Google OAuth Device Flow support for FNL

services/authentication/accounts_db_manager.h

+// Copyright 2015 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.
+
+#ifndef SERVICES_AUTHENTICATION_ACCOUNTS_DB_MANAGER_H_
+#define SERVICES_AUTHENTICATION_ACCOUNTS_DB_MANAGER_H_
+
+#include <type_traits>
+
+#include "base/macros.h"
+#include "mojo/services/files/interfaces/files.mojom.h"
+#include "services/authentication/authentication_impl_db.mojom.h"
+
+namespace authentication {
+
+// Implementation of user account management service on systems like FNL. This
+// uses native mojo files service as the underlying mechanism to store user
+// credentials and supports operations such as to add a new user account, update
+// existing user credentials and fetching current credentials for a given user.
+class AccountsDbManager {
+ public:
+  AccountsDbManager();
+  explicit AccountsDbManager(const mojo::files::DirectoryPtr directory);

[qsr, 2016/02/16 14:17:06]

Can you add some comment about those 2 constructors. When should the first one
be used?

[ukode, 2016/02/26 21:35:50]

Got rid of one constructor.

+  ~AccountsDbManager();
+  // Updates or adds new auth credentials for a given user account.
+  void UpdateAccount(const mojo::String& username,
+                     const mojo::String& account_data);
+  // Fetches auth credentials for a given user account.
+  mojo::String GetAccountDataForUser(const mojo::String& username);
+  // Fetches auth credentials for all user accounts.
+  mojo::String GetAllUserAccounts();

[qsr, 2016/02/16 14:17:06]

What is the return value?

[ukode, 2016/02/26 21:35:50]

Made this to return an array of usernames instead. Pls check teh refactored
code.

+  // Returns previously used account name for the given application or null if
+  // not found.
+  mojo::String GetAuthorizedUserForApp(mojo::String app_url);
+  // Updates the grants database for the given application and username.
+  void UpdateAuthorization(mojo::String app_url, mojo::String username);
+
+ private:
+  // Generates new contents of the accounts database during an update operation.
+  // Performs one of the two operations:
+  //   1. If the user already exists, updates the existing record in database.
+  //   2. If its a new user, adds a new record to the existing database content.
+  mojo::String GetUpdatedDbContents(const mojo::String& username,
+                                    const mojo::String& new_account_data,
+                                    bool user_exists);
+  // Populates contents with existing user credentials.
+  void Initialize();
+  // Reads from credentials file and populates in-memory contents cache.
+  void OnReadResponse(const mojo::files::Error error,
+                      const mojo::Array<uint8_t> bytes_read);
+  // Parses response from credentials file write operation
+  void OnWriteResponse(const mojo::files::Error error,
+                       const uint32_t num_bytes_written);
+  // Reads from auth file and populates in-memory grants cache.
+  void OnAuthFileReadResponse(const mojo::files::Error error,
+                              const mojo::Array<uint8_t> bytes_read);
+  // Parses response from auth file write operation
+  void OnAuthFileWriteResponse(const mojo::files::Error error,
+                               const uint32_t num_bytes_written);
+
+  // File pointer to the stored account credentials db file.
+  mojo::files::FilePtr creds_db_file_;
+  // File pointer to the list of authorized modules.
+  mojo::files::FilePtr auth_db_file_;
+  // Stores the cached account data for all users.

[qsr, 2016/02/16 14:17:06]

What is the format of this string?

[ukode, 2016/02/26 21:35:50]

removed this completely. Made it a credentials db struct.

+  std::string contents_;
+  // In-memory store for list of authorized apps.
+  authentication::Db auth_grants;

[qsr, 2016/02/16 14:17:06]

auth_grants_

[ukode, 2016/02/26 21:35:49]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(AccountsDbManager);
+};
+
+}  // namespace authentication
+
+#endif  // SERVICES_AUTHENTICATION_ACCOUNTS_DB_MANAGER_H_