1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "chrome/browser/metrics/variations/variations_registry_syncer_win.h"
6
7#include "base/files/file_path.h"
8#include "base/metrics/field_trial.h"
9#include "base/path_service.h"
10#include "base/strings/string16.h"
11#include "chrome/common/variations/experiment_labels.h"
12#include "chrome/installer/util/google_update_settings.h"
13#include "chrome/installer/util/install_util.h"
14
15namespace {
16
17// Delay before performing a registry sync, in seconds.
18const int kRegistrySyncDelaySeconds = 5;
19
20}  // namespace
21
22namespace chrome_variations {
23
24VariationsRegistrySyncer::VariationsRegistrySyncer() {
25}
26
27VariationsRegistrySyncer::~VariationsRegistrySyncer() {
28}
29
30void VariationsRegistrySyncer::RequestRegistrySync() {
31  if (timer_.IsRunning()) {
32    timer_.Reset();
33    return;
34  }
35
36  timer_.Start(FROM_HERE,
37               base::TimeDelta::FromSeconds(kRegistrySyncDelaySeconds),
38               this, &VariationsRegistrySyncer::SyncWithRegistry);
39}
40
41void VariationsRegistrySyncer::SyncWithRegistry() {
42  // Note that all registry operations are done here on the UI thread as there
43  // are no threading restrictions on them.
44  base::FilePath chrome_exe;
45  if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
46    NOTREACHED() << "Failed to get chrome exe path";
47    return;
48  }
49  const bool is_system_install =
50      !InstallUtil::IsPerUserInstall(chrome_exe.value().c_str());
51
52  // Read the current bits from the registry.
53  base::string16 registry_labels;
54  bool success = GoogleUpdateSettings::ReadExperimentLabels(is_system_install,
55                                                            &registry_labels);
56  if (!success) {
57    DVLOG(1) << "Error reading Variation labels from the registry.";
58    return;
59  }
60
61  // Since the non-Variations contents of experiment_labels should not be,
62  // clobbered, separate them from the Variations contents.
63  const base::string16 other_labels =
64      ExtractNonVariationLabels(registry_labels);
65
66  // Compute the new Variations part of the label.
67  base::FieldTrial::ActiveGroups active_groups;
68  base::FieldTrialList::GetActiveFieldTrialGroups(&active_groups);
69  const base::string16 variation_labels =
70      BuildGoogleUpdateExperimentLabel(active_groups);
71
72  // Append the old non-Variations labels with the new Variations labels and
73  // write it back to the registry.
74  const base::string16 combined_labels =
75      CombineExperimentLabels(variation_labels, other_labels);
76
77  if (!GoogleUpdateSettings::SetExperimentLabels(is_system_install,
78                                                 combined_labels)) {
79    DVLOG(1) << "Error writing Variation labels to the registry: "
80             << combined_labels;
81  }
82}
83
84}  // namespace chrome_variations
85