sync: Introduce ModelTypeRegistry and helpers

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.  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>
 
-#include "base/stl_util.h"
 #include "sync/base/sync_export.h"
-#include "sync/engine/sync_directory_commit_contributor.h"
-#include "sync/engine/sync_directory_update_handler.h"
+#include "sync/engine/committer_list.h"
 #include "sync/engine/sync_engine_event.h"
-#include "sync/engine/syncer_types.h"
 #include "sync/engine/traffic_recorder.h"
+#include "sync/engine/updater_list.h"
 #include "sync/internal_api/public/engine/model_safe_worker.h"
-#include "sync/protocol/sync.pb.h"
 #include "sync/sessions/debug_info_getter.h"
 
 namespace syncer {
 
 class ExtensionsActivity;
 class ServerConnectionManager;
 
 namespace syncable {
 class Directory;
 }
@@ skipping 23 matching lines @@
     return connection_manager_;
   }
   syncable::Directory* directory() {
     return directory_;
   }
 
   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_;
-  }
+  void SetRoutingInfo(const ModelSafeRoutingInfo& routing_info);
 
   ExtensionsActivity* extensions_activity() {
     return extensions_activity_.get();
   }
 
   DebugInfoGetter* debug_info_getter() {
     return debug_info_getter_;
   }
 
   // Talk notification status.
@@ skipping 41 matching lines @@
 
   bool ShouldFetchUpdatesBeforeCommit() const {
     return !(server_enabled_pre_commit_update_avoidance_ ||
              client_enabled_pre_commit_update_avoidance_);
   }
 
   void set_server_enabled_pre_commit_update_avoidance(bool value) {
     server_enabled_pre_commit_update_avoidance_ = value;
   }
 
+  UpdaterList* updater_list() {
+    return &updater_list_;
+  }
+
+  CommitterList* committer_list() {
+    return &committer_list_;
+  }
+
  private:
   // 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_;
 
   // 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::map<ModelSafeGroup, scoped_refptr<ModelSafeWorker> > workers_;
+  std::vector<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 24 matching lines @@
 
   // Flag to enable or disable the no pre-commit GetUpdates experiment.  When
   // this flag is set to false, the syncer has the option of not performing at
   // GetUpdates request when there is nothing to fetch.
   bool server_enabled_pre_commit_update_avoidance_;
 
   // If true, indicates that we've been passed a command-line flag to force
   // enable the pre-commit update avoidance experiment described above.
   const bool client_enabled_pre_commit_update_avoidance_;
 
+  // Classes to manage the types hooked up to receive and commit sync data.
+  UpdaterList updater_list_;
+  CommitterList committer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(SyncSessionContext);
 };
 
 }  // namespace sessions
 }  // namespace syncer
 
 #endif  // SYNC_SESSIONS_SYNC_SESSION_CONTEXT_H_