自学教程：C++ EndTransaction函数代码示例

/* static */ boolWheelTransaction::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 intCheckDirtyRead(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_IMETHODIMPnsTransactionManager::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_IMETHODIMPnsTransactionManager::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();}

boolWheelBlockState::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 */ voidWheelTransaction::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;	}}

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

boolLayerManagerD3D9::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 intCheckPhantom(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;}

/* static */ voidWheelTransaction::BeginTransaction(nsIFrame* aTargetFrame,                                   WidgetWheelEvent* aEvent){  NS_ASSERTION(!sTargetFrame, "previous transaction is not finished!");  MOZ_ASSERT(aEvent->mMessage == eWheel,             "Transaction must be started with a wheel event");  ScrollbarsForWheel::OwnWheelTransaction(false);  sTargetFrame = aTargetFrame;  sScrollSeriesCounter = 0;  if (!UpdateTransaction(aEvent)) {    NS_ERROR("BeginTransaction is called even cannot scroll the frame");    EndTransaction();  }}

static intCheckNonrepeatableRead(void){	SQLRETURN RetCode;	/* transaction 2 read a row */	SWAP_CONN();	odbc_command("SELECT * FROM test_transaction WHERE t = 'initial' AND n = 1");	SQLMoreResults(odbc_stmt);	/* transaction 1 change a row and commit */	SWAP_CONN();	RetCode = odbc_command2("UPDATE test_transaction SET t = 'second' WHERE n = 1", "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 = 'second' AND n = 1");	CHKFetch("S");	CHKFetch("No");	SQLMoreResults(odbc_stmt);	EndTransaction(SQL_ROLLBACK);	SWAP_CONN();	odbc_command("UPDATE test_transaction SET t = 'initial' WHERE n = 1");	EndTransaction(SQL_COMMIT);	return 1;}

FReply FGridSlotExtension::HandleShiftColumn(int32 ShiftAmount){	BeginTransaction(LOCTEXT("MoveWidget", "Move Widget"));	for ( FWidgetReference& Selection : SelectionCache )	{		ShiftColumn(Selection.GetPreview(), ShiftAmount);		ShiftColumn(Selection.GetTemplate(), ShiftAmount);	}	EndTransaction();	FBlueprintEditorUtils::MarkBlueprintAsModified(Blueprint);	return FReply::Handled();}

FReply FVerticalSlotExtension::HandleShiftVertical(int32 ShiftAmount){	BeginTransaction(LOCTEXT("MoveWidget", "Move Widget"));	for ( FWidgetReference& Selection : SelectionCache )	{		ShiftVertical(Selection.GetPreview(), ShiftAmount);		ShiftVertical(Selection.GetTemplate(), ShiftAmount);	}	EndTransaction();	//TODO UMG Reorder the live slot without rebuilding the structure	FBlueprintEditorUtils::MarkBlueprintAsStructurallyModified(Blueprint);	return FReply::Handled();}

fsal_posixdb_status_t fsal_posixdb_deleteHandle(fsal_posixdb_conn * p_conn,     /* IN */                                                posixfsal_handle_t *                                                p_parent_directory_handle /* IN */ ){/*    char           handleid_str[MAX_HANDLEIDSTR_SIZE];    char           handlets_str[MAX_HANDLETSSTR_SIZE];    const char    *paramValues[2]; */  int found;  result_handle_t res;  fsal_posixdb_status_t st;  char query[2048];  BeginTransaction(p_conn);  LogFullDebug(COMPONENT_FSAL, "Deleting %llu.%u/n", p_parent_directory_handle->data.id,         p_parent_directory_handle->data.ts);  snprintf(query, 2048,           "SELECT Handle.deviceid, Handle.inode, Handle.nlink, Handle.ctime, Handle.ftype "           "FROM Handle WHERE handleid=%llu AND handlets=%u FOR UPDATE",           p_parent_directory_handle->data.id, p_parent_directory_handle->data.ts);  st = db_exec_sql(p_conn, query, &res);  if(FSAL_POSIXDB_IS_ERROR(st))    goto rollback;  found = mysql_num_rows(res);  mysql_free_result(res);  if(found)    {      /* entry found */      st = fsal_posixdb_recursiveDelete(p_conn, p_parent_directory_handle->data.id,                                        p_parent_directory_handle->data.ts, FSAL_TYPE_DIR);      if(FSAL_POSIXDB_IS_ERROR(st))        goto rollback;    }  return EndTransaction(p_conn); rollback:  RollbackTransaction(p_conn);  return st;}

void FSCSEditorViewportClient::TrackingStopped() {	if( bIsManipulating )	{		// Re-run construction scripts if we haven't done so yet (so that the components in the preview actor can update their transforms)		AActor* PreviewActor = GetPreviewActor();		if(PreviewActor != NULL && PreviewBlueprint != NULL && !PreviewBlueprint->bRunConstructionScriptOnDrag)		{			PreviewActor->RerunConstructionScripts();		}		// End transaction		bIsManipulating = false;		EndTransaction();		// Restore component delta modification		GEditor->DisableDeltaModification(false);	}}

void FMoveSection::OnEndDrag(TSharedPtr<FTrackNode> SequencerNode){	DraggedKeyHandles.Empty();	if (Section.IsValid())	{		SequencerNode->FixRowIndices();		UMovieSceneTrack* OuterTrack = Cast<UMovieSceneTrack>(Section->GetOuter());		if (OuterTrack)		{			OuterTrack->Modify();			OuterTrack->OnSectionMoved(*Section);		}	}	EndTransaction();}

NS_IMETHODIMPnsTransactionManager::DoTransaction(nsITransaction *aTransaction){  nsresult result;  if (!aTransaction)    return NS_ERROR_NULL_POINTER;  LOCK_TX_MANAGER(this);  PRBool doInterrupt = PR_FALSE;  result = WillDoNotify(aTransaction, &doInterrupt);  if (NS_FAILED(result)) {    UNLOCK_TX_MANAGER(this);    return result;  }  if (doInterrupt) {    UNLOCK_TX_MANAGER(this);    return NS_OK;  }  result = BeginTransaction(aTransaction);  if (NS_FAILED(result)) {    DidDoNotify(aTransaction, result);    UNLOCK_TX_MANAGER(this);    return result;  }  result = EndTransaction();  nsresult result2 = DidDoNotify(aTransaction, result);  if (NS_SUCCEEDED(result))    result = result2;  UNLOCK_TX_MANAGER(this);  return result;}

/* static */ voidWheelTransaction::OnFailToScrollTarget(){  NS_PRECONDITION(sTargetFrame, "We don't have mouse scrolling transaction");  if (Preferences::GetBool("test.mousescroll", false)) {    // This event is used for automated tests, see bug 442774.    nsContentUtils::DispatchTrustedEvent(                      sTargetFrame->GetContent()->OwnerDoc(),                      sTargetFrame->GetContent(),                      NS_LITERAL_STRING("MozMouseScrollFailed"),                      true, true);  }  // The target frame might be destroyed in the event handler, at that time,  // we need to finish the current transaction  if (!sTargetFrame) {    EndTransaction();  }}

voidWheelBlockState::OnMouseMove(const ScreenIntPoint& aPoint){  MOZ_ASSERT(InTransaction());  if (!GetTargetApzc()->Contains(aPoint)) {    EndTransaction();    return;  }  if (mLastMouseMove.IsNull()) {    // If the cursor is moving inside the frame, and it is more than the    // ignoremovedelay time since the last scroll operation, we record    // this as the most recent mouse movement.    TimeStamp now = TimeStamp::Now();    TimeDuration duration = now - mLastEventTime;    if (duration.ToMilliseconds() >= gfxPrefs::MouseWheelIgnoreMoveDelayMs()) {      mLastMouseMove = now;    }  }}