How long did it take to run an Observable using RxJava (ReactiveX)?

Question

I'm using java ReactiveX (RxJava) in scala Play Framework 2.5 to communicate with couchbase asynchronously I would like to know how long it took for my observable to run? I define my observable using the code below.

def get(id: String) : Observable[Profile] = {
  this.bucket
    .async()
    // can I have a start time here possibly using map?
    .get(id)
    .map[Profile](toProfile)
    // can I have an end time here possibly using map?
}

I call it using the following

Thread.sleep(1000)

val observable = get("myID")

Thread.sleep(1000)

// measure start time here
println("observable: " + observable.toBlocking.first())
// measure end time here

Thread.sleep(1000)

How can I measure how long it took for the observable to run?

Thanking you in advance

Francis

score 11 · Accepted Answer · answered Apr 27 '16 at 20:40

You'll want to start your timer in a doOnSubscribe() block and then complete it in the onTerminated().

An example might be something like:

long start;
observable()
    .doOnSubscribe(() -> start = System.nanoTime())
    .doOnTerminate(() -> System.out.println(System.nanoTime() - start));

Alternatively you could follow what Netflix do with RxNetty and return the start time as part of the object flowing through the chain and use that at the end.

How long did it take to run an Observable using RxJava (ReactiveX)?

1 Answers1