chrome/browser/sync_file_system/sync_process_runner.cc

   1 // Copyright 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/sync_file_system/sync_process_runner.h"
   6
   7 #include "base/format_macros.h"
   8 #include "chrome/browser/sync_file_system/logger.h"
   9
  10 namespace sync_file_system {
  11
  12 const int64 SyncProcessRunner::kSyncDelayInMilliseconds =
  13     1 * base::Time::kMillisecondsPerSecond; // 1 sec
  14 const int64 SyncProcessRunner::kSyncDelayWithSyncError =
  15     3 * base::Time::kMillisecondsPerSecond; // 3 sec
  16 const int64 SyncProcessRunner::kSyncDelayFastInMilliseconds = 100;  // 100 ms
  17 const int SyncProcessRunner::kPendingChangeThresholdForFastSync = 10;
  18 const int64 SyncProcessRunner::kSyncDelaySlowInMilliseconds =
  19     30 * base::Time::kMillisecondsPerSecond;  // 30 sec
  20 const int64 SyncProcessRunner::kSyncDelayMaxInMilliseconds =
  21     30 * 60 * base::Time::kMillisecondsPerSecond;  // 30 min
  22
  23 namespace {
  24
  25 class BaseTimerHelper : public SyncProcessRunner::TimerHelper {
  26  public:
  27   BaseTimerHelper() {}
  28
  29   virtual bool IsRunning() override {
  30     return timer_.IsRunning();
  31   }
  32
  33   virtual void Start(const tracked_objects::Location& from_here,
  34                      const base::TimeDelta& delay,
  35                      const base::Closure& closure) override {
  36     timer_.Start(from_here, delay, closure);
  37   }
  38
  39   virtual base::TimeTicks Now() const override {
  40     return base::TimeTicks::Now();
  41   }
  42
  43   virtual ~BaseTimerHelper() {}
  44
  45  private:
  46   base::OneShotTimer<SyncProcessRunner> timer_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(BaseTimerHelper);
  49 };
  50
  51 bool WasSuccessfulSync(SyncStatusCode status) {
  52   return status == SYNC_STATUS_OK ||
  53          status == SYNC_STATUS_HAS_CONFLICT ||
  54          status == SYNC_STATUS_NO_CONFLICT ||
  55          status == SYNC_STATUS_NO_CHANGE_TO_SYNC ||
  56          status == SYNC_STATUS_UNKNOWN_ORIGIN ||
  57          status == SYNC_STATUS_RETRY;
  58 }
  59
  60 }  // namespace
  61
  62 SyncProcessRunner::SyncProcessRunner(
  63     const std::string& name,
  64     Client* client,
  65     scoped_ptr<TimerHelper> timer_helper,
  66     size_t max_parallel_task)
  67     : name_(name),
  68       client_(client),
  69       max_parallel_task_(max_parallel_task),
  70       running_tasks_(0),
  71       timer_helper_(timer_helper.Pass()),
  72       service_state_(SYNC_SERVICE_RUNNING),
  73       pending_changes_(0),
  74       factory_(this) {
  75   DCHECK_LE(1u, max_parallel_task_);
  76   if (!timer_helper_)
  77     timer_helper_.reset(new BaseTimerHelper);
  78 }
  79
  80 SyncProcessRunner::~SyncProcessRunner() {}
  81
  82 void SyncProcessRunner::Schedule() {
  83   if (pending_changes_ == 0) {
  84     ScheduleInternal(kSyncDelayMaxInMilliseconds);
  85     return;
  86   }
  87
  88   SyncServiceState last_service_state = service_state_;
  89   service_state_ = GetServiceState();
  90
  91   switch (service_state_) {
  92     case SYNC_SERVICE_RUNNING:
  93       ResetThrottling();
  94       if (pending_changes_ > kPendingChangeThresholdForFastSync)
  95         ScheduleInternal(kSyncDelayFastInMilliseconds);
  96       else
  97         ScheduleInternal(kSyncDelayInMilliseconds);
  98       return;
  99
 100     case SYNC_SERVICE_TEMPORARY_UNAVAILABLE:
 101       if (last_service_state != service_state_)
 102         ThrottleSync(kSyncDelaySlowInMilliseconds);
 103       ScheduleInternal(kSyncDelaySlowInMilliseconds);
 104       return;
 105
 106     case SYNC_SERVICE_AUTHENTICATION_REQUIRED:
 107     case SYNC_SERVICE_DISABLED:
 108       if (last_service_state != service_state_)
 109         ThrottleSync(kSyncDelaySlowInMilliseconds);
 110       ScheduleInternal(kSyncDelayMaxInMilliseconds);
 111       return;
 112   }
 113
 114   NOTREACHED();
 115   ScheduleInternal(kSyncDelayMaxInMilliseconds);
 116 }
 117
 118 void SyncProcessRunner::ThrottleSync(int64 base_delay) {
 119   base::TimeTicks now = timer_helper_->Now();
 120   base::TimeDelta elapsed = std::min(now, throttle_until_) - throttle_from_;
 121   DCHECK(base::TimeDelta() <= elapsed);
 122
 123   throttle_from_ = now;
 124   // Extend throttling duration by twice the elapsed time.
 125   // That is, if the backoff repeats in a short period, the throttling period
 126   // doesn't grow exponentially.  If the backoff happens on the end of
 127   // throttling period, it causes another throttling period that is twice as
 128   // long as previous.
 129   base::TimeDelta base_delay_delta =
 130       base::TimeDelta::FromMilliseconds(base_delay);
 131   const base::TimeDelta max_delay =
 132       base::TimeDelta::FromMilliseconds(kSyncDelayMaxInMilliseconds);
 133   throttle_until_ =
 134       std::min(now + max_delay,
 135                std::max(now + base_delay_delta, throttle_until_ + 2 * elapsed));
 136 }
 137
 138 void SyncProcessRunner::ResetOldThrottling() {
 139   if (throttle_until_ < base::TimeTicks::Now())
 140     ResetThrottling();
 141 }
 142
 143 void SyncProcessRunner::ResetThrottling() {
 144   throttle_from_ = base::TimeTicks();
 145   throttle_until_ = base::TimeTicks();
 146 }
 147
 148 SyncServiceState SyncProcessRunner::GetServiceState() {
 149   return client_->GetSyncServiceState();
 150 }
 151
 152 void SyncProcessRunner::OnChangesUpdated(
 153     int64 pending_changes) {
 154   DCHECK_GE(pending_changes, 0);
 155   int64 old_pending_changes = pending_changes_;
 156   pending_changes_ = pending_changes;
 157   if (old_pending_changes != pending_changes) {
 158     CheckIfIdle();
 159     util::Log(logging::LOG_VERBOSE, FROM_HERE,
 160               "[%s] pending_changes updated: %" PRId64,
 161               name_.c_str(), pending_changes);
 162   }
 163   Schedule();
 164 }
 165
 166 SyncFileSystemService* SyncProcessRunner::GetSyncService() {
 167   return client_->GetSyncService();
 168 }
 169
 170 void SyncProcessRunner::Finished(const base::TimeTicks& start_time,
 171                                  SyncStatusCode status) {
 172   DCHECK_LT(0u, running_tasks_);
 173   DCHECK_LE(running_tasks_, max_parallel_task_);
 174   --running_tasks_;
 175   CheckIfIdle();
 176   util::Log(logging::LOG_VERBOSE, FROM_HERE,
 177             "[%s] * Finished (elapsed: %" PRId64 " ms)", name_.c_str(),
 178             (timer_helper_->Now() - start_time).InMilliseconds());
 179
 180   if (status == SYNC_STATUS_NO_CHANGE_TO_SYNC ||
 181       status == SYNC_STATUS_FILE_BUSY) {
 182     ScheduleInternal(kSyncDelayMaxInMilliseconds);
 183     return;
 184   }
 185
 186   if (WasSuccessfulSync(status))
 187     ResetOldThrottling();
 188   else
 189     ThrottleSync(kSyncDelayWithSyncError);
 190
 191   Schedule();
 192 }
 193
 194 void SyncProcessRunner::Run() {
 195   if (running_tasks_ >= max_parallel_task_)
 196     return;
 197   ++running_tasks_;
 198   base::TimeTicks now = timer_helper_->Now();
 199   last_run_ = now;
 200
 201   util::Log(logging::LOG_VERBOSE, FROM_HERE,
 202             "[%s] * Started", name_.c_str());
 203
 204   StartSync(base::Bind(&SyncProcessRunner::Finished, factory_.GetWeakPtr(),
 205                        now));
 206   if (running_tasks_ < max_parallel_task_)
 207     Schedule();
 208 }
 209
 210 void SyncProcessRunner::ScheduleInternal(int64 delay) {
 211   base::TimeTicks now = timer_helper_->Now();
 212   base::TimeTicks next_scheduled;
 213
 214   if (timer_helper_->IsRunning()) {
 215     next_scheduled = last_run_ + base::TimeDelta::FromMilliseconds(delay);
 216     if (next_scheduled < now) {
 217       next_scheduled =
 218           now + base::TimeDelta::FromMilliseconds(kSyncDelayFastInMilliseconds);
 219     }
 220   } else {
 221     next_scheduled = now + base::TimeDelta::FromMilliseconds(delay);
 222   }
 223
 224   if (next_scheduled < throttle_until_)
 225     next_scheduled = throttle_until_;
 226
 227   if (timer_helper_->IsRunning() && last_scheduled_ == next_scheduled)
 228     return;
 229
 230   util::Log(logging::LOG_VERBOSE, FROM_HERE,
 231             "[%s] Scheduling task in %" PRId64 " ms",
 232             name_.c_str(), (next_scheduled - now).InMilliseconds());
 233
 234   last_scheduled_ = next_scheduled;
 235
 236   timer_helper_->Start(
 237       FROM_HERE, next_scheduled - now,
 238       base::Bind(&SyncProcessRunner::Run, base::Unretained(this)));
 239 }
 240
 241 void SyncProcessRunner::CheckIfIdle() {
 242   if (pending_changes_ == 0 && running_tasks_ == 0)
 243     client_->OnSyncIdle();
 244 }
 245
 246 }  // namespace sync_file_system