sync/engine/sync_scheduler.h

   1 // Copyright 2012 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 // A class to schedule syncer tasks intelligently.
   6 #ifndef SYNC_ENGINE_SYNC_SCHEDULER_H_
   7 #define SYNC_ENGINE_SYNC_SCHEDULER_H_
   8
   9 #include <string>
  10
  11 #include "base/callback.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/time.h"
  14 #include "sync/base/sync_export.h"
  15 #include "sync/engine/nudge_source.h"
  16 #include "sync/internal_api/public/base/model_type_invalidation_map.h"
  17 #include "sync/sessions/sync_session.h"
  18
  19 class MessageLoop;
  20
  21 namespace tracked_objects {
  22 class Location;
  23 }  // namespace tracked_objects
  24
  25 namespace syncer {
  26
  27 struct ServerConnectionEvent;
  28
  29 struct SYNC_EXPORT_PRIVATE ConfigurationParams {
  30   ConfigurationParams();
  31   ConfigurationParams(
  32       const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource& source,
  33       ModelTypeSet types_to_download,
  34       const ModelSafeRoutingInfo& routing_info,
  35       const base::Closure& ready_task);
  36   ~ConfigurationParams();
  37
  38   // Source for the configuration.
  39   sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source;
  40   // The types that should be downloaded.
  41   ModelTypeSet types_to_download;
  42   // The new routing info (superset of types to be downloaded).
  43   ModelSafeRoutingInfo routing_info;
  44   // Callback to invoke on configuration completion.
  45   base::Closure ready_task;
  46 };
  47
  48 class SYNC_EXPORT_PRIVATE SyncScheduler
  49     : public sessions::SyncSession::Delegate {
  50  public:
  51   enum Mode {
  52     // In this mode, the thread only performs configuration tasks.  This is
  53     // designed to make the case where we want to download updates for a
  54     // specific type only, and not continue syncing until we are moved into
  55     // normal mode.
  56     CONFIGURATION_MODE,
  57     // Resumes polling and allows nudges, drops configuration tasks.  Runs
  58     // through entire sync cycle.
  59     NORMAL_MODE,
  60   };
  61
  62   // All methods of SyncScheduler must be called on the same thread
  63   // (except for RequestEarlyExit()).
  64
  65   SyncScheduler();
  66   virtual ~SyncScheduler();
  67
  68   // Start the scheduler with the given mode.  If the scheduler is
  69   // already started, switch to the given mode, although some
  70   // scheduled tasks from the old mode may still run.
  71   virtual void Start(Mode mode) = 0;
  72
  73   // Schedules the configuration task specified by |params|. Returns true if
  74   // the configuration task executed immediately, false if it had to be
  75   // scheduled for a later attempt. |params.ready_task| is invoked whenever the
  76   // configuration task executes.
  77   // Note: must already be in CONFIGURATION mode.
  78   virtual bool ScheduleConfiguration(const ConfigurationParams& params) = 0;
  79
  80   // Request that any running syncer task stop as soon as possible and
  81   // cancel all scheduled tasks. This function can be called from any thread,
  82   // and should in fact be called from a thread that isn't the sync loop to
  83   // allow preempting ongoing sync cycles.
  84   // Invokes |callback| from the sync loop once syncer is idle and all tasks
  85   // are cancelled.
  86   virtual void RequestStop(const base::Closure& callback) = 0;
  87
  88   // The meat and potatoes. Both of these methods will post a delayed task
  89   // to attempt the actual nudge (see ScheduleNudgeImpl).
  90   // NOTE: |desired_delay| is best-effort. If a nudge is already scheduled to
  91   // depart earlier than Now() + delay, the scheduler can and will prefer to
  92   // batch the two so that only one nudge is sent (at the earlier time). Also,
  93   // as always with delayed tasks and timers, it's possible the task gets run
  94   // any time after |desired_delay|.
  95   virtual void ScheduleNudgeAsync(
  96       const base::TimeDelta& desired_delay,
  97       NudgeSource source,
  98       ModelTypeSet types,
  99       const tracked_objects::Location& nudge_location) = 0;
 100   virtual void ScheduleNudgeWithStatesAsync(
 101       const base::TimeDelta& desired_delay, NudgeSource source,
 102       const ModelTypeInvalidationMap& invalidation_map,
 103       const tracked_objects::Location& nudge_location) = 0;
 104
 105   // Change status of notifications in the SyncSessionContext.
 106   virtual void SetNotificationsEnabled(bool notifications_enabled) = 0;
 107
 108   virtual base::TimeDelta GetSessionsCommitDelay() const = 0;
 109
 110   // Called when credentials are updated by the user.
 111   virtual void OnCredentialsUpdated() = 0;
 112
 113   // Called when the network layer detects a connection status change.
 114   virtual void OnConnectionStatusChange() = 0;
 115 };
 116
 117 }  // namespace syncer
 118
 119 #endif  // SYNC_ENGINE_SYNC_SCHEDULER_H_