C++ EndTransaction函數代碼示例

/* static */ bool
WheelTransaction::WillHandleDefaultAction(WidgetWheelEvent* aWheelEvent,
                                          nsWeakFrame& aTargetWeakFrame)
{
  nsIFrame* lastTargetFrame = GetTargetFrame();
  if (!lastTargetFrame) {
    BeginTransaction(aTargetWeakFrame.GetFrame(), aWheelEvent);
  } else if (lastTargetFrame != aTargetWeakFrame.GetFrame()) {
    EndTransaction();
    BeginTransaction(aTargetWeakFrame.GetFrame(), aWheelEvent);
  } else {
    UpdateTransaction(aWheelEvent);
  }

  // When the wheel event will not be handled with any frames,
  // UpdateTransaction() fires MozMouseScrollFailed event which is for
  // automated testing.  In the event handler, the target frame might be
  // destroyed.  Then, the caller shouldn't try to handle the default action.
  if (!aTargetWeakFrame.IsAlive()) {
    EndTransaction();
    return false;
  }

  return true;
}

static int
CheckDirtyRead(void)
{
	SQLRETURN RetCode;

	/* transaction 1 try to change a row but not commit */
	odbc_command("UPDATE test_transaction SET t = 'second' WHERE n = 1");

	SWAP_CONN();

	/* second transaction try to fetch uncommited row */
	RetCode = odbc_command2("SELECT * FROM test_transaction WHERE t = 'second' AND n = 1", "SE");
	if (RetCode == SQL_ERROR) {
		EndTransaction(SQL_ROLLBACK);
		SWAP_CONN();
		EndTransaction(SQL_ROLLBACK);
		return 0;	/* no dirty read */
	}

	CHKFetch("S");
	CHKFetch("No");
	SQLMoreResults(odbc_stmt);
	EndTransaction(SQL_ROLLBACK);
	SWAP_CONN();
	EndTransaction(SQL_ROLLBACK);
	return 1;
}

NS_IMETHODIMP
nsTransactionManager::DoTransaction(nsITransaction *aTransaction)
{
  nsresult result;

  NS_ENSURE_TRUE(aTransaction, NS_ERROR_NULL_POINTER);

  bool doInterrupt = false;

  result = WillDoNotify(aTransaction, &doInterrupt);

  if (NS_FAILED(result)) {
    return result;
  }

  if (doInterrupt) {
    return NS_OK;
  }

  result = BeginTransaction(aTransaction);

  if (NS_FAILED(result)) {
    DidDoNotify(aTransaction, result);
    return result;
  }

  result = EndTransaction();

  nsresult result2 = DidDoNotify(aTransaction, result);

  if (NS_SUCCEEDED(result))
    result = result2;

  return result;
}

void FSpriteEditorViewportClient::NotifySpriteBeingEditedHasChanged()
{
	//@TODO: Ideally we do this before switching
	EndTransaction();

	// Refresh the viewport in case we were not in realtime mode
	Invalidate();

	// Update components to know about the new sprite being edited
	UPaperSprite* Sprite = GetSpriteBeingEdited();

	RenderSpriteComponent->SetSprite(Sprite);
	UpdateSourceTextureSpriteFromSprite(Sprite);

	InternalActivateNewMode(CurrentMode);

	//@TODO: Only do this if the sprite isn't visible (may consider doing a flashing pulse around the source region rect?)
	RequestFocusOnSelection(/*bInstant=*/ true);

	if (Sprite != nullptr)
	{
		// Create and display a notification about the new sprite being edited
		const FText NotificationErrorText = FText::Format(LOCTEXT("SwitchingToSprite", "Editing {0}"), FText::AsCultureInvariant(Sprite->GetName()));
		FNotificationInfo Info(NotificationErrorText);
		Info.ExpireDuration = 2.0f;
		FSlateNotificationManager::Get().AddNotification(Info);
	}
}

fsal_posixdb_status_t fsal_posixdb_delete(fsal_posixdb_conn * p_conn,   /* IN */
                                          posixfsal_handle_t * p_parent_directory_handle,       /* IN */
                                          fsal_name_t * p_filename,     /* IN */
                                          fsal_posixdb_fileinfo_t *
                                          p_object_info /* IN */ )
{
  result_handle_t res;
  fsal_posixdb_status_t st;
  char query[2048];

    /*******************
     * 1/ sanity check *
     *******************/

  if(!p_conn || !p_parent_directory_handle || !p_filename)
    ReturnCodeDB(ERR_FSAL_POSIXDB_FAULT, 0);

  BeginTransaction(p_conn);

    /*******************************
     * 2/ we check the file exists *
     *******************************/

  snprintf(query, 2048, "SELECT Parent.handleid, Parent.handlets, "
           "Handle.deviceid, Handle.inode, Handle.nlink, Handle.ctime, Handle.ftype "
           "FROM Parent INNER JOIN Handle ON Parent.handleid = Handle.handleid "
           "AND Parent.handlets=Handle.handlets "
           "WHERE handleidparent=%llu AND handletsparent=%u AND name='%s' "
           "FOR UPDATE", p_parent_directory_handle->data.id,
           p_parent_directory_handle->data.ts, p_filename->name);

  st = db_exec_sql(p_conn, query, &res);
  if(FSAL_POSIXDB_IS_ERROR(st))
    goto rollback;

  if(mysql_num_rows(res) != 1)
    {
      /* parent entry not found */
      mysql_free_result(res);
      RollbackTransaction(p_conn);
      ReturnCodeDB(ERR_FSAL_POSIXDB_NOENT, 0);
    }
  mysql_free_result(res);

    /***********************************************
     * 3/ Get information about the file to delete *
     ***********************************************/

  st = fsal_posixdb_internal_delete(p_conn, p_parent_directory_handle->data.id,
                                    p_parent_directory_handle->data.ts,
                                    p_filename->name, p_object_info);
  if(FSAL_POSIXDB_IS_ERROR(st))
    goto rollback;

  return EndTransaction(p_conn);

 rollback:
  RollbackTransaction(p_conn);
  return st;
}

WheelBlockState::WheelBlockState(const RefPtr<AsyncPanZoomController>& aTargetApzc,
                                 bool aTargetConfirmed,
                                 const ScrollWheelInput& aInitialEvent)
  : CancelableBlockState(aTargetApzc, aTargetConfirmed)
  , mScrollSeriesCounter(0)
  , mTransactionEnded(false)
{
  sLastWheelBlockId = GetBlockId();

  if (aTargetConfirmed) {
    // Find the nearest APZC in the overscroll handoff chain that is scrollable.
    // If we get a content confirmation later that the apzc is different, then
    // content should have found a scrollable apzc, so we don't need to handle
    // that case.
    RefPtr<AsyncPanZoomController> apzc =
      mOverscrollHandoffChain->FindFirstScrollable(aInitialEvent);

    // If nothing is scrollable, we don't consider this block as starting a
    // transaction.
    if (!apzc) {
      EndTransaction();
      return;
    }

    if (apzc != GetTargetApzc()) {
      UpdateTargetApzc(apzc);
    }
  }
}

NS_IMETHODIMP
nsTransactionManager::EndBatch()
{
  nsRefPtr<nsTransactionItem> tx;
  nsCOMPtr<nsITransaction> ti;
  nsresult result;

  LOCK_TX_MANAGER(this);

  // XXX: Need to add some mechanism to detect the case where the transaction
  //      at the top of the do stack isn't the dummy transaction, so we can
  //      throw an error!! This can happen if someone calls EndBatch() within
  //      the DoTransaction() method of a transaction.
  //
  //      For now, we can detect this case by checking the value of the
  //      dummy transaction's mTransaction field. If it is our dummy
  //      transaction, it should be NULL. This may not be true in the
  //      future when we allow users to execute a transaction when beginning
  //      a batch!!!!

  result = mDoStack.Peek(getter_AddRefs(tx));

  if (NS_FAILED(result)) {
    UNLOCK_TX_MANAGER(this);
    return result;
  }

  if (tx)
    tx->GetTransaction(getter_AddRefs(ti));

  if (!tx || ti) {
    UNLOCK_TX_MANAGER(this);
    return NS_ERROR_FAILURE;
  }

  PRBool doInterrupt = PR_FALSE;

  result = WillEndBatchNotify(&doInterrupt);

  if (NS_FAILED(result)) {
    UNLOCK_TX_MANAGER(this);
    return result;
  }

  if (doInterrupt) {
    UNLOCK_TX_MANAGER(this);
    return NS_OK;
  }

  result = EndTransaction();

  nsresult result2 = DidEndBatchNotify(result);

  if (NS_SUCCEEDED(result))
    result = result2;

  UNLOCK_TX_MANAGER(this);

  return result;
}

FReply FCanvasSlotExtension::HandleAnchorEndDrag(const FGeometry& Geometry, const FPointerEvent& Event, EAnchorWidget::Type AnchorType)
{
	EndTransaction();

	bMovingAnchor = false;
	return FReply::Handled().ReleaseMouseCapture();
}

bool
WheelBlockState::SetContentResponse(bool aPreventDefault)
{
  if (aPreventDefault) {
    EndTransaction();
  }
  return CancelableBlockState::SetContentResponse(aPreventDefault);
}

FSCSEditorViewportClient::~FSCSEditorViewportClient()
{
	// Ensure that an in-progress transaction is ended
	EndTransaction();

	// Clean up the preview
	DestroyPreview();
}

/* static */ void
WheelTransaction::MayEndTransaction()
{
  if (!sOwnScrollbars && ScrollbarsForWheel::IsActive()) {
    ScrollbarsForWheel::OwnWheelTransaction(true);
  } else {
    EndTransaction();
  }
}

void FSingleTileEditorViewportClient::TrackingStopped()
{
	// Stop transacting.  Give the current editor mode an opportunity to do the transacting.
	const bool bTransactingHandledByEditorMode = ModeTools->EndTracking(this, Viewport);

	if (bManipulating && !bTransactingHandledByEditorMode)
	{
		EndTransaction();
		bManipulating = false;
	}
}

bool
LayerManagerComposite::EndEmptyTransaction(EndTransactionFlags aFlags)
{
  NS_ASSERTION(mInTransaction, "Didn't call BeginTransaction?");
  if (!mRoot) {
    mInTransaction = false;
    mIsCompositorReady = false;
    return false;
  }

  EndTransaction(nullptr, nullptr);
  return true;
}

bool
LayerManagerD3D9::EndEmptyTransaction()
{
  // If the device reset count from our last EndTransaction doesn't match
  // the current device reset count, the device must have been reset one or
  // more times since our last transaction. In that case, an empty transaction
  // is not possible, because layers may need to be rerendered.
  if (!mRoot || mDeviceResetCount != mDeviceManager->GetDeviceResetCount())
    return false;

  EndTransaction(nsnull, nsnull);
  return true;
}

static int
CheckPhantom(void)
{
	SQLRETURN RetCode;

	/* transaction 2 read a row */
	SWAP_CONN();
	odbc_command("SELECT * FROM test_transaction WHERE t = 'initial'");
	SQLMoreResults(odbc_stmt);

	/* transaction 1 insert a row that match critera */
	SWAP_CONN();
	RetCode = odbc_command2("INSERT INTO test_transaction(n, t) VALUES(2, 'initial')", "SE");
	if (RetCode == SQL_ERROR) {
		EndTransaction(SQL_ROLLBACK);
		SWAP_CONN();
		EndTransaction(SQL_ROLLBACK);
		SWAP_CONN();
		return 0;	/* no dirty read */
	}
	EndTransaction(SQL_COMMIT);

	SWAP_CONN();

	/* second transaction try to fetch commited row */
	odbc_command("SELECT * FROM test_transaction WHERE t = 'initial'");

	CHKFetch("S");
	CHKFetch("S");
	CHKFetch("No");
	SQLMoreResults(odbc_stmt);
	EndTransaction(SQL_ROLLBACK);
	SWAP_CONN();
	odbc_command("DELETE test_transaction WHERE n = 2");
	EndTransaction(SQL_COMMIT);
	return 1;
}