mojo leveldb: Get profile and leveldb connected to DOMStorageContext.

components/profile_service/profile_app.cc

 // Copyright 2016 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/profile_service/profile_app.h"
 
-#include "base/lazy_instance.h"
+#include "base/bind.h"
+#include "base/memory/weak_ptr.h"
+#include "components/filesystem/lock_table.h"
 #include "components/leveldb/leveldb_service_impl.h"
 #include "components/profile_service/profile_service_impl.h"
+#include "components/profile_service/user_id_map.h"
+#include "mojo/public/cpp/bindings/callback.h"
 #include "mojo/shell/public/cpp/connection.h"
 
 namespace profile {
 
-namespace {
+class ProfileApp::ProfileServiceObjects
+    : public base::SupportsWeakPtr<ProfileServiceObjects> {
+ public:
+  // Created on the main thread.
+  ProfileServiceObjects(base::FilePath profile_data_dir)
+      : profile_data_dir_(profile_data_dir) {}
 
-base::LazyInstance<std::map<std::string, base::FilePath>>
-    g_user_id_to_data_dir = LAZY_INSTANCE_INITIALIZER;
+  // Destroyed on the |profile_service_runner_|.
+  ~ProfileServiceObjects() {}
 
-}  // namespace
+  // Called on the |profile_service_runner_|.
+  void OnProfileServiceRequest(mojo::Connection* connection,
+                               ProfileServiceRequest request) {
+    if (!lock_table_)
+      lock_table_ = new filesystem::LockTable;
+    profile_service_bindings_.AddBinding(
+        new ProfileServiceImpl(profile_data_dir_, lock_table_),
+        std::move(request));
+  }
 
-scoped_ptr<mojo::ShellClient> CreateProfileApp() {
-  return make_scoped_ptr(new ProfileApp);
+ private:
+  mojo::BindingSet<ProfileService> profile_service_bindings_;
+  scoped_refptr<filesystem::LockTable> lock_table_;
+  base::FilePath profile_data_dir_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProfileServiceObjects);
+};
+
+class ProfileApp::LevelDBServiceObjects

[michaeln, 2016/03/17 22:35:41]

nice arrangement for thread safety!

+    : public base::SupportsWeakPtr<LevelDBServiceObjects> {
+ public:
+  // Created on the main thread.
+  LevelDBServiceObjects() {}
+
+  // Destroyed on the |leveldb_service_runner_|.
+  ~LevelDBServiceObjects() {}
+
+  // Called on the |leveldb_service_runner_|.
+  void OnLevelDBServiceRequest(mojo::Connection* connection,
+                               leveldb::LevelDBServiceRequest request) {
+    if (!leveldb_service_)
+      leveldb_service_.reset(new leveldb::LevelDBServiceImpl);

[michaeln, 2016/03/17 22:35:41]

does this direct instantiation mean we're not using the LevelDBApp? just
curious?

[Elliot Glaysher, 2016/03/18 19:41:12]

Correct. Apps don't contain other apps. Apps contain services. And the services
should be arranged in a way that they're reusable across apps.

(If you look at components/leveldb/BUILD.gn, you'll see we don't even compile
the LevelDBApp into the general library.)

+    leveldb_bindings_.AddBinding(leveldb_service_.get(), std::move(request));
+  }
+
+ private:
+  // Variables that are only accessible on the |leveldb_service_runner_| thread.
+  scoped_ptr<leveldb::LevelDBService> leveldb_service_;
+  mojo::BindingSet<leveldb::LevelDBService> leveldb_bindings_;
+
+  DISALLOW_COPY_AND_ASSIGN(LevelDBServiceObjects);
+};
+
+scoped_ptr<mojo::ShellClient> CreateProfileApp(
+    const scoped_refptr<base::SingleThreadTaskRunner>& profile_service_runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& leveldb_service_runner) {
+  return make_scoped_ptr(
+      new ProfileApp(profile_service_runner, leveldb_service_runner));
 }
 
-ProfileApp::ProfileApp()
-    : lock_table_(new filesystem::LockTable) {
-}
+ProfileApp::ProfileApp(
+    const scoped_refptr<base::SingleThreadTaskRunner>& profile_service_runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& leveldb_service_runner)
+    : profile_service_runner_(profile_service_runner),
+      leveldb_service_runner_(leveldb_service_runner) {}
 
-ProfileApp::~ProfileApp() {}
-
-// static
-void ProfileApp::AssociateMojoUserIDWithProfileDir(
-    const std::string& user_id,
-    const base::FilePath& profile_data_dir) {
-  g_user_id_to_data_dir.Get()[user_id] = profile_data_dir;
+ProfileApp::~ProfileApp() {
+  profile_service_runner_->DeleteSoon(FROM_HERE, profile_objects_.release());
+  leveldb_service_runner_->DeleteSoon(FROM_HERE, leveldb_objects_.release());
 }
 
 void ProfileApp::Initialize(mojo::Connector* connector,
                             const mojo::Identity& identity,
                             uint32_t id) {
   tracing_.Initialize(connector, identity.name());
-  leveldb_service_.reset(new leveldb::LevelDBServiceImpl);
-
-  auto it = g_user_id_to_data_dir.Get().find(identity.user_id());
-  DCHECK(it != g_user_id_to_data_dir.Get().end());
-  profile_data_dir_ = it->second;
+  profile_objects_.reset(new ProfileApp::ProfileServiceObjects(
+      GetProfileDirForUserID(identity.user_id())));
+  leveldb_objects_.reset(new ProfileApp::LevelDBServiceObjects);
 }
 
 bool ProfileApp::AcceptConnection(mojo::Connection* connection) {
   connection->AddInterface<leveldb::LevelDBService>(this);
   connection->AddInterface<ProfileService>(this);
   return true;
 }
 
 void ProfileApp::Create(mojo::Connection* connection,
                         ProfileServiceRequest request) {
-  // No, we need one of these per connection.
-  new ProfileServiceImpl(connection,
-                         std::move(request),
-                         profile_data_dir_,
-                         lock_table_.get());
+  profile_service_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ProfileApp::ProfileServiceObjects::OnProfileServiceRequest,
+                 profile_objects_->AsWeakPtr(), connection,
+                 base::Passed(&request)));
 }
 
 void ProfileApp::Create(mojo::Connection* connection,
                         leveldb::LevelDBServiceRequest request) {
-  leveldb_bindings_.AddBinding(leveldb_service_.get(), std::move(request));
+  leveldb_service_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&ProfileApp::LevelDBServiceObjects::OnLevelDBServiceRequest,
+                 leveldb_objects_->AsWeakPtr(), connection,
+                 base::Passed(&request)));
 }
 
 }  // namespace profile