Merge "Define an extension for user scoped event listeners"

Documentation/dev-plugins.txt

@@ -381,10 +381,16 @@ listeners.
 
 * `com.google.gerrit.common.EventListener`:
 +
-Allows to listen to events. These are the same
-link:cmd-stream-events.html#events[events] that are also streamed by
+Allows to listen to events without user visibility restrictions. These
+are the same link:cmd-stream-events.html#events[events] that are also streamed by
 the link:cmd-stream-events.html[gerrit stream-events] command.
 
+* `com.google.gerrit.common.UserScopedEventListener`:
++
+Allows to listen to events visible to the specified user. These are the
+same link:cmd-stream-events.html#events[events] that are also streamed
+by the link:cmd-stream-events.html[gerrit stream-events] command.
+
 * `com.google.gerrit.extensions.events.LifecycleListener`:
 +
 Plugin start and stop

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java

@@ -31,8 +31,7 @@ import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.NoHttpd;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.TestProjectInput;
-import com.google.gerrit.common.EventListener;
-import com.google.gerrit.common.EventSource;
+import com.google.gerrit.common.UserScopedEventListener;
 import com.google.gerrit.extensions.api.changes.SubmitInput;
 import com.google.gerrit.extensions.api.projects.BranchInfo;
 import com.google.gerrit.extensions.api.projects.ProjectInput;
@@ -43,6 +42,8 @@ import com.google.gerrit.extensions.client.SubmitType;
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.common.ChangeMessageInfo;
 import com.google.gerrit.extensions.common.LabelInfo;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.registration.RegistrationHandle;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.extensions.webui.UiAction;
@@ -106,9 +107,9 @@ public abstract class AbstractSubmit extends AbstractDaemonTest {
   private Submit submitHandler;
 
   @Inject
-  EventSource source;
+  DynamicSet<UserScopedEventListener> eventListeners;
 
-  private EventListener eventListener;
+  private RegistrationHandle eventListenerRegistration;
 
   private String systemTimeZone;
 
@@ -127,26 +128,30 @@ public abstract class AbstractSubmit extends AbstractDaemonTest {
   @Before
   public void setUp() throws Exception {
     mergeResults = Maps.newHashMap();
-    CurrentUser listenerUser = factory.create(user.id);
-    eventListener = new EventListener() {
-      @Override
-      public void onEvent(Event event) {
-        if (!(event instanceof ChangeMergedEvent)) {
-          return;
-        }
-        ChangeMergedEvent e = (ChangeMergedEvent) event;
-        ChangeAttribute c = e.change.get();
-        PatchSetAttribute ps = e.patchSet.get();
-        log.debug("Merged {},{} as {}", ps.number, c.number, e.newRev);
-        mergeResults.put(e.change.get().number, e.newRev);
-      }
-    };
-    source.addEventListener(eventListener, listenerUser);
+    eventListenerRegistration =
+        eventListeners.add(new UserScopedEventListener() {
+          @Override
+          public void onEvent(Event event) {
+            if (!(event instanceof ChangeMergedEvent)) {
+              return;
+            }
+            ChangeMergedEvent e = (ChangeMergedEvent) event;
+            ChangeAttribute c = e.change.get();
+            PatchSetAttribute ps = e.patchSet.get();
+            log.debug("Merged {},{} as {}", ps.number, c.number, e.newRev);
+            mergeResults.put(e.change.get().number, e.newRev);
+          }
+
+          @Override
+          public CurrentUser getUser() {
+            return factory.create(user.id);
+          }
+        });
   }
 
   @After
   public void cleanup() {
-    source.removeEventListener(eventListener);
+    eventListenerRegistration.remove();
     db.close();
   }
 

gerrit-server/src/main/java/com/google/gerrit/common/ChangeHookRunner.java

@@ -92,7 +92,6 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.Callable;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.FutureTask;
@@ -102,7 +101,7 @@ import java.util.concurrent.TimeoutException;
 /** Spawns local executables when a hook action occurs. */
 @Singleton
 public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
-  EventSource, LifecycleListener, NewProjectCreatedListener {
+    LifecycleListener, NewProjectCreatedListener {
     /** A logger for this class. */
     private static final Logger log = LoggerFactory.getLogger(ChangeHookRunner.class);
 
@@ -112,22 +111,11 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
         bind(ChangeHookRunner.class);
         bind(ChangeHooks.class).to(ChangeHookRunner.class);
         bind(EventDispatcher.class).to(ChangeHookRunner.class);
-        bind(EventSource.class).to(ChangeHookRunner.class);
         DynamicSet.bind(binder(), NewProjectCreatedListener.class).to(ChangeHookRunner.class);
         listener().to(ChangeHookRunner.class);
       }
     }
 
-    private static class EventListenerHolder {
-      final EventListener listener;
-      final CurrentUser user;
-
-      EventListenerHolder(EventListener l, CurrentUser u) {
-        listener = l;
-        user = u;
-      }
-    }
-
     /** Container class used to hold the return code and output of script hook execution */
     public static class HookResult {
       private int exitValue = -1;
@@ -177,9 +165,8 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
     }
 
     /** Listeners to receive changes as they happen (limited by visibility
-     *  of holder's user). */
-    private final Map<EventListener, EventListenerHolder> listeners =
-        new ConcurrentHashMap<>();
+     *  of user). */
+    private final DynamicSet<UserScopedEventListener> listeners;
 
     /** Listeners to receive all changes as they happen. */
     private final DynamicSet<EventListener> unrestrictedListeners;
@@ -268,6 +255,7 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
       ProjectCache projectCache,
       AccountCache accountCache,
       EventFactory eventFactory,
+      DynamicSet<UserScopedEventListener> listeners,
       DynamicSet<EventListener> unrestrictedListeners,
       ChangeNotes.Factory notesFactory) {
         this.anonymousCowardName = anonymousCowardName;
@@ -277,6 +265,7 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
         this.accountCache = accountCache;
         this.eventFactory = eventFactory;
         this.sitePaths = sitePath;
+        this.listeners = listeners;
         this.unrestrictedListeners = unrestrictedListeners;
         this.notesFactory = notesFactory;
 
@@ -319,16 +308,6 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
       return Files.exists(p) ? Optional.of(p) : Optional.<Path>absent();
     }
 
-    @Override
-    public void addEventListener(EventListener listener, CurrentUser user) {
-      listeners.put(listener, new EventListenerHolder(listener, user));
-    }
-
-    @Override
-    public void removeEventListener(EventListener listener) {
-      listeners.remove(listener);
-    }
-
     /**
      * Get the Repository for the given project name, or null on error.
      *
@@ -923,9 +902,9 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
 
     private void fireEvent(Change change, ChangeEvent event, ReviewDb db)
         throws OrmException {
-      for (EventListenerHolder holder : listeners.values()) {
-        if (isVisibleTo(change, holder.user, db)) {
-          holder.listener.onEvent(event);
+      for (UserScopedEventListener listener : listeners) {
+        if (isVisibleTo(change, listener.getUser(), db)) {
+          listener.onEvent(event);
         }
       }
 
@@ -933,9 +912,9 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
     }
 
     private void fireEvent(Project.NameKey project, ProjectEvent event) {
-      for (EventListenerHolder holder : listeners.values()) {
-        if (isVisibleTo(project, holder.user)) {
-          holder.listener.onEvent(event);
+      for (UserScopedEventListener listener : listeners) {
+        if (isVisibleTo(project, listener.getUser())) {
+          listener.onEvent(event);
         }
       }
 
@@ -943,9 +922,9 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
     }
 
     private void fireEvent(Branch.NameKey branchName, RefEvent event) {
-      for (EventListenerHolder holder : listeners.values()) {
-        if (isVisibleTo(branchName, holder.user)) {
-          holder.listener.onEvent(event);
+      for (UserScopedEventListener listener : listeners) {
+        if (isVisibleTo(branchName, listener.getUser())) {
+          listener.onEvent(event);
         }
       }
 
@@ -954,9 +933,9 @@ public class ChangeHookRunner implements ChangeHooks, EventDispatcher,
 
     private void fireEvent(com.google.gerrit.server.events.Event event,
         ReviewDb db) throws OrmException {
-      for (EventListenerHolder holder : listeners.values()) {
-        if (isVisibleTo(event, holder.user, db)) {
-          holder.listener.onEvent(event);
+      for (UserScopedEventListener listener : listeners) {
+        if (isVisibleTo(event, listener.getUser(), db)) {
+          listener.onEvent(event);
         }
       }
 

gerrit-server/src/main/java/com/google/gerrit/common/DisabledChangeHooks.java

@@ -21,7 +21,6 @@ import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.events.ChangeEvent;
 import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.events.ProjectEvent;
@@ -34,12 +33,7 @@ import java.util.Map;
 import java.util.Set;
 
 /** Does not invoke hooks. */
-public final class DisabledChangeHooks implements ChangeHooks, EventDispatcher,
-    EventSource {
-  @Override
-  public void addEventListener(EventListener listener, CurrentUser user) {
-  }
-
+public final class DisabledChangeHooks implements ChangeHooks, EventDispatcher {
   @Override
   public void doChangeAbandonedHook(Change change, Account account,
       PatchSet patchSet, String reason, ReviewDb db) {
@@ -105,10 +99,6 @@ public final class DisabledChangeHooks implements ChangeHooks, EventDispatcher,
       Set<String> removed, Set<String> hashtags, ReviewDb db) {
   }
 
-  @Override
-  public void removeEventListener(EventListener listener) {
-  }
-
   @Override
   public HookResult doRefUpdateHook(Project project, String refName,
       Account uploader, ObjectId oldId, ObjectId newId) {

gerrit-server/src/main/java/com/google/gerrit/common/EventListener.java

@@ -17,6 +17,10 @@ package com.google.gerrit.common;
 import com.google.gerrit.extensions.annotations.ExtensionPoint;
 import com.google.gerrit.server.events.Event;
 
+/**
+ * Allows to listen to events without user visibility restrictions. To listen to
+ * events visible to a specific user, use {@link UserScopedEventListener}.
+ */
 @ExtensionPoint
 public interface EventListener {
   void onEvent(Event event);

gerrit-server/src/main/java/com/google/gerrit/common/UserScopedEventListener.java

@@ -1,4 +1,4 @@
-// Copyright (C) 2014 The Android Open Source Project
+// Copyright (C) 2016 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -11,14 +11,16 @@
 // 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 com.google.gerrit.common;
 
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
 import com.google.gerrit.server.CurrentUser;
 
-/** Distributes Events to ChangeListeners.  Register listeners here. */
-public interface EventSource {
-  void addEventListener(EventListener listener, CurrentUser user);
-
-  void removeEventListener(EventListener listener);
+/**
+ * Allows to listen to events visible to the specified user. To listen to events
+ * without user visibility restrictions, use {@link EventListener}.
+ */
+@ExtensionPoint
+public interface UserScopedEventListener extends EventListener {
+  CurrentUser getUser();
 }

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -19,6 +19,7 @@ import static com.google.inject.Scopes.SINGLETON;
 import com.google.common.cache.Cache;
 import com.google.gerrit.audit.AuditModule;
 import com.google.gerrit.common.EventListener;
+import com.google.gerrit.common.UserScopedEventListener;
 import com.google.gerrit.extensions.auth.oauth.OAuthLoginProvider;
 import com.google.gerrit.extensions.config.CapabilityDefinition;
 import com.google.gerrit.extensions.config.CloneCommand;
@@ -281,6 +282,7 @@ public class GerritGlobalModule extends FactoryModule {
         .to(ProjectConfigEntry.UpdateChecker.class);
     DynamicSet.setOf(binder(), EventListener.class);
     DynamicSet.bind(binder(), EventListener.class).to(EventsMetrics.class);
+    DynamicSet.setOf(binder(), UserScopedEventListener.class);
     DynamicSet.setOf(binder(), CommitValidationListener.class);
     DynamicSet.setOf(binder(), RefOperationValidationListener.class);
     DynamicSet.setOf(binder(), MergeValidationListener.class);

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/StreamEvents.java

@@ -18,10 +18,12 @@ import static com.google.gerrit.sshd.CommandMetaData.Mode.MASTER;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.base.Supplier;
-import com.google.gerrit.common.EventListener;
-import com.google.gerrit.common.EventSource;
+import com.google.gerrit.common.UserScopedEventListener;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.extensions.annotations.RequiresCapability;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.registration.RegistrationHandle;
+import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.events.EventTypes;
@@ -63,7 +65,7 @@ final class StreamEvents extends BaseCommand {
   private IdentifiedUser currentUser;
 
   @Inject
-  private EventSource source;
+  private DynamicSet<UserScopedEventListener> eventListeners;
 
   @Inject
   @StreamCommandExecutor
@@ -75,6 +77,8 @@ final class StreamEvents extends BaseCommand {
 
   private Gson gson;
 
+  private RegistrationHandle eventListenerRegistration;
+
   /** Special event to notify clients they missed other events. */
   private static final class DroppedOutputEvent extends Event {
     private final static String TYPE = "dropped-output";
@@ -87,16 +91,6 @@ final class StreamEvents extends BaseCommand {
     EventTypes.register(DroppedOutputEvent.TYPE, DroppedOutputEvent.class);
   }
 
-  private final EventListener listener = new EventListener() {
-    @Override
-    public void onEvent(final Event event) {
-      if (subscribedToEvents.isEmpty()
-          || subscribedToEvents.contains(event.getType())) {
-        offer(event);
-      }
-    }
-  };
-
   private final CancelableRunnable writer = new CancelableRunnable() {
     @Override
     public void run() {
@@ -150,7 +144,21 @@ final class StreamEvents extends BaseCommand {
     }
 
     stdout = toPrintWriter(out);
-    source.addEventListener(listener, currentUser);
+    eventListenerRegistration =
+        eventListeners.add(new UserScopedEventListener() {
+          @Override
+          public void onEvent(final Event event) {
+            if (subscribedToEvents.isEmpty()
+                || subscribedToEvents.contains(event.getType())) {
+              offer(event);
+            }
+          }
+
+          @Override
+          public CurrentUser getUser() {
+            return currentUser;
+          }
+        });
 
     gson = new GsonBuilder()
         .registerTypeAdapter(Supplier.class, new SupplierSerializer())
@@ -159,7 +167,7 @@ final class StreamEvents extends BaseCommand {
 
   @Override
   protected void onExit(final int rc) {
-    source.removeEventListener(listener);
+    eventListenerRegistration.remove();
 
     synchronized (taskLock) {
       done = true;
@@ -170,7 +178,7 @@ final class StreamEvents extends BaseCommand {
 
   @Override
   public void destroy() {
-    source.removeEventListener(listener);
+    eventListenerRegistration.remove();
 
     final boolean exit;
     synchronized (taskLock) {
@@ -218,7 +226,7 @@ final class StreamEvents extends BaseCommand {
         // destroy() above, or it closed the stream and is no longer
         // accepting output. Either way terminate this instance.
         //
-        source.removeEventListener(listener);
+        eventListenerRegistration.remove();
         flush();
         onExit(0);
         return;