[Sync] Refactor sync configuration logic.

sync/engine/sync_scheduler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A class to schedule syncer tasks intelligently.
 #ifndef SYNC_ENGINE_SYNC_SCHEDULER_H_
 #define SYNC_ENGINE_SYNC_SCHEDULER_H_
 #pragma once
 
 #include <string>
@@ skipping 19 matching lines @@
 class MessageLoop;
 
 namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects
 
 namespace browser_sync {
 
 struct ServerConnectionEvent;
 
+struct ConfigureParams {
+  ConfigureParams();
+  ConfigureParams(
+      const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource& source,
+      const syncable::ModelTypeSet& types_to_config,
+      const browser_sync::ModelSafeRoutingInfo& routing_info,
+      bool need_encryption_key,
+      const base::Closure& ready_task);
+  ~ConfigureParams();
+
+  // Source for the configuration.
+  sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source;
+  // The types that should be downloaded.
+  syncable::ModelTypeSet types_to_config;
+  // The new routing info (superset of types to be downloaded).
+  ModelSafeRoutingInfo routing_info;
+  // Whether we need to perform a GetKey command.
+  bool need_encryption_key;
+  // Callback to invoke on configuration completion.
+  base::Closure ready_task;
+};
+
 class SyncScheduler : public sessions::SyncSession::Delegate {
  public:
   enum Mode {
     // In this mode, the thread only performs configuration tasks.  This is
     // designed to make the case where we want to download updates for a
     // specific type only, and not continue syncing until we are moved into
     // normal mode.
     CONFIGURATION_MODE,
     // Resumes polling and allows nudges, drops configuration tasks.  Runs
     // through entire sync cycle.
     NORMAL_MODE,
   };
 
   // All methods of SyncScheduler must be called on the same thread
   // (except for RequestEarlyExit()).
 
   // |name| is a display string to identify the syncer thread.  Takes
   // |ownership of |syncer|.
   SyncScheduler(const std::string& name,
                 sessions::SyncSessionContext* context, Syncer* syncer);
 
   // Calls Stop().
   virtual ~SyncScheduler();
 
   // Start the scheduler with the given mode.  If the scheduler is
   // already started, switch to the given mode, although some
-  // scheduled tasks from the old mode may still run.  If non-NULL,
-  // |callback| will be invoked when the mode has been changed to
-  // |mode|.  Takes ownership of |callback|.
-  void Start(Mode mode, const base::Closure& callback);
+  // scheduled tasks from the old mode may still run.
+  void Start(Mode mode);
+
+  // Performs the configuration tasks specified by |params|. Returns true if
+  // the configuration task completes, false if a retry had to be scheduled
+  // for later completion. |params.ready_task| is invoked whenever the
+  // configuration task completes.
+  // Note: must already be in CONFIGURATION mode.
+  bool Configure(const ConfigureParams& params);
 
   // Request that any running syncer task stop as soon as possible and
   // cancel all scheduled tasks. This function can be called from any thread,
   // and should in fact be called from a thread that isn't the sync loop to
   // allow preempting ongoing sync cycles.
   // Invokes |callback| from the sync loop once syncer is idle and all tasks
   // are cancelled.
   void RequestStop(const base::Closure& callback);
 
   // The meat and potatoes.
   void ScheduleNudge(const base::TimeDelta& delay, NudgeSource source,
                      syncable::ModelTypeSet types,
                      const tracked_objects::Location& nudge_location);
   void ScheduleNudgeWithPayloads(
       const base::TimeDelta& delay, NudgeSource source,
       const syncable::ModelTypePayloadMap& types_with_payloads,
       const tracked_objects::Location& nudge_location);
 
-  // Note: The source argument of this function must come from the subset of
-  // GetUpdatesCallerInfo values related to configurations.
-  void Configure(
-      syncable::ModelTypeSet types,
-      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
-
   void ClearUserData();
 
   void CleanupDisabledTypes();
 
   // Change status of notifications in the SyncSessionContext.
   void set_notifications_enabled(bool notifications_enabled);
 
   base::TimeDelta sessions_commit_delay() const;
 
   // DDOS avoidance function.  Calculates how long we should wait before trying
@@ skipping 49 matching lines @@
       // during initial sync or reconfiguration.  We don't run all steps of
       // the sync cycle for these (e.g. CleanupDisabledTypes is skipped).
       CONFIGURATION,
       // The user disabled some types and we have to clean up the data
       // for those.
       CLEANUP_DISABLED_TYPES,
     };
     SyncSessionJob();
     SyncSessionJob(SyncSessionJobPurpose purpose, base::TimeTicks start,
         linked_ptr<sessions::SyncSession> session, bool is_canary_job,
+        ConfigureParams config_params,
         const tracked_objects::Location& nudge_location);
     ~SyncSessionJob();
     static const char* GetPurposeString(SyncSessionJobPurpose purpose);
 
     SyncSessionJobPurpose purpose;
     base::TimeTicks scheduled_start;
     linked_ptr<sessions::SyncSession> session;
     bool is_canary_job;
+    ConfigureParams config_params;
 
     // This is the location the job came from.  Used for debugging.
     // In case of multiple nudges getting coalesced this stores the
     // first location that came in.
     tracked_objects::Location from_here;
   };
   friend class SyncSchedulerTest;
   friend class SyncSchedulerWhiteboxTest;
   friend class SyncerTest;
 
@@ skipping 221 matching lines @@
   scoped_ptr<Syncer> syncer_;
 
   sessions::SyncSessionContext *session_context_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncScheduler);
 };
 
 }  // namespace browser_sync
 
 #endif  // SYNC_ENGINE_SYNC_SCHEDULER_H_