src/google_apis/gcm/engine/gcm_store_impl.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "google_apis/gcm/engine/gcm_store_impl.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/bind.h"
   9 #include "base/callback.h"
  10 #include "base/file_util.h"
  11 #include "base/files/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/message_loop/message_loop_proxy.h"
  14 #include "base/metrics/histogram.h"
  15 #include "base/sequenced_task_runner.h"
  16 #include "base/stl_util.h"
  17 #include "base/strings/string_number_conversions.h"
  18 #include "base/strings/string_piece.h"
  19 #include "base/tracked_objects.h"
  20 #include "components/webdata/encryptor/encryptor.h"
  21 #include "google_apis/gcm/base/mcs_message.h"
  22 #include "google_apis/gcm/base/mcs_util.h"
  23 #include "google_apis/gcm/protocol/mcs.pb.h"
  24 #include "third_party/leveldatabase/src/include/leveldb/db.h"
  25
  26 namespace gcm {
  27
  28 namespace {
  29
  30 // Limit to the number of outstanding messages per app.
  31 const int kMessagesPerAppLimit = 20;
  32
  33 // ---- LevelDB keys. ----
  34 // Key for this device's android id.
  35 const char kDeviceAIDKey[] = "device_aid_key";
  36 // Key for this device's android security token.
  37 const char kDeviceTokenKey[] = "device_token_key";
  38 // Lowest lexicographically ordered incoming message key.
  39 // Used for prefixing messages.
  40 const char kIncomingMsgKeyStart[] = "incoming1-";
  41 // Key guaranteed to be higher than all incoming message keys.
  42 // Used for limiting iteration.
  43 const char kIncomingMsgKeyEnd[] = "incoming2-";
  44 // Key for next serial number assigned to the user.
  45 const char kNextSerialNumberKey[] = "next_serial_number_key";
  46 // Lowest lexicographically ordered outgoing message key.
  47 // Used for prefixing outgoing messages.
  48 const char kOutgoingMsgKeyStart[] = "outgoing1-";
  49 // Key guaranteed to be higher than all outgoing message keys.
  50 // Used for limiting iteration.
  51 const char kOutgoingMsgKeyEnd[] = "outgoing2-";
  52 // Lowest lexicographically ordered username.
  53 // Used for prefixing username to serial number mappings.
  54 const char kUserSerialNumberKeyStart[] = "user1-";
  55 // Key guaranteed to be higher than all usernames.
  56 // Used for limiting iteration.
  57 const char kUserSerialNumberKeyEnd[] = "user2-";
  58
  59 // Value indicating that serial number was not assigned.
  60 const int64 kSerialNumberMissing = -1LL;
  61
  62 std::string MakeIncomingKey(const std::string& persistent_id) {
  63   return kIncomingMsgKeyStart + persistent_id;
  64 }
  65
  66 std::string MakeOutgoingKey(const std::string& persistent_id) {
  67   return kOutgoingMsgKeyStart + persistent_id;
  68 }
  69
  70 std::string MakeUserSerialNumberKey(const std::string& username) {
  71   return kUserSerialNumberKeyStart + username;
  72 }
  73
  74 std::string ParseOutgoingKey(const std::string& key) {
  75   return key.substr(arraysize(kOutgoingMsgKeyStart) - 1);
  76 }
  77
  78 std::string ParseUsername(const std::string& key) {
  79   return key.substr(arraysize(kUserSerialNumberKeyStart) - 1);
  80 }
  81
  82 // Note: leveldb::Slice keeps a pointer to the data in |s|, which must therefore
  83 // outlive the slice.
  84 // For example: MakeSlice(MakeOutgoingKey(x)) is invalid.
  85 leveldb::Slice MakeSlice(const base::StringPiece& s) {
  86   return leveldb::Slice(s.begin(), s.size());
  87 }
  88
  89 }  // namespace
  90
  91 class GCMStoreImpl::Backend
  92     : public base::RefCountedThreadSafe<GCMStoreImpl::Backend> {
  93  public:
  94   Backend(const base::FilePath& path,
  95           scoped_refptr<base::SequencedTaskRunner> foreground_runner);
  96
  97   // Blocking implementations of GCMStoreImpl methods.
  98   void Load(const LoadCallback& callback);
  99   void Destroy(const UpdateCallback& callback);
 100   void SetDeviceCredentials(uint64 device_android_id,
 101                             uint64 device_security_token,
 102                             const UpdateCallback& callback);
 103   void AddIncomingMessage(const std::string& persistent_id,
 104                           const UpdateCallback& callback);
 105   void RemoveIncomingMessages(const PersistentIdList& persistent_ids,
 106                               const UpdateCallback& callback);
 107   void AddOutgoingMessage(const std::string& persistent_id,
 108                           const MCSMessage& message,
 109                           const UpdateCallback& callback);
 110   void RemoveOutgoingMessages(
 111       const PersistentIdList& persistent_ids,
 112       const base::Callback<void(bool, const AppIdToMessageCountMap&)>
 113           callback);
 114   void AddUserSerialNumber(const std::string& username,
 115                            int64 serial_number,
 116                            const UpdateCallback& callback);
 117   void RemoveUserSerialNumber(const std::string& username,
 118                               const UpdateCallback& callback);
 119   void SetNextSerialNumber(int64 serial_number, const UpdateCallback& callback);
 120
 121  private:
 122   friend class base::RefCountedThreadSafe<Backend>;
 123   ~Backend();
 124
 125   bool LoadDeviceCredentials(uint64* android_id, uint64* security_token);
 126   bool LoadIncomingMessages(std::vector<std::string>* incoming_messages);
 127   bool LoadOutgoingMessages(OutgoingMessageMap* outgoing_messages);
 128   bool LoadNextSerialNumber(int64* next_serial_number);
 129   bool LoadUserSerialNumberMap(
 130       std::map<std::string, int64>* user_serial_number_map);
 131
 132   const base::FilePath path_;
 133   scoped_refptr<base::SequencedTaskRunner> foreground_task_runner_;
 134
 135   scoped_ptr<leveldb::DB> db_;
 136 };
 137
 138 GCMStoreImpl::Backend::Backend(
 139     const base::FilePath& path,
 140     scoped_refptr<base::SequencedTaskRunner> foreground_task_runner)
 141     : path_(path), foreground_task_runner_(foreground_task_runner) {}
 142
 143 GCMStoreImpl::Backend::~Backend() {}
 144
 145 void GCMStoreImpl::Backend::Load(const LoadCallback& callback) {
 146   scoped_ptr<LoadResult> result(new LoadResult());
 147   if (db_.get()) {
 148     LOG(ERROR) << "Attempting to reload open database.";
 149     foreground_task_runner_->PostTask(FROM_HERE,
 150                                       base::Bind(callback,
 151                                                  base::Passed(&result)));
 152     return;
 153   }
 154
 155   leveldb::Options options;
 156   options.create_if_missing = true;
 157   leveldb::DB* db;
 158   leveldb::Status status =
 159       leveldb::DB::Open(options, path_.AsUTF8Unsafe(), &db);
 160   UMA_HISTOGRAM_BOOLEAN("GCM.LoadSucceeded", status.ok());
 161   if (!status.ok()) {
 162     LOG(ERROR) << "Failed to open database " << path_.value() << ": "
 163                << status.ToString();
 164     foreground_task_runner_->PostTask(FROM_HERE,
 165                                       base::Bind(callback,
 166                                                  base::Passed(&result)));
 167     return;
 168   }
 169   db_.reset(db);
 170
 171   if (!LoadDeviceCredentials(&result->device_android_id,
 172                              &result->device_security_token) ||
 173       !LoadIncomingMessages(&result->incoming_messages) ||
 174       !LoadOutgoingMessages(&result->outgoing_messages) ||
 175       !LoadNextSerialNumber(
 176            &result->serial_number_mappings.next_serial_number) ||
 177       !LoadUserSerialNumberMap(
 178            &result->serial_number_mappings.user_serial_numbers)) {
 179     result->device_android_id = 0;
 180     result->device_security_token = 0;
 181     result->incoming_messages.clear();
 182     result->outgoing_messages.clear();
 183     foreground_task_runner_->PostTask(FROM_HERE,
 184                                       base::Bind(callback,
 185                                                  base::Passed(&result)));
 186     return;
 187   }
 188
 189   // Only record histograms if GCM had already been set up for this device.
 190   if (result->device_android_id != 0 && result->device_security_token != 0) {
 191     int64 file_size = 0;
 192     if (base::GetFileSize(path_, &file_size)) {
 193       UMA_HISTOGRAM_COUNTS("GCM.StoreSizeKB",
 194                            static_cast<int>(file_size / 1024));
 195     }
 196     UMA_HISTOGRAM_COUNTS("GCM.RestoredOutgoingMessages",
 197                          result->outgoing_messages.size());
 198     UMA_HISTOGRAM_COUNTS("GCM.RestoredIncomingMessages",
 199                          result->incoming_messages.size());
 200     UMA_HISTOGRAM_COUNTS(
 201         "GCM.NumUsers",
 202         result->serial_number_mappings.user_serial_numbers.size());
 203   }
 204
 205   DVLOG(1) << "Succeeded in loading " << result->incoming_messages.size()
 206            << " unacknowledged incoming messages and "
 207            << result->outgoing_messages.size()
 208            << " unacknowledged outgoing messages.";
 209   result->success = true;
 210   foreground_task_runner_->PostTask(FROM_HERE,
 211                                     base::Bind(callback,
 212                                                base::Passed(&result)));
 213   return;
 214 }
 215
 216 void GCMStoreImpl::Backend::Destroy(const UpdateCallback& callback) {
 217   DVLOG(1) << "Destroying GCM store.";
 218   db_.reset();
 219   const leveldb::Status s =
 220       leveldb::DestroyDB(path_.AsUTF8Unsafe(), leveldb::Options());
 221   if (s.ok()) {
 222     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 223     return;
 224   }
 225   LOG(ERROR) << "Destroy failed: " << s.ToString();
 226   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 227 }
 228
 229 void GCMStoreImpl::Backend::SetDeviceCredentials(
 230     uint64 device_android_id,
 231     uint64 device_security_token,
 232     const UpdateCallback& callback) {
 233   DVLOG(1) << "Saving device credentials with AID " << device_android_id;
 234   if (!db_.get()) {
 235     LOG(ERROR) << "GCMStore db doesn't exist.";
 236     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 237     return;
 238   }
 239
 240   leveldb::WriteOptions write_options;
 241   write_options.sync = true;
 242
 243   std::string encrypted_token;
 244   Encryptor::EncryptString(base::Uint64ToString(device_security_token),
 245                            &encrypted_token);
 246   std::string android_id_str = base::Uint64ToString(device_android_id);
 247   leveldb::Status s =
 248       db_->Put(write_options,
 249                MakeSlice(kDeviceAIDKey),
 250                MakeSlice(android_id_str));
 251   if (s.ok()) {
 252     s = db_->Put(
 253         write_options, MakeSlice(kDeviceTokenKey), MakeSlice(encrypted_token));
 254   }
 255   if (s.ok()) {
 256     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 257     return;
 258   }
 259   LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 260   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 261 }
 262
 263 void GCMStoreImpl::Backend::AddIncomingMessage(const std::string& persistent_id,
 264                                                const UpdateCallback& callback) {
 265   DVLOG(1) << "Saving incoming message with id " << persistent_id;
 266   if (!db_.get()) {
 267     LOG(ERROR) << "GCMStore db doesn't exist.";
 268     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 269     return;
 270   }
 271
 272   leveldb::WriteOptions write_options;
 273   write_options.sync = true;
 274
 275   std::string key = MakeIncomingKey(persistent_id);
 276   const leveldb::Status s = db_->Put(write_options,
 277                                      MakeSlice(key),
 278                                      MakeSlice(persistent_id));
 279   if (s.ok()) {
 280     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 281     return;
 282   }
 283   LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 284   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 285 }
 286
 287 void GCMStoreImpl::Backend::RemoveIncomingMessages(
 288     const PersistentIdList& persistent_ids,
 289     const UpdateCallback& callback) {
 290   if (!db_.get()) {
 291     LOG(ERROR) << "GCMStore db doesn't exist.";
 292     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 293     return;
 294   }
 295   leveldb::WriteOptions write_options;
 296   write_options.sync = true;
 297
 298   leveldb::Status s;
 299   for (PersistentIdList::const_iterator iter = persistent_ids.begin();
 300        iter != persistent_ids.end();
 301        ++iter) {
 302     DVLOG(1) << "Removing incoming message with id " << *iter;
 303     std::string key = MakeIncomingKey(*iter);
 304     s = db_->Delete(write_options, MakeSlice(key));
 305     if (!s.ok())
 306       break;
 307   }
 308   if (s.ok()) {
 309     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 310     return;
 311   }
 312   LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
 313   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 314 }
 315
 316 void GCMStoreImpl::Backend::AddOutgoingMessage(const std::string& persistent_id,
 317                                                const MCSMessage& message,
 318                                                const UpdateCallback& callback) {
 319   DVLOG(1) << "Saving outgoing message with id " << persistent_id;
 320   if (!db_.get()) {
 321     LOG(ERROR) << "GCMStore db doesn't exist.";
 322     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 323     return;
 324   }
 325   leveldb::WriteOptions write_options;
 326   write_options.sync = true;
 327
 328   std::string data =
 329       static_cast<char>(message.tag()) + message.SerializeAsString();
 330   std::string key = MakeOutgoingKey(persistent_id);
 331   const leveldb::Status s = db_->Put(write_options,
 332                                      MakeSlice(key),
 333                                      MakeSlice(data));
 334   if (s.ok()) {
 335     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 336     return;
 337   }
 338   LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 339   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 340 }
 341
 342 void GCMStoreImpl::Backend::RemoveOutgoingMessages(
 343     const PersistentIdList& persistent_ids,
 344     const base::Callback<void(bool, const AppIdToMessageCountMap&)>
 345         callback) {
 346   if (!db_.get()) {
 347     LOG(ERROR) << "GCMStore db doesn't exist.";
 348     foreground_task_runner_->PostTask(FROM_HERE,
 349                                       base::Bind(callback,
 350                                                  false,
 351                                                  AppIdToMessageCountMap()));
 352     return;
 353   }
 354   leveldb::ReadOptions read_options;
 355   leveldb::WriteOptions write_options;
 356   write_options.sync = true;
 357
 358   AppIdToMessageCountMap removed_message_counts;
 359
 360   leveldb::Status s;
 361   for (PersistentIdList::const_iterator iter = persistent_ids.begin();
 362        iter != persistent_ids.end();
 363        ++iter) {
 364     DVLOG(1) << "Removing outgoing message with id " << *iter;
 365     std::string outgoing_message;
 366     std::string key = MakeOutgoingKey(*iter);
 367     s = db_->Get(read_options,
 368                  MakeSlice(key),
 369                  &outgoing_message);
 370     if (!s.ok())
 371       break;
 372     mcs_proto::DataMessageStanza data_message;
 373     // Skip the initial tag byte and parse the rest to extract the message.
 374     if (data_message.ParseFromString(outgoing_message.substr(1))) {
 375       DCHECK(!data_message.category().empty());
 376       if (removed_message_counts.count(data_message.category()) != 0)
 377         removed_message_counts[data_message.category()]++;
 378       else
 379         removed_message_counts[data_message.category()] = 1;
 380     }
 381     DVLOG(1) << "Removing outgoing message with id " << *iter;
 382     s = db_->Delete(write_options, MakeSlice(key));
 383     if (!s.ok())
 384       break;
 385   }
 386   if (s.ok()) {
 387     foreground_task_runner_->PostTask(FROM_HERE,
 388                                       base::Bind(callback,
 389                                                  true,
 390                                                  removed_message_counts));
 391     return;
 392   }
 393   LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
 394   foreground_task_runner_->PostTask(FROM_HERE,
 395                                     base::Bind(callback,
 396                                                false,
 397                                                AppIdToMessageCountMap()));
 398 }
 399
 400 void GCMStoreImpl::Backend::AddUserSerialNumber(
 401     const std::string& username,
 402     int64 serial_number,
 403     const UpdateCallback& callback) {
 404   DVLOG(1) << "Saving username to serial number mapping for user: " << username;
 405   if (!db_.get()) {
 406     LOG(ERROR) << "GCMStore db doesn't exist.";
 407     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 408     return;
 409   }
 410   leveldb::WriteOptions write_options;
 411   write_options.sync = true;
 412
 413   std::string key = MakeUserSerialNumberKey(username);
 414   std::string serial_number_str = base::Int64ToString(serial_number);
 415   const leveldb::Status status =
 416       db_->Put(write_options,
 417                MakeSlice(key),
 418                MakeSlice(serial_number_str));
 419   if (status.ok()) {
 420     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 421     return;
 422   }
 423   LOG(ERROR) << "LevelDB put failed: " << status.ToString();
 424   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 425 }
 426
 427 void GCMStoreImpl::Backend::RemoveUserSerialNumber(
 428     const std::string& username,
 429     const UpdateCallback& callback) {
 430   if (!db_.get()) {
 431     LOG(ERROR) << "GCMStore db doesn't exist.";
 432     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 433     return;
 434   }
 435   leveldb::WriteOptions write_options;
 436   write_options.sync = true;
 437
 438   leveldb::Status status = db_->Delete(write_options, MakeSlice(username));
 439   if (status.ok()) {
 440     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 441     return;
 442   }
 443   LOG(ERROR) << "LevelDB remove failed: " << status.ToString();
 444   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 445 }
 446
 447 void GCMStoreImpl::Backend::SetNextSerialNumber(
 448     int64 next_serial_number,
 449     const UpdateCallback& callback) {
 450   DVLOG(1) << "Updating the value of next user serial number to: "
 451            << next_serial_number;
 452   if (!db_.get()) {
 453     LOG(ERROR) << "GCMStore db doesn't exist.";
 454     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 455     return;
 456   }
 457   leveldb::WriteOptions write_options;
 458   write_options.sync = true;
 459
 460   std::string serial_number_str = base::Int64ToString(next_serial_number);
 461   const leveldb::Status status =
 462       db_->Put(write_options,
 463                MakeSlice(kNextSerialNumberKey),
 464                MakeSlice(serial_number_str));
 465   if (status.ok()) {
 466     foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, true));
 467     return;
 468   }
 469   LOG(ERROR) << "LevelDB put failed: " << status.ToString();
 470   foreground_task_runner_->PostTask(FROM_HERE, base::Bind(callback, false));
 471 }
 472
 473 bool GCMStoreImpl::Backend::LoadDeviceCredentials(uint64* android_id,
 474                                                   uint64* security_token) {
 475   leveldb::ReadOptions read_options;
 476   read_options.verify_checksums = true;
 477
 478   std::string result;
 479   leveldb::Status s = db_->Get(read_options, MakeSlice(kDeviceAIDKey), &result);
 480   if (s.ok()) {
 481     if (!base::StringToUint64(result, android_id)) {
 482       LOG(ERROR) << "Failed to restore device id.";
 483       return false;
 484     }
 485     result.clear();
 486     s = db_->Get(read_options, MakeSlice(kDeviceTokenKey), &result);
 487   }
 488   if (s.ok()) {
 489     std::string decrypted_token;
 490     Encryptor::DecryptString(result, &decrypted_token);
 491     if (!base::StringToUint64(decrypted_token, security_token)) {
 492       LOG(ERROR) << "Failed to restore security token.";
 493       return false;
 494     }
 495     return true;
 496   }
 497
 498   if (s.IsNotFound()) {
 499     DVLOG(1) << "No credentials found.";
 500     return true;
 501   }
 502
 503   LOG(ERROR) << "Error reading credentials from store.";
 504   return false;
 505 }
 506
 507 bool GCMStoreImpl::Backend::LoadIncomingMessages(
 508     std::vector<std::string>* incoming_messages) {
 509   leveldb::ReadOptions read_options;
 510   read_options.verify_checksums = true;
 511
 512   scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
 513   for (iter->Seek(MakeSlice(kIncomingMsgKeyStart));
 514        iter->Valid() && iter->key().ToString() < kIncomingMsgKeyEnd;
 515        iter->Next()) {
 516     leveldb::Slice s = iter->value();
 517     if (s.empty()) {
 518       LOG(ERROR) << "Error reading incoming message with key "
 519                  << iter->key().ToString();
 520       return false;
 521     }
 522     DVLOG(1) << "Found incoming message with id " << s.ToString();
 523     incoming_messages->push_back(s.ToString());
 524   }
 525
 526   return true;
 527 }
 528
 529 bool GCMStoreImpl::Backend::LoadOutgoingMessages(
 530     OutgoingMessageMap* outgoing_messages) {
 531   leveldb::ReadOptions read_options;
 532   read_options.verify_checksums = true;
 533
 534   scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
 535   for (iter->Seek(MakeSlice(kOutgoingMsgKeyStart));
 536        iter->Valid() && iter->key().ToString() < kOutgoingMsgKeyEnd;
 537        iter->Next()) {
 538     leveldb::Slice s = iter->value();
 539     if (s.size() <= 1) {
 540       LOG(ERROR) << "Error reading incoming message with key " << s.ToString();
 541       return false;
 542     }
 543     uint8 tag = iter->value().data()[0];
 544     std::string id = ParseOutgoingKey(iter->key().ToString());
 545     scoped_ptr<google::protobuf::MessageLite> message(
 546         BuildProtobufFromTag(tag));
 547     if (!message.get() ||
 548         !message->ParseFromString(iter->value().ToString().substr(1))) {
 549       LOG(ERROR) << "Failed to parse outgoing message with id " << id
 550                  << " and tag " << tag;
 551       return false;
 552     }
 553     DVLOG(1) << "Found outgoing message with id " << id << " of type "
 554              << base::IntToString(tag);
 555     (*outgoing_messages)[id] = make_linked_ptr(message.release());
 556   }
 557
 558   return true;
 559 }
 560
 561 bool GCMStoreImpl::Backend::LoadNextSerialNumber(int64* next_serial_number) {
 562   leveldb::ReadOptions read_options;
 563   read_options.verify_checksums = true;
 564
 565   std::string result;
 566   leveldb::Status status =
 567       db_->Get(read_options, MakeSlice(kNextSerialNumberKey), &result);
 568   if (status.ok()) {
 569     if (!base::StringToInt64(result, next_serial_number)) {
 570       LOG(ERROR) << "Failed to restore the next serial number.";
 571       return false;
 572     }
 573     return true;
 574   }
 575
 576   if (status.IsNotFound()) {
 577     DVLOG(1) << "No next serial number found.";
 578     return true;
 579   }
 580
 581   LOG(ERROR) << "Error when reading the next serial number.";
 582   return false;
 583 }
 584
 585 bool GCMStoreImpl::Backend::LoadUserSerialNumberMap(
 586     std::map<std::string, int64>* user_serial_number_map) {
 587   leveldb::ReadOptions read_options;
 588   read_options.verify_checksums = true;
 589
 590   scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
 591   for (iter->Seek(MakeSlice(kUserSerialNumberKeyStart));
 592        iter->Valid() && iter->key().ToString() < kUserSerialNumberKeyEnd;
 593        iter->Next()) {
 594     std::string username = ParseUsername(iter->key().ToString());
 595     if (username.empty()) {
 596       LOG(ERROR) << "Error reading username. It should not be empty.";
 597       return false;
 598     }
 599     std::string serial_number_string = iter->value().ToString();
 600     int64 serial_number = kSerialNumberMissing;
 601     if (!base::StringToInt64(serial_number_string, &serial_number)) {
 602       LOG(ERROR) << "Error reading user serial number for user: " << username;
 603       return false;
 604     }
 605
 606     (*user_serial_number_map)[username] = serial_number;
 607   }
 608
 609   return true;
 610 }
 611
 612 GCMStoreImpl::GCMStoreImpl(
 613     bool use_mock_keychain,
 614     const base::FilePath& path,
 615     scoped_refptr<base::SequencedTaskRunner> blocking_task_runner)
 616     : backend_(new Backend(path, base::MessageLoopProxy::current())),
 617       blocking_task_runner_(blocking_task_runner),
 618       weak_ptr_factory_(this) {
 619 // On OSX, prevent the Keychain permissions popup during unit tests.
 620 #if defined(OS_MACOSX)
 621   Encryptor::UseMockKeychain(use_mock_keychain);
 622 #endif
 623 }
 624
 625 GCMStoreImpl::~GCMStoreImpl() {}
 626
 627 void GCMStoreImpl::Load(const LoadCallback& callback) {
 628   blocking_task_runner_->PostTask(
 629       FROM_HERE,
 630       base::Bind(&GCMStoreImpl::Backend::Load,
 631                  backend_,
 632                  base::Bind(&GCMStoreImpl::LoadContinuation,
 633                             weak_ptr_factory_.GetWeakPtr(),
 634                             callback)));
 635 }
 636
 637 void GCMStoreImpl::Destroy(const UpdateCallback& callback) {
 638   blocking_task_runner_->PostTask(
 639       FROM_HERE,
 640       base::Bind(&GCMStoreImpl::Backend::Destroy, backend_, callback));
 641 }
 642
 643 void GCMStoreImpl::SetDeviceCredentials(uint64 device_android_id,
 644                                         uint64 device_security_token,
 645                                         const UpdateCallback& callback) {
 646   blocking_task_runner_->PostTask(
 647       FROM_HERE,
 648       base::Bind(&GCMStoreImpl::Backend::SetDeviceCredentials,
 649                  backend_,
 650                  device_android_id,
 651                  device_security_token,
 652                  callback));
 653 }
 654
 655 void GCMStoreImpl::AddIncomingMessage(const std::string& persistent_id,
 656                                       const UpdateCallback& callback) {
 657   blocking_task_runner_->PostTask(
 658       FROM_HERE,
 659       base::Bind(&GCMStoreImpl::Backend::AddIncomingMessage,
 660                  backend_,
 661                  persistent_id,
 662                  callback));
 663 }
 664
 665 void GCMStoreImpl::RemoveIncomingMessage(const std::string& persistent_id,
 666                                          const UpdateCallback& callback) {
 667   blocking_task_runner_->PostTask(
 668       FROM_HERE,
 669       base::Bind(&GCMStoreImpl::Backend::RemoveIncomingMessages,
 670                  backend_,
 671                  PersistentIdList(1, persistent_id),
 672                  callback));
 673 }
 674
 675 void GCMStoreImpl::RemoveIncomingMessages(
 676     const PersistentIdList& persistent_ids,
 677     const UpdateCallback& callback) {
 678   blocking_task_runner_->PostTask(
 679       FROM_HERE,
 680       base::Bind(&GCMStoreImpl::Backend::RemoveIncomingMessages,
 681                  backend_,
 682                  persistent_ids,
 683                  callback));
 684 }
 685
 686 bool GCMStoreImpl::AddOutgoingMessage(const std::string& persistent_id,
 687                                       const MCSMessage& message,
 688                                       const UpdateCallback& callback) {
 689   DCHECK_EQ(message.tag(), kDataMessageStanzaTag);
 690   std::string app_id = reinterpret_cast<const mcs_proto::DataMessageStanza*>(
 691                            &message.GetProtobuf())->category();
 692   DCHECK(!app_id.empty());
 693   if (app_message_counts_.count(app_id) == 0)
 694     app_message_counts_[app_id] = 0;
 695   if (app_message_counts_[app_id] < kMessagesPerAppLimit) {
 696     app_message_counts_[app_id]++;
 697
 698     blocking_task_runner_->PostTask(
 699         FROM_HERE,
 700         base::Bind(&GCMStoreImpl::Backend::AddOutgoingMessage,
 701                    backend_,
 702                    persistent_id,
 703                    message,
 704                    base::Bind(&GCMStoreImpl::AddOutgoingMessageContinuation,
 705                               weak_ptr_factory_.GetWeakPtr(),
 706                               callback,
 707                               app_id)));
 708     return true;
 709   }
 710   return false;
 711 }
 712
 713 void GCMStoreImpl::OverwriteOutgoingMessage(const std::string& persistent_id,
 714                                             const MCSMessage& message,
 715                                             const UpdateCallback& callback) {
 716   DCHECK_EQ(message.tag(), kDataMessageStanzaTag);
 717   std::string app_id = reinterpret_cast<const mcs_proto::DataMessageStanza*>(
 718                            &message.GetProtobuf())->category();
 719   DCHECK(!app_id.empty());
 720   // There should already be pending messages for this app.
 721   DCHECK(app_message_counts_.count(app_id));
 722   // TODO(zea): consider verifying the specific message already exists.
 723   blocking_task_runner_->PostTask(
 724       FROM_HERE,
 725       base::Bind(&GCMStoreImpl::Backend::AddOutgoingMessage,
 726                  backend_,
 727                  persistent_id,
 728                  message,
 729                  callback));
 730 }
 731
 732 void GCMStoreImpl::RemoveOutgoingMessage(const std::string& persistent_id,
 733                                          const UpdateCallback& callback) {
 734   blocking_task_runner_->PostTask(
 735       FROM_HERE,
 736       base::Bind(&GCMStoreImpl::Backend::RemoveOutgoingMessages,
 737                  backend_,
 738                  PersistentIdList(1, persistent_id),
 739                  base::Bind(&GCMStoreImpl::RemoveOutgoingMessagesContinuation,
 740                             weak_ptr_factory_.GetWeakPtr(),
 741                             callback)));
 742 }
 743
 744 void GCMStoreImpl::RemoveOutgoingMessages(
 745     const PersistentIdList& persistent_ids,
 746     const UpdateCallback& callback) {
 747   blocking_task_runner_->PostTask(
 748       FROM_HERE,
 749       base::Bind(&GCMStoreImpl::Backend::RemoveOutgoingMessages,
 750                  backend_,
 751                  persistent_ids,
 752                  base::Bind(&GCMStoreImpl::RemoveOutgoingMessagesContinuation,
 753                             weak_ptr_factory_.GetWeakPtr(),
 754                             callback)));
 755 }
 756
 757 void GCMStoreImpl::SetNextSerialNumber(int64 next_serial_number,
 758                                        const UpdateCallback& callback) {
 759   blocking_task_runner_->PostTask(
 760       FROM_HERE,
 761       base::Bind(&GCMStoreImpl::Backend::SetNextSerialNumber,
 762                  backend_,
 763                  next_serial_number,
 764                  callback));
 765 }
 766
 767 void GCMStoreImpl::AddUserSerialNumber(const std::string& username,
 768                                        int64 serial_number,
 769                                        const UpdateCallback& callback) {
 770   blocking_task_runner_->PostTask(
 771       FROM_HERE,
 772       base::Bind(&GCMStoreImpl::Backend::AddUserSerialNumber,
 773                  backend_,
 774                  username,
 775                  serial_number,
 776                  callback));
 777 }
 778
 779 void GCMStoreImpl::RemoveUserSerialNumber(const std::string& username,
 780                                           const UpdateCallback& callback) {
 781   blocking_task_runner_->PostTask(
 782       FROM_HERE,
 783       base::Bind(&GCMStoreImpl::Backend::RemoveUserSerialNumber,
 784                  backend_,
 785                  username,
 786                  callback));
 787 }
 788
 789 void GCMStoreImpl::LoadContinuation(const LoadCallback& callback,
 790                                     scoped_ptr<LoadResult> result) {
 791   if (!result->success) {
 792     callback.Run(result.Pass());
 793     return;
 794   }
 795   int num_throttled_apps = 0;
 796   for (OutgoingMessageMap::const_iterator
 797            iter = result->outgoing_messages.begin();
 798        iter != result->outgoing_messages.end(); ++iter) {
 799     const mcs_proto::DataMessageStanza* data_message =
 800         reinterpret_cast<mcs_proto::DataMessageStanza*>(iter->second.get());
 801     DCHECK(!data_message->category().empty());
 802     if (app_message_counts_.count(data_message->category()) == 0)
 803       app_message_counts_[data_message->category()] = 1;
 804     else
 805       app_message_counts_[data_message->category()]++;
 806     if (app_message_counts_[data_message->category()] == kMessagesPerAppLimit)
 807       num_throttled_apps++;
 808   }
 809   UMA_HISTOGRAM_COUNTS("GCM.NumThrottledApps", num_throttled_apps);
 810   callback.Run(result.Pass());
 811 }
 812
 813 void GCMStoreImpl::AddOutgoingMessageContinuation(
 814     const UpdateCallback& callback,
 815     const std::string& app_id,
 816     bool success) {
 817   if (!success) {
 818     DCHECK(app_message_counts_[app_id] > 0);
 819     app_message_counts_[app_id]--;
 820   }
 821   callback.Run(success);
 822 }
 823
 824 void GCMStoreImpl::RemoveOutgoingMessagesContinuation(
 825     const UpdateCallback& callback,
 826     bool success,
 827     const AppIdToMessageCountMap& removed_message_counts) {
 828   if (!success) {
 829     callback.Run(false);
 830     return;
 831   }
 832   for (AppIdToMessageCountMap::const_iterator iter =
 833            removed_message_counts.begin();
 834        iter != removed_message_counts.end(); ++iter) {
 835     DCHECK_NE(app_message_counts_.count(iter->first), 0U);
 836     app_message_counts_[iter->first] -= iter->second;
 837     DCHECK_GE(app_message_counts_[iter->first], 0);
 838   }
 839   callback.Run(true);
 840 }
 841
 842 }  // namespace gcm