storage/mozStorageService.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/Attributes.h"
   8 #include "mozilla/DebugOnly.h"
   9 #include "mozilla/SpinEventLoopUntil.h"
  10
  11 #include "mozStorageService.h"
  12 #include "mozStorageConnection.h"
  13 #include "nsComponentManagerUtils.h"
  14 #include "nsEmbedCID.h"
  15 #include "nsExceptionHandler.h"
  16 #include "nsThreadUtils.h"
  17 #include "mozStoragePrivateHelpers.h"
  18 #include "nsIObserverService.h"
  19 #include "nsIPropertyBag2.h"
  20 #include "mozilla/Services.h"
  21 #include "mozilla/LateWriteChecks.h"
  22 #include "mozIStorageCompletionCallback.h"
  23 #include "mozIStoragePendingStatement.h"
  24 #include "mozilla/StaticPrefs_storage.h"
  25 #include "mozilla/intl/Collator.h"
  26 #include "mozilla/intl/LocaleService.h"
  27
  28 #include "sqlite3.h"
  29 #include "mozilla/AutoSQLiteLifetime.h"
  30
  31 #ifdef XP_WIN
  32 // "windows.h" was included and it can #define lots of things we care about...
  33 #  undef CompareString
  34 #endif
  35
  36 using mozilla::intl::Collator;
  37
  38 namespace mozilla {
  39 namespace storage {
  40
  41 ////////////////////////////////////////////////////////////////////////////////
  42 //// Memory Reporting
  43
  44 #ifdef MOZ_DMD
  45 mozilla::Atomic<size_t> gSqliteMemoryUsed;
  46 #endif
  47
  48 static int64_t StorageSQLiteDistinguishedAmount() {
  49   return ::sqlite3_memory_used();
  50 }
  51
  52 /**
  53  * Passes a single SQLite memory statistic to a memory reporter callback.
  54  *
  55  * @param aHandleReport
  56  *        The callback.
  57  * @param aData
  58  *        The data for the callback.
  59  * @param aConn
  60  *        The SQLite connection.
  61  * @param aPathHead
  62  *        Head of the path for the memory report.
  63  * @param aKind
  64  *        The memory report statistic kind, one of "stmt", "cache" or
  65  *        "schema".
  66  * @param aDesc
  67  *        The memory report description.
  68  * @param aOption
  69  *        The SQLite constant for getting the measurement.
  70  * @param aTotal
  71  *        The accumulator for the measurement.
  72  */
  73 static void ReportConn(nsIHandleReportCallback* aHandleReport,
  74                        nsISupports* aData, Connection* aConn,
  75                        const nsACString& aPathHead, const nsACString& aKind,
  76                        const nsACString& aDesc, int32_t aOption,
  77                        size_t* aTotal) {
  78   nsCString path(aPathHead);
  79   path.Append(aKind);
  80   path.AppendLiteral("-used");
  81
  82   int32_t val = aConn->getSqliteRuntimeStatus(aOption);
  83   aHandleReport->Callback(""_ns, path, nsIMemoryReporter::KIND_HEAP,
  84                           nsIMemoryReporter::UNITS_BYTES, int64_t(val), aDesc,
  85                           aData);
  86   *aTotal += val;
  87 }
  88
  89 // Warning: To get a Connection's measurements requires holding its lock.
  90 // There may be a delay getting the lock if another thread is accessing the
  91 // Connection.  This isn't very nice if CollectReports is called from the main
  92 // thread!  But at the time of writing this function is only called when
  93 // about:memory is loaded (not, for example, when telemetry pings occur) and
  94 // any delays in that case aren't so bad.
  95 NS_IMETHODIMP
  96 Service::CollectReports(nsIHandleReportCallback* aHandleReport,
  97                         nsISupports* aData, bool aAnonymize) {
  98   size_t totalConnSize = 0;
  99   {
 100     nsTArray<RefPtr<Connection>> connections;
 101     getConnections(connections);
 102
 103     for (uint32_t i = 0; i < connections.Length(); i++) {
 104       RefPtr<Connection>& conn = connections[i];
 105
 106       // Someone may have closed the Connection, in which case we skip it.
 107       // Note that we have consumers of the synchronous API that are off the
 108       // main-thread, like the DOM Cache and IndexedDB, and as such we must be
 109       // sure that we have a connection.
 110       MutexAutoLock lockedAsyncScope(conn->sharedAsyncExecutionMutex);
 111       if (!conn->connectionReady()) {
 112         continue;
 113       }
 114
 115       nsCString pathHead("explicit/storage/sqlite/");
 116       // This filename isn't privacy-sensitive, and so is never anonymized.
 117       pathHead.Append(conn->getFilename());
 118       pathHead.Append('/');
 119
 120       SQLiteMutexAutoLock lockedScope(conn->sharedDBMutex);
 121
 122       constexpr auto stmtDesc =
 123           "Memory (approximate) used by all prepared statements used by "
 124           "connections to this database."_ns;
 125       ReportConn(aHandleReport, aData, conn, pathHead, "stmt"_ns, stmtDesc,
 126                  SQLITE_DBSTATUS_STMT_USED, &totalConnSize);
 127
 128       constexpr auto cacheDesc =
 129           "Memory (approximate) used by all pager caches used by connections "
 130           "to this database."_ns;
 131       ReportConn(aHandleReport, aData, conn, pathHead, "cache"_ns, cacheDesc,
 132                  SQLITE_DBSTATUS_CACHE_USED_SHARED, &totalConnSize);
 133
 134       constexpr auto schemaDesc =
 135           "Memory (approximate) used to store the schema for all databases "
 136           "associated with connections to this database."_ns;
 137       ReportConn(aHandleReport, aData, conn, pathHead, "schema"_ns, schemaDesc,
 138                  SQLITE_DBSTATUS_SCHEMA_USED, &totalConnSize);
 139     }
 140
 141 #ifdef MOZ_DMD
 142     if (::sqlite3_memory_used() != int64_t(gSqliteMemoryUsed)) {
 143       NS_WARNING(
 144           "memory consumption reported by SQLite doesn't match "
 145           "our measurements");
 146     }
 147 #endif
 148   }
 149
 150   int64_t other = ::sqlite3_memory_used() - totalConnSize;
 151
 152   MOZ_COLLECT_REPORT("explicit/storage/sqlite/other", KIND_HEAP, UNITS_BYTES,
 153                      other, "All unclassified sqlite memory.");
 154
 155   return NS_OK;
 156 }
 157
 158 ////////////////////////////////////////////////////////////////////////////////
 159 //// Service
 160
 161 NS_IMPL_ISUPPORTS(Service, mozIStorageService, nsIObserver, nsIMemoryReporter)
 162
 163 Service* Service::gService = nullptr;
 164
 165 already_AddRefed<Service> Service::getSingleton() {
 166   if (gService) {
 167     return do_AddRef(gService);
 168   }
 169
 170   // The first reference to the storage service must be obtained on the
 171   // main thread.
 172   NS_ENSURE_TRUE(NS_IsMainThread(), nullptr);
 173   RefPtr<Service> service = new Service();
 174   if (NS_SUCCEEDED(service->initialize())) {
 175     // Note: This is cleared in the Service destructor.
 176     gService = service.get();
 177     return service.forget();
 178   }
 179
 180   return nullptr;
 181 }
 182
 183 int Service::AutoVFSRegistration::Init(UniquePtr<sqlite3_vfs> aVFS) {
 184   MOZ_ASSERT(!mVFS);
 185   if (aVFS) {
 186     mVFS = std::move(aVFS);
 187     return sqlite3_vfs_register(mVFS.get(), 0);
 188   }
 189   NS_WARNING("Failed to register VFS");
 190   return SQLITE_OK;
 191 }
 192
 193 Service::AutoVFSRegistration::~AutoVFSRegistration() {
 194   if (mVFS) {
 195     int rc = sqlite3_vfs_unregister(mVFS.get());
 196     if (rc != SQLITE_OK) {
 197       NS_WARNING("Failed to unregister sqlite vfs wrapper.");
 198     }
 199   }
 200 }
 201
 202 Service::Service()
 203     : mMutex("Service::mMutex"),
 204       mRegistrationMutex("Service::mRegistrationMutex"),
 205       mConnections() {}
 206
 207 Service::~Service() {
 208   mozilla::UnregisterWeakMemoryReporter(this);
 209   mozilla::UnregisterStorageSQLiteDistinguishedAmount();
 210
 211   gService = nullptr;
 212 }
 213
 214 void Service::registerConnection(Connection* aConnection) {
 215   mRegistrationMutex.AssertNotCurrentThreadOwns();
 216   MutexAutoLock mutex(mRegistrationMutex);
 217   (void)mConnections.AppendElement(aConnection);
 218 }
 219
 220 void Service::unregisterConnection(Connection* aConnection) {
 221   // If this is the last Connection it might be the only thing keeping Service
 222   // alive.  So ensure that Service is destroyed only after the Connection is
 223   // cleanly unregistered and destroyed.
 224   RefPtr<Service> kungFuDeathGrip(this);
 225   RefPtr<Connection> forgettingRef;
 226   {
 227     mRegistrationMutex.AssertNotCurrentThreadOwns();
 228     MutexAutoLock mutex(mRegistrationMutex);
 229
 230     for (uint32_t i = 0; i < mConnections.Length(); ++i) {
 231       if (mConnections[i] == aConnection) {
 232         // Because dropping the final reference can potentially result in
 233         // spinning a nested event loop if the connection was not properly
 234         // shutdown, we want to do that outside this loop so that we can finish
 235         // mutating the array and drop our mutex.
 236         forgettingRef = std::move(mConnections[i]);
 237         mConnections.RemoveElementAt(i);
 238         break;
 239       }
 240     }
 241   }
 242
 243   MOZ_ASSERT(forgettingRef,
 244              "Attempt to unregister unknown storage connection!");
 245
 246   // Do not proxy the release anywhere, just let this reference drop here. (We
 247   // previously did proxy the release, but that was because we invoked Close()
 248   // in the destructor and Close() likes to complain if it's not invoked on the
 249   // opener event target, so it was essential that the last reference be dropped
 250   // on the opener event target.  We now enqueue Close() inside our caller,
 251   // Release(), so it doesn't actually matter what thread our reference drops
 252   // on.)
 253 }
 254
 255 void Service::getConnections(
 256     /* inout */ nsTArray<RefPtr<Connection>>& aConnections) {
 257   mRegistrationMutex.AssertNotCurrentThreadOwns();
 258   MutexAutoLock mutex(mRegistrationMutex);
 259   aConnections.Clear();
 260   aConnections.AppendElements(mConnections);
 261 }
 262
 263 void Service::minimizeMemory() {
 264   nsTArray<RefPtr<Connection>> connections;
 265   getConnections(connections);
 266
 267   for (uint32_t i = 0; i < connections.Length(); i++) {
 268     RefPtr<Connection> conn = connections[i];
 269     // For non-main-thread owning/opening threads, we may be racing against them
 270     // closing their connection or their thread.  That's okay, see below.
 271     if (!conn->connectionReady()) {
 272       continue;
 273     }
 274
 275     constexpr auto shrinkPragma = "PRAGMA shrink_memory"_ns;
 276
 277     if (!conn->operationSupported(Connection::SYNCHRONOUS)) {
 278       // This is a mozIStorageAsyncConnection, it can only be used on the main
 279       // thread, so we can do a straight API call.
 280       nsCOMPtr<mozIStoragePendingStatement> ps;
 281       DebugOnly<nsresult> rv = conn->ExecuteSimpleSQLAsync(
 282           shrinkPragma, nullptr, getter_AddRefs(ps));
 283       MOZ_ASSERT(NS_SUCCEEDED(rv), "Should have purged sqlite caches");
 284     } else if (IsOnCurrentSerialEventTarget(conn->eventTargetOpenedOn)) {
 285       if (conn->isAsyncExecutionThreadAvailable()) {
 286         nsCOMPtr<mozIStoragePendingStatement> ps;
 287         DebugOnly<nsresult> rv = conn->ExecuteSimpleSQLAsync(
 288             shrinkPragma, nullptr, getter_AddRefs(ps));
 289         MOZ_ASSERT(NS_SUCCEEDED(rv), "Should have purged sqlite caches");
 290       } else {
 291         conn->ExecuteSimpleSQL(shrinkPragma);
 292       }
 293     } else {
 294       // We are on the wrong event target, the query should be executed on the
 295       // opener event target, so we must dispatch to it.
 296       // It's possible the connection is already closed or will be closed by the
 297       // time our runnable runs. ExecuteSimpleSQL will safely return with a
 298       // failure in that case. If the event target is shutting down or shut
 299       // down, the dispatch will fail and that's okay.
 300       nsCOMPtr<nsIRunnable> event = NewRunnableMethod<const nsCString>(
 301           "Connection::ExecuteSimpleSQL", conn, &Connection::ExecuteSimpleSQL,
 302           shrinkPragma);
 303       Unused << conn->eventTargetOpenedOn->Dispatch(event, NS_DISPATCH_NORMAL);
 304     }
 305   }
 306 }
 307
 308 UniquePtr<sqlite3_vfs> ConstructBaseVFS(bool);
 309 const char* GetBaseVFSName(bool);
 310
 311 UniquePtr<sqlite3_vfs> ConstructQuotaVFS(const char* aBaseVFSName);
 312 const char* GetQuotaVFSName();
 313
 314 UniquePtr<sqlite3_vfs> ConstructObfuscatingVFS(const char* aBaseVFSName);
 315
 316 UniquePtr<sqlite3_vfs> ConstructReadOnlyNoLockVFS();
 317
 318 static const char* sObserverTopics[] = {"memory-pressure",
 319                                         "xpcom-shutdown-threads"};
 320
 321 nsresult Service::initialize() {
 322   MOZ_ASSERT(NS_IsMainThread(), "Must be initialized on the main thread");
 323
 324   int rc = AutoSQLiteLifetime::getInitResult();
 325   if (rc != SQLITE_OK) {
 326     return convertResultCode(rc);
 327   }
 328
 329   /**
 330    *                    The virtual file system hierarchy
 331    *
 332    *                                 obfsvfs
 333    *                                    |
 334    *                                    |
 335    *                                    |
 336    *                                 quotavfs
 337    *                                   / \
 338    *                                 /     \
 339    *                               /         \
 340    *                             /             \
 341    *                           /                 \
 342    *                     base-vfs-excl        base-vfs
 343    *                          / \               / \
 344    *                        /     \           /     \
 345    *                      /         \       /         \
 346    *                 unix-excl     win32  unix       win32
 347    */
 348
 349   rc = mBaseSqliteVFS.Init(ConstructBaseVFS(false));
 350   if (rc != SQLITE_OK) {
 351     return convertResultCode(rc);
 352   }
 353
 354   rc = mBaseExclSqliteVFS.Init(ConstructBaseVFS(true));
 355   if (rc != SQLITE_OK) {
 356     return convertResultCode(rc);
 357   }
 358
 359   rc = mQuotaSqliteVFS.Init(ConstructQuotaVFS(
 360       GetBaseVFSName(StaticPrefs::storage_sqlite_exclusiveLock_enabled())));
 361   if (rc != SQLITE_OK) {
 362     return convertResultCode(rc);
 363   }
 364
 365   rc = mObfuscatingSqliteVFS.Init(ConstructObfuscatingVFS(GetQuotaVFSName()));
 366   if (rc != SQLITE_OK) {
 367     return convertResultCode(rc);
 368   }
 369
 370   rc = mReadOnlyNoLockSqliteVFS.Init(ConstructReadOnlyNoLockVFS());
 371   if (rc != SQLITE_OK) {
 372     return convertResultCode(rc);
 373   }
 374
 375   nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
 376   NS_ENSURE_TRUE(os, NS_ERROR_FAILURE);
 377
 378   for (size_t i = 0; i < ArrayLength(sObserverTopics); ++i) {
 379     nsresult rv = os->AddObserver(this, sObserverTopics[i], false);
 380     if (NS_WARN_IF(NS_FAILED(rv))) {
 381       return rv;
 382     }
 383   }
 384
 385   mozilla::RegisterWeakMemoryReporter(this);
 386   mozilla::RegisterStorageSQLiteDistinguishedAmount(
 387       StorageSQLiteDistinguishedAmount);
 388
 389   return NS_OK;
 390 }
 391
 392 int Service::localeCompareStrings(const nsAString& aStr1,
 393                                   const nsAString& aStr2,
 394                                   Collator::Sensitivity aSensitivity) {
 395   // The mozilla::intl::Collator is not thread safe, since the Collator::Options
 396   // can be changed.
 397   MutexAutoLock mutex(mMutex);
 398
 399   Collator* collator = getCollator();
 400   if (!collator) {
 401     NS_ERROR("Storage service has no collation");
 402     return 0;
 403   }
 404
 405   if (aSensitivity != mLastSensitivity) {
 406     Collator::Options options{};
 407     options.sensitivity = aSensitivity;
 408     auto result = mCollator->SetOptions(options);
 409
 410     if (result.isErr()) {
 411       NS_WARNING("Could not configure the mozilla::intl::Collation.");
 412       return 0;
 413     }
 414     mLastSensitivity = aSensitivity;
 415   }
 416
 417   return collator->CompareStrings(aStr1, aStr2);
 418 }
 419
 420 Collator* Service::getCollator() {
 421   mMutex.AssertCurrentThreadOwns();
 422
 423   if (mCollator) {
 424     return mCollator.get();
 425   }
 426
 427   auto result = mozilla::intl::LocaleService::TryCreateComponent<Collator>();
 428   if (result.isErr()) {
 429     NS_WARNING("Could not create mozilla::intl::Collation.");
 430     return nullptr;
 431   }
 432
 433   mCollator = result.unwrap();
 434
 435   // Sort in a case-insensitive way, where "base" letters are considered
 436   // equal, e.g: a = á, a = A, a ≠ b.
 437   Collator::Options options{};
 438   options.sensitivity = Collator::Sensitivity::Base;
 439   auto optResult = mCollator->SetOptions(options);
 440
 441   if (optResult.isErr()) {
 442     NS_WARNING("Could not configure the mozilla::intl::Collation.");
 443     mCollator = nullptr;
 444     return nullptr;
 445   }
 446
 447   return mCollator.get();
 448 }
 449
 450 ////////////////////////////////////////////////////////////////////////////////
 451 //// mozIStorageService
 452
 453 NS_IMETHODIMP
 454 Service::OpenSpecialDatabase(const nsACString& aStorageKey,
 455                              const nsACString& aName, uint32_t aConnectionFlags,
 456                              mozIStorageConnection** _connection) {
 457   if (!aStorageKey.Equals(kMozStorageMemoryStorageKey)) {
 458     return NS_ERROR_INVALID_ARG;
 459   }
 460
 461   const bool interruptible =
 462       aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
 463
 464   int flags = SQLITE_OPEN_READWRITE;
 465
 466   if (!aName.IsEmpty()) {
 467     flags |= SQLITE_OPEN_URI;
 468   }
 469
 470   RefPtr<Connection> msc =
 471       new Connection(this, flags, Connection::SYNCHRONOUS, interruptible);
 472
 473   const nsresult rv = msc->initialize(aStorageKey, aName);
 474   NS_ENSURE_SUCCESS(rv, rv);
 475
 476   msc.forget(_connection);
 477   return NS_OK;
 478 }
 479
 480 namespace {
 481
 482 class AsyncInitDatabase final : public Runnable {
 483  public:
 484   AsyncInitDatabase(Connection* aConnection, nsIFile* aStorageFile,
 485                     int32_t aGrowthIncrement,
 486                     mozIStorageCompletionCallback* aCallback)
 487       : Runnable("storage::AsyncInitDatabase"),
 488         mConnection(aConnection),
 489         mStorageFile(aStorageFile),
 490         mGrowthIncrement(aGrowthIncrement),
 491         mCallback(aCallback) {
 492     MOZ_ASSERT(NS_IsMainThread());
 493   }
 494
 495   NS_IMETHOD Run() override {
 496     MOZ_ASSERT(!NS_IsMainThread());
 497     nsresult rv = mConnection->initializeOnAsyncThread(mStorageFile);
 498     if (NS_FAILED(rv)) {
 499       return DispatchResult(rv, nullptr);
 500     }
 501
 502     if (mGrowthIncrement >= 0) {
 503       // Ignore errors. In the future, we might wish to log them.
 504       (void)mConnection->SetGrowthIncrement(mGrowthIncrement, ""_ns);
 505     }
 506
 507     return DispatchResult(
 508         NS_OK, NS_ISUPPORTS_CAST(mozIStorageAsyncConnection*, mConnection));
 509   }
 510
 511  private:
 512   nsresult DispatchResult(nsresult aStatus, nsISupports* aValue) {
 513     RefPtr<CallbackComplete> event =
 514         new CallbackComplete(aStatus, aValue, mCallback.forget());
 515     return NS_DispatchToMainThread(event);
 516   }
 517
 518   ~AsyncInitDatabase() {
 519     NS_ReleaseOnMainThread("AsyncInitDatabase::mStorageFile",
 520                            mStorageFile.forget());
 521     NS_ReleaseOnMainThread("AsyncInitDatabase::mConnection",
 522                            mConnection.forget());
 523
 524     // Generally, the callback will be released by CallbackComplete.
 525     // However, if for some reason Run() is not executed, we still
 526     // need to ensure that it is released here.
 527     NS_ReleaseOnMainThread("AsyncInitDatabase::mCallback", mCallback.forget());
 528   }
 529
 530   RefPtr<Connection> mConnection;
 531   nsCOMPtr<nsIFile> mStorageFile;
 532   int32_t mGrowthIncrement;
 533   RefPtr<mozIStorageCompletionCallback> mCallback;
 534 };
 535
 536 }  // namespace
 537
 538 NS_IMETHODIMP
 539 Service::OpenAsyncDatabase(nsIVariant* aDatabaseStore, uint32_t aOpenFlags,
 540                            uint32_t /* aConnectionFlags */,
 541                            mozIStorageCompletionCallback* aCallback) {
 542   if (!NS_IsMainThread()) {
 543     return NS_ERROR_NOT_SAME_THREAD;
 544   }
 545   NS_ENSURE_ARG(aDatabaseStore);
 546   NS_ENSURE_ARG(aCallback);
 547
 548   const bool shared = aOpenFlags & mozIStorageService::OPEN_SHARED;
 549   const bool ignoreLockingMode =
 550       aOpenFlags & mozIStorageService::OPEN_IGNORE_LOCKING_MODE;
 551   // Specifying ignoreLockingMode will force use of the readOnly flag:
 552   const bool readOnly =
 553       ignoreLockingMode || (aOpenFlags & mozIStorageService::OPEN_READONLY);
 554   int flags = readOnly ? SQLITE_OPEN_READONLY : SQLITE_OPEN_READWRITE;
 555
 556   nsCOMPtr<nsIFile> storageFile;
 557   nsCOMPtr<nsISupports> dbStore;
 558   nsresult rv = aDatabaseStore->GetAsISupports(getter_AddRefs(dbStore));
 559   if (NS_SUCCEEDED(rv)) {
 560     // Generally, aDatabaseStore holds the database nsIFile.
 561     storageFile = do_QueryInterface(dbStore, &rv);
 562     if (NS_FAILED(rv)) {
 563       return NS_ERROR_INVALID_ARG;
 564     }
 565
 566     nsCOMPtr<nsIFile> cloned;
 567     rv = storageFile->Clone(getter_AddRefs(cloned));
 568     MOZ_ASSERT(NS_SUCCEEDED(rv));
 569     storageFile = std::move(cloned);
 570
 571     if (!readOnly) {
 572       // Ensure that SQLITE_OPEN_CREATE is passed in for compatibility reasons.
 573       flags |= SQLITE_OPEN_CREATE;
 574     }
 575
 576     // Apply the shared-cache option.
 577     flags |= shared ? SQLITE_OPEN_SHAREDCACHE : SQLITE_OPEN_PRIVATECACHE;
 578   } else {
 579     // Sometimes, however, it's a special database name.
 580     nsAutoCString keyString;
 581     rv = aDatabaseStore->GetAsACString(keyString);
 582     if (NS_FAILED(rv) || !keyString.Equals(kMozStorageMemoryStorageKey)) {
 583       return NS_ERROR_INVALID_ARG;
 584     }
 585
 586     // Just fall through with nullptr storageFile, this will cause the storage
 587     // connection to use a memory DB.
 588   }
 589
 590   // Create connection on this thread, but initialize it on its helper thread.
 591   RefPtr<Connection> msc =
 592       new Connection(this, flags, Connection::ASYNCHRONOUS,
 593                      /* interruptible */ true, ignoreLockingMode);
 594   nsCOMPtr<nsIEventTarget> target = msc->getAsyncExecutionTarget();
 595   MOZ_ASSERT(target,
 596              "Cannot initialize a connection that has been closed already");
 597
 598   RefPtr<AsyncInitDatabase> asyncInit = new AsyncInitDatabase(
 599       msc, storageFile, /* growthIncrement */ -1, aCallback);
 600   return target->Dispatch(asyncInit, nsIEventTarget::DISPATCH_NORMAL);
 601 }
 602
 603 NS_IMETHODIMP
 604 Service::OpenDatabase(nsIFile* aDatabaseFile, uint32_t aConnectionFlags,
 605                       mozIStorageConnection** _connection) {
 606   NS_ENSURE_ARG(aDatabaseFile);
 607
 608   const bool interruptible =
 609       aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
 610
 611   // Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
 612   // reasons.
 613   const int flags =
 614       SQLITE_OPEN_READWRITE | SQLITE_OPEN_SHAREDCACHE | SQLITE_OPEN_CREATE;
 615   RefPtr<Connection> msc =
 616       new Connection(this, flags, Connection::SYNCHRONOUS, interruptible);
 617
 618   const nsresult rv = msc->initialize(aDatabaseFile);
 619   NS_ENSURE_SUCCESS(rv, rv);
 620
 621   msc.forget(_connection);
 622   return NS_OK;
 623 }
 624
 625 NS_IMETHODIMP
 626 Service::OpenUnsharedDatabase(nsIFile* aDatabaseFile, uint32_t aConnectionFlags,
 627                               mozIStorageConnection** _connection) {
 628   NS_ENSURE_ARG(aDatabaseFile);
 629
 630   const bool interruptible =
 631       aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
 632
 633   // Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
 634   // reasons.
 635   const int flags =
 636       SQLITE_OPEN_READWRITE | SQLITE_OPEN_PRIVATECACHE | SQLITE_OPEN_CREATE;
 637   RefPtr<Connection> msc =
 638       new Connection(this, flags, Connection::SYNCHRONOUS, interruptible);
 639
 640   const nsresult rv = msc->initialize(aDatabaseFile);
 641   NS_ENSURE_SUCCESS(rv, rv);
 642
 643   msc.forget(_connection);
 644   return NS_OK;
 645 }
 646
 647 NS_IMETHODIMP
 648 Service::OpenDatabaseWithFileURL(nsIFileURL* aFileURL,
 649                                  const nsACString& aTelemetryFilename,
 650                                  uint32_t aConnectionFlags,
 651                                  mozIStorageConnection** _connection) {
 652   NS_ENSURE_ARG(aFileURL);
 653
 654   const bool interruptible =
 655       aConnectionFlags & mozIStorageService::CONNECTION_INTERRUPTIBLE;
 656
 657   // Always ensure that SQLITE_OPEN_CREATE is passed in for compatibility
 658   // reasons.
 659   const int flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_SHAREDCACHE |
 660                     SQLITE_OPEN_CREATE | SQLITE_OPEN_URI;
 661   RefPtr<Connection> msc =
 662       new Connection(this, flags, Connection::SYNCHRONOUS, interruptible);
 663
 664   const nsresult rv = msc->initialize(aFileURL, aTelemetryFilename);
 665   NS_ENSURE_SUCCESS(rv, rv);
 666
 667   msc.forget(_connection);
 668   return NS_OK;
 669 }
 670
 671 NS_IMETHODIMP
 672 Service::BackupDatabaseFile(nsIFile* aDBFile, const nsAString& aBackupFileName,
 673                             nsIFile* aBackupParentDirectory, nsIFile** backup) {
 674   nsresult rv;
 675   nsCOMPtr<nsIFile> parentDir = aBackupParentDirectory;
 676   if (!parentDir) {
 677     // This argument is optional, and defaults to the same parent directory
 678     // as the current file.
 679     rv = aDBFile->GetParent(getter_AddRefs(parentDir));
 680     NS_ENSURE_SUCCESS(rv, rv);
 681   }
 682
 683   nsCOMPtr<nsIFile> backupDB;
 684   rv = parentDir->Clone(getter_AddRefs(backupDB));
 685   NS_ENSURE_SUCCESS(rv, rv);
 686
 687   rv = backupDB->Append(aBackupFileName);
 688   NS_ENSURE_SUCCESS(rv, rv);
 689
 690   rv = backupDB->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
 691   NS_ENSURE_SUCCESS(rv, rv);
 692
 693   nsAutoString fileName;
 694   rv = backupDB->GetLeafName(fileName);
 695   NS_ENSURE_SUCCESS(rv, rv);
 696
 697   rv = backupDB->Remove(false);
 698   NS_ENSURE_SUCCESS(rv, rv);
 699
 700   backupDB.forget(backup);
 701
 702   return aDBFile->CopyTo(parentDir, fileName);
 703 }
 704
 705 ////////////////////////////////////////////////////////////////////////////////
 706 //// nsIObserver
 707
 708 NS_IMETHODIMP
 709 Service::Observe(nsISupports*, const char* aTopic, const char16_t*) {
 710   if (strcmp(aTopic, "memory-pressure") == 0) {
 711     minimizeMemory();
 712   } else if (strcmp(aTopic, "xpcom-shutdown-threads") == 0) {
 713     // The Service is kept alive by our strong observer references and
 714     // references held by Connection instances.  Since we're about to remove the
 715     // former and then wait for the latter ones to go away, it behooves us to
 716     // hold a strong reference to ourselves so our calls to getConnections() do
 717     // not happen on a deleted object.
 718     RefPtr<Service> kungFuDeathGrip = this;
 719
 720     nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
 721
 722     for (size_t i = 0; i < ArrayLength(sObserverTopics); ++i) {
 723       (void)os->RemoveObserver(this, sObserverTopics[i]);
 724     }
 725
 726     SpinEventLoopUntil("storage::Service::Observe(xpcom-shutdown-threads)"_ns,
 727                        [&]() -> bool {
 728                          // We must wait until all the closing connections are
 729                          // closed.
 730                          nsTArray<RefPtr<Connection>> connections;
 731                          getConnections(connections);
 732                          for (auto& conn : connections) {
 733                            if (conn->isClosing()) {
 734                              return false;
 735                            }
 736                          }
 737                          return true;
 738                        });
 739
 740 #ifdef DEBUG
 741     nsTArray<RefPtr<Connection>> connections;
 742     getConnections(connections);
 743     for (uint32_t i = 0, n = connections.Length(); i < n; i++) {
 744       if (!connections[i]->isClosed()) {
 745         // getFilename is only the leaf name for the database file,
 746         // so it shouldn't contain privacy-sensitive information.
 747         CrashReporter::AnnotateCrashReport(
 748             CrashReporter::Annotation::StorageConnectionNotClosed,
 749             connections[i]->getFilename());
 750         printf_stderr("Storage connection not closed: %s",
 751                       connections[i]->getFilename().get());
 752         MOZ_CRASH();
 753       }
 754     }
 755 #endif
 756   }
 757
 758   return NS_OK;
 759 }
 760
 761 }  // namespace storage
 762 }  // namespace mozilla