
+    }
 
     private static final long serialVersionUID = 1L;
 }

core/src/main/java/hudson/scm/browsers/ViewSVN.java

@@ -29,6 +29,7 @@ import hudson.scm.RepositoryBrowser;
 import hudson.scm.SubversionChangeLogSet;
 import hudson.scm.SubversionChangeLogSet.Path;
 import hudson.scm.SubversionRepositoryBrowser;
+import hudson.Extension;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.DataBoundConstructor;
 
@@ -80,15 +81,10 @@ public class ViewSVN extends SubversionRepositoryBrowser {
         return new QueryBuilder(url.getQuery());
     }
 
-    public DescriptorImpl getDescriptor() {
-        return DescriptorImpl.INSTANCE;
-    }
-
     private static final long serialVersionUID = 1L;
 
+    @Extension
     public static final class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
-        public static final DescriptorImpl INSTANCE = new DescriptorImpl();
-
         public String getDisplayName() {
             return "ViewSVN";
         }

core/src/main/java/hudson/scm/browsers/WebSVN.java

@@ -32,6 +32,7 @@ import hudson.scm.SubversionChangeLogSet;
 import hudson.scm.SubversionChangeLogSet.Path;
 
 import hudson.scm.SubversionRepositoryBrowser;
+import hudson.Extension;
 
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.DataBoundConstructor;
@@ -51,12 +52,12 @@ import java.net.URL;
  */
 public class WebSVN extends SubversionRepositoryBrowser {
 
-    public static final Descriptor<RepositoryBrowser<?>> DESCRIPTOR =
-        new Descriptor<RepositoryBrowser<?>>() {
+    @Extension
+    public static class DescriptorImpl extends Descriptor<RepositoryBrowser<?>> {
         public String getDisplayName() {
             return "WebSVN";
         }
-        };
+    }
 
 
     private static final long serialVersionUID = 1L;
@@ -135,13 +136,4 @@ public class WebSVN extends SubversionRepositoryBrowser {
     private QueryBuilder param() {
         return new QueryBuilder(url.getQuery());
     }
-
-    /**
-     * Returns the descriptor value.
-     *
-     * @return  the descriptor value.
-     */
-    public Descriptor<RepositoryBrowser<?>> getDescriptor() {
-        return DESCRIPTOR;
-    }
 }

core/src/main/java/hudson/util/Memoizer.java

+/*
+ * The MIT License
+ *
+ * Copyright (c) 2004-2009, Sun Microsystems, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package hudson.util;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Implements memoization semantics.
+ *
+ * <p>
+ * Conceputually a function from K -> V that computes values lazily and remembers the results.
+ * Often used to implement a data store per key.
+ *
+ * @author Kohsuke Kawaguchi
+ * @since 1.281
+ */
+public abstract class Memoizer<K,V> {
+    private final ConcurrentHashMap<K,V> store = new ConcurrentHashMap<K,V>();
+
+    public V get(K key) {
+        V v = store.get(key);
+        if(v!=null)     return v;
+
+        // TODO: if we want to, we can avoid locking altogether by putting a sentinel value
+        // that represents "the value is being computed". FingerprintMap does this.
+        synchronized (this) {
+            v = store.get(key);
+            if(v!=null)     return v;
+
+            v = compute(key);
+            store.put(key,v);
+            return v;
+        }
+    }
+
+    /**
+     * Creates a new instance.
+     */
+    public abstract V compute(K key);
+}

test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java

@@ -30,7 +30,6 @@ import hudson.WebAppMain;
 import hudson.Launcher.LocalLauncher;
 import hudson.matrix.MatrixProject;
 import hudson.maven.MavenModuleSet;
-import hudson.maven.MavenReporters;
 import hudson.model.Descriptor;
 import hudson.model.FreeStyleProject;
 import hudson.model.Hudson;
@@ -300,7 +299,7 @@ public abstract class HudsonTestCase extends TestCase {
         String home = System.getProperty("maven.home");
         if(home!=null) {
             MavenInstallation mavenInstallation = new MavenInstallation("default",home);
-			Maven.DESCRIPTOR.setInstallations(mavenInstallation);
+			((Maven.DescriptorImpl)hudson.getDescriptor(Maven.class)).setInstallations(mavenInstallation);
             return mavenInstallation;
         }
 
@@ -320,7 +319,7 @@ public abstract class HudsonTestCase extends TestCase {
 
         MavenInstallation mavenInstallation = new MavenInstallation("default",
                 new File(mvnHome,"maven-2.0.7").getAbsolutePath());
-		Maven.DESCRIPTOR.setInstallations(mavenInstallation);
+		((Maven.DescriptorImpl)hudson.getDescriptor(Maven.class)).setInstallations(mavenInstallation);
 		return mavenInstallation;
     }