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.
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.
14 #ifndef SYNC_SESSIONS_SYNC_SESSION_H_
15 #define SYNC_SESSIONS_SYNC_SESSION_H_
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/status_controller.h"
31 #include "sync/sessions/sync_session_context.h"
34 class ModelSafeWorker;
40 class SYNC_EXPORT_PRIVATE SyncSession {
42 // The Delegate services events that occur during the session requiring an
43 // explicit (and session-global) action, as opposed to events that are simply
44 // recorded in per-session state.
45 class SYNC_EXPORT_PRIVATE Delegate {
47 // The client was throttled and should cease-and-desist syncing activity
48 // until the specified time.
49 virtual void OnThrottled(const base::TimeDelta& throttle_duration) = 0;
51 // Some of the client's types were throttled.
52 virtual void OnTypesThrottled(
54 const base::TimeDelta& throttle_duration) = 0;
56 // Silenced intervals can be out of phase with individual sessions, so the
57 // delegate is the only thing that can give an authoritative answer for
58 // "is syncing silenced right now". This shouldn't be necessary very often
59 // as the delegate ensures no session is started if syncing is silenced.
60 // ** Note ** This will return true if silencing commenced during this
61 // session and the interval has not yet elapsed, but the contract here is
62 // solely based on absolute time values. So, this cannot be used to infer
63 // that any given session _instance_ is silenced. An example of reasonable
64 // use is for UI reporting.
65 virtual bool IsCurrentlyThrottled() = 0;
67 // The client has been instructed to change its short poll interval.
68 virtual void OnReceivedShortPollIntervalUpdate(
69 const base::TimeDelta& new_interval) = 0;
71 // The client has been instructed to change its long poll interval.
72 virtual void OnReceivedLongPollIntervalUpdate(
73 const base::TimeDelta& new_interval) = 0;
75 // The client has been instructed to change its sessions commit
77 virtual void OnReceivedSessionsCommitDelay(
78 const base::TimeDelta& new_delay) = 0;
80 // The client needs to cease and desist syncing at once. This occurs when
81 // the Syncer detects that the backend store has fundamentally changed or
82 // is a different instance altogether (e.g. swapping from a test instance
83 // to production, or a global stop syncing operation has wiped the store).
84 // TODO(lipalani) : Replace this function with the one below. This function
85 // stops the current sync cycle and purges the client. In the new model
86 // the former would be done by the |SyncProtocolError| and
87 // the latter(which is an action) would be done in ProfileSyncService
88 // along with the rest of the actions.
89 virtual void OnShouldStopSyncingPermanently() = 0;
91 // Called for the syncer to respond to the error sent by the server.
92 virtual void OnSyncProtocolError(
93 const sessions::SyncSessionSnapshot& snapshot) = 0;
95 // Called when the server wants to change the number of hints the client
96 // will buffer locally.
97 virtual void OnReceivedClientInvalidationHintBufferSize(int size) = 0;
100 virtual ~Delegate() {}
103 // Build a session without a nudge tracker. Used for poll or configure type
105 static SyncSession* Build(SyncSessionContext* context,
109 // Builds a thread-safe and read-only copy of the current session state.
110 SyncSessionSnapshot TakeSnapshot() const;
111 SyncSessionSnapshot TakeSnapshotWithSource(
112 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource legacy_updates_source)
115 // Builds and sends a snapshot to the session context's listeners.
116 void SendSyncCycleEndEventNotification(
117 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
118 void SendEventNotification(SyncEngineEvent::EventCause cause);
120 // TODO(akalin): Split this into context() and mutable_context().
121 SyncSessionContext* context() const { return context_; }
122 Delegate* delegate() const { return delegate_; }
123 const StatusController& status_controller() const {
124 return *status_controller_.get();
126 StatusController* mutable_status_controller() {
127 return status_controller_.get();
131 SyncSession(SyncSessionContext* context, Delegate* delegate);
133 // The context for this session, guaranteed to outlive |this|.
134 SyncSessionContext* const context_;
136 // The delegate for this session, must never be NULL.
137 Delegate* const delegate_;
139 // Our controller for various status and error counters.
140 scoped_ptr<StatusController> status_controller_;
142 DISALLOW_COPY_AND_ASSIGN(SyncSession);
145 } // namespace sessions
146 } // namespace syncer
148 #endif // SYNC_SESSIONS_SYNC_SESSION_H_