sync: Per-type update application

sync/sessions/sync_session_context.h

 // Copyright 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.
 
 // SyncSessionContext encapsulates the contextual information and engine
-// components specific to a SyncSession. A context is accessible via
-// a SyncSession so that session SyncerCommands and parts of the engine have
-// a convenient way to access other parts. In this way it can be thought of as
-// the surrounding environment for the SyncSession. The components of this
-// environment are either valid or not valid for the entire context lifetime,
-// or they are valid for explicitly scoped periods of time by using Scoped
-// installation utilities found below. This means that the context assumes no
-// ownership whatsoever of any object that was not created by the context
-// itself.
+// components specific to a SyncSession.  Unlike the SyncSession, the context
+// can be reused across several sync cycles.
+//
+// The context does not take ownership of its pointer members.  It's up to
+// the surrounding classes to ensure those members remain valid while the
+// context is in use.
 //
 // It can only be used from the SyncerThread.
 
 #ifndef SYNC_SESSIONS_SYNC_SESSION_CONTEXT_H_
 #define SYNC_SESSIONS_SYNC_SESSION_CONTEXT_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
@@ skipping 38 matching lines @@
 
   ~SyncSessionContext();
 
   ServerConnectionManager* connection_manager() {
     return connection_manager_;
   }
   syncable::Directory* directory() {
     return directory_;
   }
 
-  const ModelSafeRoutingInfo& routing_info() const {
-    return routing_info_;
+  ModelTypeSet enabled_types() const {
+    return enabled_types_;
   }
 
   void set_routing_info(const ModelSafeRoutingInfo& routing_info);
 
   UpdateHandlerMap* update_handler_map() {
     return &update_handler_map_;
   }
 
   CommitContributorMap* commit_contributor_map() {
     return &commit_contributor_map_;
   }
 
-  const std::vector<scoped_refptr<ModelSafeWorker> >& workers() const {
-    return workers_;
-  }
-
   ExtensionsActivity* extensions_activity() {
     return extensions_activity_.get();
   }
 
   DebugInfoGetter* debug_info_getter() {
     return debug_info_getter_;
   }
 
   // Talk notification status.
   void set_notifications_enabled(bool enabled) {
@@ skipping 51 matching lines @@
   // Rather than force clients to set and null-out various context members, we
   // extend our encapsulation boundary to scoped helpers that take care of this
   // once they are allocated. See definitions of these below.
   friend class TestScopedSessionEventListener;
 
   ObserverList<SyncEngineEventListener> listeners_;
 
   ServerConnectionManager* const connection_manager_;
   syncable::Directory* const directory_;
 
-  // A cached copy of SyncBackendRegistrar's routing info.
-  // Must be updated manually when SBR's state is modified.
-  ModelSafeRoutingInfo routing_info_;
+  // The set of enabled types.  Derrived from the routing info set with
+  // set_routing_info().
+  ModelTypeSet enabled_types_;
 
   // A map of 'update handlers', one for each enabled type.
   // This must be kept in sync with the routing info.  Our temporary solution to
   // that problem is to initialize this map in set_routing_info().
   UpdateHandlerMap update_handler_map_;
 
   // Deleter for the |update_handler_map_|.
   STLValueDeleter<UpdateHandlerMap> update_handler_deleter_;
 
   // A map of 'commit contributors', one for each enabled type.
   // This must be kept in sync with the routing info.  Our temporary solution to
   // that problem is to initialize this map in set_routing_info().
   CommitContributorMap commit_contributor_map_;
 
   // Deleter for the |commit_contributor_map_|.
   STLValueDeleter<CommitContributorMap> commit_contributor_deleter_;
 
   // The set of ModelSafeWorkers.  Used to execute tasks of various threads.
-  std::vector<scoped_refptr<ModelSafeWorker> > workers_;
+  std::map<ModelSafeGroup, scoped_refptr<ModelSafeWorker> > workers_;
 
   // We use this to stuff extensions activity into CommitMessages so the server
   // can correlate commit traffic with extension-related bookmark mutations.
   scoped_refptr<ExtensionsActivity> extensions_activity_;
 
   // Kept up to date with talk events to determine whether notifications are
   // enabled. True only if the notification channel is authorized and open.
   bool notifications_enabled_;
 
   // The name of the account being synced.
@@ skipping 31 matching lines @@
   // enable the pre-commit update avoidance experiment described above.
   const bool client_enabled_pre_commit_update_avoidance_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSessionContext);
 };
 
 }  // namespace sessions
 }  // namespace syncer
 
 #endif  // SYNC_SESSIONS_SYNC_SESSION_CONTEXT_H_