Make audit of account group membership changes pluggable

Account group membership changes were logged in a database table.

Now, the audit log service allows to register listeners to group
member added and group member deleted events. A default listener logs
these events to the database as before. But additional listeners may
now be registered for these events using the GroupMemberAuditListener
interface.

Change-Id: I73872c26479a78be31bacc2cbc8eb850a097d473

gerrit-server/src/main/java/com/google/gerrit/audit/AuditModule.java

@@ -22,6 +22,7 @@ public class AuditModule extends AbstractModule {
   @Override
   protected void configure() {
     DynamicSet.setOf(binder(), AuditListener.class);
+    DynamicSet.setOf(binder(), GroupMemberAuditListener.class);
     bind(AuditService.class);
   }
 

gerrit-server/src/main/java/com/google/gerrit/audit/AuditService.java

@@ -15,16 +15,30 @@
 package com.google.gerrit.audit;
 
 import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountGroupById;
+import com.google.gerrit.reviewdb.client.AccountGroupMember;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Collection;
+
 @Singleton
 public class AuditService {
+  private static final Logger log = LoggerFactory.getLogger(AuditService.class);
+
   private final DynamicSet<AuditListener> auditListeners;
+  private final DynamicSet<GroupMemberAuditListener> groupMemberAuditListeners;
 
   @Inject
-  public AuditService(DynamicSet<AuditListener> auditListeners) {
+  public AuditService(DynamicSet<AuditListener> auditListeners,
+      DynamicSet<GroupMemberAuditListener> groupMemberAuditListeners) {
     this.auditListeners = auditListeners;
+    this.groupMemberAuditListeners = groupMemberAuditListeners;
   }
 
   public void dispatch(AuditEvent action) {
@@ -32,4 +46,48 @@ public class AuditService {
       auditListener.onAuditableAction(action);
     }
   }
+
+  public void dispatchAddAccountsToGroup(Account.Id actor,
+      Collection<AccountGroupMember> added) {
+    for (GroupMemberAuditListener auditListener : groupMemberAuditListeners) {
+      try {
+        auditListener.onAddAccountsToGroup(actor, added);
+      } catch (RuntimeException e) {
+        log.error("failed to log add accounts to group event", e);
+      }
+    }
+  }
+
+  public void dispatchDeleteAccountsFromGroup(Account.Id actor,
+      Collection<AccountGroupMember> removed) {
+    for (GroupMemberAuditListener auditListener : groupMemberAuditListeners) {
+      try {
+        auditListener.onDeleteAccountsFromGroup(actor, removed);
+      } catch (RuntimeException e) {
+        log.error("failed to log delete accounts from group event", e);
+      }
+    }
+  }
+
+  public void dispatchAddGroupsToGroup(Account.Id actor,
+      Collection<AccountGroupById> added) {
+    for (GroupMemberAuditListener auditListener : groupMemberAuditListeners) {
+      try {
+        auditListener.onAddGroupsToGroup(actor, added);
+      } catch (RuntimeException e) {
+        log.error("failed to log add groups to group event", e);
+      }
+    }
+  }
+
+  public void dispatchDeleteGroupsFromGroup(Account.Id actor,
+      Collection<AccountGroupById> removed) {
+    for (GroupMemberAuditListener auditListener : groupMemberAuditListeners) {
+      try {
+        auditListener.onDeleteGroupsFromGroup(actor, removed);
+      } catch (RuntimeException e) {
+        log.error("failed to log delete groups from group event", e);
+      }
+    }
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/audit/GroupMemberAuditListener.java

@@ -0,0 +1,37 @@
+// 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.audit;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Account.Id;
+import com.google.gerrit.reviewdb.client.AccountGroupById;
+import com.google.gerrit.reviewdb.client.AccountGroupMember;
+
+import java.util.Collection;
+
+@ExtensionPoint
+public interface GroupMemberAuditListener {
+
+  void onAddAccountsToGroup(Account.Id actor,
+      Collection<AccountGroupMember> added);
+
+  void onDeleteAccountsFromGroup(Account.Id actor,
+      Collection<AccountGroupMember> removed);
+
+  void onAddGroupsToGroup(Id actor, Collection<AccountGroupById> added);
+
+  void onDeleteGroupsFromGroup(Id actor, Collection<AccountGroupById> deleted);
+}