Friday, September 30, 2005

measuring elapsed time for blocks of code (Delphi version)

in a production application quite often is nice to see how long each part of the program takes, i.e. you have an application that performs an operation on a database, then on some files, is nice (and useful) to see something like:

db access time: 120ms
file creation : 420ms

if you didn't have that information, and your program one day started working slow (perhaps after a Windows update), you would have no idea where the problem is, but by adding this small feature to your program, you know where you should focus to solve the problem:

db access time: 15000ms
file creation : 420ms

now, to create this information you tipically need to declare some variables:

DBLastTime:Cardinal; //stores the last time it took for this operation
DBTotal :Cardinal; //a sum of all the time it has taken
DBCount :Cardinal; //how many times the operation has been executed
DBAvg :Real; //average time for this operation (unless you wanted to calculate it every time)

I have seen countless times when developers start adding a set of those 4 variables for each operation that they want to measure on the application, and not only that, but also add code to capture the times:

SomeOperation; //
Inc(DBTotal, DBLastTime);
DBAvg:=DBTotal div DBCount;


this greatly bloats the code and makes it hard to see what the intent was, when all it is, is duplicated code, for such simple task

my approach is as follows:

I create a structure to store all the required values for an operation:

TTimeRecord = record
Total :Cardinal;
Count :Cardinal;
Avg :Real;

I have some constants:

TR_OPEN_DB = 0; //time it takes to connect to the database
TR_MOVE_ZIP = 2; //time it takes to move one zip


I declare an array of those structures

TimeRecords : array[0..TR_MAX_SITES-1, 0..TR_MAX_TR_COUNTS-1] of TTimeRecord;

on this example this is a bidimensional array, that I use to have counters on the same operations for both a local and a remote sites

by using those constants you an easily extend your code to add another operation that you want to measure

then I have these 2 functions to do all the "dirty" work:

procedure OpenTime(var timeRecord:TTimeRecord);

procedure CloseTime(var timeRecord:TTimeRecord);
Inc(, timeRecord.lastTime);
timeRecord.Avg:=timeRecord.Total div timeRecord.Count;

and the code is simplified to:



of course you could go further and make this a class or a component, where you specify which controls are updated with the values, etc... but the idea here is to simplify a task

I hope you can use this technique, I'll post the C# version soon, that version should make things even easier, because we can use Static Classes there

Friday, September 23, 2005

what's new in Excel 12? more rows!

one of the most requested features of all times to MS Excel was to have more rows/columns, with the next version of Microsoft Office 12 products, Excel will have 1,048,576 rows by 16,384 columns

I wonder how long this will be enough

check the Excel blog here for more features coming in Excel 12
Creating a complete login screen in ASP.NET 2.0

Visual Studio 2005 has a series of controls for common tasks, like login, user creation, etc,
for example the login control makes it very easy to create complete login pages with a "create user wizard" page, without writing a single line of code, you just drop a login control and you get the appropiate labels, a text box for the login name, another text box for the password, even labels that indicate that you entered the wrong password, and of course you can change the text in any of those, or change the style by using CSS.
The login control can connect to any datasource (SQL, XML, etc) where you store the users/passwords, everything that you do today to create a login page, is already built-in in a single control, you get all that in a single control that has properties like DestionationPageUrl, that you use to redirect the user when it has been authenticated

check the video that shows all this:
Building a quick lookup screen in .NET 2.0

check this out:

nice!!... just like the ones Delphi has had for the last 10 years

Thursday, September 22, 2005

Windows Vista: Clarity in the user interface

you have to download this video and check this feature of Windows Vista, is awesome

Windows Vista: Clarity in the user interface
on passwords...

I don't know about you, but my passwords already have those =o)

Tuesday, September 20, 2005

googlebombing "failure"

a few days ago it was noted that if you enter "failure" or "miserable failure" in google and hit "I'm feeling lucky" you get the Biography of President George W. Bush, some people started saying that it had some political connotations from google. Then google replied in their blog that the cause of this was a googlebombing and they explain how this works, I quote from their blog:

Pranks like this may be distracting to some, but they don't affect the
overall quality of our search service

so nobody else is using this technique to get their site to the top right?
seems like google is broken, welcome to being #1