sync: Implement per-type update processing

sync/sessions/sync_session_context.cc

 // 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.
 
 #include "sync/sessions/sync_session_context.h"
 
 #include "sync/sessions/debug_info_getter.h"
 #include "sync/util/extensions_activity.h"
 
 namespace syncer {
 namespace sessions {
 
 SyncSessionContext::SyncSessionContext(
     ServerConnectionManager* connection_manager,
     syncable::Directory* directory,
     const std::vector<ModelSafeWorker*>& workers,
     ExtensionsActivity* extensions_activity,
     const std::vector<SyncEngineEventListener*>& listeners,
     DebugInfoGetter* debug_info_getter,
     TrafficRecorder* traffic_recorder,
     bool keystore_encryption_enabled,
     bool client_enabled_pre_commit_update_avoidance,
     const std::string& invalidator_client_id)
     : connection_manager_(connection_manager),
       directory_(directory),
+      update_handler_deleter_(&update_handler_map_),
       commit_contributor_deleter_(&commit_contributor_map_),
       extensions_activity_(extensions_activity),
       notifications_enabled_(false),
       max_commit_batch_size_(kDefaultMaxCommitBatchSize),
       debug_info_getter_(debug_info_getter),
       traffic_recorder_(traffic_recorder),
       keystore_encryption_enabled_(keystore_encryption_enabled),
       invalidator_client_id_(invalidator_client_id),
       server_enabled_pre_commit_update_avoidance_(false),
       client_enabled_pre_commit_update_avoidance_(
           client_enabled_pre_commit_update_avoidance) {
   for (size_t i = 0u; i < workers.size(); ++i)
     workers_.push_back(workers[i]);
 
   std::vector<SyncEngineEventListener*>::const_iterator it;
   for (it = listeners.begin(); it != listeners.end(); ++it)
     listeners_.AddObserver(*it);
 }
 
 SyncSessionContext::~SyncSessionContext() {
 }
 
 void SyncSessionContext::set_routing_info(
     const ModelSafeRoutingInfo& routing_info) {
   routing_info_ = routing_info;
 
   // TODO(rlarocque): This is not a good long-term solution.  We must find a
-  // better way to initialize the set of CommitContributors.
+  // better way to initialize the set of CommitContributors and UpdateHandlers.
+  ModelTypeSet enabled_types = GetRoutingInfoTypes(routing_info);
+
   STLDeleteValues<CommitContributorMap>(&commit_contributor_map_);
-  ModelTypeSet enabled_types = GetRoutingInfoTypes(routing_info);
   for (ModelTypeSet::Iterator it = enabled_types.First(); it.Good(); it.Inc()) {
     SyncDirectoryCommitContributor* contributor =
         new SyncDirectoryCommitContributor(directory(), it.Get());
     commit_contributor_map_.insert(std::make_pair(it.Get(), contributor));
   }
+
+  STLDeleteValues<UpdateHandlerMap>(&update_handler_map_);
+  for (ModelTypeSet::Iterator it = enabled_types.First(); it.Good(); it.Inc()) {
+    SyncDirectoryUpdateHandler* handler =
+        new SyncDirectoryUpdateHandler(directory(), it.Get());
+    update_handler_map_.insert(std::make_pair(it.Get(), handler));
+  }
 }
 
 }  // namespace sessions
 }  // namespace syncer