Add more abstract events to the event hierarchy.

The various ChangeEvents implement a lot of common duplicated
functionality. Create new abstract events to consolidate some of that
functionality. The new events are, Event, ProjectEvent, RefEvent, and
PatchSetEvent. Make Event the new base class for all other events, and
now use ChangeEvent only for events related to Changes.

Change-Id: I287c6524b826b42e78d8a3ce2d0951c045bb11b8

Documentation/dev-plugins.txt

@@ -379,9 +379,9 @@ Certain operations in Gerrit trigger events. Plugins may receive
 notifications of these events by implementing the corresponding
 listeners.
 
-* `com.google.gerrit.common.ChangeListener`:
+* `com.google.gerrit.common.EventListener`:
 +
-Allows to listen to change events. These are the same
+Allows to listen to events. 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.
 
@@ -413,7 +413,8 @@ Gerrit's `stream-events` ssh command will receive them.
 
 To send an event, the plugin must invoke one of the `postEvent`
 methods in the `ChangeHookRunner` class, passing an instance of
-its own custom event class derived from `ChangeEvent`.
+its own custom event class derived from
+`com.google.gerrit.server.events.Event`.
 
 [[validation]]
 == Validation Listeners

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

@@ -29,7 +29,7 @@ import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.RestResponse;
 import com.google.gerrit.acceptance.SshSession;
 import com.google.gerrit.common.ChangeHooks;
-import com.google.gerrit.common.ChangeListener;
+import com.google.gerrit.common.EventListener;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
 import com.google.gerrit.extensions.api.changes.SubmitInput;
 import com.google.gerrit.extensions.common.ChangeInfo;
@@ -46,8 +46,8 @@ import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.ApprovalsUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.gerrit.server.events.ChangeEvent;
 import com.google.gerrit.server.events.ChangeMergedEvent;
+import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.project.ListBranches.BranchInfo;
 import com.google.gerrit.server.project.PutConfig;
@@ -96,13 +96,14 @@ public abstract class AbstractSubmit extends AbstractDaemonTest {
   public void setUp() throws Exception {
     mergeResults = Maps.newHashMap();
     CurrentUser listenerUser = factory.create(user.id);
-    hooks.addChangeListener(new ChangeListener() {
+    hooks.addEventListener(new EventListener() {
 
       @Override
-      public void onChangeEvent(ChangeEvent event) {
+      public void onEvent(Event event) {
         if (event instanceof ChangeMergedEvent) {
-          ChangeMergedEvent cMEvent = (ChangeMergedEvent) event;
-          mergeResults.put(cMEvent.change.number, cMEvent.newRev);
+          ChangeMergedEvent changeMergedEvent = (ChangeMergedEvent) event;
+          mergeResults.put(changeMergedEvent.change.number,
+              changeMergedEvent.newRev);
         }
       }
 

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

@@ -36,11 +36,11 @@ import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.data.ApprovalAttribute;
 import com.google.gerrit.server.events.ChangeAbandonedEvent;
-import com.google.gerrit.server.events.ChangeEvent;
 import com.google.gerrit.server.events.ChangeMergedEvent;
 import com.google.gerrit.server.events.ChangeRestoredEvent;
 import com.google.gerrit.server.events.CommentAddedEvent;
 import com.google.gerrit.server.events.DraftPublishedEvent;
+import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.events.EventFactory;
 import com.google.gerrit.server.events.HashtagsChangedEvent;
 import com.google.gerrit.server.events.MergeFailedEvent;
@@ -99,11 +99,11 @@ public class ChangeHookRunner implements ChangeHooks, LifecycleListener {
       }
     }
 
-    private static class ChangeListenerHolder {
-        final ChangeListener listener;
+    private static class EventListenerHolder {
+        final EventListener listener;
         final CurrentUser user;
 
-        ChangeListenerHolder(ChangeListener l, CurrentUser u) {
+        EventListenerHolder(EventListener l, CurrentUser u) {
             listener = l;
             user = u;
         }
@@ -159,11 +159,11 @@ public class ChangeHookRunner implements ChangeHooks, LifecycleListener {
 
     /** Listeners to receive changes as they happen (limited by visibility
      *  of holder's user). */
-    private final Map<ChangeListener, ChangeListenerHolder> listeners =
+    private final Map<EventListener, EventListenerHolder> listeners =
         new ConcurrentHashMap<>();
 
     /** Listeners to receive all changes as they happen. */
-    private final DynamicSet<ChangeListener> unrestrictedListeners;
+    private final DynamicSet<EventListener> unrestrictedListeners;
 
     /** Filename of the new patchset hook. */
     private final File patchsetCreatedHook;
@@ -244,7 +244,7 @@ public class ChangeHookRunner implements ChangeHooks, LifecycleListener {
       final ProjectCache projectCache,
       final AccountCache accountCache,
       final EventFactory eventFactory,
-      final DynamicSet<ChangeListener> unrestrictedListeners) {
+      final DynamicSet<EventListener> unrestrictedListeners) {
         this.anonymousCowardName = anonymousCowardName;
         this.repoManager = repoManager;
         this.hookQueue = queue.createQueue(1, "hook");
@@ -277,12 +277,12 @@ public class ChangeHookRunner implements ChangeHooks, LifecycleListener {
     }
 
     @Override
-    public void addChangeListener(ChangeListener listener, CurrentUser user) {
-        listeners.put(listener, new ChangeListenerHolder(listener, user));
+    public void addEventListener(EventListener listener, CurrentUser user) {
+        listeners.put(listener, new EventListenerHolder(listener, user));
     }
 
     @Override
-    public void removeChangeListener(ChangeListener listener) {
+    public void removeEventListener(EventListener listener) {
         listeners.remove(listener);
     }
 
@@ -686,37 +686,38 @@ public class ChangeHookRunner implements ChangeHooks, LifecycleListener {
     }
 
     @Override
-    public void postEvent(final Change change, final ChangeEvent event,
+    public void postEvent(final Change change, final Event event,
         final ReviewDb db) throws OrmException {
       fireEvent(change, event, db);
     }
 
     @Override
     public void postEvent(final Branch.NameKey branchName,
-        final ChangeEvent event) {
+        final Event event) {
       fireEvent(branchName, event);
     }
 
-    private void fireEventForUnrestrictedListeners(final ChangeEvent event) {
-      for (ChangeListener listener : unrestrictedListeners) {
-          listener.onChangeEvent(event);
+    private void fireEventForUnrestrictedListeners(final Event event) {
+      for (EventListener listener : unrestrictedListeners) {
+          listener.onEvent(event);
       }
     }
 
-    private void fireEvent(final Change change, final ChangeEvent event, final ReviewDb db) throws OrmException {
-      for (ChangeListenerHolder holder : listeners.values()) {
+    private void fireEvent(final Change change, final Event event,
+        final ReviewDb db) throws OrmException {
+      for (EventListenerHolder holder : listeners.values()) {
           if (isVisibleTo(change, holder.user, db)) {
-              holder.listener.onChangeEvent(event);
+              holder.listener.onEvent(event);
           }
       }
 
       fireEventForUnrestrictedListeners( event );
     }
 
-    private void fireEvent(Branch.NameKey branchName, final ChangeEvent event) {
-      for (ChangeListenerHolder holder : listeners.values()) {
+    private void fireEvent(Branch.NameKey branchName, final Event event) {
+      for (EventListenerHolder holder : listeners.values()) {
           if (isVisibleTo(branchName, holder.user)) {
-              holder.listener.onChangeEvent(event);
+              holder.listener.onEvent(event);
           }
       }
 

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

@@ -23,7 +23,7 @@ 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.gwtorm.server.OrmException;
 
 import org.eclipse.jgit.lib.ObjectId;
@@ -34,9 +34,9 @@ import java.util.Set;
 
 /** Invokes hooks on server actions. */
 public interface ChangeHooks {
-  public void addChangeListener(ChangeListener listener, CurrentUser user);
+  public void addEventListener(EventListener listener, CurrentUser user);
 
-  public void removeChangeListener(ChangeListener listener);
+  public void removeEventListener(EventListener listener);
 
   /**
    * Fire the Patchset Created Hook.
@@ -196,7 +196,7 @@ public interface ChangeHooks {
    * @param db The database
    * @throws OrmException
    */
-  public void postEvent(Change change, ChangeEvent event, ReviewDb db)
+  public void postEvent(Change change, Event event, ReviewDb db)
       throws OrmException;
 
   /**
@@ -205,5 +205,5 @@ public interface ChangeHooks {
    * @param branchName The branch that the event is related to
    * @param event The event to post
    */
-  public void postEvent(Branch.NameKey branchName, ChangeEvent event);
+  public void postEvent(Branch.NameKey branchName, Event event);
 }

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

@@ -23,7 +23,7 @@ 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 org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -34,7 +34,7 @@ import java.util.Set;
 /** Does not invoke hooks. */
 public final class DisabledChangeHooks implements ChangeHooks {
   @Override
-  public void addChangeListener(ChangeListener listener, CurrentUser user) {
+  public void addEventListener(EventListener listener, CurrentUser user) {
   }
 
   @Override
@@ -103,7 +103,7 @@ public final class DisabledChangeHooks implements ChangeHooks {
   }
 
   @Override
-  public void removeChangeListener(ChangeListener listener) {
+  public void removeEventListener(EventListener listener) {
   }
 
   @Override
@@ -113,10 +113,10 @@ public final class DisabledChangeHooks implements ChangeHooks {
   }
 
   @Override
-  public void postEvent(Change change, ChangeEvent event, ReviewDb db) {
+  public void postEvent(Change change, Event event, ReviewDb db) {
   }
 
   @Override
-  public void postEvent(Branch.NameKey branchName, ChangeEvent event) {
+  public void postEvent(Branch.NameKey branchName, Event event) {
   }
 }

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

@@ -15,9 +15,9 @@
 package com.google.gerrit.common;
 
 import com.google.gerrit.extensions.annotations.ExtensionPoint;
-import com.google.gerrit.server.events.ChangeEvent;
+import com.google.gerrit.server.events.Event;
 
 @ExtensionPoint
-public interface ChangeListener {
-    public void onChangeEvent(ChangeEvent event);
+public interface EventListener {
+  public void onEvent(Event event);
 }

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

@@ -18,7 +18,7 @@ import static com.google.inject.Scopes.SINGLETON;
 
 import com.google.common.cache.Cache;
 import com.google.gerrit.audit.AuditModule;
-import com.google.gerrit.common.ChangeListener;
+import com.google.gerrit.common.EventListener;
 import com.google.gerrit.extensions.config.CapabilityDefinition;
 import com.google.gerrit.extensions.config.DownloadCommand;
 import com.google.gerrit.extensions.config.DownloadScheme;
@@ -271,7 +271,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.bind(binder(), GitReferenceUpdatedListener.class).to(ReindexAfterUpdate.class);
     DynamicSet.bind(binder(), GitReferenceUpdatedListener.class)
         .to(ProjectConfigEntry.UpdateChecker.class);
-    DynamicSet.setOf(binder(), ChangeListener.class);
+    DynamicSet.setOf(binder(), EventListener.class);
     DynamicSet.setOf(binder(), CommitValidationListener.class);
     DynamicSet.setOf(binder(), RefOperationValidationListener.class);
     DynamicSet.setOf(binder(), MergeValidationListener.class);

gerrit-server/src/main/java/com/google/gerrit/server/events/ChangeAbandonedEvent.java

@@ -14,38 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class ChangeAbandonedEvent extends ChangeEvent {
-  public final String type = "change-abandoned";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class ChangeAbandonedEvent extends PatchSetEvent {
   public AccountAttribute abandoner;
   public String reason;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public ChangeAbandonedEvent() {
+    super("change-abandoned");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/ChangeEvent.java

@@ -14,19 +14,30 @@
 
 package com.google.gerrit.server.events;
 
-import com.google.gerrit.common.TimeUtil;
+import static org.eclipse.jgit.lib.Constants.R_HEADS;
+
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.data.ChangeAttribute;
 
-public abstract class ChangeEvent {
+public abstract class ChangeEvent extends RefEvent {
+  public ChangeAttribute change;
 
-  public long eventCreatedOn = TimeUtil.nowMs() / 1000L;
+  protected ChangeEvent(String type) {
+    super(type);
+  }
 
-  public abstract String getType();
+  @Override
+  public Project.NameKey getProjectNameKey() {
+    return new Project.NameKey(change.project);
+  }
 
-  public abstract Project.NameKey getProjectNameKey();
+  @Override
+  public String getRefName() {
+    return R_HEADS + change.branch;
+  }
 
-  public abstract Change.Key getChangeKey();
-
-  public abstract String getRefName();
+  public Change.Key getChangeKey() {
+    return new Change.Key(change.id);
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/ChangeMergedEvent.java

@@ -14,38 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class ChangeMergedEvent extends ChangeEvent {
-  public final String type = "change-merged";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class ChangeMergedEvent extends PatchSetEvent {
   public AccountAttribute submitter;
   public String newRev;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public ChangeMergedEvent() {
+    super("change-merged");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/ChangeRestoredEvent.java

@@ -14,38 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class ChangeRestoredEvent extends ChangeEvent {
-  public final String type = "change-restored";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class ChangeRestoredEvent extends PatchSetEvent {
   public AccountAttribute restorer;
   public String reason;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public ChangeRestoredEvent () {
+    super("change-restored");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/CommentAddedEvent.java

@@ -14,40 +14,15 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
 import com.google.gerrit.server.data.ApprovalAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class CommentAddedEvent extends ChangeEvent {
-  public final String type = "comment-added";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class CommentAddedEvent extends PatchSetEvent {
   public AccountAttribute author;
   public ApprovalAttribute[] approvals;
   public String comment;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public CommentAddedEvent() {
+    super("comment-added");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/CommitReceivedEvent.java

@@ -14,15 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.IdentifiedUser;
 
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.transport.ReceiveCommand;
 
-public class CommitReceivedEvent extends ChangeEvent {
-  public final String type = "commit-received";
+public class CommitReceivedEvent extends RefEvent {
   public final ReceiveCommand command;
   public final Project project;
   public final String refName;
@@ -31,6 +29,7 @@ public class CommitReceivedEvent extends ChangeEvent {
 
   public CommitReceivedEvent(ReceiveCommand command, Project project,
       String refName, RevCommit commit, IdentifiedUser user) {
+    super("commit-received");
     this.command = command;
     this.project = project;
     this.refName = refName;
@@ -38,21 +37,11 @@ public class CommitReceivedEvent extends ChangeEvent {
     this.user = user;
   }
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
   @Override
   public Project.NameKey getProjectNameKey() {
     return project.getNameKey();
   }
 
-  @Override
-  public Change.Key getChangeKey() {
-    return null;
-  }
-
   @Override
   public String getRefName() {
     return refName;

gerrit-server/src/main/java/com/google/gerrit/server/events/DraftPublishedEvent.java

@@ -14,37 +14,12 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class DraftPublishedEvent extends ChangeEvent {
-  public final String type = "draft-published";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class DraftPublishedEvent extends PatchSetEvent {
   public AccountAttribute uploader;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public DraftPublishedEvent() {
+    super("draft-published");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/Event.java

@@ -0,0 +1,30 @@
+// Copyright (C) 2014 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.
+// 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 com.google.gerrit.server.events;
+
+import com.google.gerrit.common.TimeUtil;
+
+public abstract class Event {
+  public final String type;
+  public long eventCreatedOn = TimeUtil.nowMs() / 1000L;
+
+  protected Event(String type) {
+    this.type = type;
+  }
+
+  public String getType() {
+    return type;
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/events/HashtagsChangedEvent.java

@@ -14,38 +14,15 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
 
 public class HashtagsChangedEvent extends ChangeEvent {
-  public final String type = "hashtags-changed";
-  public ChangeAttribute change;
   public AccountAttribute editor;
   public String[] added;
   public String[] removed;
   public String[] hashtags;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public HashtagsChangedEvent () {
+    super("hashtags-changed");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/MergeFailedEvent.java

@@ -14,38 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class MergeFailedEvent extends ChangeEvent {
-  public final String type = "merge-failed";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class MergeFailedEvent extends PatchSetEvent {
   public AccountAttribute submitter;
   public String reason;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public MergeFailedEvent() {
+    super("merge-failed");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/PatchSetCreatedEvent.java

@@ -14,37 +14,12 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class PatchSetCreatedEvent extends ChangeEvent {
-  public final String type = "patchset-created";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class PatchSetCreatedEvent extends PatchSetEvent {
   public AccountAttribute uploader;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public PatchSetCreatedEvent() {
+    super("patchset-created");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/PatchSetEvent.java

@@ -0,0 +1,25 @@
+// Copyright (C) 2014 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.
+// 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 com.google.gerrit.server.events;
+
+import com.google.gerrit.server.data.PatchSetAttribute;
+
+public class PatchSetEvent extends ChangeEvent {
+  public PatchSetAttribute patchSet;
+
+  protected PatchSetEvent(String type) {
+    super(type);
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/events/ProjectEvent.java

@@ -0,0 +1,25 @@
+// Copyright (C) 2014 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.
+// 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 com.google.gerrit.server.events;
+
+import com.google.gerrit.reviewdb.client.Project;
+
+public abstract class ProjectEvent extends Event {
+  protected ProjectEvent(String type) {
+    super(type);
+  }
+
+  public abstract Project.NameKey getProjectNameKey();
+}

gerrit-server/src/main/java/com/google/gerrit/server/events/RefEvent.java

@@ -0,0 +1,23 @@
+// Copyright (C) 2014 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.
+// 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 com.google.gerrit.server.events;
+
+public abstract class RefEvent extends ProjectEvent {
+  protected RefEvent(String type) {
+    super(type);
+  }
+
+  public abstract String getRefName();
+}

gerrit-server/src/main/java/com/google/gerrit/server/events/RefReceivedEvent.java

@@ -13,21 +13,18 @@
 // limitations under the License.
 package com.google.gerrit.server.events;
 
-import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.IdentifiedUser;
 
 import org.eclipse.jgit.transport.ReceiveCommand;
 
-public class RefReceivedEvent extends ChangeEvent {
-  public final String type = "ref-received";
+public class RefReceivedEvent extends RefEvent {
   public ReceiveCommand command;
   public Project project;
   public IdentifiedUser user;
 
-  @Override
-  public String getType() {
-    return type;
+  public RefReceivedEvent() {
+    super("ref-received");
   }
 
   @Override
@@ -35,11 +32,6 @@ public class RefReceivedEvent extends ChangeEvent {
     return project.getNameKey();
   }
 
-  @Override
-  public Change.Key getChangeKey() {
-    return null;
-  }
-
   @Override
   public String getRefName() {
     return command.getRefName();

gerrit-server/src/main/java/com/google/gerrit/server/events/RefUpdatedEvent.java

@@ -14,19 +14,16 @@
 
 package com.google.gerrit.server.events;
 
-import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
 import com.google.gerrit.server.data.RefUpdateAttribute;
 
-public class RefUpdatedEvent extends ChangeEvent {
-  public final String type = "ref-updated";
+public class RefUpdatedEvent extends RefEvent {
   public AccountAttribute submitter;
   public RefUpdateAttribute refUpdate;
 
-  @Override
-  public String getType() {
-    return type;
+  public RefUpdatedEvent() {
+    super("ref-updated");
   }
 
   @Override
@@ -34,11 +31,6 @@ public class RefUpdatedEvent extends ChangeEvent {
     return new Project.NameKey(refUpdate.project);
   }
 
-  @Override
-  public Change.Key getChangeKey() {
-    return null;
-  }
-
   @Override
   public String getRefName() {
     return refUpdate.refName;

gerrit-server/src/main/java/com/google/gerrit/server/events/ReviewerAddedEvent.java

@@ -14,37 +14,12 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
-import com.google.gerrit.server.data.PatchSetAttribute;
 
-public class ReviewerAddedEvent extends ChangeEvent {
-  public final String type = "reviewer-added";
-  public ChangeAttribute change;
-  public PatchSetAttribute patchSet;
+public class ReviewerAddedEvent extends PatchSetEvent {
   public AccountAttribute reviewer;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public ReviewerAddedEvent() {
+    super("reviewer-added");
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/events/TopicChangedEvent.java

@@ -14,36 +14,13 @@
 
 package com.google.gerrit.server.events;
 
-import static org.eclipse.jgit.lib.Constants.R_HEADS;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.data.AccountAttribute;
-import com.google.gerrit.server.data.ChangeAttribute;
 
 public class TopicChangedEvent extends ChangeEvent {
-  public final String type = "topic-changed";
-  public ChangeAttribute change;
   public AccountAttribute changer;
   public String oldTopic;
 
-  @Override
-  public String getType() {
-    return type;
-  }
-
-  @Override
-  public Project.NameKey getProjectNameKey() {
-    return new Project.NameKey(change.project);
-  }
-
-  @Override
-  public Change.Key getChangeKey() {
-    return new Change.Key(change.id);
-  }
-
-  @Override
-  public String getRefName() {
-    return R_HEADS + change.branch;
+  public TopicChangedEvent() {
+    super("topic-changed");
   }
 }

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

@@ -17,11 +17,11 @@ package com.google.gerrit.sshd.commands;
 import static com.google.gerrit.sshd.CommandMetaData.Mode.MASTER_OR_SLAVE;
 
 import com.google.gerrit.common.ChangeHooks;
-import com.google.gerrit.common.ChangeListener;
+import com.google.gerrit.common.EventListener;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.extensions.annotations.RequiresCapability;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.gerrit.server.events.ChangeEvent;
+import com.google.gerrit.server.events.Event;
 import com.google.gerrit.server.git.WorkQueue;
 import com.google.gerrit.server.git.WorkQueue.CancelableRunnable;
 import com.google.gerrit.sshd.BaseCommand;
@@ -58,7 +58,7 @@ final class StreamEvents extends BaseCommand {
   private WorkQueue.Executor pool;
 
   /** Queue of events to stream to the connected user. */
-  private final LinkedBlockingQueue<ChangeEvent> queue =
+  private final LinkedBlockingQueue<Event> queue =
       new LinkedBlockingQueue<>(MAX_EVENTS);
 
   private final Gson gson = new Gson();
@@ -69,9 +69,9 @@ final class StreamEvents extends BaseCommand {
     final String type = "dropped-output";
   };
 
-  private final ChangeListener listener = new ChangeListener() {
+  private final EventListener listener = new EventListener() {
     @Override
-    public void onChangeEvent(final ChangeEvent event) {
+    public void onEvent(final Event event) {
       offer(event);
     }
   };
@@ -124,12 +124,12 @@ final class StreamEvents extends BaseCommand {
     }
 
     stdout = toPrintWriter(out);
-    hooks.addChangeListener(listener, currentUser);
+    hooks.addEventListener(listener, currentUser);
   }
 
   @Override
   protected void onExit(final int rc) {
-    hooks.removeChangeListener(listener);
+    hooks.removeEventListener(listener);
 
     synchronized (taskLock) {
       done = true;
@@ -140,7 +140,7 @@ final class StreamEvents extends BaseCommand {
 
   @Override
   public void destroy() {
-    hooks.removeChangeListener(listener);
+    hooks.removeEventListener(listener);
 
     final boolean exit;
     synchronized (taskLock) {
@@ -157,7 +157,7 @@ final class StreamEvents extends BaseCommand {
     }
   }
 
-  private void offer(final ChangeEvent event) {
+  private void offer(final Event event) {
     synchronized (taskLock) {
       if (!queue.offer(event)) {
         dropped = true;
@@ -169,9 +169,9 @@ final class StreamEvents extends BaseCommand {
     }
   }
 
-  private ChangeEvent poll() {
+  private Event poll() {
     synchronized (taskLock) {
-      ChangeEvent event = queue.poll();
+      Event event = queue.poll();
       if (event == null) {
         task = null;
       }
@@ -188,7 +188,7 @@ final class StreamEvents extends BaseCommand {
         // destroy() above, or it closed the stream and is no longer
         // accepting output. Either way terminate this instance.
         //
-        hooks.removeChangeListener(listener);
+        hooks.removeEventListener(listener);
         flush();
         onExit(0);
         return;
@@ -199,7 +199,7 @@ final class StreamEvents extends BaseCommand {
         dropped = false;
       }
 
-      final ChangeEvent event = poll();
+      final Event event = poll();
       if (event == null) {
         break;
       }