How fast is my code?
How fast is my code?
By Michiel van Otegem
20 June 2001
It's very important to know how fast your code, or part of it, runs. It makes it easier
to see which operations have to change, to handle many users on your site. Even though speed measurement is no
replacement for testing under (heavy) load, it could help you during the developement of an application to identify and
correct bottlenecks in advance. For real robust tests you should use a stress-tool like the
Web Application Stress Tool.
There are several (COM) objects to measure speed, like
Profiling Component 1.1.
These components are more accurate then time measurements with script. Reason for this is that time measurement
on the basis of script is dependent on the internal clock of the computer, which works on the basis of an interval
every 55 milliseconds. Your measurement will therefore only be accurate to 55 milliseconds.
The code below shows you how to measure with VBScript and JScript:
metervbscript.asp
<%
Option Explicit
Dim Starting point
Dim i
Starting point = Timer
For i = 1 To 1000
Response.Write("Do something!")
Next
Response.Write("execution time: " & (Timer - Starting point) & " seconds")
%>
meterjscript.asp
<SCRIPT LANGUAGE=JScript RUNAT=Server>
function measuring point() {
var d = new Date();
return d.getTime();
}
var starting point = measuring point();
for(var i=0; i < 1000;i++) {
Response.Write("Do something!");
}
Response.Write("execution time: " + (measuring point() - starting point) + " milliseconds")
</SCRIPT>
If you test this script you'll see the text "Do something!" a 1000 times and after that a mention of the number of
milliseconds the script took to execute. If you refresh it a couple of times, you'll see the time isn't
always the same. So you'll have to execute it a couple of times and take an average to get a good idea
of the speed. Be aware that the script has to be loaded and compiled into the server memory at least once.
The second time the script runs, this probably won't be necessary and will therefore be a bit faster.
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