Profiler: Simple Profiling Example
+ +This example shows basic usage of the Profiler for profiling a single function. A single function is +profiled and all of the information displayed.
Simple Profiling Example
+ +This example begins by creating a namespace:
+
Y.namespace("example.profiler");
This namespace serves as the core object upon which others will be added (to prevent creating global objects).
+Next, an object is created with a method:
+
//object with method to profile +Y.example.profiler.MathHelper = { + factorial : function (num){ + if (num > 1) { + return num * MathHelper.factorial(num-1); + } else { + return 1; + } + } +};
This object, MathHelper contains a single method called factorial() that computes the
+factorial of a given number. Any time factorial() is called, the argument indicates how many times
+the function will be recursively called. For example, factorial(10) results in the funtion being
+called 10 times. This makes it an ideal test case for profiling because the results are so predictable.
Registering the function
+The most important step to profile this function is to call registerFunction() with the fully-qualified
+function name, which is Y.example.profiler.MathHelper, and the object:
Y.Profiler.registerFunction("Y.example.profiler.MathHelper.factorial", Y.example.profiler.MathHelper);
Since this function is not fully accessible in the global scope, the owner object must be passed in +as the second argument.
+ +Running the example
+ +With everything setup, the last step is to run the code. This initialization is assigned to take place when the DOM has been loaded
+by using the "domready" custom event:
Y.on("domready", function (){ + Y.example.profiler.MathHelper.factorial(10); + + var calls = Y.Profiler.getCallCount("Y.example.profiler.MathHelper.factorial"); + var max = Y.Profiler.getMax("Y.example.profiler.MathHelper.factorial"); + var min = Y.Profiler.getMin("Y.example.profiler.MathHelper.factorial"); + var avg = Y.Profiler.getAverage("Y.example.profiler.MathHelper.factorial"); + + Y.Profiler.unregisterFunction("Y.example.profiler.MathHelper.factorial"); + + var msg = "Method Y.example.profiler.MathHelper was run " + calls + "times. +" + + "The average time was " + avg + "ms. +" + + "The max time was " + max + " ms. +" + + "The min time was " + min + " ms."; + alert(msg); +});
The code block begins by calling factorial() once, which gets profiled. Then, the information
+about the function can be retrieved from the Profiler. This information is output in an alert,
+displaying the number of times that the function was called along with the minimum, maximum, and average
+running times. Since this is a very simple function, the run times will most likely be 0ms on most machines.
