[Sync] Implements the loopback sync server.

components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc

Index: components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
diff --git a/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc b/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
new file mode 100644
index 0000000000000000000000000000000000000000..decea55998e14bf19fe273db197bd365098b5b22
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+++ b/components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc
@@ -0,0 +1,127 @@
+// Copyright 2014 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 "components/sync/engine_impl/loopback_server/persistent_permanent_entity.h"
+
+#include <memory>
+#include <string>
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "components/sync/base/model_type.h"
+#include "components/sync/engine_impl/loopback_server/loopback_server_entity.h"
+#include "components/sync/protocol/sync.pb.h"
+
+using std::string;
+
+using syncer::ModelType;
+
+namespace {
+// The parent tag for children of the root entity. Entities with this parent are
+// referred to as top level enities.
+static const char kRootParentTag[] = "0";
+}  // namespace
+
+namespace syncer {
+
+PersistentPermanentEntity::~PersistentPermanentEntity() {}
+
+// static
+std::unique_ptr<LoopbackServerEntity> PersistentPermanentEntity::Create(
+    const ModelType& model_type,
+    const string& server_tag,
+    const string& name,
+    const string& parent_server_tag) {
+  CHECK(model_type != syncer::UNSPECIFIED) << "The entity's ModelType is "
+                                           << "invalid.";
+  CHECK(!server_tag.empty())
+      << "A PersistentPermanentEntity must have a server tag.";
+  CHECK(!name.empty()) << "The entity must have a non-empty name.";
+  CHECK(!parent_server_tag.empty())
+      << "A PersistentPermanentEntity must have a parent "
+      << "server tag.";
+  CHECK(parent_server_tag != kRootParentTag) << "Top-level entities should not "
+                                             << "be created with this factory.";
+
+  string id = LoopbackServerEntity::CreateId(model_type, server_tag);
+  string parent_id =
+      LoopbackServerEntity::CreateId(model_type, parent_server_tag);
+  sync_pb::EntitySpecifics entity_specifics;
+  AddDefaultFieldValue(model_type, &entity_specifics);
+  return std::unique_ptr<LoopbackServerEntity>(new PersistentPermanentEntity(
+      id, 0, model_type, name, parent_id, server_tag, entity_specifics));
+}
+
+// static
+std::unique_ptr<LoopbackServerEntity> PersistentPermanentEntity::CreateTopLevel(
+    const ModelType& model_type) {
+  CHECK(model_type != syncer::UNSPECIFIED) << "The entity's ModelType is "
+                                           << "invalid.";
+  string server_tag = syncer::ModelTypeToRootTag(model_type);
+  string name = syncer::ModelTypeToString(model_type);
+  string id = LoopbackServerEntity::GetTopLevelId(model_type);
+  sync_pb::EntitySpecifics entity_specifics;
+  AddDefaultFieldValue(model_type, &entity_specifics);
+  return std::unique_ptr<LoopbackServerEntity>(new PersistentPermanentEntity(
+      id, 0, model_type, name, kRootParentTag, server_tag, entity_specifics));
+}
+
+// static
+std::unique_ptr<LoopbackServerEntity>
+PersistentPermanentEntity::CreateUpdatedNigoriEntity(
+    const sync_pb::SyncEntity& client_entity,
+    const LoopbackServerEntity& current_server_entity) {
+  ModelType model_type = current_server_entity.GetModelType();
+  CHECK(model_type == syncer::NIGORI) << "This factory only supports NIGORI "
+                                      << "entities.";
+
+  return base::WrapUnique<LoopbackServerEntity>(new PersistentPermanentEntity(
+      current_server_entity.GetId(), current_server_entity.GetVersion(),
+      model_type, current_server_entity.GetName(),
+      current_server_entity.GetParentId(),
+      syncer::ModelTypeToRootTag(model_type), client_entity.specifics()));
+}
+
+PersistentPermanentEntity::PersistentPermanentEntity(
+    const string& id,
+    int64_t version,
+    const ModelType& model_type,
+    const string& name,
+    const string& parent_id,
+    const string& server_defined_unique_tag,
+    const sync_pb::EntitySpecifics& specifics)
+    : LoopbackServerEntity(id, model_type, version, name),
+      server_defined_unique_tag_(server_defined_unique_tag),
+      parent_id_(parent_id) {
+  SetSpecifics(specifics);
+}
+
+bool PersistentPermanentEntity::RequiresParentId() const {
+  return true;
+}
+
+string PersistentPermanentEntity::GetParentId() const {
+  return parent_id_;
+}
+
+void PersistentPermanentEntity::SerializeAsProto(
+    sync_pb::SyncEntity* proto) const {
+  LoopbackServerEntity::SerializeBaseProtoFields(proto);
+  proto->set_server_defined_unique_tag(server_defined_unique_tag_);
+}
+
+bool PersistentPermanentEntity::IsFolder() const {
+  return true;
+}
+
+bool PersistentPermanentEntity::IsPermanent() const {
+  return true;
+}
+
+sync_pb::LoopbackServerEntity_Type
+PersistentPermanentEntity::GetLoopbackServerEntityType() const {
+  return sync_pb::LoopbackServerEntity_Type_PERMANENT;
+}
+
+}  // namespace syncer