Create group-indexed extension point

Change-Id: I79fb7404e10e619d87b4983346c90ca79c83ddff

Documentation/dev-plugins.txt

@@ -398,6 +398,10 @@ Update of the change secondary index
 +
 Update of the account secondary index
 
+* `com.google.gerrit.server.extensions.events.GroupIndexedListener`:
++
+Update of the group secondary index
+
 * `com.google.gerrit.httpd.WebLoginListener`:
 +
 User login or logout interactively on the Web user interface.

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/events/GroupIndexedListener.java

@@ -0,0 +1,28 @@
+// Copyright (C) 2017 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.extensions.events;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+
+/** Notified whenever a group is indexed */
+@ExtensionPoint
+public interface GroupIndexedListener {
+  /**
+   * Invoked when a group is indexed
+   *
+   * @param uuid of the group
+   */
+  void onGroupIndexed(String uuid);
+}

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

@@ -43,6 +43,7 @@ import com.google.gerrit.extensions.events.CommentAddedListener;
 import com.google.gerrit.extensions.events.DraftPublishedListener;
 import com.google.gerrit.extensions.events.GarbageCollectorListener;
 import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.events.GroupIndexedListener;
 import com.google.gerrit.extensions.events.HashtagsEditedListener;
 import com.google.gerrit.extensions.events.HeadUpdatedListener;
 import com.google.gerrit.extensions.events.LifecycleListener;
@@ -327,6 +328,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.setOf(binder(), PostUploadHook.class);
     DynamicSet.setOf(binder(), AccountIndexedListener.class);
     DynamicSet.setOf(binder(), ChangeIndexedListener.class);
+    DynamicSet.setOf(binder(), GroupIndexedListener.class);
     DynamicSet.setOf(binder(), NewProjectCreatedListener.class);
     DynamicSet.setOf(binder(), ProjectDeletedListener.class);
     DynamicSet.setOf(binder(), GarbageCollectorListener.class);

gerrit-server/src/main/java/com/google/gerrit/server/index/group/GroupIndexerImpl.java

@@ -16,6 +16,8 @@ package com.google.gerrit.server.index.group;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.events.GroupIndexedListener;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.server.account.GroupCache;
 import com.google.gerrit.server.index.Index;
@@ -33,19 +35,28 @@ public class GroupIndexerImpl implements GroupIndexer {
   }
 
   private final GroupCache groupCache;
+  private final DynamicSet<GroupIndexedListener> indexedListener;
   private final GroupIndexCollection indexes;
   private final GroupIndex index;
 
   @AssistedInject
-  GroupIndexerImpl(GroupCache groupCache, @Assisted GroupIndexCollection indexes) {
+  GroupIndexerImpl(
+      GroupCache groupCache,
+      DynamicSet<GroupIndexedListener> indexedListener,
+      @Assisted GroupIndexCollection indexes) {
     this.groupCache = groupCache;
+    this.indexedListener = indexedListener;
     this.indexes = indexes;
     this.index = null;
   }
 
   @AssistedInject
-  GroupIndexerImpl(GroupCache groupCache, @Assisted GroupIndex index) {
+  GroupIndexerImpl(
+      GroupCache groupCache,
+      DynamicSet<GroupIndexedListener> indexedListener,
+      @Assisted GroupIndex index) {
     this.groupCache = groupCache;
+    this.indexedListener = indexedListener;
     this.indexes = null;
     this.index = index;
   }
@@ -55,6 +66,13 @@ public class GroupIndexerImpl implements GroupIndexer {
     for (Index<?, AccountGroup> i : getWriteIndexes()) {
       i.replace(groupCache.get(uuid));
     }
+    fireGroupIndexedEvent(uuid.get());
+  }
+
+  private void fireGroupIndexedEvent(String uuid) {
+    for (GroupIndexedListener listener : indexedListener) {
+      listener.onGroupIndexed(uuid);
+    }
   }
 
   private Collection<GroupIndex> getWriteIndexes() {