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 // A class to track the outstanding work required to bring the client back into 6 // sync with the server. 7 #ifndef SYNC_SESSIONS_NUDGE_TRACKER_H_ 8 #define SYNC_SESSIONS_NUDGE_TRACKER_H_ 9 10 #include <list> 11 #include <map> 12 13 #include "base/compiler_specific.h" 14 #include "sync/base/sync_export.h" 15 #include "sync/internal_api/public/base/model_type.h" 16 #include "sync/protocol/sync.pb.h" 17 #include "sync/sessions/data_type_tracker.h" 18 19 namespace syncer { 20 21 class ObjectIdInvalidationMap; 22 23 namespace sessions { 24 25 class SYNC_EXPORT_PRIVATE NudgeTracker { 26 public: 27 static size_t kDefaultMaxPayloadsPerType; 28 29 NudgeTracker(); 30 ~NudgeTracker(); 31 32 // Returns true if there is a good reason for performing a sync cycle. 33 // This does not take into account whether or not this is a good *time* to 34 // perform a sync cycle; that's the scheduler's job. 35 bool IsSyncRequired() const; 36 37 // Returns true if there is a good reason for performing a get updates 38 // request as part of the next sync cycle. 39 bool IsGetUpdatesRequired() const; 40 41 // Return true if should perform a sync cycle for GU retry. 42 // 43 // This is sensitive to changes in 'current time'. Its value can be affected 44 // by SetSyncCycleStartTime(), SetNextRetryTime(), and 45 // RecordSuccessfulSyncCycle(). Please refer to those functions for more 46 // information on how this flag is maintained. 47 bool IsRetryRequired() const; 48 49 // Tells this class that all required update fetching or committing has 50 // completed successfully. 51 void RecordSuccessfulSyncCycle(); 52 53 // Takes note of a local change. 54 void RecordLocalChange(ModelTypeSet types); 55 56 // Takes note of a locally issued request to refresh a data type. 57 void RecordLocalRefreshRequest(ModelTypeSet types); 58 59 // Takes note of the receipt of an invalidation notice from the server. 60 void RecordRemoteInvalidation( 61 const ObjectIdInvalidationMap& invalidation_map); 62 63 // These functions should be called to keep this class informed of the status 64 // of the connection to the invalidations server. 65 void OnInvalidationsEnabled(); 66 void OnInvalidationsDisabled(); 67 68 // Marks |types| as being throttled from |now| until |now| + |length|. 69 void SetTypesThrottledUntil(ModelTypeSet types, 70 base::TimeDelta length, 71 base::TimeTicks now); 72 73 // Removes any throttling that have expired by time |now|. 74 void UpdateTypeThrottlingState(base::TimeTicks now); 75 76 // Returns the time of the next type unthrottling, relative to 77 // the input |now| value. 78 base::TimeDelta GetTimeUntilNextUnthrottle(base::TimeTicks now) const; 79 80 // Returns true if any type is currenlty throttled. 81 bool IsAnyTypeThrottled() const; 82 83 // Returns true if |type| is currently throttled. 84 bool IsTypeThrottled(ModelType type) const; 85 86 // Returns the set of currently throttled types. 87 ModelTypeSet GetThrottledTypes() const; 88 89 // Returns the set of types with local changes pending. 90 ModelTypeSet GetNudgedTypes() const; 91 92 // Returns the set of types that have pending invalidations. 93 ModelTypeSet GetNotifiedTypes() const; 94 95 // Returns the set of types that have pending refresh requests. 96 ModelTypeSet GetRefreshRequestedTypes() const; 97 98 // Returns the 'source' of the GetUpdate request. 99 // 100 // This flag is deprecated, but still used by the server. There can be more 101 // than one reason to perform a particular sync cycle. The GetUpdatesTrigger 102 // message will contain more reliable information about the reasons for 103 // performing a sync. 104 // 105 // See the implementation for important information about the coalesce logic. 106 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource GetLegacySource() const; 107 108 // Fills a GetUpdatesTrigger message for the next GetUpdates request. This is 109 // used by the DownloadUpdatesCommand to dump lots of useful per-type state 110 // information into the GetUpdate request before sending it off to the server. 111 void FillProtoMessage( 112 ModelType type, 113 sync_pb::GetUpdateTriggers* msg) const; 114 115 // Fills a ProgressMarker with single legacy notification hint expected by the 116 // sync server. Newer servers will rely on the data set by FillProtoMessage() 117 // instead of this. 118 void SetLegacyNotificationHint( 119 ModelType type, 120 sync_pb::DataTypeProgressMarker* progress) const; 121 122 // Flips the flag if we're due for a retry. 123 void SetSyncCycleStartTime(base::TimeTicks now); 124 125 // Adjusts the number of hints that can be stored locally. 126 void SetHintBufferSize(size_t size); 127 128 // Schedules a retry GetUpdate request for some time in the future. 129 // 130 // This is a request sent to us as part of a server response requesting 131 // that the client perform a GetUpdate request at |next_retry_time| to 132 // fetch any updates it may have missed in the first attempt. 133 // 134 // To avoid strange results from IsRetryRequired() during a sync cycle, the 135 // effects of this change are not guaranteed to take effect until 136 // SetSyncCycleStartTime() is called at the start of the *next* sync cycle. 137 void SetNextRetryTime(base::TimeTicks next_retry_time); 138 139 private: 140 typedef std::map<ModelType, DataTypeTracker> TypeTrackerMap; 141 142 TypeTrackerMap type_trackers_; 143 144 // Merged updates source. This should be obsolete, but the server still 145 // relies on it for some heuristics. 146 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource updates_source_; 147 148 // Tracks whether or not invalidations are currently enabled. 149 bool invalidations_enabled_; 150 151 // This flag is set if suspect that some technical malfunction or known bug 152 // may have left us with some unserviced invalidations. 153 // 154 // Keeps track of whether or not we're fully in sync with the invalidation 155 // server. This can be false even if invalidations are enabled and working 156 // correctly. For example, until we get ack-tracking working properly, we 157 // won't persist invalidations between restarts, so we may be out of sync when 158 // we restart. The only way to get back into sync is to have invalidations 159 // enabled, then complete a sync cycle to make sure we're fully up to date. 160 bool invalidations_out_of_sync_; 161 162 size_t num_payloads_per_type_; 163 164 base::TimeTicks last_successful_sync_time_; 165 166 // A pending update to the current_retry_time_. 167 // 168 // The GU retry time is specified by a call to SetNextRetryTime, but we don't 169 // want that change to take effect right away, since it could happen in the 170 // middle of a sync cycle. We delay the update until the start of the next 171 // sync cycle, which is indicated by a call to SetSyncCycleStartTime(). 172 base::TimeTicks next_retry_time_; 173 174 // The currently active retry GU time. Will be null if there is no retry GU 175 // pending at this time. 176 base::TimeTicks current_retry_time_; 177 178 // The time when the sync cycle started. This value is maintained by 179 // SetSyncCycleStartTime(). This may contain a stale value if we're not 180 // currently in a sync cycle. 181 base::TimeTicks sync_cycle_start_time_; 182 183 DISALLOW_COPY_AND_ASSIGN(NudgeTracker); 184 }; 185 186 } // namespace sessions 187 } // namespace syncer 188 189 #endif // SYNC_SESSIONS_NUDGE_TRACKER_H_ 190
