sync/sessions/data_type_tracker.h

   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 #ifndef SYNC_SESSIONS_DATA_TYPE_TRACKER_H_
   6 #define SYNC_SESSIONS_DATA_TYPE_TRACKER_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "base/time/time.h"
  14 #include "sync/internal_api/public/base/invalidation_interface.h"
  15 #include "sync/internal_api/public/base/model_type.h"
  16 #include "sync/protocol/sync.pb.h"
  17
  18 namespace syncer {
  19
  20 class InvalidationInterface;
  21
  22 namespace sessions {
  23
  24 // A class to track the per-type scheduling data.
  25 class DataTypeTracker {
  26  public:
  27   explicit DataTypeTracker();
  28   ~DataTypeTracker();
  29
  30   // For STL compatibility, we do not forbid the creation of a default copy
  31   // constructor and assignment operator.
  32
  33   // Tracks that a local change has been made to this type.
  34   void RecordLocalChange();
  35
  36   // Tracks that a local refresh request has been made for this type.
  37   void RecordLocalRefreshRequest();
  38
  39   // Tracks that we received invalidation notifications for this type.
  40   void RecordRemoteInvalidation(scoped_ptr<InvalidationInterface> incoming);
  41
  42   // Records that a sync cycle has been performed successfully.
  43   // Generally, this means that all local changes have been committed and all
  44   // remote changes have been downloaded, so we can clear any flags related to
  45   // pending work.
  46   void RecordSuccessfulSyncCycle();
  47
  48   // Updates the size of the invalidations payload buffer.
  49   void UpdatePayloadBufferSize(size_t new_size);
  50
  51   // Returns true if there is a good reason to perform a sync cycle.  This does
  52   // not take into account whether or not now is a good time to perform a sync
  53   // cycle.  That's for the scheduler to decide.
  54   bool IsSyncRequired() const;
  55
  56   // Returns true if there is a good reason to fetch updates for this type as
  57   // part of the next sync cycle.
  58   bool IsGetUpdatesRequired() const;
  59
  60   // Returns true if there is an uncommitted local change.
  61   bool HasLocalChangePending() const;
  62
  63   // Returns true if we've received an invalidation since we last fetched
  64   // updates.
  65   bool HasPendingInvalidation() const;
  66
  67   // Returns true if an explicit refresh request is still outstanding.
  68   bool HasRefreshRequestPending() const;
  69
  70   // Fills in the legacy invalidaiton payload information fields.
  71   void SetLegacyNotificationHint(
  72       sync_pb::DataTypeProgressMarker* progress) const;
  73
  74   // Fills some type-specific contents of a GetUpdates request protobuf.  These
  75   // messages provide the server with the information it needs to decide how to
  76   // handle a request.
  77   void FillGetUpdatesTriggersMessage(sync_pb::GetUpdateTriggers* msg) const;
  78
  79   // Returns true if the type is currently throttled.
  80   bool IsThrottled() const;
  81
  82   // Returns the time until this type's throttling interval expires.  Should not
  83   // be called unless IsThrottled() returns true.  The returned value will be
  84   // increased to zero if it would otherwise have been negative.
  85   base::TimeDelta GetTimeUntilUnthrottle(base::TimeTicks now) const;
  86
  87   // Throttles the type from |now| until |now| + |duration|.
  88   void ThrottleType(base::TimeDelta duration, base::TimeTicks now);
  89
  90   // Unthrottles the type if |now| >= the throttle expiry time.
  91   void UpdateThrottleState(base::TimeTicks now);
  92
  93  private:
  94   // Number of local change nudges received for this type since the last
  95   // successful sync cycle.
  96   int local_nudge_count_;
  97
  98   // Number of local refresh requests received for this type since the last
  99   // successful sync cycle.
 100   int local_refresh_request_count_;
 101
 102   // The list of invalidations received since the last successful sync cycle.
 103   // This list may be incomplete.  See also:
 104   // drop_tracker_.IsRecoveringFromDropEvent() and server_payload_overflow_.
 105   //
 106   // This list takes ownership of its contents.
 107   ScopedVector<InvalidationInterface> pending_invalidations_;
 108
 109   size_t payload_buffer_size_;
 110
 111   // If !unthrottle_time_.is_null(), this type is throttled and may not download
 112   // or commit data until the specified time.
 113   base::TimeTicks unthrottle_time_;
 114
 115   // A helper to keep track invalidations we dropped due to overflow.
 116   scoped_ptr<InvalidationInterface> last_dropped_invalidation_;
 117
 118   DISALLOW_COPY_AND_ASSIGN(DataTypeTracker);
 119 };
 120
 121 }  // namespace sessions
 122 }  // namespace syncer
 123
 124 #endif  // SYNC_SESSIONS_DATA_TYPE_TRACKER_H_