storage/mozStorageConnection.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 "nsThreadUtils.h"
   8 #include "nsIFile.h"
   9 #include "nsIFileURL.h"
  10 #include "nsIXPConnect.h"
  11 #include "mozilla/AppShutdown.h"
  12 #include "mozilla/Telemetry.h"
  13 #include "mozilla/Mutex.h"
  14 #include "mozilla/CondVar.h"
  15 #include "mozilla/Attributes.h"
  16 #include "mozilla/ErrorNames.h"
  17 #include "mozilla/Unused.h"
  18 #include "mozilla/dom/quota/QuotaObject.h"
  19 #include "mozilla/ScopeExit.h"
  20 #include "mozilla/SpinEventLoopUntil.h"
  21 #include "mozilla/StaticPrefs_storage.h"
  22
  23 #include "mozIStorageCompletionCallback.h"
  24 #include "mozIStorageFunction.h"
  25
  26 #include "mozStorageAsyncStatementExecution.h"
  27 #include "mozStorageSQLFunctions.h"
  28 #include "mozStorageConnection.h"
  29 #include "mozStorageService.h"
  30 #include "mozStorageStatement.h"
  31 #include "mozStorageAsyncStatement.h"
  32 #include "mozStorageArgValueArray.h"
  33 #include "mozStoragePrivateHelpers.h"
  34 #include "mozStorageStatementData.h"
  35 #include "StorageBaseStatementInternal.h"
  36 #include "SQLCollations.h"
  37 #include "FileSystemModule.h"
  38 #include "mozStorageHelper.h"
  39
  40 #include "mozilla/Logging.h"
  41 #include "mozilla/Printf.h"
  42 #include "mozilla/ProfilerLabels.h"
  43 #include "nsProxyRelease.h"
  44 #include "nsURLHelper.h"
  45
  46 #define MIN_AVAILABLE_BYTES_PER_CHUNKED_GROWTH 524288000  // 500 MiB
  47
  48 // Maximum size of the pages cache per connection.
  49 #define MAX_CACHE_SIZE_KIBIBYTES 2048  // 2 MiB
  50
  51 mozilla::LazyLogModule gStorageLog("mozStorage");
  52
  53 // Checks that the protected code is running on the main-thread only if the
  54 // connection was also opened on it.
  55 #ifdef DEBUG
  56 #  define CHECK_MAINTHREAD_ABUSE()                                   \
  57     do {                                                             \
  58       NS_WARNING_ASSERTION(                                          \
  59           eventTargetOpenedOn == GetMainThreadSerialEventTarget() || \
  60               !NS_IsMainThread(),                                    \
  61           "Using Storage synchronous API on main-thread, but "       \
  62           "the connection was opened on another thread.");           \
  63     } while (0)
  64 #else
  65 #  define CHECK_MAINTHREAD_ABUSE() \
  66     do { /* Nothing */             \
  67     } while (0)
  68 #endif
  69
  70 namespace mozilla::storage {
  71
  72 using mozilla::dom::quota::QuotaObject;
  73 using mozilla::Telemetry::AccumulateCategoricalKeyed;
  74 using mozilla::Telemetry::LABELS_SQLITE_STORE_OPEN;
  75 using mozilla::Telemetry::LABELS_SQLITE_STORE_QUERY;
  76
  77 const char* GetBaseVFSName(bool);
  78 const char* GetQuotaVFSName();
  79 const char* GetObfuscatingVFSName();
  80
  81 namespace {
  82
  83 int nsresultToSQLiteResult(nsresult aXPCOMResultCode) {
  84   if (NS_SUCCEEDED(aXPCOMResultCode)) {
  85     return SQLITE_OK;
  86   }
  87
  88   switch (aXPCOMResultCode) {
  89     case NS_ERROR_FILE_CORRUPTED:
  90       return SQLITE_CORRUPT;
  91     case NS_ERROR_FILE_ACCESS_DENIED:
  92       return SQLITE_CANTOPEN;
  93     case NS_ERROR_STORAGE_BUSY:
  94       return SQLITE_BUSY;
  95     case NS_ERROR_FILE_IS_LOCKED:
  96       return SQLITE_LOCKED;
  97     case NS_ERROR_FILE_READ_ONLY:
  98       return SQLITE_READONLY;
  99     case NS_ERROR_STORAGE_IOERR:
 100       return SQLITE_IOERR;
 101     case NS_ERROR_FILE_NO_DEVICE_SPACE:
 102       return SQLITE_FULL;
 103     case NS_ERROR_OUT_OF_MEMORY:
 104       return SQLITE_NOMEM;
 105     case NS_ERROR_UNEXPECTED:
 106       return SQLITE_MISUSE;
 107     case NS_ERROR_ABORT:
 108       return SQLITE_ABORT;
 109     case NS_ERROR_STORAGE_CONSTRAINT:
 110       return SQLITE_CONSTRAINT;
 111     default:
 112       return SQLITE_ERROR;
 113   }
 114
 115   MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Must return in switch above!");
 116 }
 117
 118 ////////////////////////////////////////////////////////////////////////////////
 119 //// Variant Specialization Functions (variantToSQLiteT)
 120
 121 int sqlite3_T_int(sqlite3_context* aCtx, int aValue) {
 122   ::sqlite3_result_int(aCtx, aValue);
 123   return SQLITE_OK;
 124 }
 125
 126 int sqlite3_T_int64(sqlite3_context* aCtx, sqlite3_int64 aValue) {
 127   ::sqlite3_result_int64(aCtx, aValue);
 128   return SQLITE_OK;
 129 }
 130
 131 int sqlite3_T_double(sqlite3_context* aCtx, double aValue) {
 132   ::sqlite3_result_double(aCtx, aValue);
 133   return SQLITE_OK;
 134 }
 135
 136 int sqlite3_T_text(sqlite3_context* aCtx, const nsCString& aValue) {
 137   ::sqlite3_result_text(aCtx, aValue.get(), aValue.Length(), SQLITE_TRANSIENT);
 138   return SQLITE_OK;
 139 }
 140
 141 int sqlite3_T_text16(sqlite3_context* aCtx, const nsString& aValue) {
 142   ::sqlite3_result_text16(
 143       aCtx, aValue.get(),
 144       aValue.Length() * sizeof(char16_t),  // Number of bytes.
 145       SQLITE_TRANSIENT);
 146   return SQLITE_OK;
 147 }
 148
 149 int sqlite3_T_null(sqlite3_context* aCtx) {
 150   ::sqlite3_result_null(aCtx);
 151   return SQLITE_OK;
 152 }
 153
 154 int sqlite3_T_blob(sqlite3_context* aCtx, const void* aData, int aSize) {
 155   ::sqlite3_result_blob(aCtx, aData, aSize, free);
 156   return SQLITE_OK;
 157 }
 158
 159 #include "variantToSQLiteT_impl.h"
 160
 161 ////////////////////////////////////////////////////////////////////////////////
 162 //// Modules
 163
 164 struct Module {
 165   const char* name;
 166   int (*registerFunc)(sqlite3*, const char*);
 167 };
 168
 169 Module gModules[] = {{"filesystem", RegisterFileSystemModule}};
 170
 171 ////////////////////////////////////////////////////////////////////////////////
 172 //// Local Functions
 173
 174 int tracefunc(unsigned aReason, void* aClosure, void* aP, void* aX) {
 175   switch (aReason) {
 176     case SQLITE_TRACE_STMT: {
 177       // aP is a pointer to the prepared statement.
 178       sqlite3_stmt* stmt = static_cast<sqlite3_stmt*>(aP);
 179       // aX is a pointer to a string containing the unexpanded SQL or a comment,
 180       // starting with "--"" in case of a trigger.
 181       char* expanded = static_cast<char*>(aX);
 182       // Simulate what sqlite_trace was doing.
 183       if (!::strncmp(expanded, "--", 2)) {
 184         MOZ_LOG(gStorageLog, LogLevel::Debug,
 185                 ("TRACE_STMT on %p: '%s'", aClosure, expanded));
 186       } else {
 187         char* sql = ::sqlite3_expanded_sql(stmt);
 188         MOZ_LOG(gStorageLog, LogLevel::Debug,
 189                 ("TRACE_STMT on %p: '%s'", aClosure, sql));
 190         ::sqlite3_free(sql);
 191       }
 192       break;
 193     }
 194     case SQLITE_TRACE_PROFILE: {
 195       // aX is pointer to a 64bit integer containing nanoseconds it took to
 196       // execute the last command.
 197       sqlite_int64 time = *(static_cast<sqlite_int64*>(aX)) / 1000000;
 198       if (time > 0) {
 199         MOZ_LOG(gStorageLog, LogLevel::Debug,
 200                 ("TRACE_TIME on %p: %lldms", aClosure, time));
 201       }
 202       break;
 203     }
 204   }
 205   return 0;
 206 }
 207
 208 void basicFunctionHelper(sqlite3_context* aCtx, int aArgc,
 209                          sqlite3_value** aArgv) {
 210   void* userData = ::sqlite3_user_data(aCtx);
 211
 212   mozIStorageFunction* func = static_cast<mozIStorageFunction*>(userData);
 213
 214   RefPtr<ArgValueArray> arguments(new ArgValueArray(aArgc, aArgv));
 215   if (!arguments) return;
 216
 217   nsCOMPtr<nsIVariant> result;
 218   nsresult rv = func->OnFunctionCall(arguments, getter_AddRefs(result));
 219   if (NS_FAILED(rv)) {
 220     nsAutoCString errorMessage;
 221     GetErrorName(rv, errorMessage);
 222     errorMessage.InsertLiteral("User function returned ", 0);
 223     errorMessage.Append('!');
 224
 225     NS_WARNING(errorMessage.get());
 226
 227     ::sqlite3_result_error(aCtx, errorMessage.get(), -1);
 228     ::sqlite3_result_error_code(aCtx, nsresultToSQLiteResult(rv));
 229     return;
 230   }
 231   int retcode = variantToSQLiteT(aCtx, result);
 232   if (retcode != SQLITE_OK) {
 233     NS_WARNING("User function returned invalid data type!");
 234     ::sqlite3_result_error(aCtx, "User function returned invalid data type",
 235                            -1);
 236   }
 237 }
 238
 239 /**
 240  * This code is heavily based on the sample at:
 241  *   http://www.sqlite.org/unlock_notify.html
 242  */
 243 class UnlockNotification {
 244  public:
 245   UnlockNotification()
 246       : mMutex("UnlockNotification mMutex"),
 247         mCondVar(mMutex, "UnlockNotification condVar"),
 248         mSignaled(false) {}
 249
 250   void Wait() {
 251     MutexAutoLock lock(mMutex);
 252     while (!mSignaled) {
 253       (void)mCondVar.Wait();
 254     }
 255   }
 256
 257   void Signal() {
 258     MutexAutoLock lock(mMutex);
 259     mSignaled = true;
 260     (void)mCondVar.Notify();
 261   }
 262
 263  private:
 264   Mutex mMutex MOZ_UNANNOTATED;
 265   CondVar mCondVar;
 266   bool mSignaled;
 267 };
 268
 269 void UnlockNotifyCallback(void** aArgs, int aArgsSize) {
 270   for (int i = 0; i < aArgsSize; i++) {
 271     UnlockNotification* notification =
 272         static_cast<UnlockNotification*>(aArgs[i]);
 273     notification->Signal();
 274   }
 275 }
 276
 277 int WaitForUnlockNotify(sqlite3* aDatabase) {
 278   UnlockNotification notification;
 279   int srv =
 280       ::sqlite3_unlock_notify(aDatabase, UnlockNotifyCallback, &notification);
 281   MOZ_ASSERT(srv == SQLITE_LOCKED || srv == SQLITE_OK);
 282   if (srv == SQLITE_OK) {
 283     notification.Wait();
 284   }
 285
 286   return srv;
 287 }
 288
 289 ////////////////////////////////////////////////////////////////////////////////
 290 //// Local Classes
 291
 292 class AsyncCloseConnection final : public Runnable {
 293  public:
 294   AsyncCloseConnection(Connection* aConnection, sqlite3* aNativeConnection,
 295                        nsIRunnable* aCallbackEvent)
 296       : Runnable("storage::AsyncCloseConnection"),
 297         mConnection(aConnection),
 298         mNativeConnection(aNativeConnection),
 299         mCallbackEvent(aCallbackEvent) {}
 300
 301   NS_IMETHOD Run() override {
 302     // Make sure we don't dispatch to the current thread.
 303     MOZ_ASSERT(!IsOnCurrentSerialEventTarget(mConnection->eventTargetOpenedOn));
 304
 305     nsCOMPtr<nsIRunnable> event =
 306         NewRunnableMethod("storage::Connection::shutdownAsyncThread",
 307                           mConnection, &Connection::shutdownAsyncThread);
 308     MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(event));
 309
 310     // Internal close.
 311     (void)mConnection->internalClose(mNativeConnection);
 312
 313     // Callback
 314     if (mCallbackEvent) {
 315       nsCOMPtr<nsIThread> thread;
 316       (void)NS_GetMainThread(getter_AddRefs(thread));
 317       (void)thread->Dispatch(mCallbackEvent, NS_DISPATCH_NORMAL);
 318     }
 319
 320     return NS_OK;
 321   }
 322
 323   ~AsyncCloseConnection() override {
 324     NS_ReleaseOnMainThread("AsyncCloseConnection::mConnection",
 325                            mConnection.forget());
 326     NS_ReleaseOnMainThread("AsyncCloseConnection::mCallbackEvent",
 327                            mCallbackEvent.forget());
 328   }
 329
 330  private:
 331   RefPtr<Connection> mConnection;
 332   sqlite3* mNativeConnection;
 333   nsCOMPtr<nsIRunnable> mCallbackEvent;
 334 };
 335
 336 /**
 337  * An event used to initialize the clone of a connection.
 338  *
 339  * Must be executed on the clone's async execution thread.
 340  */
 341 class AsyncInitializeClone final : public Runnable {
 342  public:
 343   /**
 344    * @param aConnection The connection being cloned.
 345    * @param aClone The clone.
 346    * @param aReadOnly If |true|, the clone is read only.
 347    * @param aCallback A callback to trigger once initialization
 348    *                  is complete. This event will be called on
 349    *                  aClone->eventTargetOpenedOn.
 350    */
 351   AsyncInitializeClone(Connection* aConnection, Connection* aClone,
 352                        const bool aReadOnly,
 353                        mozIStorageCompletionCallback* aCallback)
 354       : Runnable("storage::AsyncInitializeClone"),
 355         mConnection(aConnection),
 356         mClone(aClone),
 357         mReadOnly(aReadOnly),
 358         mCallback(aCallback) {
 359     MOZ_ASSERT(NS_IsMainThread());
 360   }
 361
 362   NS_IMETHOD Run() override {
 363     MOZ_ASSERT(!NS_IsMainThread());
 364     nsresult rv = mConnection->initializeClone(mClone, mReadOnly);
 365     if (NS_FAILED(rv)) {
 366       return Dispatch(rv, nullptr);
 367     }
 368     return Dispatch(NS_OK,
 369                     NS_ISUPPORTS_CAST(mozIStorageAsyncConnection*, mClone));
 370   }
 371
 372  private:
 373   nsresult Dispatch(nsresult aResult, nsISupports* aValue) {
 374     RefPtr<CallbackComplete> event =
 375         new CallbackComplete(aResult, aValue, mCallback.forget());
 376     return mClone->eventTargetOpenedOn->Dispatch(event, NS_DISPATCH_NORMAL);
 377   }
 378
 379   ~AsyncInitializeClone() override {
 380     nsCOMPtr<nsIThread> thread;
 381     DebugOnly<nsresult> rv = NS_GetMainThread(getter_AddRefs(thread));
 382     MOZ_ASSERT(NS_SUCCEEDED(rv));
 383
 384     // Handle ambiguous nsISupports inheritance.
 385     NS_ProxyRelease("AsyncInitializeClone::mConnection", thread,
 386                     mConnection.forget());
 387     NS_ProxyRelease("AsyncInitializeClone::mClone", thread, mClone.forget());
 388
 389     // Generally, the callback will be released by CallbackComplete.
 390     // However, if for some reason Run() is not executed, we still
 391     // need to ensure that it is released here.
 392     NS_ProxyRelease("AsyncInitializeClone::mCallback", thread,
 393                     mCallback.forget());
 394   }
 395
 396   RefPtr<Connection> mConnection;
 397   RefPtr<Connection> mClone;
 398   const bool mReadOnly;
 399   nsCOMPtr<mozIStorageCompletionCallback> mCallback;
 400 };
 401
 402 /**
 403  * A listener for async connection closing.
 404  */
 405 class CloseListener final : public mozIStorageCompletionCallback {
 406  public:
 407   NS_DECL_ISUPPORTS
 408   CloseListener() : mClosed(false) {}
 409
 410   NS_IMETHOD Complete(nsresult, nsISupports*) override {
 411     mClosed = true;
 412     return NS_OK;
 413   }
 414
 415   bool mClosed;
 416
 417  private:
 418   ~CloseListener() = default;
 419 };
 420
 421 NS_IMPL_ISUPPORTS(CloseListener, mozIStorageCompletionCallback)
 422
 423 class AsyncVacuumEvent final : public Runnable {
 424  public:
 425   AsyncVacuumEvent(Connection* aConnection,
 426                    mozIStorageCompletionCallback* aCallback,
 427                    bool aUseIncremental, int32_t aSetPageSize)
 428       : Runnable("storage::AsyncVacuum"),
 429         mConnection(aConnection),
 430         mCallback(aCallback),
 431         mUseIncremental(aUseIncremental),
 432         mSetPageSize(aSetPageSize),
 433         mStatus(NS_ERROR_UNEXPECTED) {}
 434
 435   NS_IMETHOD Run() override {
 436     // This is initially dispatched to the helper thread, then re-dispatched
 437     // to the opener thread, where it will callback.
 438     if (IsOnCurrentSerialEventTarget(mConnection->eventTargetOpenedOn)) {
 439       // Send the completion event.
 440       if (mCallback) {
 441         mozilla::Unused << mCallback->Complete(mStatus, nullptr);
 442       }
 443       return NS_OK;
 444     }
 445
 446     // Ensure to invoke the callback regardless of errors.
 447     auto guard = MakeScopeExit([&]() {
 448       mConnection->mIsStatementOnHelperThreadInterruptible = false;
 449       mozilla::Unused << mConnection->eventTargetOpenedOn->Dispatch(
 450           this, NS_DISPATCH_NORMAL);
 451     });
 452
 453     // Get list of attached databases.
 454     nsCOMPtr<mozIStorageStatement> stmt;
 455     nsresult rv = mConnection->CreateStatement(MOZ_STORAGE_UNIQUIFY_QUERY_STR
 456                                                "PRAGMA database_list"_ns,
 457                                                getter_AddRefs(stmt));
 458     NS_ENSURE_SUCCESS(rv, rv);
 459     // We must accumulate names and loop through them later, otherwise VACUUM
 460     // will see an ongoing statement and bail out.
 461     nsTArray<nsCString> schemaNames;
 462     bool hasResult = false;
 463     while (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
 464       nsAutoCString name;
 465       rv = stmt->GetUTF8String(1, name);
 466       if (NS_SUCCEEDED(rv) && !name.EqualsLiteral("temp")) {
 467         schemaNames.AppendElement(name);
 468       }
 469     }
 470     mStatus = NS_OK;
 471     // Mark this vacuum as an interruptible operation, so it can be interrupted
 472     // if the connection closes during shutdown.
 473     mConnection->mIsStatementOnHelperThreadInterruptible = true;
 474     for (const nsCString& schemaName : schemaNames) {
 475       rv = this->Vacuum(schemaName);
 476       if (NS_FAILED(rv)) {
 477         // This is sub-optimal since it's only keeping the last error reason,
 478         // but it will do for now.
 479         mStatus = rv;
 480       }
 481     }
 482     return mStatus;
 483   }
 484
 485   nsresult Vacuum(const nsACString& aSchemaName) {
 486     // Abort if we're in shutdown.
 487     if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
 488       return NS_ERROR_ABORT;
 489     }
 490     int32_t removablePages = mConnection->RemovablePagesInFreeList(aSchemaName);
 491     if (!removablePages) {
 492       // There's no empty pages to remove, so skip this vacuum for now.
 493       return NS_OK;
 494     }
 495     nsresult rv;
 496     bool needsFullVacuum = true;
 497
 498     if (mSetPageSize) {
 499       nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
 500       query.Append(aSchemaName);
 501       query.AppendLiteral(".page_size = ");
 502       query.AppendInt(mSetPageSize);
 503       nsCOMPtr<mozIStorageStatement> stmt;
 504       rv = mConnection->ExecuteSimpleSQL(query);
 505       NS_ENSURE_SUCCESS(rv, rv);
 506     }
 507
 508     // Check auto_vacuum.
 509     {
 510       nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
 511       query.Append(aSchemaName);
 512       query.AppendLiteral(".auto_vacuum");
 513       nsCOMPtr<mozIStorageStatement> stmt;
 514       rv = mConnection->CreateStatement(query, getter_AddRefs(stmt));
 515       NS_ENSURE_SUCCESS(rv, rv);
 516       bool hasResult = false;
 517       bool changeAutoVacuum = false;
 518       if (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
 519         bool isIncrementalVacuum = stmt->AsInt32(0) == 2;
 520         changeAutoVacuum = isIncrementalVacuum != mUseIncremental;
 521         if (isIncrementalVacuum && !changeAutoVacuum) {
 522           needsFullVacuum = false;
 523         }
 524       }
 525       // Changing auto_vacuum is only supported on the main schema.
 526       if (aSchemaName.EqualsLiteral("main") && changeAutoVacuum) {
 527         nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
 528         query.Append(aSchemaName);
 529         query.AppendLiteral(".auto_vacuum = ");
 530         query.AppendInt(mUseIncremental ? 2 : 0);
 531         rv = mConnection->ExecuteSimpleSQL(query);
 532         NS_ENSURE_SUCCESS(rv, rv);
 533       }
 534     }
 535
 536     if (needsFullVacuum) {
 537       nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "VACUUM ");
 538       query.Append(aSchemaName);
 539       rv = mConnection->ExecuteSimpleSQL(query);
 540       // TODO (Bug 1818039): Report failed vacuum telemetry.
 541       NS_ENSURE_SUCCESS(rv, rv);
 542     } else {
 543       nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
 544       query.Append(aSchemaName);
 545       query.AppendLiteral(".incremental_vacuum(");
 546       query.AppendInt(removablePages);
 547       query.AppendLiteral(")");
 548       rv = mConnection->ExecuteSimpleSQL(query);
 549       NS_ENSURE_SUCCESS(rv, rv);
 550     }
 551
 552     return NS_OK;
 553   }
 554
 555   ~AsyncVacuumEvent() override {
 556     NS_ReleaseOnMainThread("AsyncVacuum::mConnection", mConnection.forget());
 557     NS_ReleaseOnMainThread("AsyncVacuum::mCallback", mCallback.forget());
 558   }
 559
 560  private:
 561   RefPtr<Connection> mConnection;
 562   nsCOMPtr<mozIStorageCompletionCallback> mCallback;
 563   bool mUseIncremental;
 564   int32_t mSetPageSize;
 565   Atomic<nsresult> mStatus;
 566 };
 567
 568 }  // namespace
 569
 570 ////////////////////////////////////////////////////////////////////////////////
 571 //// Connection
 572
 573 Connection::Connection(Service* aService, int aFlags,
 574                        ConnectionOperation aSupportedOperations,
 575                        bool aInterruptible, bool aIgnoreLockingMode)
 576     : sharedAsyncExecutionMutex("Connection::sharedAsyncExecutionMutex"),
 577       sharedDBMutex("Connection::sharedDBMutex"),
 578       eventTargetOpenedOn(WrapNotNull(GetCurrentSerialEventTarget())),
 579       mIsStatementOnHelperThreadInterruptible(false),
 580       mDBConn(nullptr),
 581       mDefaultTransactionType(mozIStorageConnection::TRANSACTION_DEFERRED),
 582       mDestroying(false),
 583       mProgressHandler(nullptr),
 584       mStorageService(aService),
 585       mFlags(aFlags),
 586       mTransactionNestingLevel(0),
 587       mSupportedOperations(aSupportedOperations),
 588       mInterruptible(aSupportedOperations == Connection::ASYNCHRONOUS ||
 589                      aInterruptible),
 590       mIgnoreLockingMode(aIgnoreLockingMode),
 591       mAsyncExecutionThreadShuttingDown(false),
 592       mConnectionClosed(false),
 593       mGrowthChunkSize(0) {
 594   MOZ_ASSERT(!mIgnoreLockingMode || mFlags & SQLITE_OPEN_READONLY,
 595              "Can't ignore locking for a non-readonly connection!");
 596   mStorageService->registerConnection(this);
 597 }
 598
 599 Connection::~Connection() {
 600   // Failsafe Close() occurs in our custom Release method because of
 601   // complications related to Close() potentially invoking AsyncClose() which
 602   // will increment our refcount.
 603   MOZ_ASSERT(!mAsyncExecutionThread,
 604              "The async thread has not been shutdown properly!");
 605 }
 606
 607 NS_IMPL_ADDREF(Connection)
 608
 609 NS_INTERFACE_MAP_BEGIN(Connection)
 610   NS_INTERFACE_MAP_ENTRY(mozIStorageAsyncConnection)
 611   NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
 612   NS_INTERFACE_MAP_ENTRY(mozIStorageConnection)
 613   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, mozIStorageConnection)
 614 NS_INTERFACE_MAP_END
 615
 616 // This is identical to what NS_IMPL_RELEASE provides, but with the
 617 // extra |1 == count| case.
 618 NS_IMETHODIMP_(MozExternalRefCountType) Connection::Release(void) {
 619   MOZ_ASSERT(0 != mRefCnt, "dup release");
 620   nsrefcnt count = --mRefCnt;
 621   NS_LOG_RELEASE(this, count, "Connection");
 622   if (1 == count) {
 623     // If the refcount went to 1, the single reference must be from
 624     // gService->mConnections (in class |Service|).  And the code calling
 625     // Release is either:
 626     // - The "user" code that had created the connection, releasing on any
 627     //   thread.
 628     // - One of Service's getConnections() callers had acquired a strong
 629     //   reference to the Connection that out-lived the last "user" reference,
 630     //   and now that just got dropped.  Note that this reference could be
 631     //   getting dropped on the main thread or Connection->eventTargetOpenedOn
 632     //   (because of the NewRunnableMethod used by minimizeMemory).
 633     //
 634     // Either way, we should now perform our failsafe Close() and unregister.
 635     // However, we only want to do this once, and the reality is that our
 636     // refcount could go back up above 1 and down again at any time if we are
 637     // off the main thread and getConnections() gets called on the main thread,
 638     // so we use an atomic here to do this exactly once.
 639     if (mDestroying.compareExchange(false, true)) {
 640       // Close the connection, dispatching to the opening event target if we're
 641       // not on that event target already and that event target is still
 642       // accepting runnables. We do this because it's possible we're on the main
 643       // thread because of getConnections(), and we REALLY don't want to
 644       // transfer I/O to the main thread if we can avoid it.
 645       if (IsOnCurrentSerialEventTarget(eventTargetOpenedOn)) {
 646         // This could cause SpinningSynchronousClose() to be invoked and AddRef
 647         // triggered for AsyncCloseConnection's strong ref if the conn was ever
 648         // use for async purposes.  (Main-thread only, though.)
 649         Unused << synchronousClose();
 650       } else {
 651         nsCOMPtr<nsIRunnable> event =
 652             NewRunnableMethod("storage::Connection::synchronousClose", this,
 653                               &Connection::synchronousClose);
 654         if (NS_FAILED(eventTargetOpenedOn->Dispatch(event.forget(),
 655                                                     NS_DISPATCH_NORMAL))) {
 656           // The event target was dead and so we've just leaked our runnable.
 657           // This should not happen because our non-main-thread consumers should
 658           // be explicitly closing their connections, not relying on us to close
 659           // them for them.  (It's okay to let a statement go out of scope for
 660           // automatic cleanup, but not a Connection.)
 661           MOZ_ASSERT(false,
 662                      "Leaked Connection::synchronousClose(), ownership fail.");
 663           Unused << synchronousClose();
 664         }
 665       }
 666
 667       // This will drop its strong reference right here, right now.
 668       mStorageService->unregisterConnection(this);
 669     }
 670   } else if (0 == count) {
 671     mRefCnt = 1; /* stabilize */
 672 #if 0            /* enable this to find non-threadsafe destructors: */
 673     NS_ASSERT_OWNINGTHREAD(Connection);
 674 #endif
 675     delete (this);
 676     return 0;
 677   }
 678   return count;
 679 }
 680
 681 int32_t Connection::getSqliteRuntimeStatus(int32_t aStatusOption,
 682                                            int32_t* aMaxValue) {
 683   MOZ_ASSERT(connectionReady(), "A connection must exist at this point");
 684   int curr = 0, max = 0;
 685   DebugOnly<int> rc =
 686       ::sqlite3_db_status(mDBConn, aStatusOption, &curr, &max, 0);
 687   MOZ_ASSERT(NS_SUCCEEDED(convertResultCode(rc)));
 688   if (aMaxValue) *aMaxValue = max;
 689   return curr;
 690 }
 691
 692 nsIEventTarget* Connection::getAsyncExecutionTarget() {
 693   NS_ENSURE_TRUE(IsOnCurrentSerialEventTarget(eventTargetOpenedOn), nullptr);
 694
 695   // Don't return the asynchronous event target if we are shutting down.
 696   if (mAsyncExecutionThreadShuttingDown) {
 697     return nullptr;
 698   }
 699
 700   // Create the async event target if there's none yet.
 701   if (!mAsyncExecutionThread) {
 702     static nsThreadPoolNaming naming;
 703     nsresult rv = NS_NewNamedThread(naming.GetNextThreadName("mozStorage"),
 704                                     getter_AddRefs(mAsyncExecutionThread));
 705     if (NS_FAILED(rv)) {
 706       NS_WARNING("Failed to create async thread.");
 707       return nullptr;
 708     }
 709     mAsyncExecutionThread->SetNameForWakeupTelemetry("mozStorage (all)"_ns);
 710   }
 711
 712   return mAsyncExecutionThread;
 713 }
 714
 715 void Connection::RecordOpenStatus(nsresult rv) {
 716   nsCString histogramKey = mTelemetryFilename;
 717
 718   if (histogramKey.IsEmpty()) {
 719     histogramKey.AssignLiteral("unknown");
 720   }
 721
 722   if (NS_SUCCEEDED(rv)) {
 723     AccumulateCategoricalKeyed(histogramKey, LABELS_SQLITE_STORE_OPEN::success);
 724     return;
 725   }
 726
 727   switch (rv) {
 728     case NS_ERROR_FILE_CORRUPTED:
 729       AccumulateCategoricalKeyed(histogramKey,
 730                                  LABELS_SQLITE_STORE_OPEN::corrupt);
 731       break;
 732     case NS_ERROR_STORAGE_IOERR:
 733       AccumulateCategoricalKeyed(histogramKey,
 734                                  LABELS_SQLITE_STORE_OPEN::diskio);
 735       break;
 736     case NS_ERROR_FILE_ACCESS_DENIED:
 737     case NS_ERROR_FILE_IS_LOCKED:
 738     case NS_ERROR_FILE_READ_ONLY:
 739       AccumulateCategoricalKeyed(histogramKey,
 740                                  LABELS_SQLITE_STORE_OPEN::access);
 741       break;
 742     case NS_ERROR_FILE_NO_DEVICE_SPACE:
 743       AccumulateCategoricalKeyed(histogramKey,
 744                                  LABELS_SQLITE_STORE_OPEN::diskspace);
 745       break;
 746     default:
 747       AccumulateCategoricalKeyed(histogramKey,
 748                                  LABELS_SQLITE_STORE_OPEN::failure);
 749   }
 750 }
 751
 752 void Connection::RecordQueryStatus(int srv) {
 753   nsCString histogramKey = mTelemetryFilename;
 754
 755   if (histogramKey.IsEmpty()) {
 756     histogramKey.AssignLiteral("unknown");
 757   }
 758
 759   switch (srv) {
 760     case SQLITE_OK:
 761     case SQLITE_ROW:
 762     case SQLITE_DONE:
 763
 764     // Note that these are returned when we intentionally cancel a statement so
 765     // they aren't indicating a failure.
 766     case SQLITE_ABORT:
 767     case SQLITE_INTERRUPT:
 768       AccumulateCategoricalKeyed(histogramKey,
 769                                  LABELS_SQLITE_STORE_QUERY::success);
 770       break;
 771     case SQLITE_CORRUPT:
 772     case SQLITE_NOTADB:
 773       AccumulateCategoricalKeyed(histogramKey,
 774                                  LABELS_SQLITE_STORE_QUERY::corrupt);
 775       break;
 776     case SQLITE_PERM:
 777     case SQLITE_CANTOPEN:
 778     case SQLITE_LOCKED:
 779     case SQLITE_READONLY:
 780       AccumulateCategoricalKeyed(histogramKey,
 781                                  LABELS_SQLITE_STORE_QUERY::access);
 782       break;
 783     case SQLITE_IOERR:
 784     case SQLITE_NOLFS:
 785       AccumulateCategoricalKeyed(histogramKey,
 786                                  LABELS_SQLITE_STORE_QUERY::diskio);
 787       break;
 788     case SQLITE_FULL:
 789     case SQLITE_TOOBIG:
 790       AccumulateCategoricalKeyed(histogramKey,
 791                                  LABELS_SQLITE_STORE_QUERY::diskspace);
 792       break;
 793     case SQLITE_CONSTRAINT:
 794     case SQLITE_RANGE:
 795     case SQLITE_MISMATCH:
 796     case SQLITE_MISUSE:
 797       AccumulateCategoricalKeyed(histogramKey,
 798                                  LABELS_SQLITE_STORE_QUERY::misuse);
 799       break;
 800     case SQLITE_BUSY:
 801       AccumulateCategoricalKeyed(histogramKey, LABELS_SQLITE_STORE_QUERY::busy);
 802       break;
 803     default:
 804       AccumulateCategoricalKeyed(histogramKey,
 805                                  LABELS_SQLITE_STORE_QUERY::failure);
 806   }
 807 }
 808
 809 nsresult Connection::initialize(const nsACString& aStorageKey,
 810                                 const nsACString& aName) {
 811   MOZ_ASSERT(aStorageKey.Equals(kMozStorageMemoryStorageKey));
 812   NS_ASSERTION(!connectionReady(),
 813                "Initialize called on already opened database!");
 814   MOZ_ASSERT(!mIgnoreLockingMode, "Can't ignore locking on an in-memory db.");
 815   AUTO_PROFILER_LABEL("Connection::initialize", OTHER);
 816
 817   mStorageKey = aStorageKey;
 818   mName = aName;
 819
 820   // in memory database requested, sqlite uses a magic file name
 821
 822   const nsAutoCString path =
 823       mName.IsEmpty() ? nsAutoCString(":memory:"_ns)
 824                       : "file:"_ns + mName + "?mode=memory&cache=shared"_ns;
 825
 826   mTelemetryFilename.AssignLiteral(":memory:");
 827
 828   int srv =
 829       ::sqlite3_open_v2(path.get(), &mDBConn, mFlags, GetBaseVFSName(true));
 830   if (srv != SQLITE_OK) {
 831     mDBConn = nullptr;
 832     nsresult rv = convertResultCode(srv);
 833     RecordOpenStatus(rv);
 834     return rv;
 835   }
 836
 837 #ifdef MOZ_SQLITE_FTS3_TOKENIZER
 838   srv =
 839       ::sqlite3_db_config(mDBConn, SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);
 840   MOZ_ASSERT(srv == SQLITE_OK,
 841              "SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER should be enabled");
 842 #endif
 843
 844   // Do not set mDatabaseFile or mFileURL here since this is a "memory"
 845   // database.
 846
 847   nsresult rv = initializeInternal();
 848   RecordOpenStatus(rv);
 849   NS_ENSURE_SUCCESS(rv, rv);
 850
 851   return NS_OK;
 852 }
 853
 854 nsresult Connection::initialize(nsIFile* aDatabaseFile) {
 855   NS_ASSERTION(aDatabaseFile, "Passed null file!");
 856   NS_ASSERTION(!connectionReady(),
 857                "Initialize called on already opened database!");
 858   AUTO_PROFILER_LABEL("Connection::initialize", OTHER);
 859
 860   // Do not set mFileURL here since this is database does not have an associated
 861   // URL.
 862   mDatabaseFile = aDatabaseFile;
 863   aDatabaseFile->GetNativeLeafName(mTelemetryFilename);
 864
 865   nsAutoString path;
 866   nsresult rv = aDatabaseFile->GetPath(path);
 867   NS_ENSURE_SUCCESS(rv, rv);
 868
 869   bool exclusive = StaticPrefs::storage_sqlite_exclusiveLock_enabled();
 870   int srv;
 871   if (mIgnoreLockingMode) {
 872     exclusive = false;
 873     srv = ::sqlite3_open_v2(NS_ConvertUTF16toUTF8(path).get(), &mDBConn, mFlags,
 874                             "readonly-immutable-nolock");
 875   } else {
 876     srv = ::sqlite3_open_v2(NS_ConvertUTF16toUTF8(path).get(), &mDBConn, mFlags,
 877                             GetBaseVFSName(exclusive));
 878     if (exclusive && (srv == SQLITE_LOCKED || srv == SQLITE_BUSY)) {
 879       // Retry without trying to get an exclusive lock.
 880       exclusive = false;
 881       srv = ::sqlite3_open_v2(NS_ConvertUTF16toUTF8(path).get(), &mDBConn,
 882                               mFlags, GetBaseVFSName(false));
 883     }
 884   }
 885   if (srv != SQLITE_OK) {
 886     mDBConn = nullptr;
 887     rv = convertResultCode(srv);
 888     RecordOpenStatus(rv);
 889     return rv;
 890   }
 891
 892   rv = initializeInternal();
 893   if (exclusive &&
 894       (rv == NS_ERROR_STORAGE_BUSY || rv == NS_ERROR_FILE_IS_LOCKED)) {
 895     // Usually SQLite will fail to acquire an exclusive lock on opening, but in
 896     // some cases it may successfully open the database and then lock on the
 897     // first query execution. When initializeInternal fails it closes the
 898     // connection, so we can try to restart it in non-exclusive mode.
 899     srv = ::sqlite3_open_v2(NS_ConvertUTF16toUTF8(path).get(), &mDBConn, mFlags,
 900                             GetBaseVFSName(false));
 901     if (srv == SQLITE_OK) {
 902       rv = initializeInternal();
 903     }
 904   }
 905
 906   RecordOpenStatus(rv);
 907   NS_ENSURE_SUCCESS(rv, rv);
 908
 909   return NS_OK;
 910 }
 911
 912 nsresult Connection::initialize(nsIFileURL* aFileURL,
 913                                 const nsACString& aTelemetryFilename) {
 914   NS_ASSERTION(aFileURL, "Passed null file URL!");
 915   NS_ASSERTION(!connectionReady(),
 916                "Initialize called on already opened database!");
 917   AUTO_PROFILER_LABEL("Connection::initialize", OTHER);
 918
 919   nsCOMPtr<nsIFile> databaseFile;
 920   nsresult rv = aFileURL->GetFile(getter_AddRefs(databaseFile));
 921   NS_ENSURE_SUCCESS(rv, rv);
 922
 923   // Set both mDatabaseFile and mFileURL here.
 924   mFileURL = aFileURL;
 925   mDatabaseFile = databaseFile;
 926
 927   if (!aTelemetryFilename.IsEmpty()) {
 928     mTelemetryFilename = aTelemetryFilename;
 929   } else {
 930     databaseFile->GetNativeLeafName(mTelemetryFilename);
 931   }
 932
 933   nsAutoCString spec;
 934   rv = aFileURL->GetSpec(spec);
 935   NS_ENSURE_SUCCESS(rv, rv);
 936
 937   // If there is a key specified, we need to use the obfuscating VFS.
 938   nsAutoCString query;
 939   rv = aFileURL->GetQuery(query);
 940   NS_ENSURE_SUCCESS(rv, rv);
 941
 942   bool hasKey = false;
 943   bool hasDirectoryLockId = false;
 944
 945   MOZ_ALWAYS_TRUE(URLParams::Parse(
 946       query, [&hasKey, &hasDirectoryLockId](const nsAString& aName,
 947                                             const nsAString& aValue) {
 948         if (aName.EqualsLiteral("key")) {
 949           hasKey = true;
 950           return true;
 951         }
 952         if (aName.EqualsLiteral("directoryLockId")) {
 953           hasDirectoryLockId = true;
 954           return true;
 955         }
 956         return true;
 957       }));
 958
 959   bool exclusive = StaticPrefs::storage_sqlite_exclusiveLock_enabled();
 960
 961   const char* const vfs = hasKey               ? GetObfuscatingVFSName()
 962                           : hasDirectoryLockId ? GetQuotaVFSName()
 963                                                : GetBaseVFSName(exclusive);
 964
 965   int srv = ::sqlite3_open_v2(spec.get(), &mDBConn, mFlags, vfs);
 966   if (srv != SQLITE_OK) {
 967     mDBConn = nullptr;
 968     rv = convertResultCode(srv);
 969     RecordOpenStatus(rv);
 970     return rv;
 971   }
 972
 973   rv = initializeInternal();
 974   RecordOpenStatus(rv);
 975   NS_ENSURE_SUCCESS(rv, rv);
 976
 977   return NS_OK;
 978 }
 979
 980 nsresult Connection::initializeInternal() {
 981   MOZ_ASSERT(mDBConn);
 982   auto guard = MakeScopeExit([&]() { initializeFailed(); });
 983
 984   mConnectionClosed = false;
 985
 986 #ifdef MOZ_SQLITE_FTS3_TOKENIZER
 987   DebugOnly<int> srv2 =
 988       ::sqlite3_db_config(mDBConn, SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);
 989   MOZ_ASSERT(srv2 == SQLITE_OK,
 990              "SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER should be enabled");
 991 #endif
 992
 993   MOZ_ASSERT(!mTelemetryFilename.IsEmpty(),
 994              "A telemetry filename should have been set by now.");
 995
 996   // Properly wrap the database handle's mutex.
 997   sharedDBMutex.initWithMutex(sqlite3_db_mutex(mDBConn));
 998
 999   // SQLite tracing can slow down queries (especially long queries)
1000   // significantly. Don't trace unless the user is actively monitoring SQLite.
1001   if (MOZ_LOG_TEST(gStorageLog, LogLevel::Debug)) {
1002     ::sqlite3_trace_v2(mDBConn, SQLITE_TRACE_STMT | SQLITE_TRACE_PROFILE,
1003                        tracefunc, this);
1004
1005     MOZ_LOG(
1006         gStorageLog, LogLevel::Debug,
1007         ("Opening connection to '%s' (%p)", mTelemetryFilename.get(), this));
1008   }
1009
1010   int64_t pageSize = Service::kDefaultPageSize;
1011
1012   // Set page_size to the preferred default value.  This is effective only if
1013   // the database has just been created, otherwise, if the database does not
1014   // use WAL journal mode, a VACUUM operation will updated its page_size.
1015   nsAutoCString pageSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
1016                               "PRAGMA page_size = ");
1017   pageSizeQuery.AppendInt(pageSize);
1018   int srv = executeSql(mDBConn, pageSizeQuery.get());
1019   if (srv != SQLITE_OK) {
1020     return convertResultCode(srv);
1021   }
1022
1023   // Setting the cache_size forces the database open, verifying if it is valid
1024   // or corrupt.  So this is executed regardless it being actually needed.
1025   // The cache_size is calculated from the actual page_size, to save memory.
1026   nsAutoCString cacheSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
1027                                "PRAGMA cache_size = ");
1028   cacheSizeQuery.AppendInt(-MAX_CACHE_SIZE_KIBIBYTES);
1029   srv = executeSql(mDBConn, cacheSizeQuery.get());
1030   if (srv != SQLITE_OK) {
1031     return convertResultCode(srv);
1032   }
1033
1034   // Register our built-in SQL functions.
1035   srv = registerFunctions(mDBConn);
1036   if (srv != SQLITE_OK) {
1037     return convertResultCode(srv);
1038   }
1039
1040   // Register our built-in SQL collating sequences.
1041   srv = registerCollations(mDBConn, mStorageService);
1042   if (srv != SQLITE_OK) {
1043     return convertResultCode(srv);
1044   }
1045
1046   // Set the default synchronous value. Each consumer can switch this
1047   // accordingly to their needs.
1048 #if defined(ANDROID)
1049   // Android prefers synchronous = OFF for performance reasons.
1050   Unused << ExecuteSimpleSQL("PRAGMA synchronous = OFF;"_ns);
1051 #else
1052   // Normal is the suggested value for WAL journals.
1053   Unused << ExecuteSimpleSQL("PRAGMA synchronous = NORMAL;"_ns);
1054 #endif
1055
1056   // Initialization succeeded, we can stop guarding for failures.
1057   guard.release();
1058   return NS_OK;
1059 }
1060
1061 nsresult Connection::initializeOnAsyncThread(nsIFile* aStorageFile) {
1062   MOZ_ASSERT(!IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1063   nsresult rv = aStorageFile
1064                     ? initialize(aStorageFile)
1065                     : initialize(kMozStorageMemoryStorageKey, VoidCString());
1066   if (NS_FAILED(rv)) {
1067     // Shutdown the async thread, since initialization failed.
1068     MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1069     mAsyncExecutionThreadShuttingDown = true;
1070     nsCOMPtr<nsIRunnable> event =
1071         NewRunnableMethod("Connection::shutdownAsyncThread", this,
1072                           &Connection::shutdownAsyncThread);
1073     Unused << NS_DispatchToMainThread(event);
1074   }
1075   return rv;
1076 }
1077
1078 void Connection::initializeFailed() {
1079   {
1080     MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1081     mConnectionClosed = true;
1082   }
1083   MOZ_ALWAYS_TRUE(::sqlite3_close(mDBConn) == SQLITE_OK);
1084   mDBConn = nullptr;
1085   sharedDBMutex.destroy();
1086 }
1087
1088 nsresult Connection::databaseElementExists(
1089     enum DatabaseElementType aElementType, const nsACString& aElementName,
1090     bool* _exists) {
1091   if (!connectionReady()) {
1092     return NS_ERROR_NOT_AVAILABLE;
1093   }
1094   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
1095   if (NS_FAILED(rv)) {
1096     return rv;
1097   }
1098
1099   // When constructing the query, make sure to SELECT the correct db's
1100   // sqlite_master if the user is prefixing the element with a specific db. ex:
1101   // sample.test
1102   nsCString query("SELECT name FROM (SELECT * FROM ");
1103   nsDependentCSubstring element;
1104   int32_t ind = aElementName.FindChar('.');
1105   if (ind == kNotFound) {
1106     element.Assign(aElementName);
1107   } else {
1108     nsDependentCSubstring db(Substring(aElementName, 0, ind + 1));
1109     element.Assign(Substring(aElementName, ind + 1, aElementName.Length()));
1110     query.Append(db);
1111   }
1112   query.AppendLiteral(
1113       "sqlite_master UNION ALL SELECT * FROM sqlite_temp_master) WHERE type = "
1114       "'");
1115
1116   switch (aElementType) {
1117     case INDEX:
1118       query.AppendLiteral("index");
1119       break;
1120     case TABLE:
1121       query.AppendLiteral("table");
1122       break;
1123   }
1124   query.AppendLiteral("' AND name ='");
1125   query.Append(element);
1126   query.Append('\'');
1127
1128   sqlite3_stmt* stmt;
1129   int srv = prepareStatement(mDBConn, query, &stmt);
1130   if (srv != SQLITE_OK) {
1131     RecordQueryStatus(srv);
1132     return convertResultCode(srv);
1133   }
1134
1135   srv = stepStatement(mDBConn, stmt);
1136   // we just care about the return value from step
1137   (void)::sqlite3_finalize(stmt);
1138
1139   RecordQueryStatus(srv);
1140
1141   if (srv == SQLITE_ROW) {
1142     *_exists = true;
1143     return NS_OK;
1144   }
1145   if (srv == SQLITE_DONE) {
1146     *_exists = false;
1147     return NS_OK;
1148   }
1149
1150   return convertResultCode(srv);
1151 }
1152
1153 bool Connection::findFunctionByInstance(mozIStorageFunction* aInstance) {
1154   sharedDBMutex.assertCurrentThreadOwns();
1155
1156   for (const auto& data : mFunctions.Values()) {
1157     if (data.function == aInstance) {
1158       return true;
1159     }
1160   }
1161   return false;
1162 }
1163
1164 /* static */
1165 int Connection::sProgressHelper(void* aArg) {
1166   Connection* _this = static_cast<Connection*>(aArg);
1167   return _this->progressHandler();
1168 }
1169
1170 int Connection::progressHandler() {
1171   sharedDBMutex.assertCurrentThreadOwns();
1172   if (mProgressHandler) {
1173     bool result;
1174     nsresult rv = mProgressHandler->OnProgress(this, &result);
1175     if (NS_FAILED(rv)) return 0;  // Don't break request
1176     return result ? 1 : 0;
1177   }
1178   return 0;
1179 }
1180
1181 nsresult Connection::setClosedState() {
1182   // Flag that we are shutting down the async thread, so that
1183   // getAsyncExecutionTarget knows not to expose/create the async thread.
1184   MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1185   NS_ENSURE_FALSE(mAsyncExecutionThreadShuttingDown, NS_ERROR_UNEXPECTED);
1186
1187   mAsyncExecutionThreadShuttingDown = true;
1188
1189   // Set the property to null before closing the connection, otherwise the
1190   // other functions in the module may try to use the connection after it is
1191   // closed.
1192   mDBConn = nullptr;
1193
1194   return NS_OK;
1195 }
1196
1197 bool Connection::operationSupported(ConnectionOperation aOperationType) {
1198   if (aOperationType == ASYNCHRONOUS) {
1199     // Async operations are supported for all connections, on any thread.
1200     return true;
1201   }
1202   // Sync operations are supported for sync connections (on any thread), and
1203   // async connections on a background thread.
1204   MOZ_ASSERT(aOperationType == SYNCHRONOUS);
1205   return mSupportedOperations == SYNCHRONOUS || !NS_IsMainThread();
1206 }
1207
1208 nsresult Connection::ensureOperationSupported(
1209     ConnectionOperation aOperationType) {
1210   if (NS_WARN_IF(!operationSupported(aOperationType))) {
1211 #ifdef DEBUG
1212     if (NS_IsMainThread()) {
1213       nsCOMPtr<nsIXPConnect> xpc = nsIXPConnect::XPConnect();
1214       Unused << xpc->DebugDumpJSStack(false, false, false);
1215     }
1216 #endif
1217     MOZ_ASSERT(false,
1218                "Don't use async connections synchronously on the main thread");
1219     return NS_ERROR_NOT_AVAILABLE;
1220   }
1221   return NS_OK;
1222 }
1223
1224 bool Connection::isConnectionReadyOnThisThread() {
1225   MOZ_ASSERT_IF(connectionReady(), !mConnectionClosed);
1226   if (mAsyncExecutionThread && mAsyncExecutionThread->IsOnCurrentThread()) {
1227     return true;
1228   }
1229   return connectionReady();
1230 }
1231
1232 bool Connection::isClosing() {
1233   MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1234   return mAsyncExecutionThreadShuttingDown && !mConnectionClosed;
1235 }
1236
1237 bool Connection::isClosed() {
1238   MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1239   return mConnectionClosed;
1240 }
1241
1242 bool Connection::isClosed(MutexAutoLock& lock) { return mConnectionClosed; }
1243
1244 bool Connection::isAsyncExecutionThreadAvailable() {
1245   MOZ_ASSERT(IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1246   return mAsyncExecutionThread && !mAsyncExecutionThreadShuttingDown;
1247 }
1248
1249 void Connection::shutdownAsyncThread() {
1250   MOZ_ASSERT(IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1251   MOZ_ASSERT(mAsyncExecutionThread);
1252   MOZ_ASSERT(mAsyncExecutionThreadShuttingDown);
1253
1254   MOZ_ALWAYS_SUCCEEDS(mAsyncExecutionThread->Shutdown());
1255   mAsyncExecutionThread = nullptr;
1256 }
1257
1258 nsresult Connection::internalClose(sqlite3* aNativeConnection) {
1259 #ifdef DEBUG
1260   {  // Make sure we have marked our async thread as shutting down.
1261     MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1262     MOZ_ASSERT(mAsyncExecutionThreadShuttingDown,
1263                "Did not call setClosedState!");
1264     MOZ_ASSERT(!isClosed(lockedScope), "Unexpected closed state");
1265   }
1266 #endif  // DEBUG
1267
1268   if (MOZ_LOG_TEST(gStorageLog, LogLevel::Debug)) {
1269     nsAutoCString leafName(":memory");
1270     if (mDatabaseFile) (void)mDatabaseFile->GetNativeLeafName(leafName);
1271     MOZ_LOG(gStorageLog, LogLevel::Debug,
1272             ("Closing connection to '%s'", leafName.get()));
1273   }
1274
1275   // At this stage, we may still have statements that need to be
1276   // finalized. Attempt to close the database connection. This will
1277   // always disconnect any virtual tables and cleanly finalize their
1278   // internal statements. Once this is done, closing may fail due to
1279   // unfinalized client statements, in which case we need to finalize
1280   // these statements and close again.
1281   {
1282     MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1283     mConnectionClosed = true;
1284   }
1285
1286   // Nothing else needs to be done if we don't have a connection here.
1287   if (!aNativeConnection) return NS_OK;
1288
1289   int srv = ::sqlite3_close(aNativeConnection);
1290
1291   if (srv == SQLITE_BUSY) {
1292     {
1293       // Nothing else should change the connection or statements status until we
1294       // are done here.
1295       SQLiteMutexAutoLock lockedScope(sharedDBMutex);
1296       // We still have non-finalized statements. Finalize them.
1297       sqlite3_stmt* stmt = nullptr;
1298       while ((stmt = ::sqlite3_next_stmt(aNativeConnection, stmt))) {
1299         MOZ_LOG(gStorageLog, LogLevel::Debug,
1300                 ("Auto-finalizing SQL statement '%s' (%p)", ::sqlite3_sql(stmt),
1301                  stmt));
1302
1303 #ifdef DEBUG
1304         SmprintfPointer msg = ::mozilla::Smprintf(
1305             "SQL statement '%s' (%p) should have been finalized before closing "
1306             "the connection",
1307             ::sqlite3_sql(stmt), stmt);
1308         NS_WARNING(msg.get());
1309 #endif  // DEBUG
1310
1311         srv = ::sqlite3_finalize(stmt);
1312
1313 #ifdef DEBUG
1314         if (srv != SQLITE_OK) {
1315           SmprintfPointer msg = ::mozilla::Smprintf(
1316               "Could not finalize SQL statement (%p)", stmt);
1317           NS_WARNING(msg.get());
1318         }
1319 #endif  // DEBUG
1320
1321         // Ensure that the loop continues properly, whether closing has
1322         // succeeded or not.
1323         if (srv == SQLITE_OK) {
1324           stmt = nullptr;
1325         }
1326       }
1327       // Scope exiting will unlock the mutex before we invoke sqlite3_close()
1328       // again, since Sqlite will try to acquire it.
1329     }
1330
1331     // Now that all statements have been finalized, we
1332     // should be able to close.
1333     srv = ::sqlite3_close(aNativeConnection);
1334     MOZ_ASSERT(false,
1335                "Had to forcibly close the database connection because not all "
1336                "the statements have been finalized.");
1337   }
1338
1339   if (srv == SQLITE_OK) {
1340     sharedDBMutex.destroy();
1341   } else {
1342     MOZ_ASSERT(false,
1343                "sqlite3_close failed. There are probably outstanding "
1344                "statements that are listed above!");
1345   }
1346
1347   return convertResultCode(srv);
1348 }
1349
1350 nsCString Connection::getFilename() { return mTelemetryFilename; }
1351
1352 int Connection::stepStatement(sqlite3* aNativeConnection,
1353                               sqlite3_stmt* aStatement) {
1354   MOZ_ASSERT(aStatement);
1355
1356   AUTO_PROFILER_LABEL_DYNAMIC_CSTR("Connection::stepStatement", OTHER,
1357                                    ::sqlite3_sql(aStatement));
1358
1359   bool checkedMainThread = false;
1360   TimeStamp startTime = TimeStamp::Now();
1361
1362   // The connection may have been closed if the executing statement has been
1363   // created and cached after a call to asyncClose() but before the actual
1364   // sqlite3_close().  This usually happens when other tasks using cached
1365   // statements are asynchronously scheduled for execution and any of them ends
1366   // up after asyncClose. See bug 728653 for details.
1367   if (!isConnectionReadyOnThisThread()) return SQLITE_MISUSE;
1368
1369   (void)::sqlite3_extended_result_codes(aNativeConnection, 1);
1370
1371   int srv;
1372   while ((srv = ::sqlite3_step(aStatement)) == SQLITE_LOCKED_SHAREDCACHE) {
1373     if (!checkedMainThread) {
1374       checkedMainThread = true;
1375       if (::NS_IsMainThread()) {
1376         NS_WARNING("We won't allow blocking on the main thread!");
1377         break;
1378       }
1379     }
1380
1381     srv = WaitForUnlockNotify(aNativeConnection);
1382     if (srv != SQLITE_OK) {
1383       break;
1384     }
1385
1386     ::sqlite3_reset(aStatement);
1387   }
1388
1389   // Report very slow SQL statements to Telemetry
1390   TimeDuration duration = TimeStamp::Now() - startTime;
1391   const uint32_t threshold = NS_IsMainThread()
1392                                  ? Telemetry::kSlowSQLThresholdForMainThread
1393                                  : Telemetry::kSlowSQLThresholdForHelperThreads;
1394   if (duration.ToMilliseconds() >= threshold) {
1395     nsDependentCString statementString(::sqlite3_sql(aStatement));
1396     Telemetry::RecordSlowSQLStatement(statementString, mTelemetryFilename,
1397                                       duration.ToMilliseconds());
1398   }
1399
1400   (void)::sqlite3_extended_result_codes(aNativeConnection, 0);
1401   // Drop off the extended result bits of the result code.
1402   return srv & 0xFF;
1403 }
1404
1405 int Connection::prepareStatement(sqlite3* aNativeConnection,
1406                                  const nsCString& aSQL, sqlite3_stmt** _stmt) {
1407   // We should not even try to prepare statements after the connection has
1408   // been closed.
1409   if (!isConnectionReadyOnThisThread()) return SQLITE_MISUSE;
1410
1411   bool checkedMainThread = false;
1412
1413   (void)::sqlite3_extended_result_codes(aNativeConnection, 1);
1414
1415   int srv;
1416   while ((srv = ::sqlite3_prepare_v2(aNativeConnection, aSQL.get(), -1, _stmt,
1417                                      nullptr)) == SQLITE_LOCKED_SHAREDCACHE) {
1418     if (!checkedMainThread) {
1419       checkedMainThread = true;
1420       if (::NS_IsMainThread()) {
1421         NS_WARNING("We won't allow blocking on the main thread!");
1422         break;
1423       }
1424     }
1425
1426     srv = WaitForUnlockNotify(aNativeConnection);
1427     if (srv != SQLITE_OK) {
1428       break;
1429     }
1430   }
1431
1432   if (srv != SQLITE_OK) {
1433     nsCString warnMsg;
1434     warnMsg.AppendLiteral("The SQL statement '");
1435     warnMsg.Append(aSQL);
1436     warnMsg.AppendLiteral("' could not be compiled due to an error: ");
1437     warnMsg.Append(::sqlite3_errmsg(aNativeConnection));
1438
1439 #ifdef DEBUG
1440     NS_WARNING(warnMsg.get());
1441 #endif
1442     MOZ_LOG(gStorageLog, LogLevel::Error, ("%s", warnMsg.get()));
1443   }
1444
1445   (void)::sqlite3_extended_result_codes(aNativeConnection, 0);
1446   // Drop off the extended result bits of the result code.
1447   int rc = srv & 0xFF;
1448   // sqlite will return OK on a comment only string and set _stmt to nullptr.
1449   // The callers of this function are used to only checking the return value,
1450   // so it is safer to return an error code.
1451   if (rc == SQLITE_OK && *_stmt == nullptr) {
1452     return SQLITE_MISUSE;
1453   }
1454
1455   return rc;
1456 }
1457
1458 int Connection::executeSql(sqlite3* aNativeConnection, const char* aSqlString) {
1459   if (!isConnectionReadyOnThisThread()) return SQLITE_MISUSE;
1460
1461   AUTO_PROFILER_LABEL_DYNAMIC_CSTR("Connection::executeSql", OTHER, aSqlString);
1462
1463   TimeStamp startTime = TimeStamp::Now();
1464   int srv =
1465       ::sqlite3_exec(aNativeConnection, aSqlString, nullptr, nullptr, nullptr);
1466   RecordQueryStatus(srv);
1467
1468   // Report very slow SQL statements to Telemetry
1469   TimeDuration duration = TimeStamp::Now() - startTime;
1470   const uint32_t threshold = NS_IsMainThread()
1471                                  ? Telemetry::kSlowSQLThresholdForMainThread
1472                                  : Telemetry::kSlowSQLThresholdForHelperThreads;
1473   if (duration.ToMilliseconds() >= threshold) {
1474     nsDependentCString statementString(aSqlString);
1475     Telemetry::RecordSlowSQLStatement(statementString, mTelemetryFilename,
1476                                       duration.ToMilliseconds());
1477   }
1478
1479   return srv;
1480 }
1481
1482 ////////////////////////////////////////////////////////////////////////////////
1483 //// nsIInterfaceRequestor
1484
1485 NS_IMETHODIMP
1486 Connection::GetInterface(const nsIID& aIID, void** _result) {
1487   if (aIID.Equals(NS_GET_IID(nsIEventTarget))) {
1488     nsIEventTarget* background = getAsyncExecutionTarget();
1489     NS_IF_ADDREF(background);
1490     *_result = background;
1491     return NS_OK;
1492   }
1493   return NS_ERROR_NO_INTERFACE;
1494 }
1495
1496 ////////////////////////////////////////////////////////////////////////////////
1497 //// mozIStorageConnection
1498
1499 NS_IMETHODIMP
1500 Connection::Close() {
1501   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
1502   if (NS_FAILED(rv)) {
1503     return rv;
1504   }
1505   return synchronousClose();
1506 }
1507
1508 nsresult Connection::synchronousClose() {
1509   if (!connectionReady()) {
1510     return NS_ERROR_NOT_INITIALIZED;
1511   }
1512
1513 #ifdef DEBUG
1514   // Since we're accessing mAsyncExecutionThread, we need to be on the opener
1515   // event target. We make this check outside of debug code below in
1516   // setClosedState, but this is here to be explicit.
1517   MOZ_ASSERT(IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1518 #endif  // DEBUG
1519
1520   // Make sure we have not executed any asynchronous statements.
1521   // If this fails, the mDBConn may be left open, resulting in a leak.
1522   // We'll try to finalize the pending statements and close the connection.
1523   if (isAsyncExecutionThreadAvailable()) {
1524 #ifdef DEBUG
1525     if (NS_IsMainThread()) {
1526       nsCOMPtr<nsIXPConnect> xpc = nsIXPConnect::XPConnect();
1527       Unused << xpc->DebugDumpJSStack(false, false, false);
1528     }
1529 #endif
1530     MOZ_ASSERT(false,
1531                "Close() was invoked on a connection that executed asynchronous "
1532                "statements. "
1533                "Should have used asyncClose().");
1534     // Try to close the database regardless, to free up resources.
1535     Unused << SpinningSynchronousClose();
1536     return NS_ERROR_UNEXPECTED;
1537   }
1538
1539   // setClosedState nullifies our connection pointer, so we take a raw pointer
1540   // off it, to pass it through the close procedure.
1541   sqlite3* nativeConn = mDBConn;
1542   nsresult rv = setClosedState();
1543   NS_ENSURE_SUCCESS(rv, rv);
1544
1545   return internalClose(nativeConn);
1546 }
1547
1548 NS_IMETHODIMP
1549 Connection::SpinningSynchronousClose() {
1550   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
1551   if (NS_FAILED(rv)) {
1552     return rv;
1553   }
1554   if (!IsOnCurrentSerialEventTarget(eventTargetOpenedOn)) {
1555     return NS_ERROR_NOT_SAME_THREAD;
1556   }
1557
1558   // As currently implemented, we can't spin to wait for an existing AsyncClose.
1559   // Our only existing caller will never have called close; assert if misused
1560   // so that no new callers assume this works after an AsyncClose.
1561   MOZ_DIAGNOSTIC_ASSERT(connectionReady());
1562   if (!connectionReady()) {
1563     return NS_ERROR_UNEXPECTED;
1564   }
1565
1566   RefPtr<CloseListener> listener = new CloseListener();
1567   rv = AsyncClose(listener);
1568   NS_ENSURE_SUCCESS(rv, rv);
1569   MOZ_ALWAYS_TRUE(
1570       SpinEventLoopUntil("storage::Connection::SpinningSynchronousClose"_ns,
1571                          [&]() { return listener->mClosed; }));
1572   MOZ_ASSERT(isClosed(), "The connection should be closed at this point");
1573
1574   return rv;
1575 }
1576
1577 NS_IMETHODIMP
1578 Connection::AsyncClose(mozIStorageCompletionCallback* aCallback) {
1579   NS_ENSURE_TRUE(NS_IsMainThread(), NS_ERROR_NOT_SAME_THREAD);
1580   // Check if AsyncClose or Close were already invoked.
1581   if (!connectionReady()) {
1582     return NS_ERROR_NOT_INITIALIZED;
1583   }
1584   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
1585   if (NS_FAILED(rv)) {
1586     return rv;
1587   }
1588
1589   // The two relevant factors at this point are whether we have a database
1590   // connection and whether we have an async execution thread.  Here's what the
1591   // states mean and how we handle them:
1592   //
1593   // - (mDBConn && asyncThread): The expected case where we are either an
1594   //   async connection or a sync connection that has been used asynchronously.
1595   //   Either way the caller must call us and not Close().  Nothing surprising
1596   //   about this.  We'll dispatch AsyncCloseConnection to the already-existing
1597   //   async thread.
1598   //
1599   // - (mDBConn && !asyncThread): A somewhat unusual case where the caller
1600   //   opened the connection synchronously and was planning to use it
1601   //   asynchronously, but never got around to using it asynchronously before
1602   //   needing to shutdown.  This has been observed to happen for the cookie
1603   //   service in a case where Firefox shuts itself down almost immediately
1604   //   after startup (for unknown reasons).  In the Firefox shutdown case,
1605   //   we may also fail to create a new async execution thread if one does not
1606   //   already exist.  (nsThreadManager will refuse to create new threads when
1607   //   it has already been told to shutdown.)  As such, we need to handle a
1608   //   failure to create the async execution thread by falling back to
1609   //   synchronous Close() and also dispatching the completion callback because
1610   //   at least Places likes to spin a nested event loop that depends on the
1611   //   callback being invoked.
1612   //
1613   //   Note that we have considered not trying to spin up the async execution
1614   //   thread in this case if it does not already exist, but the overhead of
1615   //   thread startup (if successful) is significantly less expensive than the
1616   //   worst-case potential I/O hit of synchronously closing a database when we
1617   //   could close it asynchronously.
1618   //
1619   // - (!mDBConn && asyncThread): This happens in some but not all cases where
1620   //   OpenAsyncDatabase encountered a problem opening the database.  If it
1621   //   happened in all cases AsyncInitDatabase would just shut down the thread
1622   //   directly and we would avoid this case.  But it doesn't, so for simplicity
1623   //   and consistency AsyncCloseConnection knows how to handle this and we
1624   //   act like this was the (mDBConn && asyncThread) case in this method.
1625   //
1626   // - (!mDBConn && !asyncThread): The database was never successfully opened or
1627   //   Close() or AsyncClose() has already been called (at least) once.  This is
1628   //   undeniably a misuse case by the caller.  We could optimize for this
1629   //   case by adding an additional check of mAsyncExecutionThread without using
1630   //   getAsyncExecutionTarget() to avoid wastefully creating a thread just to
1631   //   shut it down.  But this complicates the method for broken caller code
1632   //   whereas we're still correct and safe without the special-case.
1633   nsIEventTarget* asyncThread = getAsyncExecutionTarget();
1634
1635   // Create our callback event if we were given a callback.  This will
1636   // eventually be dispatched in all cases, even if we fall back to Close() and
1637   // the database wasn't open and we return an error.  The rationale is that
1638   // no existing consumer checks our return value and several of them like to
1639   // spin nested event loops until the callback fires.  Given that, it seems
1640   // preferable for us to dispatch the callback in all cases.  (Except the
1641   // wrong thread misuse case we bailed on up above.  But that's okay because
1642   // that is statically wrong whereas these edge cases are dynamic.)
1643   nsCOMPtr<nsIRunnable> completeEvent;
1644   if (aCallback) {
1645     completeEvent = newCompletionEvent(aCallback);
1646   }
1647
1648   if (!asyncThread) {
1649     // We were unable to create an async thread, so we need to fall back to
1650     // using normal Close().  Since there is no async thread, Close() will
1651     // not complain about that.  (Close() may, however, complain if the
1652     // connection is closed, but that's okay.)
1653     if (completeEvent) {
1654       // Closing the database is more important than returning an error code
1655       // about a failure to dispatch, especially because all existing native
1656       // callers ignore our return value.
1657       Unused << NS_DispatchToMainThread(completeEvent.forget());
1658     }
1659     MOZ_ALWAYS_SUCCEEDS(synchronousClose());
1660     // Return a success inconditionally here, since Close() is unlikely to fail
1661     // and we want to reassure the consumer that its callback will be invoked.
1662     return NS_OK;
1663   }
1664
1665   // If we're closing the connection during shutdown, and there is an
1666   // interruptible statement running on the helper thread, issue a
1667   // sqlite3_interrupt() to avoid crashing when that statement takes a long
1668   // time (for example a vacuum).
1669   if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed) &&
1670       mInterruptible && mIsStatementOnHelperThreadInterruptible) {
1671     MOZ_ASSERT(!isClosing(), "Must not be closing, see Interrupt()");
1672     DebugOnly<nsresult> rv2 = Interrupt();
1673     MOZ_ASSERT(NS_SUCCEEDED(rv2));
1674   }
1675
1676   // setClosedState nullifies our connection pointer, so we take a raw pointer
1677   // off it, to pass it through the close procedure.
1678   sqlite3* nativeConn = mDBConn;
1679   rv = setClosedState();
1680   NS_ENSURE_SUCCESS(rv, rv);
1681
1682   // Create and dispatch our close event to the background thread.
1683   nsCOMPtr<nsIRunnable> closeEvent =
1684       new AsyncCloseConnection(this, nativeConn, completeEvent);
1685   rv = asyncThread->Dispatch(closeEvent, NS_DISPATCH_NORMAL);
1686   NS_ENSURE_SUCCESS(rv, rv);
1687
1688   return NS_OK;
1689 }
1690
1691 NS_IMETHODIMP
1692 Connection::AsyncClone(bool aReadOnly,
1693                        mozIStorageCompletionCallback* aCallback) {
1694   AUTO_PROFILER_LABEL("Connection::AsyncClone", OTHER);
1695
1696   NS_ENSURE_TRUE(NS_IsMainThread(), NS_ERROR_NOT_SAME_THREAD);
1697   if (!connectionReady()) {
1698     return NS_ERROR_NOT_INITIALIZED;
1699   }
1700   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
1701   if (NS_FAILED(rv)) {
1702     return rv;
1703   }
1704   if (!mDatabaseFile) return NS_ERROR_UNEXPECTED;
1705
1706   int flags = mFlags;
1707   if (aReadOnly) {
1708     // Turn off SQLITE_OPEN_READWRITE, and set SQLITE_OPEN_READONLY.
1709     flags = (~SQLITE_OPEN_READWRITE & flags) | SQLITE_OPEN_READONLY;
1710     // Turn off SQLITE_OPEN_CREATE.
1711     flags = (~SQLITE_OPEN_CREATE & flags);
1712   }
1713
1714   // The cloned connection will still implement the synchronous API, but throw
1715   // if any synchronous methods are called on the main thread.
1716   RefPtr<Connection> clone =
1717       new Connection(mStorageService, flags, ASYNCHRONOUS);
1718
1719   RefPtr<AsyncInitializeClone> initEvent =
1720       new AsyncInitializeClone(this, clone, aReadOnly, aCallback);
1721   // Dispatch to our async thread, since the originating connection must remain
1722   // valid and open for the whole cloning process.  This also ensures we are
1723   // properly serialized with a `close` operation, rather than race with it.
1724   nsCOMPtr<nsIEventTarget> target = getAsyncExecutionTarget();
1725   if (!target) {
1726     return NS_ERROR_UNEXPECTED;
1727   }
1728   return target->Dispatch(initEvent, NS_DISPATCH_NORMAL);
1729 }
1730
1731 nsresult Connection::initializeClone(Connection* aClone, bool aReadOnly) {
1732   nsresult rv;
1733   if (!mStorageKey.IsEmpty()) {
1734     rv = aClone->initialize(mStorageKey, mName);
1735   } else if (mFileURL) {
1736     rv = aClone->initialize(mFileURL, mTelemetryFilename);
1737   } else {
1738     rv = aClone->initialize(mDatabaseFile);
1739   }
1740   if (NS_FAILED(rv)) {
1741     return rv;
1742   }
1743
1744   auto guard = MakeScopeExit([&]() { aClone->initializeFailed(); });
1745
1746   rv = aClone->SetDefaultTransactionType(mDefaultTransactionType);
1747   NS_ENSURE_SUCCESS(rv, rv);
1748
1749   // Re-attach on-disk databases that were attached to the original connection.
1750   {
1751     nsCOMPtr<mozIStorageStatement> stmt;
1752     rv = CreateStatement("PRAGMA database_list"_ns, getter_AddRefs(stmt));
1753     NS_ENSURE_SUCCESS(rv, rv);
1754     bool hasResult = false;
1755     while (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
1756       nsAutoCString name;
1757       rv = stmt->GetUTF8String(1, name);
1758       if (NS_SUCCEEDED(rv) && !name.EqualsLiteral("main") &&
1759           !name.EqualsLiteral("temp")) {
1760         nsCString path;
1761         rv = stmt->GetUTF8String(2, path);
1762         if (NS_SUCCEEDED(rv) && !path.IsEmpty()) {
1763           nsCOMPtr<mozIStorageStatement> attachStmt;
1764           rv = aClone->CreateStatement("ATTACH DATABASE :path AS "_ns + name,
1765                                        getter_AddRefs(attachStmt));
1766           NS_ENSURE_SUCCESS(rv, rv);
1767           rv = attachStmt->BindUTF8StringByName("path"_ns, path);
1768           NS_ENSURE_SUCCESS(rv, rv);
1769           rv = attachStmt->Execute();
1770           NS_ENSURE_SUCCESS(rv, rv);
1771         }
1772       }
1773     }
1774   }
1775
1776   // Copy over pragmas from the original connection.
1777   // LIMITATION WARNING!  Many of these pragmas are actually scoped to the
1778   // schema ("main" and any other attached databases), and this implmentation
1779   // fails to propagate them.  This is being addressed on trunk.
1780   static const char* pragmas[] = {
1781       "cache_size",  "temp_store",         "foreign_keys", "journal_size_limit",
1782       "synchronous", "wal_autocheckpoint", "busy_timeout"};
1783   for (auto& pragma : pragmas) {
1784     // Read-only connections just need cache_size and temp_store pragmas.
1785     if (aReadOnly && ::strcmp(pragma, "cache_size") != 0 &&
1786         ::strcmp(pragma, "temp_store") != 0) {
1787       continue;
1788     }
1789
1790     nsAutoCString pragmaQuery("PRAGMA ");
1791     pragmaQuery.Append(pragma);
1792     nsCOMPtr<mozIStorageStatement> stmt;
1793     rv = CreateStatement(pragmaQuery, getter_AddRefs(stmt));
1794     NS_ENSURE_SUCCESS(rv, rv);
1795     bool hasResult = false;
1796     if (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
1797       pragmaQuery.AppendLiteral(" = ");
1798       pragmaQuery.AppendInt(stmt->AsInt32(0));
1799       rv = aClone->ExecuteSimpleSQL(pragmaQuery);
1800       NS_ENSURE_SUCCESS(rv, rv);
1801     }
1802   }
1803
1804   // Copy over temporary tables, triggers, and views from the original
1805   // connections. Entities in `sqlite_temp_master` are only visible to the
1806   // connection that created them.
1807   if (!aReadOnly) {
1808     rv = aClone->ExecuteSimpleSQL("BEGIN TRANSACTION"_ns);
1809     NS_ENSURE_SUCCESS(rv, rv);
1810
1811     nsCOMPtr<mozIStorageStatement> stmt;
1812     rv = CreateStatement(nsLiteralCString("SELECT sql FROM sqlite_temp_master "
1813                                           "WHERE type IN ('table', 'view', "
1814                                           "'index', 'trigger')"),
1815                          getter_AddRefs(stmt));
1816     // Propagate errors, because failing to copy triggers might cause schema
1817     // coherency issues when writing to the database from the cloned connection.
1818     NS_ENSURE_SUCCESS(rv, rv);
1819     bool hasResult = false;
1820     while (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
1821       nsAutoCString query;
1822       rv = stmt->GetUTF8String(0, query);
1823       NS_ENSURE_SUCCESS(rv, rv);
1824
1825       // The `CREATE` SQL statements in `sqlite_temp_master` omit the `TEMP`
1826       // keyword. We need to add it back, or we'll recreate temporary entities
1827       // as persistent ones. `sqlite_temp_master` also holds `CREATE INDEX`
1828       // statements, but those don't need `TEMP` keywords.
1829       if (StringBeginsWith(query, "CREATE TABLE "_ns) ||
1830           StringBeginsWith(query, "CREATE TRIGGER "_ns) ||
1831           StringBeginsWith(query, "CREATE VIEW "_ns)) {
1832         query.Replace(0, 6, "CREATE TEMP");
1833       }
1834
1835       rv = aClone->ExecuteSimpleSQL(query);
1836       NS_ENSURE_SUCCESS(rv, rv);
1837     }
1838
1839     rv = aClone->ExecuteSimpleSQL("COMMIT"_ns);
1840     NS_ENSURE_SUCCESS(rv, rv);
1841   }
1842
1843   // Copy any functions that have been added to this connection.
1844   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
1845   for (const auto& entry : mFunctions) {
1846     const nsACString& key = entry.GetKey();
1847     Connection::FunctionInfo data = entry.GetData();
1848
1849     rv = aClone->CreateFunction(key, data.numArgs, data.function);
1850     if (NS_FAILED(rv)) {
1851       NS_WARNING("Failed to copy function to cloned connection");
1852     }
1853   }
1854
1855   guard.release();
1856   return NS_OK;
1857 }
1858
1859 NS_IMETHODIMP
1860 Connection::Clone(bool aReadOnly, mozIStorageConnection** _connection) {
1861   MOZ_ASSERT(IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1862
1863   AUTO_PROFILER_LABEL("Connection::Clone", OTHER);
1864
1865   if (!connectionReady()) {
1866     return NS_ERROR_NOT_INITIALIZED;
1867   }
1868   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
1869   if (NS_FAILED(rv)) {
1870     return rv;
1871   }
1872
1873   int flags = mFlags;
1874   if (aReadOnly) {
1875     // Turn off SQLITE_OPEN_READWRITE, and set SQLITE_OPEN_READONLY.
1876     flags = (~SQLITE_OPEN_READWRITE & flags) | SQLITE_OPEN_READONLY;
1877     // Turn off SQLITE_OPEN_CREATE.
1878     flags = (~SQLITE_OPEN_CREATE & flags);
1879   }
1880
1881   RefPtr<Connection> clone = new Connection(
1882       mStorageService, flags, mSupportedOperations, mInterruptible);
1883
1884   rv = initializeClone(clone, aReadOnly);
1885   if (NS_FAILED(rv)) {
1886     return rv;
1887   }
1888
1889   NS_IF_ADDREF(*_connection = clone);
1890   return NS_OK;
1891 }
1892
1893 NS_IMETHODIMP
1894 Connection::Interrupt() {
1895   MOZ_ASSERT(mInterruptible, "Interrupt method not allowed");
1896   MOZ_ASSERT_IF(SYNCHRONOUS == mSupportedOperations,
1897                 !IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1898   MOZ_ASSERT_IF(ASYNCHRONOUS == mSupportedOperations,
1899                 IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1900
1901   if (!connectionReady()) {
1902     return NS_ERROR_NOT_INITIALIZED;
1903   }
1904
1905   if (isClosing()) {  // Closing already in asynchronous case
1906     return NS_OK;
1907   }
1908
1909   {
1910     // As stated on https://www.sqlite.org/c3ref/interrupt.html,
1911     // it is not safe to call sqlite3_interrupt() when
1912     // database connection is closed or might close before
1913     // sqlite3_interrupt() returns.
1914     MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
1915     if (!isClosed(lockedScope)) {
1916       MOZ_ASSERT(mDBConn);
1917       ::sqlite3_interrupt(mDBConn);
1918     }
1919   }
1920
1921   return NS_OK;
1922 }
1923
1924 NS_IMETHODIMP
1925 Connection::AsyncVacuum(mozIStorageCompletionCallback* aCallback,
1926                         bool aUseIncremental, int32_t aSetPageSize) {
1927   NS_ENSURE_TRUE(NS_IsMainThread(), NS_ERROR_NOT_SAME_THREAD);
1928   // Abort if we're shutting down.
1929   if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
1930     return NS_ERROR_ABORT;
1931   }
1932   // Check if AsyncClose or Close were already invoked.
1933   if (!connectionReady()) {
1934     return NS_ERROR_NOT_INITIALIZED;
1935   }
1936   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
1937   if (NS_FAILED(rv)) {
1938     return rv;
1939   }
1940   nsIEventTarget* asyncThread = getAsyncExecutionTarget();
1941   if (!asyncThread) {
1942     return NS_ERROR_NOT_INITIALIZED;
1943   }
1944
1945   // Create and dispatch our vacuum event to the background thread.
1946   nsCOMPtr<nsIRunnable> vacuumEvent =
1947       new AsyncVacuumEvent(this, aCallback, aUseIncremental, aSetPageSize);
1948   rv = asyncThread->Dispatch(vacuumEvent, NS_DISPATCH_NORMAL);
1949   NS_ENSURE_SUCCESS(rv, rv);
1950
1951   return NS_OK;
1952 }
1953
1954 NS_IMETHODIMP
1955 Connection::GetDefaultPageSize(int32_t* _defaultPageSize) {
1956   *_defaultPageSize = Service::kDefaultPageSize;
1957   return NS_OK;
1958 }
1959
1960 NS_IMETHODIMP
1961 Connection::GetConnectionReady(bool* _ready) {
1962   MOZ_ASSERT(IsOnCurrentSerialEventTarget(eventTargetOpenedOn));
1963   *_ready = connectionReady();
1964   return NS_OK;
1965 }
1966
1967 NS_IMETHODIMP
1968 Connection::GetDatabaseFile(nsIFile** _dbFile) {
1969   if (!connectionReady()) {
1970     return NS_ERROR_NOT_INITIALIZED;
1971   }
1972   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
1973   if (NS_FAILED(rv)) {
1974     return rv;
1975   }
1976
1977   NS_IF_ADDREF(*_dbFile = mDatabaseFile);
1978
1979   return NS_OK;
1980 }
1981
1982 NS_IMETHODIMP
1983 Connection::GetLastInsertRowID(int64_t* _id) {
1984   if (!connectionReady()) {
1985     return NS_ERROR_NOT_INITIALIZED;
1986   }
1987   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
1988   if (NS_FAILED(rv)) {
1989     return rv;
1990   }
1991
1992   sqlite_int64 id = ::sqlite3_last_insert_rowid(mDBConn);
1993   *_id = id;
1994
1995   return NS_OK;
1996 }
1997
1998 NS_IMETHODIMP
1999 Connection::GetAffectedRows(int32_t* _rows) {
2000   if (!connectionReady()) {
2001     return NS_ERROR_NOT_INITIALIZED;
2002   }
2003   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2004   if (NS_FAILED(rv)) {
2005     return rv;
2006   }
2007
2008   *_rows = ::sqlite3_changes(mDBConn);
2009
2010   return NS_OK;
2011 }
2012
2013 NS_IMETHODIMP
2014 Connection::GetLastError(int32_t* _error) {
2015   if (!connectionReady()) {
2016     return NS_ERROR_NOT_INITIALIZED;
2017   }
2018   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2019   if (NS_FAILED(rv)) {
2020     return rv;
2021   }
2022
2023   *_error = ::sqlite3_errcode(mDBConn);
2024
2025   return NS_OK;
2026 }
2027
2028 NS_IMETHODIMP
2029 Connection::GetLastErrorString(nsACString& _errorString) {
2030   if (!connectionReady()) {
2031     return NS_ERROR_NOT_INITIALIZED;
2032   }
2033   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2034   if (NS_FAILED(rv)) {
2035     return rv;
2036   }
2037
2038   const char* serr = ::sqlite3_errmsg(mDBConn);
2039   _errorString.Assign(serr);
2040
2041   return NS_OK;
2042 }
2043
2044 NS_IMETHODIMP
2045 Connection::GetSchemaVersion(int32_t* _version) {
2046   if (!connectionReady()) {
2047     return NS_ERROR_NOT_INITIALIZED;
2048   }
2049   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2050   if (NS_FAILED(rv)) {
2051     return rv;
2052   }
2053
2054   nsCOMPtr<mozIStorageStatement> stmt;
2055   (void)CreateStatement("PRAGMA user_version"_ns, getter_AddRefs(stmt));
2056   NS_ENSURE_TRUE(stmt, NS_ERROR_OUT_OF_MEMORY);
2057
2058   *_version = 0;
2059   bool hasResult;
2060   if (NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult)
2061     *_version = stmt->AsInt32(0);
2062
2063   return NS_OK;
2064 }
2065
2066 NS_IMETHODIMP
2067 Connection::SetSchemaVersion(int32_t aVersion) {
2068   if (!connectionReady()) {
2069     return NS_ERROR_NOT_INITIALIZED;
2070   }
2071   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2072   if (NS_FAILED(rv)) {
2073     return rv;
2074   }
2075
2076   nsAutoCString stmt("PRAGMA user_version = "_ns);
2077   stmt.AppendInt(aVersion);
2078
2079   return ExecuteSimpleSQL(stmt);
2080 }
2081
2082 NS_IMETHODIMP
2083 Connection::CreateStatement(const nsACString& aSQLStatement,
2084                             mozIStorageStatement** _stmt) {
2085   NS_ENSURE_ARG_POINTER(_stmt);
2086   if (!connectionReady()) {
2087     return NS_ERROR_NOT_INITIALIZED;
2088   }
2089   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2090   if (NS_FAILED(rv)) {
2091     return rv;
2092   }
2093
2094   RefPtr<Statement> statement(new Statement());
2095   NS_ENSURE_TRUE(statement, NS_ERROR_OUT_OF_MEMORY);
2096
2097   rv = statement->initialize(this, mDBConn, aSQLStatement);
2098   NS_ENSURE_SUCCESS(rv, rv);
2099
2100   Statement* rawPtr;
2101   statement.forget(&rawPtr);
2102   *_stmt = rawPtr;
2103   return NS_OK;
2104 }
2105
2106 NS_IMETHODIMP
2107 Connection::CreateAsyncStatement(const nsACString& aSQLStatement,
2108                                  mozIStorageAsyncStatement** _stmt) {
2109   NS_ENSURE_ARG_POINTER(_stmt);
2110   if (!connectionReady()) {
2111     return NS_ERROR_NOT_INITIALIZED;
2112   }
2113   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2114   if (NS_FAILED(rv)) {
2115     return rv;
2116   }
2117
2118   RefPtr<AsyncStatement> statement(new AsyncStatement());
2119   NS_ENSURE_TRUE(statement, NS_ERROR_OUT_OF_MEMORY);
2120
2121   rv = statement->initialize(this, mDBConn, aSQLStatement);
2122   NS_ENSURE_SUCCESS(rv, rv);
2123
2124   AsyncStatement* rawPtr;
2125   statement.forget(&rawPtr);
2126   *_stmt = rawPtr;
2127   return NS_OK;
2128 }
2129
2130 NS_IMETHODIMP
2131 Connection::ExecuteSimpleSQL(const nsACString& aSQLStatement) {
2132   CHECK_MAINTHREAD_ABUSE();
2133   if (!connectionReady()) {
2134     return NS_ERROR_NOT_INITIALIZED;
2135   }
2136   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2137   if (NS_FAILED(rv)) {
2138     return rv;
2139   }
2140
2141   int srv = executeSql(mDBConn, PromiseFlatCString(aSQLStatement).get());
2142   return convertResultCode(srv);
2143 }
2144
2145 NS_IMETHODIMP
2146 Connection::ExecuteAsync(
2147     const nsTArray<RefPtr<mozIStorageBaseStatement>>& aStatements,
2148     mozIStorageStatementCallback* aCallback,
2149     mozIStoragePendingStatement** _handle) {
2150   nsTArray<StatementData> stmts(aStatements.Length());
2151   for (uint32_t i = 0; i < aStatements.Length(); i++) {
2152     nsCOMPtr<StorageBaseStatementInternal> stmt =
2153         do_QueryInterface(aStatements[i]);
2154     NS_ENSURE_STATE(stmt);
2155
2156     // Obtain our StatementData.
2157     StatementData data;
2158     nsresult rv = stmt->getAsynchronousStatementData(data);
2159     NS_ENSURE_SUCCESS(rv, rv);
2160
2161     NS_ASSERTION(stmt->getOwner() == this,
2162                  "Statement must be from this database connection!");
2163
2164     // Now append it to our array.
2165     stmts.AppendElement(data);
2166   }
2167
2168   // Dispatch to the background
2169   return AsyncExecuteStatements::execute(std::move(stmts), this, mDBConn,
2170                                          aCallback, _handle);
2171 }
2172
2173 NS_IMETHODIMP
2174 Connection::ExecuteSimpleSQLAsync(const nsACString& aSQLStatement,
2175                                   mozIStorageStatementCallback* aCallback,
2176                                   mozIStoragePendingStatement** _handle) {
2177   NS_ENSURE_TRUE(NS_IsMainThread(), NS_ERROR_NOT_SAME_THREAD);
2178
2179   nsCOMPtr<mozIStorageAsyncStatement> stmt;
2180   nsresult rv = CreateAsyncStatement(aSQLStatement, getter_AddRefs(stmt));
2181   if (NS_FAILED(rv)) {
2182     return rv;
2183   }
2184
2185   nsCOMPtr<mozIStoragePendingStatement> pendingStatement;
2186   rv = stmt->ExecuteAsync(aCallback, getter_AddRefs(pendingStatement));
2187   if (NS_FAILED(rv)) {
2188     return rv;
2189   }
2190
2191   pendingStatement.forget(_handle);
2192   return rv;
2193 }
2194
2195 NS_IMETHODIMP
2196 Connection::TableExists(const nsACString& aTableName, bool* _exists) {
2197   return databaseElementExists(TABLE, aTableName, _exists);
2198 }
2199
2200 NS_IMETHODIMP
2201 Connection::IndexExists(const nsACString& aIndexName, bool* _exists) {
2202   return databaseElementExists(INDEX, aIndexName, _exists);
2203 }
2204
2205 NS_IMETHODIMP
2206 Connection::GetTransactionInProgress(bool* _inProgress) {
2207   if (!connectionReady()) {
2208     return NS_ERROR_NOT_INITIALIZED;
2209   }
2210   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2211   if (NS_FAILED(rv)) {
2212     return rv;
2213   }
2214
2215   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2216   *_inProgress = transactionInProgress(lockedScope);
2217   return NS_OK;
2218 }
2219
2220 NS_IMETHODIMP
2221 Connection::GetDefaultTransactionType(int32_t* _type) {
2222   *_type = mDefaultTransactionType;
2223   return NS_OK;
2224 }
2225
2226 NS_IMETHODIMP
2227 Connection::SetDefaultTransactionType(int32_t aType) {
2228   NS_ENSURE_ARG_RANGE(aType, TRANSACTION_DEFERRED, TRANSACTION_EXCLUSIVE);
2229   mDefaultTransactionType = aType;
2230   return NS_OK;
2231 }
2232
2233 NS_IMETHODIMP
2234 Connection::GetVariableLimit(int32_t* _limit) {
2235   if (!connectionReady()) {
2236     return NS_ERROR_NOT_INITIALIZED;
2237   }
2238   int limit = ::sqlite3_limit(mDBConn, SQLITE_LIMIT_VARIABLE_NUMBER, -1);
2239   if (limit < 0) {
2240     return NS_ERROR_UNEXPECTED;
2241   }
2242   *_limit = limit;
2243   return NS_OK;
2244 }
2245
2246 NS_IMETHODIMP
2247 Connection::BeginTransaction() {
2248   if (!connectionReady()) {
2249     return NS_ERROR_NOT_INITIALIZED;
2250   }
2251   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2252   if (NS_FAILED(rv)) {
2253     return rv;
2254   }
2255
2256   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2257   return beginTransactionInternal(lockedScope, mDBConn,
2258                                   mDefaultTransactionType);
2259 }
2260
2261 nsresult Connection::beginTransactionInternal(
2262     const SQLiteMutexAutoLock& aProofOfLock, sqlite3* aNativeConnection,
2263     int32_t aTransactionType) {
2264   if (transactionInProgress(aProofOfLock)) {
2265     return NS_ERROR_FAILURE;
2266   }
2267   nsresult rv;
2268   switch (aTransactionType) {
2269     case TRANSACTION_DEFERRED:
2270       rv = convertResultCode(executeSql(aNativeConnection, "BEGIN DEFERRED"));
2271       break;
2272     case TRANSACTION_IMMEDIATE:
2273       rv = convertResultCode(executeSql(aNativeConnection, "BEGIN IMMEDIATE"));
2274       break;
2275     case TRANSACTION_EXCLUSIVE:
2276       rv = convertResultCode(executeSql(aNativeConnection, "BEGIN EXCLUSIVE"));
2277       break;
2278     default:
2279       return NS_ERROR_ILLEGAL_VALUE;
2280   }
2281   return rv;
2282 }
2283
2284 NS_IMETHODIMP
2285 Connection::CommitTransaction() {
2286   if (!connectionReady()) {
2287     return NS_ERROR_NOT_INITIALIZED;
2288   }
2289   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2290   if (NS_FAILED(rv)) {
2291     return rv;
2292   }
2293
2294   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2295   return commitTransactionInternal(lockedScope, mDBConn);
2296 }
2297
2298 nsresult Connection::commitTransactionInternal(
2299     const SQLiteMutexAutoLock& aProofOfLock, sqlite3* aNativeConnection) {
2300   if (!transactionInProgress(aProofOfLock)) {
2301     return NS_ERROR_UNEXPECTED;
2302   }
2303   nsresult rv =
2304       convertResultCode(executeSql(aNativeConnection, "COMMIT TRANSACTION"));
2305   return rv;
2306 }
2307
2308 NS_IMETHODIMP
2309 Connection::RollbackTransaction() {
2310   if (!connectionReady()) {
2311     return NS_ERROR_NOT_INITIALIZED;
2312   }
2313   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2314   if (NS_FAILED(rv)) {
2315     return rv;
2316   }
2317
2318   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2319   return rollbackTransactionInternal(lockedScope, mDBConn);
2320 }
2321
2322 nsresult Connection::rollbackTransactionInternal(
2323     const SQLiteMutexAutoLock& aProofOfLock, sqlite3* aNativeConnection) {
2324   if (!transactionInProgress(aProofOfLock)) {
2325     return NS_ERROR_UNEXPECTED;
2326   }
2327
2328   nsresult rv =
2329       convertResultCode(executeSql(aNativeConnection, "ROLLBACK TRANSACTION"));
2330   return rv;
2331 }
2332
2333 NS_IMETHODIMP
2334 Connection::CreateTable(const char* aTableName, const char* aTableSchema) {
2335   if (!connectionReady()) {
2336     return NS_ERROR_NOT_INITIALIZED;
2337   }
2338   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2339   if (NS_FAILED(rv)) {
2340     return rv;
2341   }
2342
2343   SmprintfPointer buf =
2344       ::mozilla::Smprintf("CREATE TABLE %s (%s)", aTableName, aTableSchema);
2345   if (!buf) return NS_ERROR_OUT_OF_MEMORY;
2346
2347   int srv = executeSql(mDBConn, buf.get());
2348
2349   return convertResultCode(srv);
2350 }
2351
2352 NS_IMETHODIMP
2353 Connection::CreateFunction(const nsACString& aFunctionName,
2354                            int32_t aNumArguments,
2355                            mozIStorageFunction* aFunction) {
2356   if (!connectionReady()) {
2357     return NS_ERROR_NOT_INITIALIZED;
2358   }
2359   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2360   if (NS_FAILED(rv)) {
2361     return rv;
2362   }
2363
2364   // Check to see if this function is already defined.  We only check the name
2365   // because a function can be defined with the same body but different names.
2366   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2367   NS_ENSURE_FALSE(mFunctions.Contains(aFunctionName), NS_ERROR_FAILURE);
2368
2369   int srv = ::sqlite3_create_function(
2370       mDBConn, nsPromiseFlatCString(aFunctionName).get(), aNumArguments,
2371       SQLITE_ANY, aFunction, basicFunctionHelper, nullptr, nullptr);
2372   if (srv != SQLITE_OK) return convertResultCode(srv);
2373
2374   FunctionInfo info = {aFunction, aNumArguments};
2375   mFunctions.InsertOrUpdate(aFunctionName, info);
2376
2377   return NS_OK;
2378 }
2379
2380 NS_IMETHODIMP
2381 Connection::RemoveFunction(const nsACString& aFunctionName) {
2382   if (!connectionReady()) {
2383     return NS_ERROR_NOT_INITIALIZED;
2384   }
2385   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2386   if (NS_FAILED(rv)) {
2387     return rv;
2388   }
2389
2390   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2391   NS_ENSURE_TRUE(mFunctions.Get(aFunctionName, nullptr), NS_ERROR_FAILURE);
2392
2393   int srv = ::sqlite3_create_function(
2394       mDBConn, nsPromiseFlatCString(aFunctionName).get(), 0, SQLITE_ANY,
2395       nullptr, nullptr, nullptr, nullptr);
2396   if (srv != SQLITE_OK) return convertResultCode(srv);
2397
2398   mFunctions.Remove(aFunctionName);
2399
2400   return NS_OK;
2401 }
2402
2403 NS_IMETHODIMP
2404 Connection::SetProgressHandler(int32_t aGranularity,
2405                                mozIStorageProgressHandler* aHandler,
2406                                mozIStorageProgressHandler** _oldHandler) {
2407   if (!connectionReady()) {
2408     return NS_ERROR_NOT_INITIALIZED;
2409   }
2410   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2411   if (NS_FAILED(rv)) {
2412     return rv;
2413   }
2414
2415   // Return previous one
2416   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2417   NS_IF_ADDREF(*_oldHandler = mProgressHandler);
2418
2419   if (!aHandler || aGranularity <= 0) {
2420     aHandler = nullptr;
2421     aGranularity = 0;
2422   }
2423   mProgressHandler = aHandler;
2424   ::sqlite3_progress_handler(mDBConn, aGranularity, sProgressHelper, this);
2425
2426   return NS_OK;
2427 }
2428
2429 NS_IMETHODIMP
2430 Connection::RemoveProgressHandler(mozIStorageProgressHandler** _oldHandler) {
2431   if (!connectionReady()) {
2432     return NS_ERROR_NOT_INITIALIZED;
2433   }
2434   nsresult rv = ensureOperationSupported(ASYNCHRONOUS);
2435   if (NS_FAILED(rv)) {
2436     return rv;
2437   }
2438
2439   // Return previous one
2440   SQLiteMutexAutoLock lockedScope(sharedDBMutex);
2441   NS_IF_ADDREF(*_oldHandler = mProgressHandler);
2442
2443   mProgressHandler = nullptr;
2444   ::sqlite3_progress_handler(mDBConn, 0, nullptr, nullptr);
2445
2446   return NS_OK;
2447 }
2448
2449 NS_IMETHODIMP
2450 Connection::SetGrowthIncrement(int32_t aChunkSize,
2451                                const nsACString& aDatabaseName) {
2452   if (!connectionReady()) {
2453     return NS_ERROR_NOT_INITIALIZED;
2454   }
2455   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2456   if (NS_FAILED(rv)) {
2457     return rv;
2458   }
2459
2460   // Bug 597215: Disk space is extremely limited on Android
2461   // so don't preallocate space. This is also not effective
2462   // on log structured file systems used by Android devices
2463 #if !defined(ANDROID) && !defined(MOZ_PLATFORM_MAEMO)
2464   // Don't preallocate if less than 500MiB is available.
2465   int64_t bytesAvailable;
2466   rv = mDatabaseFile->GetDiskSpaceAvailable(&bytesAvailable);
2467   NS_ENSURE_SUCCESS(rv, rv);
2468   if (bytesAvailable < MIN_AVAILABLE_BYTES_PER_CHUNKED_GROWTH) {
2469     return NS_ERROR_FILE_TOO_BIG;
2470   }
2471
2472   int srv = ::sqlite3_file_control(
2473       mDBConn,
2474       aDatabaseName.Length() ? nsPromiseFlatCString(aDatabaseName).get()
2475                              : nullptr,
2476       SQLITE_FCNTL_CHUNK_SIZE, &aChunkSize);
2477   if (srv == SQLITE_OK) {
2478     mGrowthChunkSize = aChunkSize;
2479   }
2480 #endif
2481   return NS_OK;
2482 }
2483
2484 int32_t Connection::RemovablePagesInFreeList(const nsACString& aSchemaName) {
2485   int32_t freeListPagesCount = 0;
2486   if (!isConnectionReadyOnThisThread()) {
2487     MOZ_ASSERT(false, "Database connection is not ready");
2488     return freeListPagesCount;
2489   }
2490   {
2491     nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
2492     query.Append(aSchemaName);
2493     query.AppendLiteral(".freelist_count");
2494     nsCOMPtr<mozIStorageStatement> stmt;
2495     DebugOnly<nsresult> rv = CreateStatement(query, getter_AddRefs(stmt));
2496     MOZ_ASSERT(NS_SUCCEEDED(rv));
2497     bool hasResult = false;
2498     if (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
2499       freeListPagesCount = stmt->AsInt32(0);
2500     }
2501   }
2502   // If there's no chunk size set, any page is good to be removed.
2503   if (mGrowthChunkSize == 0 || freeListPagesCount == 0) {
2504     return freeListPagesCount;
2505   }
2506   int32_t pageSize;
2507   {
2508     nsAutoCString query(MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA ");
2509     query.Append(aSchemaName);
2510     query.AppendLiteral(".page_size");
2511     nsCOMPtr<mozIStorageStatement> stmt;
2512     DebugOnly<nsresult> rv = CreateStatement(query, getter_AddRefs(stmt));
2513     MOZ_ASSERT(NS_SUCCEEDED(rv));
2514     bool hasResult = false;
2515     if (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
2516       pageSize = stmt->AsInt32(0);
2517     } else {
2518       MOZ_ASSERT(false, "Couldn't get page_size");
2519       return 0;
2520     }
2521   }
2522   return std::max(0, freeListPagesCount - (mGrowthChunkSize / pageSize));
2523 }
2524
2525 NS_IMETHODIMP
2526 Connection::EnableModule(const nsACString& aModuleName) {
2527   if (!connectionReady()) {
2528     return NS_ERROR_NOT_INITIALIZED;
2529   }
2530   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2531   if (NS_FAILED(rv)) {
2532     return rv;
2533   }
2534
2535   for (auto& gModule : gModules) {
2536     struct Module* m = &gModule;
2537     if (aModuleName.Equals(m->name)) {
2538       int srv = m->registerFunc(mDBConn, m->name);
2539       if (srv != SQLITE_OK) return convertResultCode(srv);
2540
2541       return NS_OK;
2542     }
2543   }
2544
2545   return NS_ERROR_FAILURE;
2546 }
2547
2548 // Implemented in QuotaVFS.cpp
2549 already_AddRefed<QuotaObject> GetQuotaObjectForFile(sqlite3_file* pFile);
2550
2551 NS_IMETHODIMP
2552 Connection::GetQuotaObjects(QuotaObject** aDatabaseQuotaObject,
2553                             QuotaObject** aJournalQuotaObject) {
2554   MOZ_ASSERT(aDatabaseQuotaObject);
2555   MOZ_ASSERT(aJournalQuotaObject);
2556
2557   if (!connectionReady()) {
2558     return NS_ERROR_NOT_INITIALIZED;
2559   }
2560   nsresult rv = ensureOperationSupported(SYNCHRONOUS);
2561   if (NS_FAILED(rv)) {
2562     return rv;
2563   }
2564
2565   sqlite3_file* file;
2566   int srv = ::sqlite3_file_control(mDBConn, nullptr, SQLITE_FCNTL_FILE_POINTER,
2567                                    &file);
2568   if (srv != SQLITE_OK) {
2569     return convertResultCode(srv);
2570   }
2571
2572   RefPtr<QuotaObject> databaseQuotaObject = GetQuotaObjectForFile(file);
2573   if (NS_WARN_IF(!databaseQuotaObject)) {
2574     return NS_ERROR_FAILURE;
2575   }
2576
2577   srv = ::sqlite3_file_control(mDBConn, nullptr, SQLITE_FCNTL_JOURNAL_POINTER,
2578                                &file);
2579   if (srv != SQLITE_OK) {
2580     return convertResultCode(srv);
2581   }
2582
2583   RefPtr<QuotaObject> journalQuotaObject = GetQuotaObjectForFile(file);
2584   if (NS_WARN_IF(!journalQuotaObject)) {
2585     return NS_ERROR_FAILURE;
2586   }
2587
2588   databaseQuotaObject.forget(aDatabaseQuotaObject);
2589   journalQuotaObject.forget(aJournalQuotaObject);
2590   return NS_OK;
2591 }
2592
2593 SQLiteMutex& Connection::GetSharedDBMutex() { return sharedDBMutex; }
2594
2595 uint32_t Connection::GetTransactionNestingLevel(
2596     const mozilla::storage::SQLiteMutexAutoLock& aProofOfLock) {
2597   return mTransactionNestingLevel;
2598 }
2599
2600 uint32_t Connection::IncreaseTransactionNestingLevel(
2601     const mozilla::storage::SQLiteMutexAutoLock& aProofOfLock) {
2602   return ++mTransactionNestingLevel;
2603 }
2604
2605 uint32_t Connection::DecreaseTransactionNestingLevel(
2606     const mozilla::storage::SQLiteMutexAutoLock& aProofOfLock) {
2607   return --mTransactionNestingLevel;
2608 }
2609
2610 }  // namespace mozilla::storage