Home | History | Annotate | Download | only in sessions 
      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 throughout the sync cycle.  The SyncSession is not reused across
      8 // sync cycles; each cycle starts with a new one.
      9 
     10 #ifndef SYNC_SESSIONS_SYNC_SESSION_H_
     11 #define SYNC_SESSIONS_SYNC_SESSION_H_
     12 
     13 #include <map>
     14 #include <set>
     15 #include <string>
     16 #include <utility>
     17 #include <vector>
     18 
     19 #include "base/basictypes.h"
     20 #include "base/memory/scoped_ptr.h"
     21 #include "base/time/time.h"
     22 #include "sync/base/sync_export.h"
     23 #include "sync/engine/sync_cycle_event.h"
     24 #include "sync/internal_api/public/base/model_type.h"
     25 #include "sync/internal_api/public/engine/model_safe_worker.h"
     26 #include "sync/internal_api/public/sessions/sync_session_snapshot.h"
     27 #include "sync/protocol/sync_protocol_error.h"
     28 #include "sync/sessions/status_controller.h"
     29 #include "sync/sessions/sync_session_context.h"
     30 
     31 namespace syncer {
     32 class ModelSafeWorker;
     33 class ProtocolEvent;
     34 
     35 namespace sessions {
     36 
     37 class NudgeTracker;
     38 
     39 class SYNC_EXPORT_PRIVATE SyncSession {
     40  public:
     41   // The Delegate services events that occur during the session requiring an
     42   // explicit (and session-global) action, as opposed to events that are simply
     43   // recorded in per-session state.
     44   class SYNC_EXPORT_PRIVATE Delegate {
     45    public:
     46     // The client was throttled and should cease-and-desist syncing activity
     47     // until the specified time.
     48     virtual void OnThrottled(const base::TimeDelta& throttle_duration) = 0;
     49 
     50     // Some of the client's types were throttled.
     51     virtual void OnTypesThrottled(
     52         ModelTypeSet types,
     53         const base::TimeDelta& throttle_duration) = 0;
     54 
     55     // Silenced intervals can be out of phase with individual sessions, so the
     56     // delegate is the only thing that can give an authoritative answer for
     57     // "is syncing silenced right now". This shouldn't be necessary very often
     58     // as the delegate ensures no session is started if syncing is silenced.
     59     // ** Note **  This will return true if silencing commenced during this
     60     // session and the interval has not yet elapsed, but the contract here is
     61     // solely based on absolute time values. So, this cannot be used to infer
     62     // that any given session _instance_ is silenced.  An example of reasonable
     63     // use is for UI reporting.
     64     virtual bool IsCurrentlyThrottled() = 0;
     65 
     66     // The client has been instructed to change its short poll interval.
     67     virtual void OnReceivedShortPollIntervalUpdate(
     68         const base::TimeDelta& new_interval) = 0;
     69 
     70     // The client has been instructed to change its long poll interval.
     71     virtual void OnReceivedLongPollIntervalUpdate(
     72         const base::TimeDelta& new_interval) = 0;
     73 
     74     // The client has been instructed to change a nudge delay.
     75     virtual void OnReceivedCustomNudgeDelays(
     76         const std::map<ModelType, base::TimeDelta>& nudge_delays) = 0;
     77 
     78     // Called for the syncer to respond to the error sent by the server.
     79     virtual void OnSyncProtocolError(
     80         const SyncProtocolError& sync_protocol_error) = 0;
     81 
     82     // Called when the server wants to change the number of hints the client
     83     // will buffer locally.
     84     virtual void OnReceivedClientInvalidationHintBufferSize(int size) = 0;
     85 
     86     // Called when server wants to schedule a retry GU.
     87     virtual void OnReceivedGuRetryDelay(const base::TimeDelta& delay) = 0;
     88 
     89     // Called when server requests a migration.
     90     virtual void OnReceivedMigrationRequest(ModelTypeSet types) = 0;
     91 
     92    protected:
     93     virtual ~Delegate() {}
     94   };
     95 
     96   // Build a session without a nudge tracker.  Used for poll or configure type
     97   // sync cycles.
     98   static SyncSession* Build(SyncSessionContext* context,
     99                             Delegate* delegate);
    100   ~SyncSession();
    101 
    102   // Builds a thread-safe and read-only copy of the current session state.
    103   SyncSessionSnapshot TakeSnapshot() const;
    104   SyncSessionSnapshot TakeSnapshotWithSource(
    105       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource legacy_updates_source)
    106       const;
    107 
    108   // Builds and sends a snapshot to the session context's listeners.
    109   void SendSyncCycleEndEventNotification(
    110       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
    111   void SendEventNotification(SyncCycleEvent::EventCause cause);
    112 
    113   void SendProtocolEvent(const ProtocolEvent& event);
    114 
    115   // TODO(akalin): Split this into context() and mutable_context().
    116   SyncSessionContext* context() const { return context_; }
    117   Delegate* delegate() const { return delegate_; }
    118   const StatusController& status_controller() const {
    119     return *status_controller_.get();
    120   }
    121   StatusController* mutable_status_controller() {
    122     return status_controller_.get();
    123   }
    124 
    125  private:
    126   SyncSession(SyncSessionContext* context, Delegate* delegate);
    127 
    128   // The context for this session, guaranteed to outlive |this|.
    129   SyncSessionContext* const context_;
    130 
    131   // The delegate for this session, must never be NULL.
    132   Delegate* const delegate_;
    133 
    134   // Our controller for various status and error counters.
    135   scoped_ptr<StatusController> status_controller_;
    136 
    137   DISALLOW_COPY_AND_ASSIGN(SyncSession);
    138 };
    139 
    140 }  // namespace sessions
    141 }  // namespace syncer
    142 
    143 #endif  // SYNC_SESSIONS_SYNC_SESSION_H_
    144