chrome/browser/metrics/variations/variations_registry_syncer_win.cc

   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 "base/threading/thread_restrictions.h"
  12 #include "chrome/common/variations/experiment_labels.h"
  13 #include "chrome/installer/util/google_update_settings.h"
  14 #include "chrome/installer/util/install_util.h"
  15 #include "content/public/browser/browser_thread.h"
  16
  17 namespace chrome_variations {
  18
  19 namespace {
  20
  21 // Delay before performing a registry sync, in seconds.
  22 const int kRegistrySyncDelaySeconds = 5;
  23
  24 // Performs the actual synchronization process with the registry, which should
  25 // be done on a blocking pool thread.
  26 void SyncWithRegistryOnBlockingPool() {
  27   base::ThreadRestrictions::AssertIOAllowed();
  28
  29   // Note that all registry operations are done here on the UI thread as there
  30   // are no threading restrictions on them.
  31   base::FilePath chrome_exe;
  32   if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
  33     NOTREACHED() << "Failed to get chrome exe path";
  34     return;
  35   }
  36   const bool is_system_install = !InstallUtil::IsPerUserInstall(chrome_exe);
  37
  38   // Read the current bits from the registry.
  39   base::string16 registry_labels;
  40   bool success = GoogleUpdateSettings::ReadExperimentLabels(is_system_install,
  41                                                             &registry_labels);
  42   if (!success) {
  43     DVLOG(1) << "Error reading Variation labels from the registry.";
  44     return;
  45   }
  46
  47   // Since the non-Variations contents of experiment_labels should not be,
  48   // clobbered, separate them from the Variations contents.
  49   const base::string16 other_labels =
  50       ExtractNonVariationLabels(registry_labels);
  51
  52   // Compute the new Variations part of the label.
  53   base::FieldTrial::ActiveGroups active_groups;
  54   base::FieldTrialList::GetActiveFieldTrialGroups(&active_groups);
  55   const base::string16 variation_labels =
  56       BuildGoogleUpdateExperimentLabel(active_groups);
  57
  58   // Append the old non-Variations labels with the new Variations labels and
  59   // write it back to the registry.
  60   const base::string16 combined_labels =
  61       CombineExperimentLabels(variation_labels, other_labels);
  62
  63   if (!GoogleUpdateSettings::SetExperimentLabels(is_system_install,
  64                                                  combined_labels)) {
  65     DVLOG(1) << "Error writing Variation labels to the registry: "
  66              << combined_labels;
  67   }
  68 }
  69
  70 }  // namespace
  71
  72 VariationsRegistrySyncer::VariationsRegistrySyncer() {
  73 }
  74
  75 VariationsRegistrySyncer::~VariationsRegistrySyncer() {
  76 }
  77
  78 void VariationsRegistrySyncer::RequestRegistrySync() {
  79   if (timer_.IsRunning()) {
  80     timer_.Reset();
  81     return;
  82   }
  83
  84   timer_.Start(FROM_HERE,
  85                base::TimeDelta::FromSeconds(kRegistrySyncDelaySeconds),
  86                this,
  87                &VariationsRegistrySyncer::StartRegistrySync);
  88 }
  89
  90 void VariationsRegistrySyncer::StartRegistrySync() {
  91   // Do the work on a blocking pool thread, as chrome://profiler has shown
  92   // that it can cause jank if done on the UI thrread.
  93   content::BrowserThread::GetBlockingPool()->PostTask(
  94       FROM_HERE, base::Bind(&SyncWithRegistryOnBlockingPool));
  95 }
  96
  97 }  // namespace chrome_variations