sync/sessions/sync_session.h

   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 its sessions commit
  75     // delay.
  76     virtual void OnReceivedSessionsCommitDelay(
  77         const base::TimeDelta& new_delay) = 0;
  78
  79     // Called for the syncer to respond to the error sent by the server.
  80     virtual void OnSyncProtocolError(
  81         const SyncProtocolError& sync_protocol_error) = 0;
  82
  83     // Called when the server wants to change the number of hints the client
  84     // will buffer locally.
  85     virtual void OnReceivedClientInvalidationHintBufferSize(int size) = 0;
  86
  87     // Called when server wants to schedule a retry GU.
  88     virtual void OnReceivedGuRetryDelay(const base::TimeDelta& delay) = 0;
  89
  90     // Called when server requests a migration.
  91     virtual void OnReceivedMigrationRequest(ModelTypeSet types) = 0;
  92
  93    protected:
  94     virtual ~Delegate() {}
  95   };
  96
  97   // Build a session without a nudge tracker.  Used for poll or configure type
  98   // sync cycles.
  99   static SyncSession* Build(SyncSessionContext* context,
 100                             Delegate* delegate);
 101   ~SyncSession();
 102
 103   // Builds a thread-safe and read-only copy of the current session state.
 104   SyncSessionSnapshot TakeSnapshot() const;
 105   SyncSessionSnapshot TakeSnapshotWithSource(
 106       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource legacy_updates_source)
 107       const;
 108
 109   // Builds and sends a snapshot to the session context's listeners.
 110   void SendSyncCycleEndEventNotification(
 111       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
 112   void SendEventNotification(SyncCycleEvent::EventCause cause);
 113
 114   void SendProtocolEvent(const ProtocolEvent& event);
 115
 116   // TODO(akalin): Split this into context() and mutable_context().
 117   SyncSessionContext* context() const { return context_; }
 118   Delegate* delegate() const { return delegate_; }
 119   const StatusController& status_controller() const {
 120     return *status_controller_.get();
 121   }
 122   StatusController* mutable_status_controller() {
 123     return status_controller_.get();
 124   }
 125
 126  private:
 127   SyncSession(SyncSessionContext* context, Delegate* delegate);
 128
 129   // The context for this session, guaranteed to outlive |this|.
 130   SyncSessionContext* const context_;
 131
 132   // The delegate for this session, must never be NULL.
 133   Delegate* const delegate_;
 134
 135   // Our controller for various status and error counters.
 136   scoped_ptr<StatusController> status_controller_;
 137
 138   DISALLOW_COPY_AND_ASSIGN(SyncSession);
 139 };
 140
 141 }  // namespace sessions
 142 }  // namespace syncer
 143
 144 #endif  // SYNC_SESSIONS_SYNC_SESSION_H_