G-services settings v3 implementation

google_apis/gcm/engine/gservices_settings.h

 // 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.
 
 #ifndef GOOGLE_APIS_GCM_ENGINE_GSERVICES_SETTINGS_H_
 #define GOOGLE_APIS_GCM_ENGINE_GSERVICES_SETTINGS_H_
 
 #include <map>
 #include <string>
 
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "google_apis/gcm/base/gcm_export.h"
 #include "google_apis/gcm/engine/gcm_store.h"
 #include "google_apis/gcm/protocol/checkin.pb.h"
 #include "url/gurl.h"
 
 namespace gcm {
 
 // Class responsible for handling G-services settings. It takes care of
 // extracting them from checkin response and storing in GCMStore.
 class GCM_EXPORT GServicesSettings {
  public:
+  typedef std::map<std::string, std::string> SettingsMap;

[jianli, 2014/05/13 21:41:52]

nit: empty line

[fgorski, 2014/05/13 23:53:28]

Done.

   // Minimum periodic checkin interval in seconds.
   static const base::TimeDelta MinimumCheckinInterval();
 
   // Default checkin URL.
   static const GURL DefaultCheckinURL();
 
+  // Calculates digest of provided settings.
+  static std::string CalculateDigest(const SettingsMap& settings);
+
   GServicesSettings();
   ~GServicesSettings();
 
   // Updates the settings based on |checkin_response|.
   bool UpdateFromCheckinResponse(
       const checkin_proto::AndroidCheckinResponse& checkin_response);
 
   // Updates the settings based on |load_result|. Returns true if update was
   // successful, false otherwise.
   void UpdateFromLoadResult(const GCMStore::LoadResult& load_result);
 
   // Gets the settings as a map of string to string for storing.
-  std::map<std::string, std::string> GetSettingsMap() const;
+  SettingsMap GetSettingsMap() const;
 
   std::string digest() const { return digest_; }
 
-  base::TimeDelta checkin_interval() const { return checkin_interval_; }
+  // Gets the interval at which device should perform a checkin.
+  base::TimeDelta checkin_interval() const;

[jianli, 2014/05/13 21:41:52]

Since now we provide more complicated implementation, it would be better to
define it as a normal method, instead of getter. Probably something like
GetCheckinInterval. 

[fgorski, 2014/05/13 23:53:28]

Done. Applied that to all settings, as they all have similar level of complexity
in implementation

 
-  GURL checkin_url() const { return checkin_url_; }
+  // Gets a URL to use when checkin in.
+  GURL checkin_url() const;
 
-  GURL mcs_main_endpoint() const { return mcs_main_endpoint_; }
+  // Gets address of main MCS endpoint.
+  GURL mcs_main_endpoint() const;
 
-  GURL mcs_fallback_endpoint() const { return mcs_fallback_endpoint_; }
+  // Gets address of fallback MCS endpoint.
+  GURL mcs_fallback_endpoint() const;
 
-  GURL registration_url() const { return registration_url_; }
+  // Gets a URL to use when registering or unregistering the apps.
+  GURL registration_url() const;
 
  private:
   // Parses the |settings| to fill in specific fields.
   // TODO(fgorski): Change to a status variable that can be logged to UMA.
-  bool UpdateSettings(const std::map<std::string, std::string>& settings);
+  bool UpdateSettings(const SettingsMap& settings);
+
+  // Functions to verify correctnes of newly proposed settings.
+  bool VerifySettings(const SettingsMap& settings) const;
+  bool VerifyCheckinInterval(const SettingsMap& settings) const;
+  bool VerifyCheckinURL(const SettingsMap& settings) const;
+  bool VerifyMCSEndpoint(const SettingsMap& settings) const;
+  bool VerifyRegistrationURL(const SettingsMap& settings) const;
+
+  // Settings digest verification.
+  bool VerifyDigest(const SettingsMap& settings,
+                    const std::string& expected_digest) const;
 
   // Digest (hash) of the settings, used to check whether settings need update.
   // It is meant to be sent with checkin request, instead of sending the whole
   // settings table.
   std::string digest_;
 
-  // Time delta between periodic checkins.
-  base::TimeDelta checkin_interval_;
-
-  // URL that should be used for checkins.
-  GURL checkin_url_;
-
-  // Main MCS endpoint.
-  GURL mcs_main_endpoint_;
-
-  // Fallback MCS endpoint.
-  GURL mcs_fallback_endpoint_;
-
-  // URL that should be used for regisrations and unregistrations.
-  GURL registration_url_;
+  // G-services settings as provided by checkin response.
+  SettingsMap settings_;
 
   // Factory for creating references in callbacks.
   base::WeakPtrFactory<GServicesSettings> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GServicesSettings);
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_ENGINE_GSERVICES_SETTINGS_H_