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 representing an attempt to synchronize the local syncable data 6 // store with a sync server. A SyncSession instance is passed as a stateful 7 // bundle to and from various SyncerCommands with the goal of converging the 8 // client view of data with that of the server. The commands twiddle with 9 // session status in response to events and hiccups along the way, set and 10 // query session progress with regards to conflict resolution and applying 11 // server updates, and access the SyncSessionContext for the current session 12 // via SyncSession instances. 13 14 #ifndef SYNC_SESSIONS_SYNC_SESSION_H_ 15 #define SYNC_SESSIONS_SYNC_SESSION_H_ 16 17 #include <map> 18 #include <set> 19 #include <string> 20 #include <utility> 21 #include <vector> 22 23 #include "base/basictypes.h" 24 #include "base/memory/scoped_ptr.h" 25 #include "base/time/time.h" 26 #include "sync/base/sync_export.h" 27 #include "sync/internal_api/public/base/model_type.h" 28 #include "sync/internal_api/public/engine/model_safe_worker.h" 29 #include "sync/internal_api/public/sessions/sync_session_snapshot.h" 30 #include "sync/sessions/ordered_commit_set.h" 31 #include "sync/sessions/status_controller.h" 32 #include "sync/sessions/sync_session_context.h" 33 34 namespace syncer { 35 class ModelSafeWorker; 36 37 namespace sessions { 38 39 class NudgeTracker; 40 41 class SYNC_EXPORT_PRIVATE SyncSession { 42 public: 43 // The Delegate services events that occur during the session requiring an 44 // explicit (and session-global) action, as opposed to events that are simply 45 // recorded in per-session state. 46 class SYNC_EXPORT_PRIVATE Delegate { 47 public: 48 // The client was throttled and should cease-and-desist syncing activity 49 // until the specified time. 50 virtual void OnThrottled(const base::TimeDelta& throttle_duration) = 0; 51 52 // Some of the client's types were throttled. 53 virtual void OnTypesThrottled( 54 ModelTypeSet types, 55 const base::TimeDelta& throttle_duration) = 0; 56 57 // Silenced intervals can be out of phase with individual sessions, so the 58 // delegate is the only thing that can give an authoritative answer for 59 // "is syncing silenced right now". This shouldn't be necessary very often 60 // as the delegate ensures no session is started if syncing is silenced. 61 // ** Note ** This will return true if silencing commenced during this 62 // session and the interval has not yet elapsed, but the contract here is 63 // solely based on absolute time values. So, this cannot be used to infer 64 // that any given session _instance_ is silenced. An example of reasonable 65 // use is for UI reporting. 66 virtual bool IsCurrentlyThrottled() = 0; 67 68 // The client has been instructed to change its short poll interval. 69 virtual void OnReceivedShortPollIntervalUpdate( 70 const base::TimeDelta& new_interval) = 0; 71 72 // The client has been instructed to change its long poll interval. 73 virtual void OnReceivedLongPollIntervalUpdate( 74 const base::TimeDelta& new_interval) = 0; 75 76 // The client has been instructed to change its sessions commit 77 // delay. 78 virtual void OnReceivedSessionsCommitDelay( 79 const base::TimeDelta& new_delay) = 0; 80 81 // The client needs to cease and desist syncing at once. This occurs when 82 // the Syncer detects that the backend store has fundamentally changed or 83 // is a different instance altogether (e.g. swapping from a test instance 84 // to production, or a global stop syncing operation has wiped the store). 85 // TODO(lipalani) : Replace this function with the one below. This function 86 // stops the current sync cycle and purges the client. In the new model 87 // the former would be done by the |SyncProtocolError| and 88 // the latter(which is an action) would be done in ProfileSyncService 89 // along with the rest of the actions. 90 virtual void OnShouldStopSyncingPermanently() = 0; 91 92 // Called for the syncer to respond to the error sent by the server. 93 virtual void OnSyncProtocolError( 94 const sessions::SyncSessionSnapshot& snapshot) = 0; 95 96 // Called when the server wants to change the number of hints the client 97 // will buffer locally. 98 virtual void OnReceivedClientInvalidationHintBufferSize(int size) = 0; 99 100 protected: 101 virtual ~Delegate() {} 102 }; 103 104 // Build a session without a nudge tracker. Used for poll or configure type 105 // sync cycles. 106 static SyncSession* Build(SyncSessionContext* context, 107 Delegate* delegate); 108 ~SyncSession(); 109 110 // Builds a thread-safe and read-only copy of the current session state. 111 SyncSessionSnapshot TakeSnapshot() const; 112 SyncSessionSnapshot TakeSnapshotWithSource( 113 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource legacy_updates_source) 114 const; 115 116 // Builds and sends a snapshot to the session context's listeners. 117 void SendSyncCycleEndEventNotification( 118 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source); 119 void SendEventNotification(SyncEngineEvent::EventCause cause); 120 121 // TODO(akalin): Split this into context() and mutable_context(). 122 SyncSessionContext* context() const { return context_; } 123 Delegate* delegate() const { return delegate_; } 124 const StatusController& status_controller() const { 125 return *status_controller_.get(); 126 } 127 StatusController* mutable_status_controller() { 128 return status_controller_.get(); 129 } 130 131 private: 132 SyncSession(SyncSessionContext* context, Delegate* delegate); 133 134 // The context for this session, guaranteed to outlive |this|. 135 SyncSessionContext* const context_; 136 137 // The delegate for this session, must never be NULL. 138 Delegate* const delegate_; 139 140 // Our controller for various status and error counters. 141 scoped_ptr<StatusController> status_controller_; 142 143 DISALLOW_COPY_AND_ASSIGN(SyncSession); 144 }; 145 146 } // namespace sessions 147 } // namespace syncer 148 149 #endif // SYNC_SESSIONS_SYNC_SESSION_H_ 150
