components/sync_driver/backup_rollback_controller.cc

   1 // Copyright 2014 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 "components/sync_driver/backup_rollback_controller.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/location.h"
   9 #include "base/metrics/field_trial.h"
  10 #include "base/single_thread_task_runner.h"
  11 #include "base/thread_task_runner_handle.h"
  12 #include "components/sync_driver/signin_manager_wrapper.h"
  13 #include "components/sync_driver/sync_driver_switches.h"
  14 #include "components/sync_driver/sync_prefs.h"
  15
  16 namespace sync_driver {
  17
  18 #if defined(ENABLE_PRE_SYNC_BACKUP)
  19 // Number of rollback attempts to try before giving up.
  20 static const int kRollbackLimits = 3;
  21
  22 // Finch experiment name and group.
  23 static char kSyncBackupFinchName[] = "SyncBackup";
  24 static char kSyncBackupFinchDisabled[] = "disabled";
  25 #endif
  26
  27 BackupRollbackController::BackupRollbackController(
  28     sync_driver::SyncPrefs* sync_prefs,
  29     const SigninManagerWrapper* signin,
  30     base::Closure start_backup,
  31     base::Closure start_rollback)
  32     : sync_prefs_(sync_prefs),
  33       signin_(signin),
  34       start_backup_(start_backup),
  35       start_rollback_(start_rollback) {}
  36
  37 BackupRollbackController::~BackupRollbackController() {}
  38
  39 bool BackupRollbackController::StartBackup() {
  40   if (!IsBackupEnabled())
  41     return false;
  42
  43   // Disable rollback to previous backup DB because it will be overwritten by
  44   // new backup.
  45   sync_prefs_->SetRemainingRollbackTries(0);
  46   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, start_backup_);
  47   return true;
  48 }
  49
  50 bool BackupRollbackController::StartRollback() {
  51   if (!IsBackupEnabled())
  52     return false;
  53
  54   // Don't roll back if disabled or user is signed in.
  55   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  56           switches::kSyncDisableRollback) ||
  57       !signin_->GetEffectiveUsername().empty()) {
  58     sync_prefs_->SetRemainingRollbackTries(0);
  59     return false;
  60   }
  61
  62   int rollback_tries = sync_prefs_->GetRemainingRollbackTries();
  63   if (rollback_tries <= 0)
  64     return false;  // No pending rollback.
  65
  66   sync_prefs_->SetRemainingRollbackTries(rollback_tries - 1);
  67   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, start_rollback_);
  68   return true;
  69 }
  70
  71 void BackupRollbackController::OnRollbackReceived() {
  72 #if defined(ENABLE_PRE_SYNC_BACKUP)
  73   sync_prefs_->SetRemainingRollbackTries(kRollbackLimits);
  74 #endif
  75 }
  76
  77 void BackupRollbackController::OnRollbackDone() {
  78 #if defined(ENABLE_PRE_SYNC_BACKUP)
  79   sync_prefs_->SetRemainingRollbackTries(0);
  80 #endif
  81 }
  82
  83 // static
  84 bool BackupRollbackController::IsBackupEnabled() {
  85 #if defined(ENABLE_PRE_SYNC_BACKUP)
  86   const std::string group_name =
  87       base::FieldTrialList::FindFullName(kSyncBackupFinchName);
  88
  89   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  90           switches::kSyncDisableBackup) ||
  91       group_name == kSyncBackupFinchDisabled) {
  92     return false;
  93   }
  94   return true;
  95 #else
  96   return false;
  97 #endif
  98 }
  99
 100 }  // namespace sync_driver