Implement a more capable servlet auditing interface.

In order to facilitate action-specific auditing, the RestResource,
RestView, and HttpServletRequest are incorporated into a new extended
audit event class, supplementing all existing fields (some redundant)
in HttpAuditEvent. Although the request is already available from the
Guice injector, adding this high-value information as a field
facilitates convenient access.

Change-Id: I3ebd629c90921237bbcfbb00d9ea990740099104

gerrit-httpd/src/main/java/com/google/gerrit/httpd/restapi/RestApiServlet.java

@@ -46,7 +46,7 @@ import com.google.common.io.BaseEncoding;
 import com.google.common.math.IntMath;
 import com.google.common.net.HttpHeaders;
 import com.google.gerrit.audit.AuditService;
-import com.google.gerrit.audit.HttpAuditEvent;
+import com.google.gerrit.audit.ExtendedHttpAuditEvent;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.extensions.registration.DynamicItem;
@@ -204,6 +204,8 @@ public class RestApiServlet extends HttpServlet {
     Object result = null;
     Multimap<String, String> params = LinkedHashMultimap.create();
     Object inputRequestBody = null;
+    RestResource rsrc = TopLevelResource.INSTANCE;
+    ViewData viewData = null;
 
     try {
       checkUserSession(req);
@@ -213,8 +215,8 @@ public class RestApiServlet extends HttpServlet {
       CapabilityUtils.checkRequiresCapability(globals.currentUser,
           null, rc.getClass());
 
-      RestResource rsrc = TopLevelResource.INSTANCE;
-      ViewData viewData = new ViewData(null, null);
+      viewData = new ViewData(null, null);
+
       if (path.isEmpty()) {
         if (isGetOrHead(req)) {
           viewData = new ViewData(null, rc.list());
@@ -386,10 +388,10 @@ public class RestApiServlet extends HttpServlet {
       status = SC_INTERNAL_SERVER_ERROR;
       handleException(e, req, res);
     } finally {
-      globals.auditService.dispatch(new HttpAuditEvent(globals.webSession.get()
-          .getSessionId(), globals.currentUser.get(), req.getRequestURI(),
-          auditStartTs, params, req.getMethod(), inputRequestBody, status,
-          result));
+      globals.auditService.dispatch(new ExtendedHttpAuditEvent(globals.webSession.get()
+          .getSessionId(), globals.currentUser.get(), req,
+          auditStartTs, params, inputRequestBody, status,
+          result, rsrc, viewData.view));
     }
   }
 

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

@@ -0,0 +1,55 @@
+// Copyright (C) 2015 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.common.base.Preconditions;
+import com.google.common.collect.Multimap;
+import com.google.gerrit.extensions.restapi.RestResource;
+import com.google.gerrit.extensions.restapi.RestView;
+import com.google.gerrit.server.CurrentUser;
+
+import javax.servlet.http.HttpServletRequest;
+
+/**
+ * Extended audit event. Adds request, resource and view data to HttpAuditEvent.
+ */
+public class ExtendedHttpAuditEvent extends HttpAuditEvent {
+  public final HttpServletRequest httpRequest;
+  public final RestResource resource;
+  public final RestView<? extends RestResource> view;
+
+  /**
+   * Creates a new audit event with results
+   *
+   * @param sessionId session id the event belongs to
+   * @param who principal that has generated the event
+   * @param httpRequest the HttpServletRequest
+   * @param when time-stamp of when the event started
+   * @param params parameters of the event
+   * @param result result of the event
+   * @param resource REST resource data
+   * @param view view rendering object
+   */
+  public ExtendedHttpAuditEvent(String sessionId, CurrentUser who,
+      HttpServletRequest httpRequest, long when, Multimap<String, ?> params,
+      Object input, int status, Object result, RestResource resource,
+      RestView<RestResource> view) {
+    super(sessionId, who, httpRequest.getRequestURI(), when, params, httpRequest.getMethod(),
+        input, status, result);
+    this.httpRequest = Preconditions.checkNotNull(httpRequest);
+    this.resource = resource;
+    this.view = view;
+  }
+}