[GCM] Adding basic G-services handling

google_apis/gcm/engine/gcm_store_impl.cc

 // 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 "google_apis/gcm/engine/gcm_store_impl.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/sequenced_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
+#include "base/time/time.h"
 #include "base/tracked_objects.h"
 #include "components/os_crypt/os_crypt.h"
 #include "google_apis/gcm/base/mcs_message.h"
 #include "google_apis/gcm/base/mcs_util.h"
 #include "google_apis/gcm/protocol/mcs.pb.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
+#include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
 
 namespace gcm {
 
 namespace {
 
 // Limit to the number of outstanding messages per app.
 const int kMessagesPerAppLimit = 20;
 
 // ---- LevelDB keys. ----
 // Key for this device's android id.
@@ skipping 11 matching lines @@
 const char kIncomingMsgKeyStart[] = "incoming1-";
 // Key guaranteed to be higher than all incoming message keys.
 // Used for limiting iteration.
 const char kIncomingMsgKeyEnd[] = "incoming2-";
 // Lowest lexicographically ordered outgoing message key.
 // Used for prefixing outgoing messages.
 const char kOutgoingMsgKeyStart[] = "outgoing1-";
 // Key guaranteed to be higher than all outgoing message keys.
 // Used for limiting iteration.
 const char kOutgoingMsgKeyEnd[] = "outgoing2-";
+// Lowest lexicographically ordered G service settings key.
+// Used for prefixing G services settings.
+const char kGServiceSettingKeyStart[] = "Gservice1-";
+// Key guaranteed to be higher than all G services settings keys.
+// Used for limiting iteration.
+const char kGServiceSettingKeyEnd[] = "Gservice2-";
+// Key used to timestamp last checkin (marked with G services settings update).
+const char kLastCheckinTimeKey[] = "last_checkin_time";
 
 std::string MakeRegistrationKey(const std::string& app_id) {
   return kRegistrationKeyStart + app_id;
 }
 
 std::string ParseRegistrationKey(const std::string& key) {
   return key.substr(arraysize(kRegistrationKeyStart) - 1);
 }
 
 std::string MakeIncomingKey(const std::string& persistent_id) {
   return kIncomingMsgKeyStart + persistent_id;
 }
 
 std::string MakeOutgoingKey(const std::string& persistent_id) {
   return kOutgoingMsgKeyStart + persistent_id;
 }
 
 std::string ParseOutgoingKey(const std::string& key) {
   return key.substr(arraysize(kOutgoingMsgKeyStart) - 1);
 }
 
+std::string MakeGServiceSettingKey(const std::string& setting_name) {
+  return kGServiceSettingKeyStart + setting_name;
+}
+
+std::string ParseGServiceSettingKey(const std::string& key) {
+  return key.substr(arraysize(kGServiceSettingKeyStart) - 1);
+}
+
 // Note: leveldb::Slice keeps a pointer to the data in |s|, which must therefore
 // outlive the slice.
 // For example: MakeSlice(MakeOutgoingKey(x)) is invalid.
 leveldb::Slice MakeSlice(const base::StringPiece& s) {
   return leveldb::Slice(s.begin(), s.size());
 }
 
 }  // namespace
 
 class GCMStoreImpl::Backend
@@ skipping 24 matching lines @@
   void RemoveOutgoingMessages(
       const PersistentIdList& persistent_ids,
       const base::Callback<void(bool, const AppIdToMessageCountMap&)>
           callback);
   void AddUserSerialNumber(const std::string& username,
                            int64 serial_number,
                            const UpdateCallback& callback);
   void RemoveUserSerialNumber(const std::string& username,
                               const UpdateCallback& callback);
   void SetNextSerialNumber(int64 serial_number, const UpdateCallback& callback);
+  void UpdateGServicesSettings(
+      const std::vector<std::string>& settings_to_remove,
+      const std::map<std::string, std::string>& settings_to_add,
+      const base::Time& last_checkin_time,
+      const UpdateCallback& callback);
 
  private:
   friend class base::RefCountedThreadSafe<Backend>;
   ~Backend();
 
   bool LoadDeviceCredentials(uint64* android_id, uint64* security_token);
   bool LoadRegistrations(RegistrationInfoMap* registrations);
   bool LoadIncomingMessages(std::vector<std::string>* incoming_messages);
   bool LoadOutgoingMessages(OutgoingMessageMap* outgoing_messages);
+  bool LoadGServicesSettings(std::map<std::string, std::string>* settings,
+                             base::Time* last_checkin_time);
 
   const base::FilePath path_;
   scoped_refptr<base::SequencedTaskRunner> foreground_task_runner_;
 
   scoped_ptr<leveldb::DB> db_;
 };
 
 GCMStoreImpl::Backend::Backend(
     const base::FilePath& path,
     scoped_refptr<base::SequencedTaskRunner> foreground_task_runner)
@@ skipping 24 matching lines @@
                                       base::Bind(callback,
                                                  base::Passed(&result)));
     return;
   }
   db_.reset(db);
 
   if (!LoadDeviceCredentials(&result->device_android_id,
                              &result->device_security_token) ||
       !LoadRegistrations(&result->registrations) ||
       !LoadIncomingMessages(&result->incoming_messages) ||
-      !LoadOutgoingMessages(&result->outgoing_messages)) {
+      !LoadOutgoingMessages(&result->outgoing_messages) ||
+      !LoadGServicesSettings(&result->gservices_settings,
+                             &result->last_checkin_time)) {
     result->device_android_id = 0;
     result->device_security_token = 0;
     result->registrations.clear();
     result->incoming_messages.clear();
     result->outgoing_messages.clear();
+    result->last_checkin_time = base::Time::FromInternalValue(0LL);
     foreground_task_runner_->PostTask(FROM_HERE,
                                       base::Bind(callback,
                                                  base::Passed(&result)));
     return;
   }
 
   // Only record histograms if GCM had already been set up for this device.
   if (result->device_android_id != 0 && result->device_security_token != 0) {
     int64 file_size = 0;
     if (base::GetFileSize(path_, &file_size)) {
@@ skipping 248 matching lines @@
                                                  removed_message_counts));
     return;
   }
   LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
   foreground_task_runner_->PostTask(FROM_HERE,
                                     base::Bind(callback,
                                                false,
                                                AppIdToMessageCountMap()));
 }
 
+void GCMStoreImpl::Backend::UpdateGServicesSettings(

[jianli, 2014/03/31 17:45:35]

It seems that the whole update logic becomes quite complicated. Could we just
save/load the settings as a whole? Or even better, could we just save/load a
particular setting value we have interest, like checkin interval, if we are sure
we only need this?

[fgorski, 2014/03/31 21:50:08]

Done, this has been simplified based on our conversation to replace the whole
set of settings every time. That way we support both the old and new version of
the checkin protocol. For now it is version 2

+    const std::vector<std::string>& settings_to_remove,
+    const std::map<std::string, std::string>& settings_to_add,
+    const base::Time& last_checkin_time,
+    const UpdateCallback& callback) {
+  leveldb::WriteBatch write_batch;
+
+  // Delete settings to remove.
+  for (std::vector<std::string>::const_iterator iter =
+           settings_to_remove.begin();
+       iter != settings_to_remove.end(); ++iter) {
+    write_batch.Delete(MakeSlice(MakeGServiceSettingKey(*iter)));
+  }
+
+  // Add settings to add.
+  for (std::map<std::string, std::string>::const_iterator iter =
+           settings_to_add.begin();
+       iter != settings_to_add.end(); ++iter) {
+    write_batch.Put(MakeSlice(MakeGServiceSettingKey(iter->first)),
+                    MakeSlice(iter->second));
+  }
+
+  // Update last checkin time.
+  int64 last_checkin_time_internal = last_checkin_time.ToInternalValue();
+  write_batch.Put(MakeSlice(kLastCheckinTimeKey),
+                  MakeSlice(base::Int64ToString(last_checkin_time_internal)));
+
+  // Write it all in batch.
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  leveldb::Status s = db_->Write(write_options, &write_batch);
+  if (!s.ok())
+    LOG(ERROR) << "LevelDB GService Settings update failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, s.ok()));
+}
+
 bool GCMStoreImpl::Backend::LoadDeviceCredentials(uint64* android_id,
                                                   uint64* security_token) {
   leveldb::ReadOptions read_options;
   read_options.verify_checksums = true;
 
   std::string result;
   leveldb::Status s = db_->Get(read_options, MakeSlice(kDeviceAIDKey), &result);
   if (s.ok()) {
     if (!base::StringToUint64(result, android_id)) {
       LOG(ERROR) << "Failed to restore device id.";
@@ skipping 95 matching lines @@
       return false;
     }
     DVLOG(1) << "Found outgoing message with id " << id << " of type "
              << base::IntToString(tag);
     (*outgoing_messages)[id] = make_linked_ptr(message.release());
   }
 
   return true;
 }
 
+bool GCMStoreImpl::Backend::LoadGServicesSettings(
+    std::map<std::string, std::string>* settings,
+    base::Time* last_checkin_time) {
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;
+
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
+  for (iter->Seek(MakeSlice(kGServiceSettingKeyStart));
+       iter->Valid() && iter->key().ToString() < kGServiceSettingKeyEnd;
+       iter->Next()) {
+    std::string value = iter->value().ToString();
+    if (value.empty()) {
+      LOG(ERROR) << "Error reading GService Settings " << value;
+      return false;
+    }
+    std::string id = ParseGServiceSettingKey(iter->key().ToString());
+    (*settings)[id] = value;
+    DVLOG(1) << "Found G Service setting with key: " << id
+             << ", and value: " << value;
+  }
+
+  std::string result;
+  leveldb::Status s = db_->Get(read_options,
+                               MakeSlice(kLastCheckinTimeKey),
+                               &result);
+  int64 time_internal = 0LL;
+  if (s.ok()) {
+    if (!base::StringToInt64(result, &time_internal)) {
+      LOG(ERROR) << "Failed to restore last checkin time.";
+      return false;
+    }
+  }
+
+  // In case we cannot read last checkin time, we default it to 0, as we don't
+  // want that situation to cause the whole load to fail.
+  *last_checkin_time = base::Time::FromInternalValue(time_internal);
+
+  return true;
+}
+
 GCMStoreImpl::GCMStoreImpl(
     bool use_mock_keychain,
     const base::FilePath& path,
     scoped_refptr<base::SequencedTaskRunner> blocking_task_runner)
     : backend_(new Backend(path, base::MessageLoopProxy::current())),
       blocking_task_runner_(blocking_task_runner),
       weak_ptr_factory_(this) {
 // On OSX, prevent the Keychain permissions popup during unit tests.
 #if defined(OS_MACOSX)
   OSCrypt::UseMockKeychain(use_mock_keychain);
@@ skipping 154 matching lines @@
   blocking_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&GCMStoreImpl::Backend::RemoveOutgoingMessages,
                  backend_,
                  persistent_ids,
                  base::Bind(&GCMStoreImpl::RemoveOutgoingMessagesContinuation,
                             weak_ptr_factory_.GetWeakPtr(),
                             callback)));
 }
 
+void GCMStoreImpl::UpdateGServicesSettings(
+    const std::vector<std::string>& settings_to_remove,
+    const std::map<std::string, std::string>& settings_to_add,
+    const base::Time& last_checkin_time,
+    const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&GCMStoreImpl::Backend::UpdateGServicesSettings,
+                 backend_,
+                 settings_to_remove,
+                 settings_to_add,
+                 last_checkin_time,
+                 callback));
+}
+
 void GCMStoreImpl::LoadContinuation(const LoadCallback& callback,
                                     scoped_ptr<LoadResult> result) {
   if (!result->success) {
     callback.Run(result.Pass());
     return;
   }
   int num_throttled_apps = 0;
   for (OutgoingMessageMap::const_iterator
            iter = result->outgoing_messages.begin();
        iter != result->outgoing_messages.end(); ++iter) {
@@ skipping 34 matching lines @@
            removed_message_counts.begin();
        iter != removed_message_counts.end(); ++iter) {
     DCHECK_NE(app_message_counts_.count(iter->first), 0U);
     app_message_counts_[iter->first] -= iter->second;
     DCHECK_GE(app_message_counts_[iter->first], 0);
   }
   callback.Run(true);
 }
 
 }  // namespace gcm