Test the performance of functions calls in JavaScriptCore in iOS 8+

JavascriptCorePerfTest.swift

class JSCContextTests: XCTestCase {

    var jscContext: JSContext!

    override func setUp() {
        
        jscContext = JSContext()

        let log_Binder: @convention(block) String -> Void = { input in
            print(input)
        }

        let copyArray_Binder: @convention(block) [NSNumber] -> Void = { data in
            var dataAsArray = [GLubyte]()
            for i in 0 ..< data.count {
                let num = data[i]
                dataAsArray.append(num.unsignedCharValue)
            }
        }

        // Pre allocate space is much faster than append
        let copyArrayPreAllocate_Binder: @convention(block) [NSNumber] -> Void = { data in
            var dataAsArray = [GLubyte](count: data.count, repeatedValue: 0)
            for i in 0 ..< data.count {
                let num = data[i]
                dataAsArray[i] = num.unsignedCharValue
            }
        }

        let global = "global"
        jscContext.evaluateScript("var \(global) = {};")
        let jsObject = jscContext.objectForKeyedSubscript(global)
        jsObject!.setObject(unsafeBitCast(log_Binder, AnyObject.self), forKeyedSubscript: "log")
        jsObject!.setObject(unsafeBitCast(copyArray_Binder, AnyObject.self), forKeyedSubscript: "copyArray")
        jsObject!.setObject(unsafeBitCast(copyArrayPreAllocate_Binder, AnyObject.self), forKeyedSubscript: "copyArrayPre")

        jscContext.evaluateScript("function foo() { global.log('foo'); }")
        jscContext.evaluateScript("function emptyMethod() { }")

        jscContext.exceptionHandler = { (ctx: JSContext!, value: JSValue!) in
            Logger.error("JS ERROR: \(value)")
        }
        
        var script = "function foo10000() {" +
            "  for(var i = 0; i<100000; i++) {" +
            "    global.log('foo');" +
            "  }" +
        "}"
        self.jscContext.evaluateScript(script)
        
        var arrayScript = "var byteArray = new Uint8Array([0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1])"
        self.jscContext.evaluateScript(arrayScript)
        script = "function copyArray10000() {" +
            "  for(var i = 0; i<100000; i++) {" +
            "    global.copyArray(byteArray);" +
            "  }" +
        "}"
        self.jscContext.evaluateScript(script)
        
        arrayScript = "var byteArrayPre2 = new Uint8Array([0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1])"
        self.jscContext.evaluateScript(arrayScript)
        script = "function copyArrayPre210000() {" +
        "  for(var i = 0; i<100000; i++) {" +
        "    copyArrayPre(byteArrayPre2);" +
        "  }" +
        "}"
        self.jscContext.evaluateScript(script)
        
        
        arrayScript = "var byteArrayPre = new Uint8Array([0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1])"
        self.jscContext.evaluateScript(arrayScript)
        
        script = "function copyArrayPre10000() {" +
        "  for(var i = 0; i<100000; i++) {" +
        "    copyArrayPre(byteArrayPre);" +
        "  }" +
        "}"
        self.jscContext.evaluateScript(script)
    }

    override func tearDown() {

    }

    func testPerformanceEmpty() {
        self.measureBlock()  {
            for _ in 1...100000 {
                self.jscContext.evaluateScript("emptyMethod();")
            }
        }
    }

    func testPerformance() {
        self.measureBlock() {
            for _ in 1...100000 {
                self.jscContext.evaluateScript("foo();")
            }
        }
    }

    func testPerformance2() {
        self.measureBlock { () -> Void in
            self.jscContext.evaluateScript("foo10000();")
        }
    }

    func testCopyArrayPerformance() {
        // Increase the size of array from 8 to 15 and the time increased by about 40%

        // 8 elements array: 0.102 sec
        // 16 elements array: 0.146 sec
        self.measureBlock { () -> Void in
            self.jscContext.evaluateScript("copyArray10000();")
        }
    }

    func testCopyArrayPreAllocatePerformance2() {
        // Increase the size of array from 8 to 15 and the time increased by about 40%

        // 8 elements array: 0.102 sec
        // 16 elements array: 0.146 sec

        // 64 elements?
        self.measureBlock { () -> Void in
            self.jscContext.evaluateScript("copyArrayPre210000();")
        }
    }

    func testCopyArrayPreAllocatePerformance() {
        // Increase the size of array from 8 to 15 and the time increased by about 40%

        // 8 elements array: 0.102 sec
        // 16 elements array: 0.146 sec
        self.measureBlock { () -> Void in
            self.jscContext.evaluateScript("copyArrayPre10000();")
        }
    }
}