Backpressure for window(size) #2820
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Could you change the javadoc for this operator in Observable.java as well: http://reactivex.io/RxJava/javadoc/rx/Observable.html#window(int) It currently reads: Backpressure Support: |
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Sure. |
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Isn't supporting backpressure on the inner effectively the same as 'onBackpressureBuffer'? |
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Yes. BufferUntilSubscriber would need to be smartened to do proper backpressure. |
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What has happened recently causing tests to fail? I don't see any recent commits at should do it. Ideas? |
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I have no idea. I thought it was my commit for testOnBackpressureDropWithAction but reverting that didn't fix the master. My best guess is that something changed in the Travis-CI environment; perhaps we don't get 3GB memory anymore (on Windows, the tests take up to 1GB of memory). |
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So to confirm, merging this would be adding back pressure on the outer but still need us to come back later and fix the inner? |
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Yes. |
| child.setProducer(new Producer() { | ||
| @Override | ||
| public void request(long n) { | ||
| if (n > 0) { |
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Curious, why not use BackpressureUtils here? Is it because you are just passing the value through rather than maintaining the AtomicLong in this class?
Backpressure for window(size)
Changes to the
window(size)operator to respect the backpressure on its outer Observable: asking for 1 window will requestsizevalues from upstream.Backpressure is ignored on the inner Observable for now, partially because the
BufferUntilSubscriberdoesn't support it, partially because coordinating the inner requests with the outer requests needs more thoughts. The problem is that the outer has to request at least 1 element from upstream in order to open the window, but the inner subscriber may not want that single element just yet or would request more than the remaining window size and it would trigger new windows whose value it can't receive but would overflow the next window's observers.window(size, skip)is not changed as I need to think about it more.