How to profile methods in Scala?

function scala profiling aspect
sheki picture sheki · Feb 6, 2012 · Viewed 48.7k times · Source

What is a standard way of profiling Scala method calls?

What I need are hooks around a method, using which I can use to start and stop Timers.

In Java I use aspect programming, aspectJ, to define the methods to be profiled and inject bytecode to achieve the same.

Is there a more natural way in Scala, where I can define a bunch of functions to be called before and after a function without losing any static typing in the process?

Answer

Jesper picture Jesper · Feb 6, 2012

Do you want to do this without changing the code that you want to measure timings for? If you don't mind changing the code, then you could do something like this:

def time[R](block: => R): R = {
    val t0 = System.nanoTime()
    val result = block    // call-by-name
    val t1 = System.nanoTime()
    println("Elapsed time: " + (t1 - t0) + "ns")
    result
}

// Now wrap your method calls, for example change this...
val result = 1 to 1000 sum

// ... into this
val result = time { 1 to 1000 sum }

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