sync: Introduce ModelTypeRegistry and helpers

sync/engine/model_type_registry.cc

+// Copyright (c) 2013 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/engine/model_type_registry.h"
+
+#include "sync/engine/committer_list.h"
+#include "sync/engine/sync_directory_commit_contributor.h"
+#include "sync/engine/sync_directory_update_handler.h"
+#include "sync/engine/updater_list.h"
+
+namespace syncer {
+
+ModelTypeRegistry::ModelTypeRegistry(
+    const std::vector<ModelSafeWorker* >& workers,
+    syncable::Directory* directory)
+    : updater_list_(new UpdaterList()),

[Nicolas Zea, 2014/01/07 23:11:40]

why allocate updater list and commiter list here? Doesn't
SetEnabledDirectoryTypes have to be called anyways?

[rlarocque, 2014/01/08 01:37:24]

I think it's sensible to guarantee that these lists are always not NULL as long
as the class exists.

When we start configuring non-directory types, this could start to matter.  I'd
prefer to not bake in any assumptions about calling SetEnabledDirectoryTypes
unless I have to.

+      committer_list_(new CommitterList()),
+      directory_(directory) {
+  for (size_t i = 0u; i < workers.size(); ++i) {
+    workers_map_.insert(
+        std::make_pair(workers[i]->GetModelSafeGroup(), workers[i]));
+  }
+}
+
+ModelTypeRegistry::~ModelTypeRegistry() {}
+
+void ModelTypeRegistry::SetEnabledDirectoryTypes(
+    const ModelSafeRoutingInfo& routing_info) {
+  updater_list_.reset(new UpdaterList());
+  committer_list_.reset(new CommitterList());
+
+  for (ModelSafeRoutingInfo::const_iterator routing_iter = routing_info.begin();
+       routing_iter != routing_info.end(); ++routing_iter) {
+    ModelType type = routing_iter->first;
+    ModelSafeGroup group = routing_iter->second;
+    std::map<ModelSafeGroup, scoped_refptr<ModelSafeWorker> >::iterator
+        worker_it = workers_map_.find(group);
+    DCHECK(worker_it != workers_map_.end());
+    scoped_refptr<ModelSafeWorker> worker = worker_it->second;
+
+    SyncDirectoryCommitContributor* committer =
+        new SyncDirectoryCommitContributor(directory_, type);
+    SyncDirectoryUpdateHandler* updater =
+        new SyncDirectoryUpdateHandler(directory_, type, worker);
+
+    committer_list_->RegisterType(type, committer);
+    updater_list_->RegisterType(type, updater);
+  }
+}
+
+UpdaterList* ModelTypeRegistry::updater_list() {
+  return updater_list_.get();
+}
+
+CommitterList* ModelTypeRegistry::committer_list() {
+  return committer_list_.get();
+}
+
+}  // namespace syncer