Signed settings refactoring: Proper caching and more tests.

chrome/browser/chromeos/device_settings_provider.h

+// Copyright (c) 2011 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 CHROME_BROWSER_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_
+#define CHROME_BROWSER_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/hash_tables.h"
+#include "chrome/browser/chromeos/cros_settings_provider.h"
+#include "chrome/browser/chromeos/login/signed_settings_helper.h"
+#include "chrome/browser/chromeos/signed_settings_migration_helper.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+#include "content/public/browser/notification_registrar.h"
+
+namespace em = enterprise_management;
+
+class PrefService;
+
+namespace base {
+class ListValue;
+}
+
+namespace chromeos {
+
+class OwnershipService;
+
+// CrosSettingsProvider implementation that works with SignedSettings.
+class DeviceSettingsProvider : public CrosSettingsProvider,
+                               public content::NotificationObserver {
+ public:
+  DeviceSettingsProvider();
+  virtual ~DeviceSettingsProvider();
+
+  // CrosSettingsProvider implementation.
+  virtual const base::Value* Get(const std::string& path) const OVERRIDE;
+  virtual bool GetTrusted(const std::string& path,
+                          const base::Closure& callback) OVERRIDE;
+  virtual bool HandlesSetting(const std::string& path) const OVERRIDE;
+  virtual void Reload() OVERRIDE;
+
+ private:
+  // CrosSettingsProvider implementation:
+  virtual void DoSet(const std::string& path,
+                     const base::Value& value) OVERRIDE;
+
+  // content::NotificationObserver implementation:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  const em::PolicyData policy() const;
+
+  // Populates in-memory cache from the local_state cache that is used to store
+  // signed settings before the device is owned and to speed up policy
+  // availability before the policy blob is fetched on boot.
+  void RetrieveCachedData();
+
+  // Stores a value in the signed settings. If the device is not owned yet the
+  // data ends up only in the local_state cache and is serialized once ownership
+  // is acquired.
+  void SetInPolicy(const std::string& prop, const base::Value& value);
+
+  // Finalizes stores to the policy file if the cache is dirty.
+  void FinishSetInPolicy(const std::string& prop,
+                         const base::Value* value,
+                         SignedSettings::ReturnCode code,
+                         const em::PolicyFetchResponse& policy);
+
+  // Parses the policy cache and fills the cache of base::Value objects.
+  void UpdateValuesCache();
+
+  // Applies the metrics policy and if not set migrates the legacy file.
+  void ApplyMetricsSetting(bool use_file, bool new_value) const;
+
+  // Applies the data roaming policy.
+  void ApplyRoamingSetting(bool new_value) const;
+
+  // Applies any changes of the policies that are not handled by the respective
+  // subsystms.
+  void ApplySideEffects() const;
+
+  // Called right before boolean property is changed.
+  void OnBooleanPropertyChange(const std::string& path, bool new_value);
+
+  // Checks if the current cache value can be trusted for being representative
+  // for the disk cache.
+  bool RequestTrustedEntity();
+
+  // Called right after signed value was checked.
+  void OnPropertyRetrieve(const std::string& path,
+                          const base::Value* value,
+                          bool use_default_value);
+
+  // Callback of StorePolicyOp for ordinary policy stores.
+  void OnStorePolicyCompleted(SignedSettings::ReturnCode code);
+
+  // Callback of RetrievePolicyOp for ordinary policy [re]loads.
+  void OnRetrievePolicyCompleted(SignedSettings::ReturnCode code,
+                                 const em::PolicyFetchResponse& policy);
+
+  // Pending callbacks that need to be invoked after settings verification.
+  std::vector<base::Closure> callbacks_;
+
+  OwnershipService::Status ownership_status_;
+  mutable scoped_ptr<SignedSettingsMigrationHelper> migration_helper_;
+
+  content::NotificationRegistrar registrar_;
+
+  // In order to guard against occasional failure to fetch a property
+  // we allow for some number of retries.
+  int retries_left_;
+
+  em::PolicyData policy_;
+  bool trusted_;
+
+  PrefValueMap values_cache_;
+
+  friend class SignedSettingsHelper;
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceSettingsProvider);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_DEVICE_SETTINGS_PROVIDER_H_