DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (a81015259a98)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Places code.
 *
 * The Initial Developer of the Original Code is
 * the Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Marco Bonardo <mak77@bonardo.net>
 *
 * Original contributor(s) of code moved from nsNavHistory.cpp:
 *   Brett Wilson <brettw@gmail.com> (original author)
 *   Dietrich Ayala <dietrich@mozilla.com>
 *   Seth Spitzer <sspitzer@mozilla.com>
 *   Asaf Romano <mano@mozilla.com>
 *   Marco Bonardo <mak77@bonardo.net>
 *   Edward Lee <edward.lee@engineering.uiuc.edu>
 *   Michael Ventnor <m.ventnor@gmail.com>
 *   Ehsan Akhgari <ehsan.akhgari@gmail.com>
 *   Drew Willcoxon <adw@mozilla.com>
 *   Philipp von Weitershausen <philipp@weitershausen.de>
 *   Paolo Amadini <http://www.amadzone.org/>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "Database.h"

#include "nsINavBookmarksService.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsILocalFile.h"

#include "nsNavHistory.h"
#include "nsPlacesTables.h"
#include "nsPlacesIndexes.h"
#include "nsPlacesTriggers.h"
#include "nsPlacesMacros.h"
#include "SQLFunctions.h"
#include "Helpers.h"

#include "nsAppDirectoryServiceDefs.h"
#include "nsDirectoryServiceUtils.h"
#include "prsystem.h"
#include "nsPrintfCString.h"
#include "mozilla/Util.h"
#include "mozilla/Preferences.h"
#include "mozilla/Services.h"

// Time between corrupt database backups.
#define RECENT_BACKUP_TIME_MICROSEC (PRInt64)86400 * PR_USEC_PER_SEC // 24H

// Filename of the database.
#define DATABASE_FILENAME NS_LITERAL_STRING("places.sqlite")
// Filename used to backup corrupt databases.
#define DATABASE_CORRUPT_FILENAME NS_LITERAL_STRING("places.sqlite.corrupt")

// Set when the database file was found corrupt by a previous maintenance.
#define PREF_FORCE_DATABASE_REPLACEMENT "places.database.replaceOnStartup"

// The wanted size of the cache.  This is calculated based on current database
// size and clamped to the limits specified below.
#define DATABASE_CACHE_TO_DATABASE_PERC 10
// The minimum size of the cache.  We should never work without a cache, since
// that would badly hurt WAL journaling mode.
#define DATABASE_CACHE_MIN_BYTES (PRUint64)4194304 // 4MiB
// The maximum size of the cache.  This is the maximum memory that each
// connection may use.
#define DATABASE_CACHE_MAX_BYTES (PRUint64)8388608 // 8MiB

// Maximum size for the WAL file.  It should be small enough since in case of
// crashes we could lose all the transactions in the file.  But a too small
// file could hurt performance.
#define DATABASE_MAX_WAL_SIZE_IN_KIBIBYTES 512

#define BYTES_PER_MEBIBYTE 1048576

// Old Sync GUID annotation.
#define SYNCGUID_ANNO NS_LITERAL_CSTRING("sync/guid")

using namespace mozilla;

namespace mozilla {
namespace places {

namespace {

////////////////////////////////////////////////////////////////////////////////
//// Helpers

/**
 * Checks whether exists a database backup created not longer than
 * RECENT_BACKUP_TIME_MICROSEC ago.
 */
bool
hasRecentCorruptDB()
{
  MOZ_ASSERT(NS_IsMainThread());

  nsCOMPtr<nsIFile> profDir;
  NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(profDir));
  NS_ENSURE_TRUE(profDir, false);
  nsCOMPtr<nsISimpleEnumerator> entries;
  profDir->GetDirectoryEntries(getter_AddRefs(entries));
  NS_ENSURE_TRUE(entries, false);
  bool hasMore;
  while (NS_SUCCEEDED(entries->HasMoreElements(&hasMore)) && hasMore) {
    nsCOMPtr<nsISupports> next;
    entries->GetNext(getter_AddRefs(next));
    NS_ENSURE_TRUE(next, false);
    nsCOMPtr<nsIFile> currFile = do_QueryInterface(next);
    NS_ENSURE_TRUE(currFile, false);

    nsAutoString leafName;
    if (NS_SUCCEEDED(currFile->GetLeafName(leafName)) &&
        leafName.Length() >= DATABASE_CORRUPT_FILENAME.Length() &&
        leafName.Find(".corrupt", DATABASE_FILENAME.Length()) != -1) {
      PRInt64 lastMod = 0;
      currFile->GetLastModifiedTime(&lastMod);
      NS_ENSURE_TRUE(lastMod > 0, false);
      return (PR_Now() - lastMod) > RECENT_BACKUP_TIME_MICROSEC;
    }
  }
  return false;
}

/**
 * Updates sqlite_stat1 table through ANALYZE.
 * Since also nsPlacesExpiration.js executes ANALYZE, the analyzed tables
 * must be the same in both components.  So ensure they are in sync.
 *
 * @param aDBConn
 *        The database connection.
 */
nsresult
updateSQLiteStatistics(mozIStorageConnection* aDBConn)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsCOMPtr<mozIStorageAsyncStatement> analyzePlacesStmt;
  aDBConn->CreateAsyncStatement(NS_LITERAL_CSTRING(
    "ANALYZE moz_places"
  ), getter_AddRefs(analyzePlacesStmt));
  NS_ENSURE_STATE(analyzePlacesStmt);
  nsCOMPtr<mozIStorageAsyncStatement> analyzeBookmarksStmt;
  aDBConn->CreateAsyncStatement(NS_LITERAL_CSTRING(
    "ANALYZE moz_bookmarks"
  ), getter_AddRefs(analyzeBookmarksStmt));
  NS_ENSURE_STATE(analyzeBookmarksStmt);
  nsCOMPtr<mozIStorageAsyncStatement> analyzeVisitsStmt;
  aDBConn->CreateAsyncStatement(NS_LITERAL_CSTRING(
    "ANALYZE moz_historyvisits"
  ), getter_AddRefs(analyzeVisitsStmt));
  NS_ENSURE_STATE(analyzeVisitsStmt);
  nsCOMPtr<mozIStorageAsyncStatement> analyzeInputStmt;
  aDBConn->CreateAsyncStatement(NS_LITERAL_CSTRING(
    "ANALYZE moz_inputhistory"
  ), getter_AddRefs(analyzeInputStmt));
  NS_ENSURE_STATE(analyzeInputStmt);

  mozIStorageBaseStatement *stmts[] = {
    analyzePlacesStmt,
    analyzeBookmarksStmt,
    analyzeVisitsStmt,
    analyzeInputStmt
  };

  nsCOMPtr<mozIStoragePendingStatement> ps;
  (void)aDBConn->ExecuteAsync(stmts, ArrayLength(stmts), nsnull,
                              getter_AddRefs(ps));
  return NS_OK;
}

/**
 * Sets the connection journal mode to one of the JOURNAL_* types.
 *
 * @param aDBConn
 *        The database connection.
 * @param aJournalMode
 *        One of the JOURNAL_* types.
 * @returns the current journal mode.
 * @note this may return a different journal mode than the required one, since
 *       setting it may fail.
 */
enum JournalMode
SetJournalMode(nsCOMPtr<mozIStorageConnection>& aDBConn,
                             enum JournalMode aJournalMode)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsCAutoString journalMode;
  switch (aJournalMode) {
    default:
      MOZ_ASSERT("Trying to set an unknown journal mode.");
      // Fall through to the default DELETE journal.
    case JOURNAL_DELETE:
      journalMode.AssignLiteral("delete");
      break;
    case JOURNAL_TRUNCATE:
      journalMode.AssignLiteral("truncate");
      break;
    case JOURNAL_MEMORY:
      journalMode.AssignLiteral("memory");
      break;
    case JOURNAL_WAL:
      journalMode.AssignLiteral("wal");
      break;
  }

  nsCOMPtr<mozIStorageStatement> statement;
  nsCAutoString query("PRAGMA journal_mode = ");
  query.Append(journalMode);
  aDBConn->CreateStatement(query, getter_AddRefs(statement));
  NS_ENSURE_TRUE(statement, JOURNAL_DELETE);

  bool hasResult = false;
  if (NS_SUCCEEDED(statement->ExecuteStep(&hasResult)) && hasResult &&
      NS_SUCCEEDED(statement->GetUTF8String(0, journalMode))) {
    if (journalMode.EqualsLiteral("delete")) {
      return JOURNAL_DELETE;
    }
    if (journalMode.EqualsLiteral("truncate")) {
      return JOURNAL_TRUNCATE;
    }
    if (journalMode.EqualsLiteral("memory")) {
      return JOURNAL_MEMORY;
    }
    if (journalMode.EqualsLiteral("wal")) {
      return JOURNAL_WAL;
    }
    // This is an unknown journal.
    MOZ_ASSERT(true);
  }

  return JOURNAL_DELETE;
}

} // Anonymous namespace

////////////////////////////////////////////////////////////////////////////////
//// Database

PLACES_FACTORY_SINGLETON_IMPLEMENTATION(Database, gDatabase)

NS_IMPL_THREADSAFE_ISUPPORTS2(Database
, nsIObserver
, nsISupportsWeakReference
)

Database::Database()
  : mMainThreadStatements(mMainConn)
  , mMainThreadAsyncStatements(mMainConn)
  , mAsyncThreadStatements(mMainConn)
  , mDBPageSize(0)
  , mCurrentJournalMode(JOURNAL_DELETE)
  , mDatabaseStatus(nsINavHistoryService::DATABASE_STATUS_OK)
  , mShuttingDown(false)
{
  // Attempting to create two instances of the service?
  MOZ_ASSERT(!gDatabase);
  gDatabase = this;
}

Database::~Database()
{
  // Check to make sure it's us, in case somebody wrongly creates an extra
  // instance of this singleton class.
  MOZ_ASSERT(gDatabase == this);

  // Remove the static reference to the service.
  if (gDatabase == this) {
    gDatabase = nsnull;
  }
}

nsresult
Database::Init()
{
  MOZ_ASSERT(NS_IsMainThread());

  nsCOMPtr<mozIStorageService> storage =
    do_GetService(MOZ_STORAGE_SERVICE_CONTRACTID);
  NS_ENSURE_STATE(storage);

  // Init the database file and connect to it.
  bool databaseCreated = false;
  nsresult rv = InitDatabaseFile(storage, &databaseCreated);
  if (NS_SUCCEEDED(rv) && databaseCreated) {
    mDatabaseStatus = nsINavHistoryService::DATABASE_STATUS_CREATE;
  }
  else if (rv == NS_ERROR_FILE_CORRUPTED) {
    // The database is corrupt, backup and replace it with a new one.
    mDatabaseStatus = nsINavHistoryService::DATABASE_STATUS_CORRUPT;
    rv = BackupAndReplaceDatabaseFile(storage);
    // Fallback to catch-all handler, that notifies a database locked failure.
  }

  // If the database connection still cannot be opened, it may just be locked
  // by third parties.  Send out a notification and interrupt initialization.
  if (NS_FAILED(rv)) {
    nsRefPtr<PlacesEvent> lockedEvent = new PlacesEvent(TOPIC_DATABASE_LOCKED);
    (void)NS_DispatchToMainThread(lockedEvent);
    return rv;
  }

  // Initialize the database schema.  In case of failure the existing schema is
  // is corrupt or incoherent, thus the database should be replaced.
  bool databaseMigrated = false;
  rv = InitSchema(&databaseMigrated);
  if (NS_FAILED(rv)) {
    mDatabaseStatus = nsINavHistoryService::DATABASE_STATUS_CORRUPT;
    rv = BackupAndReplaceDatabaseFile(storage);
    NS_ENSURE_SUCCESS(rv, rv);
    // Try to initialize the schema again on the new database.
    rv = InitSchema(&databaseMigrated);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  if (databaseMigrated) {
    mDatabaseStatus = nsINavHistoryService::DATABASE_STATUS_UPGRADED;
  }

  if (mDatabaseStatus != nsINavHistoryService::DATABASE_STATUS_OK) {
    rv = updateSQLiteStatistics(MainConn());
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Initialize here all the items that are not part of the on-disk database,
  // like views, temp triggers or temp tables.  The database should not be
  // considered corrupt if any of the following fails.

  rv = InitTempTriggers();
  NS_ENSURE_SUCCESS(rv, rv);

  // Notify we have finished database initialization.
  // Enqueue the notification, so if we init another service that requires
  // nsNavHistoryService we don't recursive try to get it.
  nsRefPtr<PlacesEvent> completeEvent =
    new PlacesEvent(TOPIC_PLACES_INIT_COMPLETE);
  rv = NS_DispatchToMainThread(completeEvent);
  NS_ENSURE_SUCCESS(rv, rv);

  // Finally observe profile shutdown notifications.
  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
  if (os) {
    (void)os->AddObserver(this, TOPIC_PROFILE_CHANGE_TEARDOWN, true);
    (void)os->AddObserver(this, TOPIC_PROFILE_BEFORE_CHANGE, true);
  }

  return NS_OK;
}

nsresult
Database::InitDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage,
                           bool* aNewDatabaseCreated)
{
  MOZ_ASSERT(NS_IsMainThread());
  *aNewDatabaseCreated = false;

  nsCOMPtr<nsIFile> databaseFile;
  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                       getter_AddRefs(databaseFile));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = databaseFile->Append(DATABASE_FILENAME);
  NS_ENSURE_SUCCESS(rv, rv);

  bool databaseFileExists = false;
  rv = databaseFile->Exists(&databaseFileExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (databaseFileExists &&
      Preferences::GetBool(PREF_FORCE_DATABASE_REPLACEMENT, false)) {
    // If this pref is set, Maintenance required a database replacement, due to
    // integrity corruption.
    // Be sure to clear the pref to avoid handling it more than once.
    (void)Preferences::ClearUser(PREF_FORCE_DATABASE_REPLACEMENT);

    return NS_ERROR_FILE_CORRUPTED;
  }

  // Open the database file.  If it does not exist a new one will be created.
  // Use an unshared connection, it will consume more memory but avoid shared
  // cache contentions across threads.
  rv = aStorage->OpenUnsharedDatabase(databaseFile, getter_AddRefs(mMainConn));
  NS_ENSURE_SUCCESS(rv, rv);

  *aNewDatabaseCreated = !databaseFileExists;
  return NS_OK;
}

nsresult
Database::BackupAndReplaceDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIFile> profDir;
  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                       getter_AddRefs(profDir));
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIFile> databaseFile;
  rv = profDir->Clone(getter_AddRefs(databaseFile));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = databaseFile->Append(DATABASE_FILENAME);
  NS_ENSURE_SUCCESS(rv, rv);

  // If we have
  // already failed in the last 24 hours avoid to create another corrupt file,
  // since doing so, in some situation, could cause us to create a new corrupt
  // file at every try to access any Places service.  That is bad because it
  // would quickly fill the user's disk space without any notice.
  if (!hasRecentCorruptDB()) {
    nsCOMPtr<nsIFile> backup;
    (void)aStorage->BackupDatabaseFile(databaseFile, DATABASE_CORRUPT_FILENAME,
                                       profDir, getter_AddRefs(backup));
  }

  // Close database connection if open.
  if (mMainConn) {
    // If there's any not finalized statement or this fails for any reason
    // we won't be able to remove the database.
    rv = mMainConn->Close();
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Remove the broken database.
  rv = databaseFile->Remove(false);
  NS_ENSURE_SUCCESS(rv, rv);

  // Create a new database file.
  // Use an unshared connection, it will consume more memory but avoid shared
  // cache contentions across threads.
  rv = aStorage->OpenUnsharedDatabase(databaseFile, getter_AddRefs(mMainConn));
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
Database::InitSchema(bool* aDatabaseMigrated)
{
  MOZ_ASSERT(NS_IsMainThread());
  *aDatabaseMigrated = false;

  // WARNING: any statement executed before setting the journal mode must be
  // finalized, since SQLite doesn't allow changing the journal mode if there
  // is any outstanding statement.

  {
    // Get the page size.  This may be different than the default if the
    // database file already existed with a different page size.
    nsCOMPtr<mozIStorageStatement> statement;
    nsresult rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "PRAGMA page_size"
    ), getter_AddRefs(statement));
    NS_ENSURE_SUCCESS(rv, rv);
    bool hasResult = false;
    rv = statement->ExecuteStep(&hasResult);
    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && hasResult, NS_ERROR_FAILURE);
    rv = statement->GetInt32(0, &mDBPageSize);
    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && mDBPageSize > 0, NS_ERROR_UNEXPECTED);
  }

  // Ensure that temp tables are held in memory, not on disk.
  nsresult rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "PRAGMA temp_store = MEMORY"));
  NS_ENSURE_SUCCESS(rv, rv);

  // Get the current database size. Due to chunked growth we have to use
  // page_count to evaluate it.
  PRUint64 databaseSizeBytes = 0;
  {
    nsCOMPtr<mozIStorageStatement> statement;
    nsresult rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "PRAGMA page_count"
    ), getter_AddRefs(statement));
    NS_ENSURE_SUCCESS(rv, rv);
    bool hasResult = false;
    rv = statement->ExecuteStep(&hasResult);
    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && hasResult, NS_ERROR_FAILURE);
    PRInt32 pageCount = 0;
    rv = statement->GetInt32(0, &pageCount);
    NS_ENSURE_SUCCESS(rv, rv);
    databaseSizeBytes = pageCount * mDBPageSize;
  }

  // Clamp the cache size to a percentage of the database size, forcing
  // meaningful limits.
  PRInt64 cacheSize = clamped(databaseSizeBytes *  DATABASE_CACHE_TO_DATABASE_PERC / 100,
                              DATABASE_CACHE_MIN_BYTES,
                              DATABASE_CACHE_MAX_BYTES);

  // Set the number of cached pages.
  // We don't use PRAGMA default_cache_size, since the database could be moved
  // among different devices and the value would adapt accordingly.
  nsCAutoString cacheSizePragma("PRAGMA cache_size = ");
  cacheSizePragma.AppendInt(cacheSize / mDBPageSize);
  rv = mMainConn->ExecuteSimpleSQL(cacheSizePragma);
  NS_ENSURE_SUCCESS(rv, rv);

  // Be sure to set journal mode after page_size.  WAL would prevent the change
  // otherwise.
  if (NS_SUCCEEDED(SetJournalMode(mMainConn, JOURNAL_WAL))) {
    // Set the WAL journal size limit.  We want it to be small, since in
    // synchronous = NORMAL mode a crash could cause loss of all the
    // transactions in the journal.  For added safety we will also force
    // checkpointing at strategic moments.
    PRInt32 checkpointPages =
      static_cast<PRInt32>(DATABASE_MAX_WAL_SIZE_IN_KIBIBYTES * 1024 / mDBPageSize);
    nsCAutoString checkpointPragma("PRAGMA wal_autocheckpoint = ");
    checkpointPragma.AppendInt(checkpointPages);
    rv = mMainConn->ExecuteSimpleSQL(checkpointPragma);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  else {
    // Ignore errors, if we fail here the database could be considered corrupt
    // and we won't be able to go on, even if it's just matter of a bogus file
    // system.  The default mode (DELETE) will be fine in such a case.
    (void)SetJournalMode(mMainConn, JOURNAL_TRUNCATE);

    // Set synchronous to FULL to ensure maximum data integrity, even in
    // case of crashes or unclean shutdowns.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "PRAGMA synchronous = FULL"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // The journal is usually free to grow for performance reasons, but it never
  // shrinks back.  Since the space taken may be problematic, especially on
  // mobile devices, limit its size.
  // Since exceeding the limit will cause a truncate, allow a slightly
  // larger limit than DATABASE_MAX_WAL_SIZE_IN_KIBIBYTES to reduce the number
  // of times it is needed.
  nsCAutoString journalSizePragma("PRAGMA journal_size_limit = ");
  journalSizePragma.AppendInt(DATABASE_MAX_WAL_SIZE_IN_KIBIBYTES * 3);
  (void)mMainConn->ExecuteSimpleSQL(journalSizePragma);

  // Grow places in 10MiB increments to limit fragmentation on disk.
  (void)mMainConn->SetGrowthIncrement(10 * BYTES_PER_MEBIBYTE, EmptyCString());

  // We use our functions during migration, so initialize them now.
  rv = InitFunctions();
  NS_ENSURE_SUCCESS(rv, rv);

  // Get the database schema version.
  PRInt32 currentSchemaVersion;
  rv = mMainConn->GetSchemaVersion(&currentSchemaVersion);
  NS_ENSURE_SUCCESS(rv, rv);
  bool databaseInitialized = currentSchemaVersion > 0;

  if (databaseInitialized && currentSchemaVersion == DATABASE_SCHEMA_VERSION) {
    // The database is up to date and ready to go.
    return NS_OK;
  }

  // We are going to update the database, so everything from now on should be in
  // a transaction for performances.
  mozStorageTransaction transaction(mMainConn, false);

  if (databaseInitialized) {
    // Migration How-to:
    //
    // 1. increment PLACES_SCHEMA_VERSION.
    // 2. implement a method that performs upgrade to your version from the
    //    previous one.
    //
    // NOTE: The downgrade process is pretty much complicated by the fact old
    //       versions cannot know what a new version is going to implement.
    //       The only thing we will do for downgrades is setting back the schema
    //       version, so that next upgrades will run again the migration step.

    if (currentSchemaVersion < DATABASE_SCHEMA_VERSION) {
      *aDatabaseMigrated = true;

      if (currentSchemaVersion < 6) {
        // These are early Firefox 3.0 alpha versions that are not supported
        // anymore.  In this case it's safer to just replace the database.
        return NS_ERROR_FILE_CORRUPTED;
      }

      // Firefox 3.0 uses schema version 6.

      if (currentSchemaVersion < 7) {
        rv = MigrateV7Up();
        NS_ENSURE_SUCCESS(rv, rv);
      }

      if (currentSchemaVersion < 8) {
        rv = MigrateV8Up();
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Firefox 3.5 uses schema version 8.

      if (currentSchemaVersion < 9) {
        rv = MigrateV9Up();
        NS_ENSURE_SUCCESS(rv, rv);
      }

      if (currentSchemaVersion < 10) {
        rv = MigrateV10Up();
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Firefox 3.6 uses schema version 10.

      if (currentSchemaVersion < 11) {
        rv = MigrateV11Up();
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Firefox 4 uses schema version 11.

      // Firefox 8 uses schema version 12.

      // Schema Upgrades must add migration code here.
    }
  }
  else {
    // This is a new database, so we have to create all the tables and indices.

    // moz_places.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_PLACES);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_URL);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_FAVICON);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_REVHOST);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_VISITCOUNT);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_FRECENCY);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_LASTVISITDATE);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_GUID);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_historyvisits.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_HISTORYVISITS);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_HISTORYVISITS_PLACEDATE);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_HISTORYVISITS_FROMVISIT);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_HISTORYVISITS_VISITDATE);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_inputhistory.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_INPUTHISTORY);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_bookmarks.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_BOOKMARKS);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_PLACETYPE);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_PARENTPOSITION);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_PLACELASTMODIFIED);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_GUID);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_bookmarks_roots.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_BOOKMARKS_ROOTS);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_keywords.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_KEYWORDS);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_KEYWORD_VALIDITY_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_favicons.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_FAVICONS);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_anno_attributes.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_ANNO_ATTRIBUTES);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_annos.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_ANNOS);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_ANNOS_PLACEATTRIBUTE);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_items_annos.
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_ITEMS_ANNOS);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_ITEMSANNOS_PLACEATTRIBUTE);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Set the schema version to the current one.
  rv = mMainConn->SetSchemaVersion(DATABASE_SCHEMA_VERSION);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = transaction.Commit();
  NS_ENSURE_SUCCESS(rv, rv);

  ForceWALCheckpoint();

  // ANY FAILURE IN THIS METHOD WILL CAUSE US TO MARK THE DATABASE AS CORRUPT
  // AND TRY TO REPLACE IT.
  // DO NOT PUT HERE ANYTHING THAT IS NOT RELATED TO INITIALIZATION OR MODIFYING
  // THE DISK DATABASE.

  return NS_OK;
}

nsresult
Database::InitFunctions()
{
  MOZ_ASSERT(NS_IsMainThread());

  nsresult rv = GetUnreversedHostFunction::create(mMainConn);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = MatchAutoCompleteFunction::create(mMainConn);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = CalculateFrecencyFunction::create(mMainConn);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = GenerateGUIDFunction::create(mMainConn);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
Database::InitTempTriggers()
{
  MOZ_ASSERT(NS_IsMainThread());

  nsresult rv = mMainConn->ExecuteSimpleSQL(CREATE_HISTORYVISITS_AFTERINSERT_TRIGGER);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = mMainConn->ExecuteSimpleSQL(CREATE_HISTORYVISITS_AFTERDELETE_TRIGGER);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
Database::CheckAndUpdateGUIDs()
{
  MOZ_ASSERT(NS_IsMainThread());

  // First, import any bookmark guids already set by Sync.
  nsCOMPtr<mozIStorageStatement> updateStmt;
  nsresult rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "UPDATE moz_bookmarks "
    "SET guid = :guid "
    "WHERE id = :item_id "
  ), getter_AddRefs(updateStmt));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<mozIStorageStatement> stmt;
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT item_id, content "
    "FROM moz_items_annos "
    "JOIN moz_anno_attributes "
    "WHERE name = :anno_name "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = stmt->BindUTF8StringByName(NS_LITERAL_CSTRING("anno_name"),
                                  SYNCGUID_ANNO);
  NS_ENSURE_SUCCESS(rv, rv);

  bool hasResult;
  while (NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
    PRInt64 itemId;
    rv = stmt->GetInt64(0, &itemId);
    NS_ENSURE_SUCCESS(rv, rv);
    nsCAutoString guid;
    rv = stmt->GetUTF8String(1, guid);
    NS_ENSURE_SUCCESS(rv, rv);

    // If we have an invalid guid, we don't need to do any more work.
    if (!IsValidGUID(guid)) {
      continue;
    }

    mozStorageStatementScoper updateScoper(updateStmt);
    rv = updateStmt->BindInt64ByName(NS_LITERAL_CSTRING("item_id"), itemId);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStmt->BindUTF8StringByName(NS_LITERAL_CSTRING("guid"), guid);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStmt->Execute();
    if (rv == NS_ERROR_STORAGE_CONSTRAINT) {
      // We just tried to insert a duplicate guid.  Ignore this error, and we
      // will generate a new one next.
      continue;
    }
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Now, remove all the bookmark guid annotations that we just imported.
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "DELETE FROM moz_items_annos "
    "WHERE anno_attribute_id = ( "
      "SELECT id "
      "FROM moz_anno_attributes "
      "WHERE name = :anno_name "
    ") "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = stmt->BindUTF8StringByName(NS_LITERAL_CSTRING("anno_name"),
                                  SYNCGUID_ANNO);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = stmt->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // Next, generate guids for any bookmark that does not already have one.
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "UPDATE moz_bookmarks "
    "SET guid = GENERATE_GUID() "
    "WHERE guid IS NULL "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = stmt->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // Now, import any history guids already set by Sync.
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "UPDATE moz_places "
    "SET guid = :guid "
    "WHERE id = :place_id "
  ), getter_AddRefs(updateStmt));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "SELECT place_id, content "
    "FROM moz_annos "
    "JOIN moz_anno_attributes "
    "WHERE name = :anno_name "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = stmt->BindUTF8StringByName(NS_LITERAL_CSTRING("anno_name"),
                                  SYNCGUID_ANNO);
  NS_ENSURE_SUCCESS(rv, rv);

  while (NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
    PRInt64 placeId;
    rv = stmt->GetInt64(0, &placeId);
    NS_ENSURE_SUCCESS(rv, rv);
    nsCAutoString guid;
    rv = stmt->GetUTF8String(1, guid);
    NS_ENSURE_SUCCESS(rv, rv);

    // If we have an invalid guid, we don't need to do any more work.
    if (!IsValidGUID(guid)) {
      continue;
    }

    mozStorageStatementScoper updateScoper(updateStmt);
    rv = updateStmt->BindInt64ByName(NS_LITERAL_CSTRING("place_id"), placeId);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStmt->BindUTF8StringByName(NS_LITERAL_CSTRING("guid"), guid);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = updateStmt->Execute();
    if (rv == NS_ERROR_STORAGE_CONSTRAINT) {
      // We just tried to insert a duplicate guid.  Ignore this error, and we
      // will generate a new one next.
      continue;
    }
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Now, remove all the place guid annotations that we just imported.
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "DELETE FROM moz_annos "
    "WHERE anno_attribute_id = ( "
      "SELECT id "
      "FROM moz_anno_attributes "
      "WHERE name = :anno_name "
    ") "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = stmt->BindUTF8StringByName(NS_LITERAL_CSTRING("anno_name"),
                                  SYNCGUID_ANNO);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = stmt->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // Finally, generate guids for any places that do not already have one.
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
    "UPDATE moz_places "
    "SET guid = GENERATE_GUID() "
    "WHERE guid IS NULL "
  ), getter_AddRefs(stmt));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = stmt->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
Database::MigrateV7Up() 
{
  MOZ_ASSERT(NS_IsMainThread());

  // Some old v6 databases come from alpha versions that missed indices.
  // Just bail out and replace the database in such a case.
  bool URLUniqueIndexExists = false;
  nsresult rv = mMainConn->IndexExists(NS_LITERAL_CSTRING(
    "moz_places_url_uniqueindex"
  ), &URLUniqueIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!URLUniqueIndexExists) {
    return NS_ERROR_FILE_CORRUPTED;
  }

  mozStorageTransaction transaction(mMainConn, false);

  // We need an index on lastModified to catch quickly last modified bookmark
  // title for tag container's children. This will be useful for sync too.
  bool lastModIndexExists = false;
  rv = mMainConn->IndexExists(
    NS_LITERAL_CSTRING("moz_bookmarks_itemlastmodifiedindex"),
    &lastModIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!lastModIndexExists) {
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_PLACELASTMODIFIED);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // We need to do a one-time change of the moz_historyvisits.pageindex
  // to speed up finding last visit date when joinin with moz_places.
  // See bug 392399 for more details.
  bool pageIndexExists = false;
  rv = mMainConn->IndexExists(
    NS_LITERAL_CSTRING("moz_historyvisits_pageindex"), &pageIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (pageIndexExists) {
    // drop old index
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "DROP INDEX IF EXISTS moz_historyvisits_pageindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create the new multi-column index
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_HISTORYVISITS_PLACEDATE);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // for existing profiles, we may not have a frecency column
  nsCOMPtr<mozIStorageStatement> hasFrecencyStatement;
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT frecency FROM moz_places"),
    getter_AddRefs(hasFrecencyStatement));

  if (NS_FAILED(rv)) {
    // Add frecency column to moz_places, default to -1 so that all the
    // frecencies are invalid
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "ALTER TABLE moz_places ADD frecency INTEGER DEFAULT -1 NOT NULL"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create index for the frecency column
    // XXX multi column index with typed, and visit_count?
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_FRECENCY);
    NS_ENSURE_SUCCESS(rv, rv);

    // Invalidate all frecencies, since they need recalculation.
    nsCOMPtr<mozIStorageAsyncStatement> stmt = GetAsyncStatement(
      "UPDATE moz_places SET frecency = ( "
        "CASE "
        "WHEN url BETWEEN 'place:' AND 'place;' "
        "THEN 0 "
        "ELSE -1 "
        "END "
      ") "
    );
    NS_ENSURE_STATE(stmt);
    nsCOMPtr<mozIStoragePendingStatement> ps;
    (void)stmt->ExecuteAsync(nsnull, getter_AddRefs(ps));
  }

  // Temporary migration code for bug 396300
  nsCOMPtr<mozIStorageStatement> moveUnfiledBookmarks;
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "UPDATE moz_bookmarks "
      "SET parent = ("
        "SELECT folder_id "
        "FROM moz_bookmarks_roots "
        "WHERE root_name = :root_name "
      ") "
      "WHERE type = :item_type "
      "AND parent = ("
        "SELECT folder_id "
        "FROM moz_bookmarks_roots "
        "WHERE root_name = :parent_name "
      ")"),
    getter_AddRefs(moveUnfiledBookmarks));
  rv = moveUnfiledBookmarks->BindUTF8StringByName(
    NS_LITERAL_CSTRING("root_name"), NS_LITERAL_CSTRING("unfiled")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = moveUnfiledBookmarks->BindInt32ByName(
    NS_LITERAL_CSTRING("item_type"), nsINavBookmarksService::TYPE_BOOKMARK
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = moveUnfiledBookmarks->BindUTF8StringByName(
    NS_LITERAL_CSTRING("parent_name"), NS_LITERAL_CSTRING("places")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = moveUnfiledBookmarks->Execute();
  NS_ENSURE_SUCCESS(rv, rv);

  // Create a statement to test for trigger creation
  nsCOMPtr<mozIStorageStatement> triggerDetection;
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT name "
      "FROM sqlite_master "
      "WHERE type = 'trigger' "
      "AND name = :trigger_name"),
    getter_AddRefs(triggerDetection));
  NS_ENSURE_SUCCESS(rv, rv);

  // Check for existence
  bool triggerExists;
  rv = triggerDetection->BindUTF8StringByName(
    NS_LITERAL_CSTRING("trigger_name"),
    NS_LITERAL_CSTRING("moz_historyvisits_afterinsert_v1_trigger")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->ExecuteStep(&triggerExists);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->Reset();
  NS_ENSURE_SUCCESS(rv, rv);

  // We need to create two triggers on moz_historyvists to maintain the
  // accuracy of moz_places.visit_count.  For this to work, we must ensure that
  // all moz_places.visit_count values are correct.
  // See bug 416313 for details.
  if (!triggerExists) {
    // First, we do a one-time reset of all the moz_places.visit_count values.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "UPDATE moz_places SET visit_count = "
          "(SELECT count(*) FROM moz_historyvisits "
           "WHERE place_id = moz_places.id "
            "AND visit_type NOT IN ") +
              nsPrintfCString("(0,%d,%d,%d) ",
                              nsINavHistoryService::TRANSITION_EMBED,
                              nsINavHistoryService::TRANSITION_FRAMED_LINK,
                              nsINavHistoryService::TRANSITION_DOWNLOAD) +
          NS_LITERAL_CSTRING(")"));
    NS_ENSURE_SUCCESS(rv, rv);

    // We used to create two triggers here, but we no longer need that with
    // schema version eight and greater.  We've removed their creation here as
    // a result.
  }

  // Check for existence
  rv = triggerDetection->BindUTF8StringByName(
    NS_LITERAL_CSTRING("trigger_name"),
    NS_LITERAL_CSTRING("moz_bookmarks_beforedelete_v1_trigger")
  );
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->ExecuteStep(&triggerExists);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = triggerDetection->Reset();
  NS_ENSURE_SUCCESS(rv, rv);

  // We need to create one trigger on moz_bookmarks to remove unused keywords.
  // See bug 421180 for details.
  if (!triggerExists) {
    // First, remove any existing dangling keywords
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "DELETE FROM moz_keywords "
        "WHERE id IN ("
          "SELECT k.id "
          "FROM moz_keywords k "
          "LEFT OUTER JOIN moz_bookmarks b "
          "ON b.keyword_id = k.id "
          "WHERE b.id IS NULL"
        ")"));
    NS_ENSURE_SUCCESS(rv, rv);

    // Now we create our trigger
    rv = mMainConn->ExecuteSimpleSQL(CREATE_KEYWORD_VALIDITY_TRIGGER);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // Add the moz_inputhistory table, if missing.
  bool tableExists = false;
  rv = mMainConn->TableExists(NS_LITERAL_CSTRING("moz_inputhistory"),
                              &tableExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (!tableExists) {
    rv = mMainConn->ExecuteSimpleSQL(CREATE_MOZ_INPUTHISTORY);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return transaction.Commit();
}


nsresult
Database::MigrateV8Up()
{
  MOZ_ASSERT(NS_IsMainThread());
  mozStorageTransaction transaction(mMainConn, false);

  nsresult rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP TRIGGER IF EXISTS moz_historyvisits_afterinsert_v1_trigger"));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP TRIGGER IF EXISTS moz_historyvisits_afterdelete_v1_trigger"));
  NS_ENSURE_SUCCESS(rv, rv);


  // bug #381795 - remove unused indexes
  rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP INDEX IF EXISTS moz_places_titleindex"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP INDEX IF EXISTS moz_annos_item_idindex"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "DROP INDEX IF EXISTS moz_annos_place_idindex"));
  NS_ENSURE_SUCCESS(rv, rv);

  // Do a one-time re-creation of the moz_annos indexes (bug 415201)
  bool oldIndexExists = false;
  rv = mMainConn->IndexExists(NS_LITERAL_CSTRING("moz_annos_attributesindex"), &oldIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);
  if (oldIndexExists) {
    // drop old uri annos index
    rv = mMainConn->ExecuteSimpleSQL(
        NS_LITERAL_CSTRING("DROP INDEX moz_annos_attributesindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create new uri annos index
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_ANNOS_PLACEATTRIBUTE);
    NS_ENSURE_SUCCESS(rv, rv);

    // drop old item annos index
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "DROP INDEX IF EXISTS moz_items_annos_attributesindex"));
    NS_ENSURE_SUCCESS(rv, rv);

    // create new item annos index
    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_ITEMSANNOS_PLACEATTRIBUTE);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return transaction.Commit();
}


nsresult
Database::MigrateV9Up()
{
  MOZ_ASSERT(NS_IsMainThread());
  mozStorageTransaction transaction(mMainConn, false);
  // Added in Bug 488966.  The last_visit_date column caches the last
  // visit date, this enhances SELECT performances when we
  // need to sort visits by visit date.
  // The cached value is synced by triggers on every added or removed visit.
  // See nsPlacesTriggers.h for details on the triggers.
  bool oldIndexExists = false;
  nsresult rv = mMainConn->IndexExists(
    NS_LITERAL_CSTRING("moz_places_lastvisitdateindex"), &oldIndexExists);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!oldIndexExists) {
    // Add last_visit_date column to moz_places.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "ALTER TABLE moz_places ADD last_visit_date INTEGER"));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_LASTVISITDATE);
    NS_ENSURE_SUCCESS(rv, rv);

    // Now let's sync the column contents with real visit dates.
    // This query can be really slow due to disk access, since it will basically
    // dupe the table contents in the journal file, and then write them down
    // in the database.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
        "UPDATE moz_places SET last_visit_date = "
          "(SELECT MAX(visit_date) "
           "FROM moz_historyvisits "
           "WHERE place_id = moz_places.id)"));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return transaction.Commit();
}


nsresult
Database::MigrateV10Up()
{
  MOZ_ASSERT(NS_IsMainThread());
  // LastModified is set to the same value as dateAdded on item creation.
  // This way we can use lastModified index to sort.
  nsresult rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "UPDATE moz_bookmarks SET lastModified = dateAdded "
      "WHERE lastModified IS NULL"));
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}


nsresult
Database::MigrateV11Up()
{
  MOZ_ASSERT(NS_IsMainThread());
  // Temp tables are going away.
  // For triggers correctness, every time we pass through this migration
  // step, we must ensure correctness of visit_count values.
  nsresult rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
    "UPDATE moz_places SET visit_count = "
      "(SELECT count(*) FROM moz_historyvisits "
       "WHERE place_id = moz_places.id "
        "AND visit_type NOT IN ") +
          nsPrintfCString("(0,%d,%d,%d) ",
                          nsINavHistoryService::TRANSITION_EMBED,
                          nsINavHistoryService::TRANSITION_FRAMED_LINK,
                          nsINavHistoryService::TRANSITION_DOWNLOAD) +
      NS_LITERAL_CSTRING(")")
  );
  NS_ENSURE_SUCCESS(rv, rv);

  // For existing profiles, we may not have a moz_bookmarks.guid column
  nsCOMPtr<mozIStorageStatement> hasGuidStatement;
  rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
      "SELECT guid FROM moz_bookmarks"),
    getter_AddRefs(hasGuidStatement));

  if (NS_FAILED(rv)) {
    // moz_bookmarks grew a guid column.  Add the column, but do not populate it
    // with anything just yet.  We will do that soon.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_bookmarks "
      "ADD COLUMN guid TEXT"
    ));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_BOOKMARKS_GUID);
    NS_ENSURE_SUCCESS(rv, rv);

    // moz_placess grew a guid column.  Add the column, but do not populate it
    // with anything just yet.  We will do that soon.
    rv = mMainConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
      "ALTER TABLE moz_places "
      "ADD COLUMN guid TEXT"
    ));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mMainConn->ExecuteSimpleSQL(CREATE_IDX_MOZ_PLACES_GUID);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // We need to update our guids before we do any real database work.
  rv = CheckAndUpdateGUIDs();
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

void
Database::Shutdown()
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(!mShuttingDown);

  mMainThreadStatements.FinalizeStatements();
  mMainThreadAsyncStatements.FinalizeStatements();

  nsRefPtr< FinalizeStatementCacheProxy<mozIStorageStatement> > event =
    new FinalizeStatementCacheProxy<mozIStorageStatement>(
          mAsyncThreadStatements, NS_ISUPPORTS_CAST(nsIObserver*, this)
        );
  DispatchToAsyncThread(event);

  nsRefPtr<PlacesEvent> closeListener =
    new PlacesEvent(TOPIC_PLACES_CONNECTION_CLOSED);
  (void)mMainConn->AsyncClose(closeListener);

  // Don't set this earlier, otherwise some internal helper used on shutdown
  // may bail out.
  mShuttingDown = true;
}

////////////////////////////////////////////////////////////////////////////////
//// nsIObserver

NS_IMETHODIMP
Database::Observe(nsISupports *aSubject,
                  const char *aTopic,
                  const PRUnichar *aData)
{
  NS_ASSERTION(NS_IsMainThread(), "This can only be called on the main thread");
 
  if (strcmp(aTopic, TOPIC_PROFILE_CHANGE_TEARDOWN) == 0) {
    // Tests simulating shutdown may cause multiple notifications.
    if (mShuttingDown) {
      return NS_OK;
    }

    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
    NS_ENSURE_STATE(os);

    // If shutdown happens in the same mainthread loop as init, observers could
    // handle the places-init-complete notification after xpcom-shutdown, when
    // the connection does not exist anymore.  Removing those observers would
    // be less expensive but may cause their RemoveObserver calls to throw.
    // Thus notify the topic now, so they stop listening for it.
    nsCOMPtr<nsISimpleEnumerator> e;
    if (NS_SUCCEEDED(os->EnumerateObservers(TOPIC_PLACES_INIT_COMPLETE,
                     getter_AddRefs(e))) && e) {
      bool hasMore = false;
      while (NS_SUCCEEDED(e->HasMoreElements(&hasMore)) && hasMore) {
        nsCOMPtr<nsIObserver> observer;
        if (NS_SUCCEEDED(e->GetNext(getter_AddRefs(observer)))) {
          (void)observer->Observe(observer, TOPIC_PLACES_INIT_COMPLETE, nsnull);
        }
      }
    }

    // Notify all Places users that we are about to shutdown.
    (void)os->NotifyObservers(nsnull, TOPIC_PLACES_SHUTDOWN, nsnull);
  }

  else if (strcmp(aTopic, TOPIC_PROFILE_BEFORE_CHANGE) == 0) {
    // Tests simulating shutdown may cause re-entrance.
    if (mShuttingDown) {
      return NS_OK;
    }

    // Fire internal shutdown notifications.
    nsCOMPtr<nsIObserverService> os = services::GetObserverService();
    if (os) {
      (void)os->NotifyObservers(nsnull, TOPIC_PLACES_WILL_CLOSE_CONNECTION, nsnull);
    }

#ifdef DEBUG
    { // Sanity check for missing guids.
      nsCOMPtr<mozIStorageStatement> stmt;
      nsresult rv = mMainConn->CreateStatement(NS_LITERAL_CSTRING(
        "SELECT 1 "
        "FROM moz_places "
        "WHERE guid IS NULL "
        "UNION ALL "
        "SELECT 1 "
        "FROM moz_bookmarks "
        "WHERE guid IS NULL "
      ), getter_AddRefs(stmt));
      NS_ENSURE_SUCCESS(rv, rv);

      bool haveNullGuids;
      rv = stmt->ExecuteStep(&haveNullGuids);
      NS_ENSURE_SUCCESS(rv, rv);
      NS_ASSERTION(!haveNullGuids,
                   "Someone added an entry without adding a GUID!");
    }
#endif

    // As the last step in the shutdown path, finalize the database handle.
    Shutdown();
  }

  return NS_OK;
}

} // namespace places
} // namespace mozilla