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