root/content/shell/renderer/leak_detector.cc

DEFINITIONS

1. previous_number_of_live_nodes_
2. TryLeakDetection

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/shell/renderer/leak_detector.h"

#include "base/json/json_writer.h"
#include "base/logging.h"
#include "base/values.h"
#include "third_party/WebKit/public/web/WebLeakDetector.h"

using blink::WebLeakDetector;

namespace content {

// The initial states of the DOM objects at about:blank. The four nodes are a
// Document, a HTML, a HEAD and a BODY.
//
// TODO(hajimehoshi): Now these are hard-corded. If we add target to count like
// RefCoutned objects whose initial state is diffcult to estimate, we stop using
// hard-coded values. Instead, we need to load about:blank ahead of the layout
// tests actually and initialize LeakDetector by the got values.
const int kInitialNumberOfLiveDocuments = 1;
const int kInitialNumberOfLiveNodes = 4;

LeakDetector::LeakDetector()
    : previous_number_of_live_documents_(kInitialNumberOfLiveDocuments),
      previous_number_of_live_nodes_(kInitialNumberOfLiveNodes) {
}

LeakDetectionResult LeakDetector::TryLeakDetection(
    blink::WebLocalFrame* frame) {
  LeakDetectionResult result;
  unsigned number_of_live_documents = 0;
  unsigned number_of_live_nodes = 0;

  WebLeakDetector::collectGarbargeAndGetDOMCounts(
      frame, &number_of_live_documents, &number_of_live_nodes);

  result.leaked =
      (previous_number_of_live_documents_ < number_of_live_documents ||
       previous_number_of_live_nodes_ < number_of_live_nodes);

  if (result.leaked) {
    base::DictionaryValue detail;
    base::ListValue* list = new base::ListValue();
    list->AppendInteger(previous_number_of_live_documents_);
    list->AppendInteger(number_of_live_documents);
    detail.Set("numberOfLiveDocuments", list);

    list = new base::ListValue();
    list->AppendInteger(previous_number_of_live_nodes_);
    list->AppendInteger(number_of_live_nodes);
    detail.Set("numberOfLiveNodes", list);

    std::string detail_str;
    base::JSONWriter::Write(&detail, &detail_str);
    result.detail = detail_str;
  }

  previous_number_of_live_documents_ = number_of_live_documents;
  previous_number_of_live_nodes_ = number_of_live_nodes;

  return result;
}

}  // namespace content