Add m-esr52 at 52.6.0

1 files changed, 2040 insertions, 0 deletions

diff --git a/storage/mozStorageConnection.cpp b/storage/mozStorageConnection.cpp
new file mode 100644
index 000000000..10297fca1
--- /dev/null
+++ b/storage/mozStorageConnection.cpp
@@ -0,0 +1,2040 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+
+#include "nsError.h"
+#include "nsIMutableArray.h"
+#include "nsAutoPtr.h"
+#include "nsIMemoryReporter.h"
+#include "nsThreadUtils.h"
+#include "nsIFile.h"
+#include "nsIFileURL.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/CondVar.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorNames.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/quota/QuotaObject.h"
+
+#include "mozIStorageAggregateFunction.h"
+#include "mozIStorageCompletionCallback.h"
+#include "mozIStorageFunction.h"
+
+#include "mozStorageAsyncStatementExecution.h"
+#include "mozStorageSQLFunctions.h"
+#include "mozStorageConnection.h"
+#include "mozStorageService.h"
+#include "mozStorageStatement.h"
+#include "mozStorageAsyncStatement.h"
+#include "mozStorageArgValueArray.h"
+#include "mozStoragePrivateHelpers.h"
+#include "mozStorageStatementData.h"
+#include "StorageBaseStatementInternal.h"
+#include "SQLCollations.h"
+#include "FileSystemModule.h"
+#include "mozStorageHelper.h"
+#include "GeckoProfiler.h"
+
+#include "mozilla/Logging.h"
+#include "prprf.h"
+#include "nsProxyRelease.h"
+#include <algorithm>
+
+#define MIN_AVAILABLE_BYTES_PER_CHUNKED_GROWTH 524288000 // 500 MiB
+
+// Maximum size of the pages cache per connection.
+#define MAX_CACHE_SIZE_KIBIBYTES 2048 // 2 MiB
+
+mozilla::LazyLogModule gStorageLog("mozStorage");
+
+// Checks that the protected code is running on the main-thread only if the
+// connection was also opened on it.
+#ifdef DEBUG
+#define CHECK_MAINTHREAD_ABUSE() \
+  do { \
+    nsCOMPtr<nsIThread> mainThread = do_GetMainThread(); \
+    NS_WARNING_ASSERTION( \
+      threadOpenedOn == mainThread || !NS_IsMainThread(), \
+      "Using Storage synchronous API on main-thread, but the connection was " \
+      "opened on another thread."); \
+  } while(0)
+#else
+#define CHECK_MAINTHREAD_ABUSE() do { /* Nothing */ } while(0)
+#endif
+
+namespace mozilla {
+namespace storage {
+
+using mozilla::dom::quota::QuotaObject;
+
+namespace {
+
+int
+nsresultToSQLiteResult(nsresult aXPCOMResultCode)
+{
+  if (NS_SUCCEEDED(aXPCOMResultCode)) {
+    return SQLITE_OK;
+  }
+
+  switch (aXPCOMResultCode) {
+    case NS_ERROR_FILE_CORRUPTED:
+      return SQLITE_CORRUPT;
+    case NS_ERROR_FILE_ACCESS_DENIED:
+      return SQLITE_CANTOPEN;
+    case NS_ERROR_STORAGE_BUSY:
+      return SQLITE_BUSY;
+    case NS_ERROR_FILE_IS_LOCKED:
+      return SQLITE_LOCKED;
+    case NS_ERROR_FILE_READ_ONLY:
+      return SQLITE_READONLY;
+    case NS_ERROR_STORAGE_IOERR:
+      return SQLITE_IOERR;
+    case NS_ERROR_FILE_NO_DEVICE_SPACE:
+      return SQLITE_FULL;
+    case NS_ERROR_OUT_OF_MEMORY:
+      return SQLITE_NOMEM;
+    case NS_ERROR_UNEXPECTED:
+      return SQLITE_MISUSE;
+    case NS_ERROR_ABORT:
+      return SQLITE_ABORT;
+    case NS_ERROR_STORAGE_CONSTRAINT:
+      return SQLITE_CONSTRAINT;
+    default:
+      return SQLITE_ERROR;
+  }
+
+  MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Must return in switch above!");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// Variant Specialization Functions (variantToSQLiteT)
+
+int
+sqlite3_T_int(sqlite3_context *aCtx,
+              int aValue)
+{
+  ::sqlite3_result_int(aCtx, aValue);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_int64(sqlite3_context *aCtx,
+                sqlite3_int64 aValue)
+{
+  ::sqlite3_result_int64(aCtx, aValue);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_double(sqlite3_context *aCtx,
+                 double aValue)
+{
+  ::sqlite3_result_double(aCtx, aValue);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_text(sqlite3_context *aCtx,
+               const nsCString &aValue)
+{
+  ::sqlite3_result_text(aCtx,
+                        aValue.get(),
+                        aValue.Length(),
+                        SQLITE_TRANSIENT);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_text16(sqlite3_context *aCtx,
+                 const nsString &aValue)
+{
+  ::sqlite3_result_text16(aCtx,
+                          aValue.get(),
+                          aValue.Length() * 2, // Number of bytes.
+                          SQLITE_TRANSIENT);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_null(sqlite3_context *aCtx)
+{
+  ::sqlite3_result_null(aCtx);
+  return SQLITE_OK;
+}
+
+int
+sqlite3_T_blob(sqlite3_context *aCtx,
+               const void *aData,
+               int aSize)
+{
+  ::sqlite3_result_blob(aCtx, aData, aSize, free);
+  return SQLITE_OK;
+}
+
+#include "variantToSQLiteT_impl.h"
+
+////////////////////////////////////////////////////////////////////////////////
+//// Modules
+
+struct Module
+{
+  const char* name;
+  int (*registerFunc)(sqlite3*, const char*);
+};
+
+Module gModules[] = {
+  { "filesystem", RegisterFileSystemModule }
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Local Functions
+
+int tracefunc (unsigned aReason, void *aClosure, void *aP, void *aX)
+{
+  switch (aReason) {
+    case SQLITE_TRACE_STMT: {
+      // aP is a pointer to the prepared statement.
+      sqlite3_stmt* stmt = static_cast<sqlite3_stmt*>(aP);
+      // aX is a pointer to a string containing the unexpanded SQL or a comment,
+      // starting with "--"" in case of a trigger.
+      char* expanded = static_cast<char*>(aX);
+      // Simulate what sqlite_trace was doing.
+      if (!::strncmp(expanded, "--", 2)) {
+        MOZ_LOG(gStorageLog, LogLevel::Debug,
+          ("TRACE_STMT on %p: '%s'", aClosure, expanded));
+      } else {
+        char* sql = ::sqlite3_expanded_sql(stmt);
+        MOZ_LOG(gStorageLog, LogLevel::Debug,
+          ("TRACE_STMT on %p: '%s'", aClosure, sql));
+        ::sqlite3_free(sql);
+      }
+      break;
+    }
+    case SQLITE_TRACE_PROFILE: {
+      // aX is pointer to a 64bit integer containing nanoseconds it took to
+      // execute the last command.
+      sqlite_int64 time = *(static_cast<sqlite_int64*>(aX)) / 1000000;
+      if (time > 0) {
+        MOZ_LOG(gStorageLog, LogLevel::Debug,
+          ("TRACE_TIME on %p: %dms", aClosure, time));
+      }
+      break;
+    }
+  }
+  return 0;
+}
+
+void
+basicFunctionHelper(sqlite3_context *aCtx,
+                    int aArgc,
+                    sqlite3_value **aArgv)
+{
+  void *userData = ::sqlite3_user_data(aCtx);
+
+  mozIStorageFunction *func = static_cast<mozIStorageFunction *>(userData);
+
+  RefPtr<ArgValueArray> arguments(new ArgValueArray(aArgc, aArgv));
+  if (!arguments)
+      return;
+
+  nsCOMPtr<nsIVariant> result;
+  nsresult rv = func->OnFunctionCall(arguments, getter_AddRefs(result));
+  if (NS_FAILED(rv)) {
+    nsAutoCString errorMessage;
+    GetErrorName(rv, errorMessage);
+    errorMessage.InsertLiteral("User function returned ", 0);
+    errorMessage.Append('!');
+
+    NS_WARNING(errorMessage.get());
+
+    ::sqlite3_result_error(aCtx, errorMessage.get(), -1);
+    ::sqlite3_result_error_code(aCtx, nsresultToSQLiteResult(rv));
+    return;
+  }
+  int retcode = variantToSQLiteT(aCtx, result);
+  if (retcode == SQLITE_IGNORE) {
+    ::sqlite3_result_int(aCtx, SQLITE_IGNORE);
+  } else if (retcode != SQLITE_OK) {
+    NS_WARNING("User function returned invalid data type!");
+    ::sqlite3_result_error(aCtx,
+                           "User function returned invalid data type",
+                           -1);
+  }
+}
+
+void
+aggregateFunctionStepHelper(sqlite3_context *aCtx,
+                            int aArgc,
+                            sqlite3_value **aArgv)
+{
+  void *userData = ::sqlite3_user_data(aCtx);
+  mozIStorageAggregateFunction *func =
+    static_cast<mozIStorageAggregateFunction *>(userData);
+
+  RefPtr<ArgValueArray> arguments(new ArgValueArray(aArgc, aArgv));
+  if (!arguments)
+    return;
+
+  if (NS_FAILED(func->OnStep(arguments)))
+    NS_WARNING("User aggregate step function returned error code!");
+}
+
+void
+aggregateFunctionFinalHelper(sqlite3_context *aCtx)
+{
+  void *userData = ::sqlite3_user_data(aCtx);
+  mozIStorageAggregateFunction *func =
+    static_cast<mozIStorageAggregateFunction *>(userData);
+
+  RefPtr<nsIVariant> result;
+  if (NS_FAILED(func->OnFinal(getter_AddRefs(result)))) {
+    NS_WARNING("User aggregate final function returned error code!");
+    ::sqlite3_result_error(aCtx,
+                           "User aggregate final function returned error code",
+                           -1);
+    return;
+  }
+
+  if (variantToSQLiteT(aCtx, result) != SQLITE_OK) {
+    NS_WARNING("User aggregate final function returned invalid data type!");
+    ::sqlite3_result_error(aCtx,
+                           "User aggregate final function returned invalid data type",
+                           -1);
+  }
+}
+
+/**
+ * This code is heavily based on the sample at:
+ *   http://www.sqlite.org/unlock_notify.html
+ */
+class UnlockNotification
+{
+public:
+  UnlockNotification()
+  : mMutex("UnlockNotification mMutex")
+  , mCondVar(mMutex, "UnlockNotification condVar")
+  , mSignaled(false)
+  {
+  }
+
+  void Wait()
+  {
+    MutexAutoLock lock(mMutex);
+    while (!mSignaled) {
+      (void)mCondVar.Wait();
+    }
+  }
+
+  void Signal()
+  {
+    MutexAutoLock lock(mMutex);
+    mSignaled = true;
+    (void)mCondVar.Notify();
+  }
+
+private:
+  Mutex mMutex;
+  CondVar mCondVar;
+  bool mSignaled;
+};
+
+void
+UnlockNotifyCallback(void **aArgs,
+                     int aArgsSize)
+{
+  for (int i = 0; i < aArgsSize; i++) {
+    UnlockNotification *notification =
+      static_cast<UnlockNotification *>(aArgs[i]);
+    notification->Signal();
+  }
+}
+
+int
+WaitForUnlockNotify(sqlite3* aDatabase)
+{
+  UnlockNotification notification;
+  int srv = ::sqlite3_unlock_notify(aDatabase, UnlockNotifyCallback,
+                                    &notification);
+  MOZ_ASSERT(srv == SQLITE_LOCKED || srv == SQLITE_OK);
+  if (srv == SQLITE_OK) {
+    notification.Wait();
+  }
+
+  return srv;
+}
+
+} // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+//// Local Classes
+
+namespace {
+
+class AsyncCloseConnection final: public Runnable
+{
+public:
+  AsyncCloseConnection(Connection *aConnection,
+                       sqlite3 *aNativeConnection,
+                       nsIRunnable *aCallbackEvent,
+                       already_AddRefed<nsIThread> aAsyncExecutionThread)
+  : mConnection(aConnection)
+  , mNativeConnection(aNativeConnection)
+  , mCallbackEvent(aCallbackEvent)
+  , mAsyncExecutionThread(aAsyncExecutionThread)
+  {
+  }
+
+  NS_IMETHOD Run() override
+  {
+#ifdef DEBUG
+    // This code is executed on the background thread
+    bool onAsyncThread = false;
+    (void)mAsyncExecutionThread->IsOnCurrentThread(&onAsyncThread);
+    MOZ_ASSERT(onAsyncThread);
+#endif // DEBUG
+
+    nsCOMPtr<nsIRunnable> event = NewRunnableMethod<nsCOMPtr<nsIThread>>
+      (mConnection, &Connection::shutdownAsyncThread, mAsyncExecutionThread);
+    (void)NS_DispatchToMainThread(event);
+
+    // Internal close.
+    (void)mConnection->internalClose(mNativeConnection);
+
+    // Callback
+    if (mCallbackEvent) {
+      nsCOMPtr<nsIThread> thread;
+      (void)NS_GetMainThread(getter_AddRefs(thread));
+      (void)thread->Dispatch(mCallbackEvent, NS_DISPATCH_NORMAL);
+    }
+
+    return NS_OK;
+  }
+
+  ~AsyncCloseConnection() {
+    NS_ReleaseOnMainThread(mConnection.forget());
+    NS_ReleaseOnMainThread(mCallbackEvent.forget());
+  }
+private:
+  RefPtr<Connection> mConnection;
+  sqlite3 *mNativeConnection;
+  nsCOMPtr<nsIRunnable> mCallbackEvent;
+  nsCOMPtr<nsIThread> mAsyncExecutionThread;
+};
+
+/**
+ * An event used to initialize the clone of a connection.
+ *
+ * Must be executed on the clone's async execution thread.
+ */
+class AsyncInitializeClone final: public Runnable
+{
+public:
+  /**
+   * @param aConnection The connection being cloned.
+   * @param aClone The clone.
+   * @param aReadOnly If |true|, the clone is read only.
+   * @param aCallback A callback to trigger once initialization
+   *                  is complete. This event will be called on
+   *                  aClone->threadOpenedOn.
+   */
+  AsyncInitializeClone(Connection* aConnection,
+                       Connection* aClone,
+                       const bool aReadOnly,
+                       mozIStorageCompletionCallback* aCallback)
+    : mConnection(aConnection)
+    , mClone(aClone)
+    , mReadOnly(aReadOnly)
+    , mCallback(aCallback)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT (NS_GetCurrentThread() == mConnection->getAsyncExecutionTarget());
+
+    nsresult rv = mConnection->initializeClone(mClone, mReadOnly);
+    if (NS_FAILED(rv)) {
+      return Dispatch(rv, nullptr);
+    }
+    return Dispatch(NS_OK,
+                    NS_ISUPPORTS_CAST(mozIStorageAsyncConnection*, mClone));
+  }
+
+private:
+  nsresult Dispatch(nsresult aResult, nsISupports* aValue) {
+    RefPtr<CallbackComplete> event = new CallbackComplete(aResult,
+                                                            aValue,
+                                                            mCallback.forget());
+    return mClone->threadOpenedOn->Dispatch(event, NS_DISPATCH_NORMAL);
+  }
+
+  ~AsyncInitializeClone() {
+    nsCOMPtr<nsIThread> thread;
+    DebugOnly<nsresult> rv = NS_GetMainThread(getter_AddRefs(thread));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    // Handle ambiguous nsISupports inheritance.
+    NS_ProxyRelease(thread, mConnection.forget());
+    NS_ProxyRelease(thread, mClone.forget());
+
+    // Generally, the callback will be released by CallbackComplete.
+    // However, if for some reason Run() is not executed, we still
+    // need to ensure that it is released here.
+    NS_ProxyRelease(thread, mCallback.forget());
+  }
+
+  RefPtr<Connection> mConnection;
+  RefPtr<Connection> mClone;
+  const bool mReadOnly;
+  nsCOMPtr<mozIStorageCompletionCallback> mCallback;
+};
+
+} // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+//// Connection
+
+Connection::Connection(Service *aService,
+                       int aFlags,
+                       bool aAsyncOnly,
+                       bool aIgnoreLockingMode)
+: sharedAsyncExecutionMutex("Connection::sharedAsyncExecutionMutex")
+, sharedDBMutex("Connection::sharedDBMutex")
+, threadOpenedOn(do_GetCurrentThread())
+, mDBConn(nullptr)
+, mAsyncExecutionThreadShuttingDown(false)
+#ifdef DEBUG
+, mAsyncExecutionThreadIsAlive(false)
+#endif
+, mConnectionClosed(false)
+, mTransactionInProgress(false)
+, mProgressHandler(nullptr)
+, mFlags(aFlags)
+, mIgnoreLockingMode(aIgnoreLockingMode)
+, mStorageService(aService)
+, mAsyncOnly(aAsyncOnly)
+{
+  MOZ_ASSERT(!mIgnoreLockingMode || mFlags & SQLITE_OPEN_READONLY,
+             "Can't ignore locking for a non-readonly connection!");
+  mStorageService->registerConnection(this);
+}
+
+Connection::~Connection()
+{
+  (void)Close();
+
+  MOZ_ASSERT(!mAsyncExecutionThread,
+             "AsyncClose has not been invoked on this connection!");
+  MOZ_ASSERT(!mAsyncExecutionThreadIsAlive,
+             "The async execution thread should have been shutdown!");
+}
+
+NS_IMPL_ADDREF(Connection)
+
+NS_INTERFACE_MAP_BEGIN(Connection)
+  NS_INTERFACE_MAP_ENTRY(mozIStorageAsyncConnection)
+  NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(mozIStorageConnection, !mAsyncOnly)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, mozIStorageConnection)
+NS_INTERFACE_MAP_END
+
+// This is identical to what NS_IMPL_RELEASE provides, but with the
+// extra |1 == count| case.
+NS_IMETHODIMP_(MozExternalRefCountType) Connection::Release(void)
+{
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  nsrefcnt count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "Connection");
+  if (1 == count) {
+    // If the refcount is 1, the single reference must be from
+    // gService->mConnections (in class |Service|).  Which means we can
+    // unregister it safely.
+    mStorageService->unregisterConnection(this);
+  } else if (0 == count) {
+    mRefCnt = 1; /* stabilize */
+#if 0 /* enable this to find non-threadsafe destructors: */
+    NS_ASSERT_OWNINGTHREAD(Connection);
+#endif
+    delete (this);
+    return 0;
+  }
+  return count;
+}
+
+int32_t
+Connection::getSqliteRuntimeStatus(int32_t aStatusOption, int32_t* aMaxValue)
+{
+  MOZ_ASSERT(mDBConn, "A connection must exist at this point");
+  int curr = 0, max = 0;
+  DebugOnly<int> rc = ::sqlite3_db_status(mDBConn, aStatusOption, &curr, &max, 0);
+  MOZ_ASSERT(NS_SUCCEEDED(convertResultCode(rc)));
+  if (aMaxValue)
+    *aMaxValue = max;
+  return curr;
+}
+
+nsIEventTarget *
+Connection::getAsyncExecutionTarget()
+{
+  MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+
+  // If we are shutting down the asynchronous thread, don't hand out any more
+  // references to the thread.
+  if (mAsyncExecutionThreadShuttingDown)
+    return nullptr;
+
+  if (!mAsyncExecutionThread) {
+    nsresult rv = ::NS_NewThread(getter_AddRefs(mAsyncExecutionThread));
+    if (NS_FAILED(rv)) {
+      NS_WARNING("Failed to create async thread.");
+      return nullptr;
+    }
+    static nsThreadPoolNaming naming;
+    naming.SetThreadPoolName(NS_LITERAL_CSTRING("mozStorage"),
+                             mAsyncExecutionThread);
+  }
+
+#ifdef DEBUG
+  mAsyncExecutionThreadIsAlive = true;
+#endif
+
+  return mAsyncExecutionThread;
+}
+
+nsresult
+Connection::initialize()
+{
+  NS_ASSERTION (!mDBConn, "Initialize called on already opened database!");
+  MOZ_ASSERT(!mIgnoreLockingMode, "Can't ignore locking on an in-memory db.");
+  PROFILER_LABEL("mozStorageConnection", "initialize",
+    js::ProfileEntry::Category::STORAGE);
+
+  // in memory database requested, sqlite uses a magic file name
+  int srv = ::sqlite3_open_v2(":memory:", &mDBConn, mFlags, nullptr);
+  if (srv != SQLITE_OK) {
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+  // Do not set mDatabaseFile or mFileURL here since this is a "memory"
+  // database.
+
+  nsresult rv = initializeInternal();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+Connection::initialize(nsIFile *aDatabaseFile)
+{
+  NS_ASSERTION (aDatabaseFile, "Passed null file!");
+  NS_ASSERTION (!mDBConn, "Initialize called on already opened database!");
+  PROFILER_LABEL("mozStorageConnection", "initialize",
+    js::ProfileEntry::Category::STORAGE);
+
+  mDatabaseFile = aDatabaseFile;
+
+  nsAutoString path;
+  nsresult rv = aDatabaseFile->GetPath(path);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+#ifdef XP_WIN
+  static const char* sIgnoreLockingVFS = "win32-none";
+#else
+  static const char* sIgnoreLockingVFS = "unix-none";
+#endif
+  const char* vfs = mIgnoreLockingMode ? sIgnoreLockingVFS : nullptr;
+
+  int srv = ::sqlite3_open_v2(NS_ConvertUTF16toUTF8(path).get(), &mDBConn,
+                              mFlags, vfs);
+  if (srv != SQLITE_OK) {
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+  // Do not set mFileURL here since this is database does not have an associated
+  // URL.
+  mDatabaseFile = aDatabaseFile;
+
+  rv = initializeInternal();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+Connection::initialize(nsIFileURL *aFileURL)
+{
+  NS_ASSERTION (aFileURL, "Passed null file URL!");
+  NS_ASSERTION (!mDBConn, "Initialize called on already opened database!");
+  PROFILER_LABEL("mozStorageConnection", "initialize",
+    js::ProfileEntry::Category::STORAGE);
+
+  nsCOMPtr<nsIFile> databaseFile;
+  nsresult rv = aFileURL->GetFile(getter_AddRefs(databaseFile));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString spec;
+  rv = aFileURL->GetSpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int srv = ::sqlite3_open_v2(spec.get(), &mDBConn, mFlags, nullptr);
+  if (srv != SQLITE_OK) {
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+  // Set both mDatabaseFile and mFileURL here.
+  mFileURL = aFileURL;
+  mDatabaseFile = databaseFile;
+
+  rv = initializeInternal();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+Connection::initializeInternal()
+{
+  MOZ_ASSERT(mDBConn);
+
+  if (mFileURL) {
+    const char* dbPath = ::sqlite3_db_filename(mDBConn, "main");
+    MOZ_ASSERT(dbPath);
+
+    const char* telemetryFilename =
+      ::sqlite3_uri_parameter(dbPath, "telemetryFilename");
+    if (telemetryFilename) {
+      if (NS_WARN_IF(*telemetryFilename == '\0')) {
+        return NS_ERROR_INVALID_ARG;
+      }
+      mTelemetryFilename = telemetryFilename;
+    }
+  }
+
+  if (mTelemetryFilename.IsEmpty()) {
+    mTelemetryFilename = getFilename();
+    MOZ_ASSERT(!mTelemetryFilename.IsEmpty());
+  }
+
+  // Properly wrap the database handle's mutex.
+  sharedDBMutex.initWithMutex(sqlite3_db_mutex(mDBConn));
+
+  // SQLite tracing can slow down queries (especially long queries)
+  // significantly. Don't trace unless the user is actively monitoring SQLite.
+  if (MOZ_LOG_TEST(gStorageLog, LogLevel::Debug)) {
+    ::sqlite3_trace_v2(mDBConn,
+                       SQLITE_TRACE_STMT | SQLITE_TRACE_PROFILE,
+                       tracefunc, this);
+
+    MOZ_LOG(gStorageLog, LogLevel::Debug, ("Opening connection to '%s' (%p)",
+                                        mTelemetryFilename.get(), this));
+  }
+
+  int64_t pageSize = Service::getDefaultPageSize();
+
+  // Set page_size to the preferred default value.  This is effective only if
+  // the database has just been created, otherwise, if the database does not
+  // use WAL journal mode, a VACUUM operation will updated its page_size.
+  nsAutoCString pageSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
+                              "PRAGMA page_size = ");
+  pageSizeQuery.AppendInt(pageSize);
+  nsresult rv = ExecuteSimpleSQL(pageSizeQuery);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Setting the cache_size forces the database open, verifying if it is valid
+  // or corrupt.  So this is executed regardless it being actually needed.
+  // The cache_size is calculated from the actual page_size, to save memory.
+  nsAutoCString cacheSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
+                               "PRAGMA cache_size = ");
+  cacheSizeQuery.AppendInt(-MAX_CACHE_SIZE_KIBIBYTES);
+  int srv = executeSql(mDBConn, cacheSizeQuery.get());
+  if (srv != SQLITE_OK) {
+    ::sqlite3_close(mDBConn);
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+#if defined(MOZ_MEMORY_TEMP_STORE_PRAGMA)
+  (void)ExecuteSimpleSQL(NS_LITERAL_CSTRING("PRAGMA temp_store = 2;"));
+#endif
+
+  // Register our built-in SQL functions.
+  srv = registerFunctions(mDBConn);
+  if (srv != SQLITE_OK) {
+    ::sqlite3_close(mDBConn);
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+  // Register our built-in SQL collating sequences.
+  srv = registerCollations(mDBConn, mStorageService);
+  if (srv != SQLITE_OK) {
+    ::sqlite3_close(mDBConn);
+    mDBConn = nullptr;
+    return convertResultCode(srv);
+  }
+
+  // Set the synchronous PRAGMA, according to the preference.
+  switch (Service::getSynchronousPref()) {
+    case 2:
+      (void)ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+          "PRAGMA synchronous = FULL;"));
+      break;
+    case 0:
+      (void)ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+          "PRAGMA synchronous = OFF;"));
+      break;
+    case 1:
+    default:
+      (void)ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+          "PRAGMA synchronous = NORMAL;"));
+      break;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+Connection::databaseElementExists(enum DatabaseElementType aElementType,
+                                  const nsACString &aElementName,
+                                  bool *_exists)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  // When constructing the query, make sure to SELECT the correct db's sqlite_master
+  // if the user is prefixing the element with a specific db. ex: sample.test
+  nsCString query("SELECT name FROM (SELECT * FROM ");
+  nsDependentCSubstring element;
+  int32_t ind = aElementName.FindChar('.');
+  if (ind == kNotFound) {
+    element.Assign(aElementName);
+  }
+  else {
+    nsDependentCSubstring db(Substring(aElementName, 0, ind + 1));
+    element.Assign(Substring(aElementName, ind + 1, aElementName.Length()));
+    query.Append(db);
+  }
+  query.AppendLiteral("sqlite_master UNION ALL SELECT * FROM sqlite_temp_master) WHERE type = '");
+
+  switch (aElementType) {
+    case INDEX:
+      query.AppendLiteral("index");
+      break;
+    case TABLE:
+      query.AppendLiteral("table");
+      break;
+  }
+  query.AppendLiteral("' AND name ='");
+  query.Append(element);
+  query.Append('\'');
+
+  sqlite3_stmt *stmt;
+  int srv = prepareStatement(mDBConn, query, &stmt);
+  if (srv != SQLITE_OK)
+    return convertResultCode(srv);
+
+  srv = stepStatement(mDBConn, stmt);
+  // we just care about the return value from step
+  (void)::sqlite3_finalize(stmt);
+
+  if (srv == SQLITE_ROW) {
+    *_exists = true;
+    return NS_OK;
+  }
+  if (srv == SQLITE_DONE) {
+    *_exists = false;
+    return NS_OK;
+  }
+
+  return convertResultCode(srv);
+}
+
+bool
+Connection::findFunctionByInstance(nsISupports *aInstance)
+{
+  sharedDBMutex.assertCurrentThreadOwns();
+
+  for (auto iter = mFunctions.Iter(); !iter.Done(); iter.Next()) {
+    if (iter.UserData().function == aInstance) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/* static */ int
+Connection::sProgressHelper(void *aArg)
+{
+  Connection *_this = static_cast<Connection *>(aArg);
+  return _this->progressHandler();
+}
+
+int
+Connection::progressHandler()
+{
+  sharedDBMutex.assertCurrentThreadOwns();
+  if (mProgressHandler) {
+    bool result;
+    nsresult rv = mProgressHandler->OnProgress(this, &result);
+    if (NS_FAILED(rv)) return 0; // Don't break request
+    return result ? 1 : 0;
+  }
+  return 0;
+}
+
+nsresult
+Connection::setClosedState()
+{
+  // Ensure that we are on the correct thread to close the database.
+  bool onOpenedThread;
+  nsresult rv = threadOpenedOn->IsOnCurrentThread(&onOpenedThread);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (!onOpenedThread) {
+    NS_ERROR("Must close the database on the thread that you opened it with!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Flag that we are shutting down the async thread, so that
+  // getAsyncExecutionTarget knows not to expose/create the async thread.
+  {
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    NS_ENSURE_FALSE(mAsyncExecutionThreadShuttingDown, NS_ERROR_UNEXPECTED);
+    mAsyncExecutionThreadShuttingDown = true;
+  }
+
+  // Set the property to null before closing the connection, otherwise the other
+  // functions in the module may try to use the connection after it is closed.
+  mDBConn = nullptr;
+
+  return NS_OK;
+}
+
+bool
+Connection::connectionReady()
+{
+  return mDBConn != nullptr;
+}
+
+bool
+Connection::isClosing()
+{
+  bool shuttingDown = false;
+  {
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    shuttingDown = mAsyncExecutionThreadShuttingDown;
+  }
+  return shuttingDown && !isClosed();
+}
+
+bool
+Connection::isClosed()
+{
+  MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+  return mConnectionClosed;
+}
+
+void
+Connection::shutdownAsyncThread(nsIThread *aThread) {
+  MOZ_ASSERT(!mAsyncExecutionThread);
+  MOZ_ASSERT(mAsyncExecutionThreadIsAlive);
+  MOZ_ASSERT(mAsyncExecutionThreadShuttingDown);
+
+  DebugOnly<nsresult> rv = aThread->Shutdown();
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+#ifdef DEBUG
+  mAsyncExecutionThreadIsAlive = false;
+#endif
+}
+
+nsresult
+Connection::internalClose(sqlite3 *aNativeConnection)
+{
+  // Sanity checks to make sure we are in the proper state before calling this.
+  // aNativeConnection can be null if OpenAsyncDatabase failed and is now just
+  // cleaning up the async thread.
+  MOZ_ASSERT(!isClosed());
+
+#ifdef DEBUG
+  { // Make sure we have marked our async thread as shutting down.
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    NS_ASSERTION(mAsyncExecutionThreadShuttingDown,
+                 "Did not call setClosedState!");
+  }
+#endif // DEBUG
+
+  if (MOZ_LOG_TEST(gStorageLog, LogLevel::Debug)) {
+    nsAutoCString leafName(":memory");
+    if (mDatabaseFile)
+        (void)mDatabaseFile->GetNativeLeafName(leafName);
+    MOZ_LOG(gStorageLog, LogLevel::Debug, ("Closing connection to '%s'",
+                                        leafName.get()));
+  }
+
+  // At this stage, we may still have statements that need to be
+  // finalized. Attempt to close the database connection. This will
+  // always disconnect any virtual tables and cleanly finalize their
+  // internal statements. Once this is done, closing may fail due to
+  // unfinalized client statements, in which case we need to finalize
+  // these statements and close again.
+  {
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    mConnectionClosed = true;
+  }
+
+  // Nothing else needs to be done if we don't have a connection here.
+  if (!aNativeConnection)
+    return NS_OK;
+
+  int srv = sqlite3_close(aNativeConnection);
+
+  if (srv == SQLITE_BUSY) {
+    // We still have non-finalized statements. Finalize them.
+
+    sqlite3_stmt *stmt = nullptr;
+    while ((stmt = ::sqlite3_next_stmt(aNativeConnection, stmt))) {
+      MOZ_LOG(gStorageLog, LogLevel::Debug,
+             ("Auto-finalizing SQL statement '%s' (%x)",
+              ::sqlite3_sql(stmt),
+              stmt));
+
+#ifdef DEBUG
+      char *msg = ::PR_smprintf("SQL statement '%s' (%x) should have been finalized before closing the connection",
+                                ::sqlite3_sql(stmt),
+                                stmt);
+      NS_WARNING(msg);
+      ::PR_smprintf_free(msg);
+      msg = nullptr;
+#endif // DEBUG
+
+      srv = ::sqlite3_finalize(stmt);
+
+#ifdef DEBUG
+      if (srv != SQLITE_OK) {
+        msg = ::PR_smprintf("Could not finalize SQL statement '%s' (%x)",
+                            ::sqlite3_sql(stmt),
+                            stmt);
+        NS_WARNING(msg);
+        ::PR_smprintf_free(msg);
+        msg = nullptr;
+      }
+#endif // DEBUG
+
+      // Ensure that the loop continues properly, whether closing has succeeded
+      // or not.
+      if (srv == SQLITE_OK) {
+        stmt = nullptr;
+      }
+    }
+
+    // Now that all statements have been finalized, we
+    // should be able to close.
+    srv = ::sqlite3_close(aNativeConnection);
+
+  }
+
+  if (srv != SQLITE_OK) {
+    MOZ_ASSERT(srv == SQLITE_OK,
+               "sqlite3_close failed. There are probably outstanding statements that are listed above!");
+  }
+
+  return convertResultCode(srv);
+}
+
+nsCString
+Connection::getFilename()
+{
+  nsCString leafname(":memory:");
+  if (mDatabaseFile) {
+    (void)mDatabaseFile->GetNativeLeafName(leafname);
+  }
+  return leafname;
+}
+
+int
+Connection::stepStatement(sqlite3 *aNativeConnection, sqlite3_stmt *aStatement)
+{
+  MOZ_ASSERT(aStatement);
+  bool checkedMainThread = false;
+  TimeStamp startTime = TimeStamp::Now();
+
+  // The connection may have been closed if the executing statement has been
+  // created and cached after a call to asyncClose() but before the actual
+  // sqlite3_close().  This usually happens when other tasks using cached
+  // statements are asynchronously scheduled for execution and any of them ends
+  // up after asyncClose. See bug 728653 for details.
+  if (isClosed())
+    return SQLITE_MISUSE;
+
+  (void)::sqlite3_extended_result_codes(aNativeConnection, 1);
+
+  int srv;
+  while ((srv = ::sqlite3_step(aStatement)) == SQLITE_LOCKED_SHAREDCACHE) {
+    if (!checkedMainThread) {
+      checkedMainThread = true;
+      if (::NS_IsMainThread()) {
+        NS_WARNING("We won't allow blocking on the main thread!");
+        break;
+      }
+    }
+
+    srv = WaitForUnlockNotify(aNativeConnection);
+    if (srv != SQLITE_OK) {
+      break;
+    }
+
+    ::sqlite3_reset(aStatement);
+  }
+
+  // Report very slow SQL statements to Telemetry
+  TimeDuration duration = TimeStamp::Now() - startTime;
+  const uint32_t threshold =
+    NS_IsMainThread() ? Telemetry::kSlowSQLThresholdForMainThread
+                      : Telemetry::kSlowSQLThresholdForHelperThreads;
+  if (duration.ToMilliseconds() >= threshold) {
+    nsDependentCString statementString(::sqlite3_sql(aStatement));
+    Telemetry::RecordSlowSQLStatement(statementString, mTelemetryFilename,
+                                      duration.ToMilliseconds());
+  }
+
+  (void)::sqlite3_extended_result_codes(aNativeConnection, 0);
+  // Drop off the extended result bits of the result code.
+  return srv & 0xFF;
+}
+
+int
+Connection::prepareStatement(sqlite3 *aNativeConnection, const nsCString &aSQL,
+                             sqlite3_stmt **_stmt)
+{
+  // We should not even try to prepare statements after the connection has
+  // been closed.
+  if (isClosed())
+    return SQLITE_MISUSE;
+
+  bool checkedMainThread = false;
+
+  (void)::sqlite3_extended_result_codes(aNativeConnection, 1);
+
+  int srv;
+  while((srv = ::sqlite3_prepare_v2(aNativeConnection,
+                                    aSQL.get(),
+                                    -1,
+                                    _stmt,
+                                    nullptr)) == SQLITE_LOCKED_SHAREDCACHE) {
+    if (!checkedMainThread) {
+      checkedMainThread = true;
+      if (::NS_IsMainThread()) {
+        NS_WARNING("We won't allow blocking on the main thread!");
+        break;
+      }
+    }
+
+    srv = WaitForUnlockNotify(aNativeConnection);
+    if (srv != SQLITE_OK) {
+      break;
+    }
+  }
+
+  if (srv != SQLITE_OK) {
+    nsCString warnMsg;
+    warnMsg.AppendLiteral("The SQL statement '");
+    warnMsg.Append(aSQL);
+    warnMsg.AppendLiteral("' could not be compiled due to an error: ");
+    warnMsg.Append(::sqlite3_errmsg(aNativeConnection));
+
+#ifdef DEBUG
+    NS_WARNING(warnMsg.get());
+#endif
+    MOZ_LOG(gStorageLog, LogLevel::Error, ("%s", warnMsg.get()));
+  }
+
+  (void)::sqlite3_extended_result_codes(aNativeConnection, 0);
+  // Drop off the extended result bits of the result code.
+  int rc = srv & 0xFF;
+  // sqlite will return OK on a comment only string and set _stmt to nullptr.
+  // The callers of this function are used to only checking the return value,
+  // so it is safer to return an error code.
+  if (rc == SQLITE_OK && *_stmt == nullptr) {
+    return SQLITE_MISUSE;
+  }
+
+  return rc;
+}
+
+
+int
+Connection::executeSql(sqlite3 *aNativeConnection, const char *aSqlString)
+{
+  if (isClosed())
+    return SQLITE_MISUSE;
+
+  TimeStamp startTime = TimeStamp::Now();
+  int srv = ::sqlite3_exec(aNativeConnection, aSqlString, nullptr, nullptr,
+                           nullptr);
+
+  // Report very slow SQL statements to Telemetry
+  TimeDuration duration = TimeStamp::Now() - startTime;
+  const uint32_t threshold =
+    NS_IsMainThread() ? Telemetry::kSlowSQLThresholdForMainThread
+                      : Telemetry::kSlowSQLThresholdForHelperThreads;
+  if (duration.ToMilliseconds() >= threshold) {
+    nsDependentCString statementString(aSqlString);
+    Telemetry::RecordSlowSQLStatement(statementString, mTelemetryFilename,
+                                      duration.ToMilliseconds());
+  }
+
+  return srv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// nsIInterfaceRequestor
+
+NS_IMETHODIMP
+Connection::GetInterface(const nsIID &aIID,
+                         void **_result)
+{
+  if (aIID.Equals(NS_GET_IID(nsIEventTarget))) {
+    nsIEventTarget *background = getAsyncExecutionTarget();
+    NS_IF_ADDREF(background);
+    *_result = background;
+    return NS_OK;
+  }
+  return NS_ERROR_NO_INTERFACE;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// mozIStorageConnection
+
+NS_IMETHODIMP
+Connection::Close()
+{
+  if (!mDBConn)
+    return NS_ERROR_NOT_INITIALIZED;
+
+  { // Make sure we have not executed any asynchronous statements.
+    // If this fails, the mDBConn will be left open, resulting in a leak.
+    // Ideally we'd schedule some code to destroy the mDBConn once all its
+    // async statements have finished executing;  see bug 704030.
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    bool asyncCloseWasCalled = !mAsyncExecutionThread;
+    NS_ENSURE_TRUE(asyncCloseWasCalled, NS_ERROR_UNEXPECTED);
+  }
+
+  // setClosedState nullifies our connection pointer, so we take a raw pointer
+  // off it, to pass it through the close procedure.
+  sqlite3 *nativeConn = mDBConn;
+  nsresult rv = setClosedState();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return internalClose(nativeConn);
+}
+
+NS_IMETHODIMP
+Connection::AsyncClose(mozIStorageCompletionCallback *aCallback)
+{
+  if (!NS_IsMainThread()) {
+    return NS_ERROR_NOT_SAME_THREAD;
+  }
+
+  // The two relevant factors at this point are whether we have a database
+  // connection and whether we have an async execution thread.  Here's what the
+  // states mean and how we handle them:
+  //
+  // - (mDBConn && asyncThread): The expected case where we are either an
+  //   async connection or a sync connection that has been used asynchronously.
+  //   Either way the caller must call us and not Close().  Nothing surprising
+  //   about this.  We'll dispatch AsyncCloseConnection to the already-existing
+  //   async thread.
+  //
+  // - (mDBConn && !asyncThread): A somewhat unusual case where the caller
+  //   opened the connection synchronously and was planning to use it
+  //   asynchronously, but never got around to using it asynchronously before
+  //   needing to shutdown.  This has been observed to happen for the cookie
+  //   service in a case where Firefox shuts itself down almost immediately
+  //   after startup (for unknown reasons).  In the Firefox shutdown case,
+  //   we may also fail to create a new async execution thread if one does not
+  //   already exist.  (nsThreadManager will refuse to create new threads when
+  //   it has already been told to shutdown.)  As such, we need to handle a
+  //   failure to create the async execution thread by falling back to
+  //   synchronous Close() and also dispatching the completion callback because
+  //   at least Places likes to spin a nested event loop that depends on the
+  //   callback being invoked.
+  //
+  //   Note that we have considered not trying to spin up the async execution
+  //   thread in this case if it does not already exist, but the overhead of
+  //   thread startup (if successful) is significantly less expensive than the
+  //   worst-case potential I/O hit of synchronously closing a database when we
+  //   could close it asynchronously.
+  //
+  // - (!mDBConn && asyncThread): This happens in some but not all cases where
+  //   OpenAsyncDatabase encountered a problem opening the database.  If it
+  //   happened in all cases AsyncInitDatabase would just shut down the thread
+  //   directly and we would avoid this case.  But it doesn't, so for simplicity
+  //   and consistency AsyncCloseConnection knows how to handle this and we
+  //   act like this was the (mDBConn && asyncThread) case in this method.
+  //
+  // - (!mDBConn && !asyncThread): The database was never successfully opened or
+  //   Close() or AsyncClose() has already been called (at least) once.  This is
+  //   undeniably a misuse case by the caller.  We could optimize for this
+  //   case by adding an additional check of mAsyncExecutionThread without using
+  //   getAsyncExecutionTarget() to avoid wastefully creating a thread just to
+  //   shut it down.  But this complicates the method for broken caller code
+  //   whereas we're still correct and safe without the special-case.
+  nsIEventTarget *asyncThread = getAsyncExecutionTarget();
+
+  // Create our callback event if we were given a callback.  This will
+  // eventually be dispatched in all cases, even if we fall back to Close() and
+  // the database wasn't open and we return an error.  The rationale is that
+  // no existing consumer checks our return value and several of them like to
+  // spin nested event loops until the callback fires.  Given that, it seems
+  // preferable for us to dispatch the callback in all cases.  (Except the
+  // wrong thread misuse case we bailed on up above.  But that's okay because
+  // that is statically wrong whereas these edge cases are dynamic.)
+  nsCOMPtr<nsIRunnable> completeEvent;
+  if (aCallback) {
+    completeEvent = newCompletionEvent(aCallback);
+  }
+
+  if (!asyncThread) {
+    // We were unable to create an async thread, so we need to fall back to
+    // using normal Close().  Since there is no async thread, Close() will
+    // not complain about that.  (Close() may, however, complain if the
+    // connection is closed, but that's okay.)
+    if (completeEvent) {
+      // Closing the database is more important than returning an error code
+      // about a failure to dispatch, especially because all existing native
+      // callers ignore our return value.
+      Unused << NS_DispatchToMainThread(completeEvent.forget());
+    }
+    return Close();
+  }
+
+  // setClosedState nullifies our connection pointer, so we take a raw pointer
+  // off it, to pass it through the close procedure.
+  sqlite3 *nativeConn = mDBConn;
+  nsresult rv = setClosedState();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Create and dispatch our close event to the background thread.
+  nsCOMPtr<nsIRunnable> closeEvent;
+  {
+    // We need to lock because we're modifying mAsyncExecutionThread
+    MutexAutoLock lockedScope(sharedAsyncExecutionMutex);
+    closeEvent = new AsyncCloseConnection(this,
+                                          nativeConn,
+                                          completeEvent,
+                                          mAsyncExecutionThread.forget());
+  }
+
+  rv = asyncThread->Dispatch(closeEvent, NS_DISPATCH_NORMAL);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::AsyncClone(bool aReadOnly,
+                       mozIStorageCompletionCallback *aCallback)
+{
+  PROFILER_LABEL("mozStorageConnection", "AsyncClone",
+    js::ProfileEntry::Category::STORAGE);
+
+  if (!NS_IsMainThread()) {
+    return NS_ERROR_NOT_SAME_THREAD;
+  }
+  if (!mDBConn)
+    return NS_ERROR_NOT_INITIALIZED;
+  if (!mDatabaseFile)
+    return NS_ERROR_UNEXPECTED;
+
+  int flags = mFlags;
+  if (aReadOnly) {
+    // Turn off SQLITE_OPEN_READWRITE, and set SQLITE_OPEN_READONLY.
+    flags = (~SQLITE_OPEN_READWRITE & flags) | SQLITE_OPEN_READONLY;
+    // Turn off SQLITE_OPEN_CREATE.
+    flags = (~SQLITE_OPEN_CREATE & flags);
+  }
+
+  RefPtr<Connection> clone = new Connection(mStorageService, flags,
+                                              mAsyncOnly);
+
+  RefPtr<AsyncInitializeClone> initEvent =
+    new AsyncInitializeClone(this, clone, aReadOnly, aCallback);
+  // Dispatch to our async thread, since the originating connection must remain
+  // valid and open for the whole cloning process.  This also ensures we are
+  // properly serialized with a `close` operation, rather than race with it.
+  nsCOMPtr<nsIEventTarget> target = getAsyncExecutionTarget();
+  if (!target) {
+    return NS_ERROR_UNEXPECTED;
+  }
+  return target->Dispatch(initEvent, NS_DISPATCH_NORMAL);
+}
+
+nsresult
+Connection::initializeClone(Connection* aClone, bool aReadOnly)
+{
+  nsresult rv = mFileURL ? aClone->initialize(mFileURL)
+                         : aClone->initialize(mDatabaseFile);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Re-attach on-disk databases that were attached to the original connection.
+  {
+    nsCOMPtr<mozIStorageStatement> stmt;
+    rv = CreateStatement(NS_LITERAL_CSTRING("PRAGMA database_list"),
+                         getter_AddRefs(stmt));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    bool hasResult = false;
+    while (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
+      nsAutoCString name;
+      rv = stmt->GetUTF8String(1, name);
+      if (NS_SUCCEEDED(rv) && !name.Equals(NS_LITERAL_CSTRING("main")) &&
+                              !name.Equals(NS_LITERAL_CSTRING("temp"))) {
+        nsCString path;
+        rv = stmt->GetUTF8String(2, path);
+        if (NS_SUCCEEDED(rv) && !path.IsEmpty()) {
+          rv = aClone->ExecuteSimpleSQL(NS_LITERAL_CSTRING("ATTACH DATABASE '") +
+            path + NS_LITERAL_CSTRING("' AS ") + name);
+          MOZ_ASSERT(NS_SUCCEEDED(rv), "couldn't re-attach database to cloned connection");
+        }
+      }
+    }
+  }
+
+  // Copy over pragmas from the original connection.
+  static const char * pragmas[] = {
+    "cache_size",
+    "temp_store",
+    "foreign_keys",
+    "journal_size_limit",
+    "synchronous",
+    "wal_autocheckpoint",
+    "busy_timeout"
+  };
+  for (uint32_t i = 0; i < ArrayLength(pragmas); ++i) {
+    // Read-only connections just need cache_size and temp_store pragmas.
+    if (aReadOnly && ::strcmp(pragmas[i], "cache_size") != 0 &&
+                     ::strcmp(pragmas[i], "temp_store") != 0) {
+      continue;
+    }
+
+    nsAutoCString pragmaQuery("PRAGMA ");
+    pragmaQuery.Append(pragmas[i]);
+    nsCOMPtr<mozIStorageStatement> stmt;
+    rv = CreateStatement(pragmaQuery, getter_AddRefs(stmt));
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    bool hasResult = false;
+    if (stmt && NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult) {
+      pragmaQuery.AppendLiteral(" = ");
+      pragmaQuery.AppendInt(stmt->AsInt32(0));
+      rv = aClone->ExecuteSimpleSQL(pragmaQuery);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+    }
+  }
+
+  // Copy any functions that have been added to this connection.
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  for (auto iter = mFunctions.Iter(); !iter.Done(); iter.Next()) {
+    const nsACString &key = iter.Key();
+    Connection::FunctionInfo data = iter.UserData();
+
+    MOZ_ASSERT(data.type == Connection::FunctionInfo::SIMPLE ||
+               data.type == Connection::FunctionInfo::AGGREGATE,
+               "Invalid function type!");
+
+    if (data.type == Connection::FunctionInfo::SIMPLE) {
+      mozIStorageFunction *function =
+        static_cast<mozIStorageFunction *>(data.function.get());
+      rv = aClone->CreateFunction(key, data.numArgs, function);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Failed to copy function to cloned connection");
+      }
+
+    } else {
+      mozIStorageAggregateFunction *function =
+        static_cast<mozIStorageAggregateFunction *>(data.function.get());
+      rv = aClone->CreateAggregateFunction(key, data.numArgs, function);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Failed to copy aggregate function to cloned connection");
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::Clone(bool aReadOnly,
+                  mozIStorageConnection **_connection)
+{
+  MOZ_ASSERT(threadOpenedOn == NS_GetCurrentThread());
+
+  PROFILER_LABEL("mozStorageConnection", "Clone",
+    js::ProfileEntry::Category::STORAGE);
+
+  if (!mDBConn)
+    return NS_ERROR_NOT_INITIALIZED;
+  if (!mDatabaseFile)
+    return NS_ERROR_UNEXPECTED;
+
+  int flags = mFlags;
+  if (aReadOnly) {
+    // Turn off SQLITE_OPEN_READWRITE, and set SQLITE_OPEN_READONLY.
+    flags = (~SQLITE_OPEN_READWRITE & flags) | SQLITE_OPEN_READONLY;
+    // Turn off SQLITE_OPEN_CREATE.
+    flags = (~SQLITE_OPEN_CREATE & flags);
+  }
+
+  RefPtr<Connection> clone = new Connection(mStorageService, flags,
+                                              mAsyncOnly);
+
+  nsresult rv = initializeClone(clone, aReadOnly);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  NS_IF_ADDREF(*_connection = clone);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetDefaultPageSize(int32_t *_defaultPageSize)
+{
+  *_defaultPageSize = Service::getDefaultPageSize();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetConnectionReady(bool *_ready)
+{
+  *_ready = connectionReady();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetDatabaseFile(nsIFile **_dbFile)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  NS_IF_ADDREF(*_dbFile = mDatabaseFile);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetLastInsertRowID(int64_t *_id)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  sqlite_int64 id = ::sqlite3_last_insert_rowid(mDBConn);
+  *_id = id;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetAffectedRows(int32_t *_rows)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  *_rows = ::sqlite3_changes(mDBConn);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetLastError(int32_t *_error)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  *_error = ::sqlite3_errcode(mDBConn);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetLastErrorString(nsACString &_errorString)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  const char *serr = ::sqlite3_errmsg(mDBConn);
+  _errorString.Assign(serr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::GetSchemaVersion(int32_t *_version)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  nsCOMPtr<mozIStorageStatement> stmt;
+  (void)CreateStatement(NS_LITERAL_CSTRING("PRAGMA user_version"),
+                        getter_AddRefs(stmt));
+  NS_ENSURE_TRUE(stmt, NS_ERROR_OUT_OF_MEMORY);
+
+  *_version = 0;
+  bool hasResult;
+  if (NS_SUCCEEDED(stmt->ExecuteStep(&hasResult)) && hasResult)
+    *_version = stmt->AsInt32(0);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::SetSchemaVersion(int32_t aVersion)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  nsAutoCString stmt(NS_LITERAL_CSTRING("PRAGMA user_version = "));
+  stmt.AppendInt(aVersion);
+
+  return ExecuteSimpleSQL(stmt);
+}
+
+NS_IMETHODIMP
+Connection::CreateStatement(const nsACString &aSQLStatement,
+                            mozIStorageStatement **_stmt)
+{
+  NS_ENSURE_ARG_POINTER(_stmt);
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  RefPtr<Statement> statement(new Statement());
+  NS_ENSURE_TRUE(statement, NS_ERROR_OUT_OF_MEMORY);
+
+  nsresult rv = statement->initialize(this, mDBConn, aSQLStatement);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  Statement *rawPtr;
+  statement.forget(&rawPtr);
+  *_stmt = rawPtr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::CreateAsyncStatement(const nsACString &aSQLStatement,
+                                 mozIStorageAsyncStatement **_stmt)
+{
+  NS_ENSURE_ARG_POINTER(_stmt);
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  RefPtr<AsyncStatement> statement(new AsyncStatement());
+  NS_ENSURE_TRUE(statement, NS_ERROR_OUT_OF_MEMORY);
+
+  nsresult rv = statement->initialize(this, mDBConn, aSQLStatement);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  AsyncStatement *rawPtr;
+  statement.forget(&rawPtr);
+  *_stmt = rawPtr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::ExecuteSimpleSQL(const nsACString &aSQLStatement)
+{
+  CHECK_MAINTHREAD_ABUSE();
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  int srv = executeSql(mDBConn, PromiseFlatCString(aSQLStatement).get());
+  return convertResultCode(srv);
+}
+
+NS_IMETHODIMP
+Connection::ExecuteAsync(mozIStorageBaseStatement **aStatements,
+                         uint32_t aNumStatements,
+                         mozIStorageStatementCallback *aCallback,
+                         mozIStoragePendingStatement **_handle)
+{
+  nsTArray<StatementData> stmts(aNumStatements);
+  for (uint32_t i = 0; i < aNumStatements; i++) {
+    nsCOMPtr<StorageBaseStatementInternal> stmt =
+      do_QueryInterface(aStatements[i]);
+
+    // Obtain our StatementData.
+    StatementData data;
+    nsresult rv = stmt->getAsynchronousStatementData(data);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NS_ASSERTION(stmt->getOwner() == this,
+                 "Statement must be from this database connection!");
+
+    // Now append it to our array.
+    NS_ENSURE_TRUE(stmts.AppendElement(data), NS_ERROR_OUT_OF_MEMORY);
+  }
+
+  // Dispatch to the background
+  return AsyncExecuteStatements::execute(stmts, this, mDBConn, aCallback,
+                                         _handle);
+}
+
+NS_IMETHODIMP
+Connection::ExecuteSimpleSQLAsync(const nsACString &aSQLStatement,
+                                  mozIStorageStatementCallback *aCallback,
+                                  mozIStoragePendingStatement **_handle)
+{
+  if (!NS_IsMainThread()) {
+    return NS_ERROR_NOT_SAME_THREAD;
+  }
+
+  nsCOMPtr<mozIStorageAsyncStatement> stmt;
+  nsresult rv = CreateAsyncStatement(aSQLStatement, getter_AddRefs(stmt));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<mozIStoragePendingStatement> pendingStatement;
+  rv = stmt->ExecuteAsync(aCallback, getter_AddRefs(pendingStatement));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  pendingStatement.forget(_handle);
+  return rv;
+}
+
+NS_IMETHODIMP
+Connection::TableExists(const nsACString &aTableName,
+                        bool *_exists)
+{
+    return databaseElementExists(TABLE, aTableName, _exists);
+}
+
+NS_IMETHODIMP
+Connection::IndexExists(const nsACString &aIndexName,
+                        bool* _exists)
+{
+    return databaseElementExists(INDEX, aIndexName, _exists);
+}
+
+NS_IMETHODIMP
+Connection::GetTransactionInProgress(bool *_inProgress)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  *_inProgress = mTransactionInProgress;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::BeginTransaction()
+{
+  return BeginTransactionAs(mozIStorageConnection::TRANSACTION_DEFERRED);
+}
+
+NS_IMETHODIMP
+Connection::BeginTransactionAs(int32_t aTransactionType)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  return beginTransactionInternal(mDBConn, aTransactionType);
+}
+
+nsresult
+Connection::beginTransactionInternal(sqlite3 *aNativeConnection,
+                                     int32_t aTransactionType)
+{
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  if (mTransactionInProgress)
+    return NS_ERROR_FAILURE;
+  nsresult rv;
+  switch(aTransactionType) {
+    case TRANSACTION_DEFERRED:
+      rv = convertResultCode(executeSql(aNativeConnection, "BEGIN DEFERRED"));
+      break;
+    case TRANSACTION_IMMEDIATE:
+      rv = convertResultCode(executeSql(aNativeConnection, "BEGIN IMMEDIATE"));
+      break;
+    case TRANSACTION_EXCLUSIVE:
+      rv = convertResultCode(executeSql(aNativeConnection, "BEGIN EXCLUSIVE"));
+      break;
+    default:
+      return NS_ERROR_ILLEGAL_VALUE;
+  }
+  if (NS_SUCCEEDED(rv))
+    mTransactionInProgress = true;
+  return rv;
+}
+
+NS_IMETHODIMP
+Connection::CommitTransaction()
+{
+  if (!mDBConn)
+    return NS_ERROR_NOT_INITIALIZED;
+
+  return commitTransactionInternal(mDBConn);
+}
+
+nsresult
+Connection::commitTransactionInternal(sqlite3 *aNativeConnection)
+{
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  if (!mTransactionInProgress)
+    return NS_ERROR_UNEXPECTED;
+  nsresult rv =
+    convertResultCode(executeSql(aNativeConnection, "COMMIT TRANSACTION"));
+  if (NS_SUCCEEDED(rv))
+    mTransactionInProgress = false;
+  return rv;
+}
+
+NS_IMETHODIMP
+Connection::RollbackTransaction()
+{
+  if (!mDBConn)
+    return NS_ERROR_NOT_INITIALIZED;
+
+  return rollbackTransactionInternal(mDBConn);
+}
+
+nsresult
+Connection::rollbackTransactionInternal(sqlite3 *aNativeConnection)
+{
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  if (!mTransactionInProgress)
+    return NS_ERROR_UNEXPECTED;
+
+  nsresult rv =
+    convertResultCode(executeSql(aNativeConnection, "ROLLBACK TRANSACTION"));
+  if (NS_SUCCEEDED(rv))
+    mTransactionInProgress = false;
+  return rv;
+}
+
+NS_IMETHODIMP
+Connection::CreateTable(const char *aTableName,
+                        const char *aTableSchema)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  char *buf = ::PR_smprintf("CREATE TABLE %s (%s)", aTableName, aTableSchema);
+  if (!buf)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  int srv = executeSql(mDBConn, buf);
+  ::PR_smprintf_free(buf);
+
+  return convertResultCode(srv);
+}
+
+NS_IMETHODIMP
+Connection::CreateFunction(const nsACString &aFunctionName,
+                           int32_t aNumArguments,
+                           mozIStorageFunction *aFunction)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  // Check to see if this function is already defined.  We only check the name
+  // because a function can be defined with the same body but different names.
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  NS_ENSURE_FALSE(mFunctions.Get(aFunctionName, nullptr), NS_ERROR_FAILURE);
+
+  int srv = ::sqlite3_create_function(mDBConn,
+                                      nsPromiseFlatCString(aFunctionName).get(),
+                                      aNumArguments,
+                                      SQLITE_ANY,
+                                      aFunction,
+                                      basicFunctionHelper,
+                                      nullptr,
+                                      nullptr);
+  if (srv != SQLITE_OK)
+    return convertResultCode(srv);
+
+  FunctionInfo info = { aFunction,
+                        Connection::FunctionInfo::SIMPLE,
+                        aNumArguments };
+  mFunctions.Put(aFunctionName, info);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::CreateAggregateFunction(const nsACString &aFunctionName,
+                                    int32_t aNumArguments,
+                                    mozIStorageAggregateFunction *aFunction)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  // Check to see if this function name is already defined.
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  NS_ENSURE_FALSE(mFunctions.Get(aFunctionName, nullptr), NS_ERROR_FAILURE);
+
+  // Because aggregate functions depend on state across calls, you cannot have
+  // the same instance use the same name.  We want to enumerate all functions
+  // and make sure this instance is not already registered.
+  NS_ENSURE_FALSE(findFunctionByInstance(aFunction), NS_ERROR_FAILURE);
+
+  int srv = ::sqlite3_create_function(mDBConn,
+                                      nsPromiseFlatCString(aFunctionName).get(),
+                                      aNumArguments,
+                                      SQLITE_ANY,
+                                      aFunction,
+                                      nullptr,
+                                      aggregateFunctionStepHelper,
+                                      aggregateFunctionFinalHelper);
+  if (srv != SQLITE_OK)
+    return convertResultCode(srv);
+
+  FunctionInfo info = { aFunction,
+                        Connection::FunctionInfo::AGGREGATE,
+                        aNumArguments };
+  mFunctions.Put(aFunctionName, info);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::RemoveFunction(const nsACString &aFunctionName)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  NS_ENSURE_TRUE(mFunctions.Get(aFunctionName, nullptr), NS_ERROR_FAILURE);
+
+  int srv = ::sqlite3_create_function(mDBConn,
+                                      nsPromiseFlatCString(aFunctionName).get(),
+                                      0,
+                                      SQLITE_ANY,
+                                      nullptr,
+                                      nullptr,
+                                      nullptr,
+                                      nullptr);
+  if (srv != SQLITE_OK)
+    return convertResultCode(srv);
+
+  mFunctions.Remove(aFunctionName);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::SetProgressHandler(int32_t aGranularity,
+                               mozIStorageProgressHandler *aHandler,
+                               mozIStorageProgressHandler **_oldHandler)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  // Return previous one
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  NS_IF_ADDREF(*_oldHandler = mProgressHandler);
+
+  if (!aHandler || aGranularity <= 0) {
+    aHandler = nullptr;
+    aGranularity = 0;
+  }
+  mProgressHandler = aHandler;
+  ::sqlite3_progress_handler(mDBConn, aGranularity, sProgressHelper, this);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::RemoveProgressHandler(mozIStorageProgressHandler **_oldHandler)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  // Return previous one
+  SQLiteMutexAutoLock lockedScope(sharedDBMutex);
+  NS_IF_ADDREF(*_oldHandler = mProgressHandler);
+
+  mProgressHandler = nullptr;
+  ::sqlite3_progress_handler(mDBConn, 0, nullptr, nullptr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::SetGrowthIncrement(int32_t aChunkSize, const nsACString &aDatabaseName)
+{
+  // Bug 597215: Disk space is extremely limited on Android
+  // so don't preallocate space. This is also not effective
+  // on log structured file systems used by Android devices
+#if !defined(ANDROID) && !defined(MOZ_PLATFORM_MAEMO)
+  // Don't preallocate if less than 500MiB is available.
+  int64_t bytesAvailable;
+  nsresult rv = mDatabaseFile->GetDiskSpaceAvailable(&bytesAvailable);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (bytesAvailable < MIN_AVAILABLE_BYTES_PER_CHUNKED_GROWTH) {
+    return NS_ERROR_FILE_TOO_BIG;
+  }
+
+  (void)::sqlite3_file_control(mDBConn,
+                               aDatabaseName.Length() ? nsPromiseFlatCString(aDatabaseName).get()
+                                                      : nullptr,
+                               SQLITE_FCNTL_CHUNK_SIZE,
+                               &aChunkSize);
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Connection::EnableModule(const nsACString& aModuleName)
+{
+  if (!mDBConn) return NS_ERROR_NOT_INITIALIZED;
+
+  for (size_t i = 0; i < ArrayLength(gModules); i++) {
+    struct Module* m = &gModules[i];
+    if (aModuleName.Equals(m->name)) {
+      int srv = m->registerFunc(mDBConn, m->name);
+      if (srv != SQLITE_OK)
+        return convertResultCode(srv);
+
+      return NS_OK;
+    }
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
+// Implemented in TelemetryVFS.cpp
+already_AddRefed<QuotaObject>
+GetQuotaObjectForFile(sqlite3_file *pFile);
+
+NS_IMETHODIMP
+Connection::GetQuotaObjects(QuotaObject** aDatabaseQuotaObject,
+                            QuotaObject** aJournalQuotaObject)
+{
+  MOZ_ASSERT(aDatabaseQuotaObject);
+  MOZ_ASSERT(aJournalQuotaObject);
+
+  if (!mDBConn) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  sqlite3_file* file;
+  int srv = ::sqlite3_file_control(mDBConn,
+                                   nullptr,
+                                   SQLITE_FCNTL_FILE_POINTER,
+                                   &file);
+  if (srv != SQLITE_OK) {
+    return convertResultCode(srv);
+  }
+
+  RefPtr<QuotaObject> databaseQuotaObject = GetQuotaObjectForFile(file);
+
+  srv = ::sqlite3_file_control(mDBConn,
+                               nullptr,
+                               SQLITE_FCNTL_JOURNAL_POINTER,
+                               &file);
+  if (srv != SQLITE_OK) {
+    return convertResultCode(srv);
+  }
+
+  RefPtr<QuotaObject> journalQuotaObject = GetQuotaObjectForFile(file);
+
+  databaseQuotaObject.forget(aDatabaseQuotaObject);
+  journalQuotaObject.forget(aJournalQuotaObject);
+  return NS_OK;
+}
+
+} // namespace storage
+} // namespace mozilla