Limiting concurrent access to a service class with RxSwift

Question

Given a service class like this:

class Service {
    let networkService = NetworkService()

    func handleJobA(input: String) -> Observable

        

Answer 1

You need a serial Scheduler that is dedicated to that service. Here is an example that can be pasted to a playground:

/// playground

import RxSwift

class Service {

    func handleJobA(input: String) -> Observable {

        return Observable.create { observer in
            print("start job a")
            sleep(3)
            observer.onNext(input)
            print("complete job a")
            observer.onCompleted()
            return Disposables.create()
        }.subscribeOn(scheduler)
    }

    func handleJobB(input: String) -> Observable {
        return Observable.create { observer in
            print("start job b")
            sleep(3)
            observer.onNext(input)
            print("complete job b")
            observer.onCompleted()
            return Disposables.create()
            return Disposables.create()
        }.subscribeOn(scheduler)
    }

    let scheduler = SerialDispatchQueueScheduler(internalSerialQueueName: "Service")
}


let service = Service()

_ = Observable.from(["hello","world","swift"])
    .flatMap { service.handleJobA(input: $0) }
    .subscribe(onNext:{
        print("result " + $0)
    })

_ = Observable.from(["hello","world","swift"])
    .flatMap { service.handleJobB(input: $0) }
    .subscribe(onNext:{
        print("result " + $0)
    })

import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true