Time Profiling in Swift

PeformanceTimer.swift

//
//  PerformanceTimer.swift
//  WordMonsters
//
//  Created by Sarah Smith on 8/6/15.
//  Copyright (c) 2015 Sarah Smith. All rights reserved.
//

import Foundation

class PerformanceTimer {
    
    static let instance = PerformanceTimer()
    
    class func addRecord( recordText: String ) {
        PerformanceTimer.instance.addTimeRecord(recordText)
    }

    class func print() {
        PerformanceTimer.instance.printTimeRecords()
    }
    
    typealias TimerRecord = ( timerName: String, timeStamp: Double )
    
    var records : [ TimerRecord ]
    
    init() {
        records = []
    }
    
    func addTimeRecord( recordText: String ) {
        let timeValue = CACurrentMediaTime()
        records.append(timerName: recordText, timeStamp: timeValue)
    }
    
    func printTimeRecords() {
        println("Time stamps:")
        if records.count > 1 {
            let baseline = records.first!.timeStamp
            for rec in records {
                println("    \(rec.timerName) - \(rec.timeStamp - baseline)")
            }
            records = []
        }
        else
        {
            println("Not enough time stamps recorded")
        }
    }
}

Add records with the static addRecord() Because there's a singleton which resets each time you call the print() function, you can log records to the PerformanceTimer from anywhere in the code. When you want to trigger a report, e.g. by touching the screen, call that print() method.

Use it like:

override func didMoveToView(view: SKView)
{
    PerformanceTimer.addRecord("Game Scene didMoveToView start")

    physicsWorld.contactDelegate = self
    physicsWorld.gravity = CGVector.zeroVector

    SKAction.afterDelay(0.2, runBlock: { () -> Void in
        SKTAudio.sharedInstance().playBackgroundMusic("Ouroboros.aifc")
    })

    PerformanceTimer.addRecord("Scheduled music")
    setupGameplay()
    PerformanceTimer.addRecord("Setup Gameplay")
    setupUI()

    launchpad.targetMissileAt(monsterManager.activeMonsters.first!)

    PerformanceTimer.addRecord("Game Scene didMoveToView end")
}

In some other file:

func targetMissileAt(monster: Monster) {
    // more code
    PerformanceTimer.addRecord("targetMissileAt")
    // more code
}

Then:

    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    /* Called when a touch begins */

    for touch in (touches as! Set<UITouch>) {
        let location = touch.locationInNode(self)

        keyboard.checkKeyPress(location)

        PerformanceTimer.print()
    }
}