Can someone help with the working of setTimeoutTimestamp() in mapGroupsWithState()?
Does setTimeoutTimestamp() delete the state after it crosses the duration specified?
According to the Scala Docs on GroupState the method setTimeoutTimestamp returns a Unit. It only sets the timeout.
Therefore, nothing is happening unless you explicitly check if the state has timed out and then remove it. An example is also given in the linked documentation and briefly shown below:
if (state.hasTimedOut) { // If called when timing out, remove the state
state.remove()
} else {
...
}
Related
What I'm wanting to accomplish is save a score to firebase that has two values attached to it. Here's the code that writes the score to firebase.
func writeToFirebase() {
DispatchQueue.global(qos: .userInteractive).async {
self.ref = Database.database().reference()
if GameManager.instance.getTopScores().contains(GameManager.instance.getGameScore()) {
self.ref?.child("user")
.child(GameManager.instance.getUsername())
.child(String(GameManager.instance.getGameScore()))
.updateChildValues( [
"badge":GameManager.instance.getBadgeLevel(),
"vehicle": GameManager.instance.getVehicleSelected()
]
)
}
}
}
The issue I'm having is when a new score is saved with its values it sometimes overwrites the other scores. This seems to be random and its not when they're the same score or anything like that. Sometimes it will only overwrite one score and sometimes multiple. I'm watching firebase and I can see it being overwritten, it turns red and then is deleted. Sometimes the new score being added will be red and get deleted. The score doesn't need to be a child, but I don't know how to attach values to it if it's not. Any help is appreciated
This issue seems to happen occasionally so I am going to post my comment as an answer.
There are situations where an observer may be added to a node and when data changes in that node, like a write or update, it will fire that observer which may then overwrite the existing data with nil.
You can see this visually in the console as when the write occurs, you can see the data change/update, then it turns red and then mysteriously vanishes.
As suggested in my comment, add a breakpoint to the function that performs the write and run the code. See if that function is called twice (or more). If that's the case, the first write is storing the data properly but upon calling it a second time, the values being written are probably nil, which then makes the node 'go away' as Firebase nodes cannot exist without a value.
Generally speaking if you see your data turn red and vanish, it's likely caused by nil values being written to the node.
I was trying to assign timestamp and watermarks to a stream by implementing the AssignerWithPeriodicWatermarks, inside the function, it implements:
override def getCurrentWatermark: Watermark = {
// this guarantees that the watermark never goes backwards.
val potentialWM = currentMaxTimestamp - maxOutOfOrderness
if (potentialWM >= lastEmittedWatermark) lastEmittedWatermark = potentialWM
new Watermark(lastEmittedWatermark)
}
override def extractTimestamp(element: T, previousElementTimestamp: Long): Long = {
val timestamp = element.streamTime // something exists in the stream
if (timestamp > currentMaxTimestamp) currentMaxTimestamp = timestamp
timestamp
}
However, I still got watermarks of the default value -9223372036854775808, and when I tried to add printing inside both functions, I found only println inside extractTimestamp was printed, which is saying function of getCurrentWatermark was never called.
The implementations seem to be right, because the same code was able to run on another script(some code not written by me).
PS: It's not the first time that I encountered negative watermark, what I found is that after a certain period of time, the watermark will go positive, however I am still quite confused what happened at the beginning.
The issue is that You are using AssignerWithPeriodicWatermark which does not generate watermarks per event but in intervals. Whenever You are using AssingerWithPeriodicWatermark You should set call the setTheAutowatermarkInterval on the execution environment. The value that You provide there will be the interval that the getCurrentWatermark will be called with.
If You haven't set it then the method will never be called, thus You will never have a watermark changed.
For testing and learning, You can consider using AssignerWithPunctuatedWatermark as this will simply emit watermark for each event.
EDIT:
As it was mentioned below this answer, the default value for autowatermarkInterval is actually 200 ms. Also, using the AssignerWithPunctuatedWatermark doesn't mean You need to emit the Watermark for each event, but the method for emitting them will be called for each event. If You don't want to emit the Watermark then the method should simply return null.
In my application I need to wait until external program (using QProcess) is finished. I want to keep the application responsible so blocking methods are unacceptable.
Also I need to disallow user input. I've tried to make QEventLoop and exec it with QEventLoop::ExcludeUserInputEvents flag, but as documentation says it only delays an event handling:
the events are not discarded; they will be delivered the next time processEvents() is called without the ExcludeUserInputEvents flag.
So I implemented simple event filter and install it on qApp (the idea is took from Qt Application: Simulating modal behaviour (enable/disable user input)). It works well, but sometimes QApplication::processEvents function never returns even if I specify the maximum timeout. Could anyone help me to understand for what reasons it periodically happens?
class UserInputEater : public QObject
{
public:
bool eventFilter(QObject *object, QEvent *event)
{
switch(event->type())
{
case QEvent::UpdateRequest:
case QEvent::UpdateLater:
case QEvent::Paint:
return QObject::eventFilter(object, event);
default:
return true;
}
}
};
-
UserInputEater eventEater;
qApp->installEventFilter(&eventEater);
QProcess prc;
prc.start("...");
while(!prc.waitForFinished(10))
{
if(qApp->hasPendingEvents())
{
// Sometimes it never returns from processEvents
qApp->processEvents(QEventLoop::AllEvents, 100);
}
}
qApp->removeEventFilter(&eventEater);
UPD: Seems like it depends of the timeout value for QProcess::waitForFinished.
I guess you are filtering some useful events (for example, QEvent::SockAct could be involved). Try to add some debug output and find out which event types you're actually filtering. Or it might be better to specify the black list of events you want to block instead of white list of events you want to allow. See this answer.
Also you shouldn't use return QObject::eventFilter(object, event);. You should use return false. All other event filters will be called automatically.
This solution however seems weird and unreasonable to me because you can just call setEnabled(false) for your top level widget to block user input, and then you can use QApplication::processEvents without any flags.
Guys help me to understand the timeouts usage. The documentation gives quite a couple of words about them:
popTimeout- Retrieves the previous timeout value from a stack, restores it as the current timeout value, and returns it.
pushTimeout - Stores the current timeout value on a stack and sets a new timeout value.
They also provide some code:
target = UIATarget.localTarget();
target.pushTimeout(2);
// attempt element access
target.popTimeout();
But I don't exactly understand how and when to use them. Can anybode give an example?
During automation testing, some elements might not become visible right away. so instruments uses a timeout (default 5 seconds) to wait for requested elements. They call this the grace period.
Sometimes the default grace period might not be what you need, so you can change the timeout to a shorter or longer value.
Using the pushTimeout and popTimeout makes sure that the previous grace period is restored after calling popTimeout, without the need to remember the previous grace period.
For example: in one of my tests, I don't want to wait for a popover to become active, but I just want to know if there is a popover active, and dismiss it if there is:
target.pushTimeout(0.0);
if ( target.isDeviceiPad() && ! isNull( popOver= app.mainWindow().popover() ) )
{
UIALogger.logDebug(" dismiss popup by tapping somewhere");
popOver.dismiss();
target.delay(0.2);
}
target.popTimeout();
BTW, the isNull() is a custom function I made, but you probably understand what is going on.
I am Using WaitforComplete() in watiN but it doesnt seems to work well. As it executes the next statement even if you have given longer time to wait. I am using thread.sleep() to stop my application until it gets the desired page or element. But the thing is pages are so much dynamic that sometimes it takes much longer time as specified.
Any better solution. Any thing that will catch the page return dynamically and dont go to execute next statments in application.
Sample of Code
'Show Details page
Assert.AreEqual("Confirmation", _internetExplorer.Title)
If (_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Exists) Then
_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Click()
Else
Assert.Fail("Could not Find Finish Booking Button on Confirmation Page")
End If
System.Threading.Thread.Sleep(100000)
'Show Booking Summary page
Assert.AreEqual("Display Booking", _internetExplorer.Title)
I want something that detect the return of page dynamically. instead of giving some constant value.
WaitForComplete only works well if there is a postback after some action. Otherwise you have to find something else to wait for. Following an example on how to wait for the specified title:
_internetExplorer.Element("title", "Confirmation").WaitUntilExists();
I would always prefer to use one of the WaitXXX methods instead of Thread.Sleep cause the WaitXXX methods do only wait until the contraint is met. Where as Sleep waits for the time you specified. If its to long, time is waisted. If its to short, problems arise.
HTH,
Jeroen
The WaitForComplete method esentially moves on once the browser has set it's readystate to comllete and the busy state to false.
What I typically do is to try and access what you need to, then perform a thread.sleep for say half a second, then try again. I also have a global timeout that quits after say 10 seconds.
int timeout = 20;
bool controlFound = false;
for (int i = 0; i < timeout; i++)
{
if (_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Exists)
{
_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Click();
controlFound = true;
break;
}
else
{
System.Threading.Thread.Sleep(500);
}
}
if (!controlFound)
{
Assert.Fail("Control not found");
}
If it is executing the next statement, it should be finding the corresponding element. I suggest posting a sample of the code you are trying.