reactive-programming

问题 Part of application I am writing requires transferring arbitrarily big (for this question I will assume 100-200 GB) files from client to server. Important thing, is that receiver (server) is not storing this file - it just read/examine stream and sends it to next point. Because at no point I need whole file, but expect multiple transfers at same time, I would like to minimize RAM usage and eliminate disk usage. I would like to process files in chunks of 1 MB. Right now, server uses Spring

问题 I'm trying to understand why a cycling use of shiny's reactivevalues causes it to use more memory. The context is a user interface with the option to automate a given strategy. The example below is based on the St. Petersburg paradox. I appreciate that it may be better practice to place the entire automation process in a seperate function file but I would like to understand why the reactive object increases in size and if there is a more immediate work around. The example below will print out

问题 When we know exactly how many observables we have with their exact types and we want to zip we do like this Observable<String> data1 = Observable.just("one", "two", "three", "four", "five"); Observable<String> data2 = Observable.just("one", "two", "three", "four", "five"); Observable<String> data3 = Observable.just("one", "two", "three", "four", "five"); Observable.zip(data1, data2, data3, (a, b, c) -> a + b + c); we use fixed argument functional interface which takes 3 arguments... and it

问题 I'm developing a whole application in RxJava/Android, trying to make the things the most Rx-way possible. I think I'm achieving what I wanted, but now I've encountered an issue that I'm sure that exists a better way to do it. It consists of: Get a Boolean from an Observable A: If it's true, you are done, return true. B: If it's false, make a request (call it firstRequest) and receive an Observable. A: The same, if it's true, you are done, return true. B: If it's false, then make another

问题 I am getting Invalid cross-thread access. When using RX Throttle Here is my code: yObs.SubscribeOnDispatcher() .DistinctUntilChanged() .Throttle(TimeSpan.FromMilliseconds(33)) .SkipWhile(y => !_isDragging) .Subscribe(y => { // Exception when trying to access image image.RenderTransform = new CompositeTransform() { TranslateY = -y }; _vm.UpdateContentDrag(y / image.ActualHeight * 100); }); But if I omit throttle everything works. As far as I understand Throttle uses thread pool so OnNext doesn

问题 I'm getting the following error: EXCEPTION: Cannot find a differ supporting object '[object Object]' in [files | async in Images@1:9] Here's the relevant part of the template: <img *ngFor="#file of files | async" [src]="file.path"> Here's my code: export class Images { public files: any; public currentPage: number = 0; private _rawFiles: any; constructor(public imagesData: ImagesData) { this.imagesData = imagesData; this._rawFiles = this.imagesData.getData() .flatMap(data => Rx.Observable

问题 I see that ReactiveX (RxJava) has an operator timeout , which will apply to every item in a subscription stream. But I only want to check the very first response with a timeout and do not care about timeouts for the following responses. How can I implement this requirement elegantly with RxJava's operators? 回答1: Here is a more functional way of doing it. It's in Scala but should be transcribed to Java: val myTimeout : Observable[Nothing] = Observable timer (10 seconds) flatMap (_ =>

问题 Using project Reactor 3.0.4.RELEASE. Conceptually, should be same in RxJava as well. public Mono<Map<String, Boolean>> refreshPods(List<String> apps) { return pods(apps) .filter(this::isRunningAndNotThisApp) .groupBy(Item::getName) .flatMap(g -> g .distinct(Item::getIp) .collectList() // TODO: This doesn't seem to be working as expected .subscribeOn(Schedulers.newParallel("par-grp")) .flatMap(client::refreshPods)) .flatMap(m -> Flux.fromIterable(m.entrySet())) .collectMap(Map.Entry::getKey,

问题 I'm looking at scala/slick streaming, and trying to understand how it works. Here is my test code val bigdata = TableQuery[BigData] val x = db.stream(bigdata.result.transactionally.withStatementParameters(fetchSize = 100)).foreach { (tuple: (Int, UUID)) => println(tuple._1 + " " + tuple._2) Thread.sleep(50)//emulating slow consumer. } Await.result(x, 100000 seconds) While the code is running I enabled postgresql query log to understand whats going under the hood. I see a re-query happening

问题 I try to model some game with RxJS. but I found some troubles with circular dependencies. So, I simplified my game to a simple simulation(I left only 'move' action). You can find code below(I omitted some parts, you can find the repo here) const rx = require('rx') const math = require('mathjs') const _ = require('underscore') const FIELD_SIZE = 10 const ctx = require('axel'); let getInitialState = () => { return { size: FIELD_SIZE, people: [ { x: 0, y: 0 }, { x: 9, y: 9 }, { x: 5, y: 5 } ] }