dgoyani is blogging !!

Measuring performance: Dictionary Vs If Else

2010-06-01T04:52:00.000-07:00

Mark Needham from Thought Works has recently blogged about using Dictionary instead of If Else statements. The usage of If Else is very common in similar situations however as number of scenarios grow things can become night mare. And at some point of time you have to think about some smart approach such as the one mentioned by Mark.

At first, I thought making entire logic dictionary based may impact performance because of key lookup calls. And that motivated me to write a sample script to verify my understanding. Along with the two approaches, I was also interested to know performance implications using Switch statement. For such quick performance tests, I really love playing with Stopwatch class.

I run the test 1k times and am very happy with the results I got. Along with better readability and maintainability, you get little bit of performance improvement as well. It’s win-win from all the sides. Such tests may seem trivial but it implant solid craftsmanship towards clean code.

Results (in ms):
Using If Else > 1130
Using Switch > 1057
Using Dictionary > 1062

Thanks!
Dhananjay

Smart Data Transfer Object

2010-05-20T05:22:00.000-07:00

Too often it happens when you work on distributed application that you communicate too many times to fulfill a single request. As in any network communication actual data transfer (serialization, compression, transfer over wire, decompression, deserialization, etc) is just one part and other network protocol activities also expense you nicely. You always want to minimize number of calls to the server by fetching all data that you require at once and in result better overall responsiveness.

In one of the web project, we had to present navigation tree on the left side. The tree nodes were populated based on authorization and node attributes such as Hidden, etc. Initially, when we started with implementation we simply fetched nodes using SELECT N+1 method. That was easy and simple. But as no. of nodes got increased, we started experiencing delayed response.

So then we come across DTO pattern and using my own efficient n-level hierarchy traversal method we fetched all tree nodes at once to be sent to the client. But then this approach has contradicted with Split the initial payload guideline (its written for web UI for good for any presentation layer) and lazy loading (loading only if required).

As to solve second round of problem, we limited traversal depth level to 3. That not just reduced number of calls to server (and conforming with DTO) but also increased initial response. At max, however it is not limited, we had depth level of 5 so once the application is loaded client only had to make two more calls to reach to the node at fifth level. Well, I think that is acceptable.

To further optimize, may be we can think of expanding entire sub-tree when client explicitly ask to drill down for a given node. It just works for us and thought to share with you.

Thanks!
Dhananjay

Do you buy Abstraction?

2010-05-10T22:55:00.000-07:00

If your answer is NO, go and read below paragraph from The Gu. He answered people questioning ASP.NET MVC on the ground of abstraction. Check his complete post.

I always find it somewhat ironic when I hear people complain about programming abstractions not being good. Especially when these complaints are published via blogs – whose content is displayed using HTML, is styled with CSS, made interactive with JavaScript, transported over the wire using HTTP, and implemented on the server with apps written in higher-level languages, using object oriented garbage collected frameworks, running on top of either interpreted or JIT-compiled byte code runtimes, and which ultimately store the blog content and comments in relational databases ultimately accessed via SQL query strings. All of this running within a VM on a hosted server – with the OS within the VM partitioning memory across kernel and user mode process boundaries, scheduling work using threads, raising device events using signals, and using an abstract storage API fo disk persistence. It is worth keeping all of that in mind the next time you are reading a “ORM vs Stored Procedures” or “server controls – good/bad?” post. The more interesting debates are about what the best abstractions are for a particular problem.

Thanks!
Dhananjay

SQL Object Search made easy!

2010-02-04T21:13:00.000-08:00

Ever since I developed DB Search Util back in 2006, it has made my life lot easier. I was trying to find a string instance in different tables and was literally clueless. Out of frustration for those two days, I decided to play with SQL system tables and figured out how tables and their schemas are stored. Next thing was quite simple as I just had to query the table to see if particular string instance exist in the row set or not. Obviously there were technical challenges but were trivial, to be honest.

Since then this tiny utility become popular among Altiris (now Symantec) people at Cybage and there is nothing more satisfying to know that the utility is being introduced in SMP sessions for new comers.

Even though, I am consciously aware about weaknesses of the tool, I have never stretched myself to developed those extra bits. Biggest among them is an ability to search for SQL Object names itself rather than data. I don’t know if I would do that but recent announcement from red-gate has filled the gap. Give it a try and please yourself when you try to find objects out of 500+.

http://www.red-gate.com/products/SQL_Search/index.htm

Note: For legal purposes I can’t show code snippet of the DB Search Util. However the first paragraph is enough and won’t take more than 6 hours to develop.

Thanks!
Dhananjay

Are you worried over cross IE browser support?

2009-09-23T23:39:00.000-07:00

If you are migrating your web application developed for IE6/IE7 to IE8, you know involved pain as much as I do. There are lot of things you have to tweak – and the list is not limited to CSS, JS or DOM. In a recent development where in my job was to support IE8 in native mode without breaking IE7 – I was heavily dependent on IETester. However that is more helpful towards rendering, CSS and DOM. So, as to get final picture I managed multiple VMs running different flavors of machines combining operating systems and browsers. This is again not so easy and full of hurdles.

Finally, today I noticed Microsoft announcement on Microsoft Expression Web SuperPreview. I have just downloaded it and checking how much it would be helpful. This tool announcement makes more sense to me because it’s from IE manufacturer – Microsoft.

Thanks!
Dhananjay

Make sure to check DOLOTO against your web 2.0 sites

2009-09-09T05:10:00.000-07:00

DOLOTO was been eagerly awaited by community for more than a year. The technique to optimize AJAX based applications named - Spitting the initial payload interested many but there was no formal tool to automate that. And most of the time people have to do that manually.

DOLOTO is brain child of Microsoft Research and more information along with installer can be found at below location. The idea is still fresh and you may want to share your results to “dolotofb at microsoft dot com”.

DOLOTO: Download time optimizer for Web 2.0 apps

Thanks!
Dhananjay

Are you jing?

2009-07-10T02:27:00.001-07:00

One of the most wonderful free tool I have ever come across – “the Jing”. Capture, Save & Share is what the mantra of Jing team. I am listing few important features that would interest you.

Jing Screen capture:

Capture screens and decorate it in one go.
Very rich image edit tool will allow you to put text, arrows, boxes, etc.
The editing tool is far better than any other including MS paint and it has just required things.

Jing Video capture:

Capture screen happening as much as you want
Save the entire video and share with your colleagues
It saves in SWF format so that you can view the video on any machine.

I would recommend this tool to any QA and Dev who want to communicate anything visually. Many a times, Dev complain about exact steps for any defect reproduction and then QA carry them to their desk to show the steps. This tool can capture your steps so that you the QA or Dev just have to send the SWF and you are done.

I played with the tool for some time today and found that it has all the power to put you in a great comfort. Check the below link.

Link: www.jingproject.com

Thanks!
Dhananjay

Rich set of .NET services for Rich client

2009-07-01T04:42:00.001-07:00

Starting from static web pages (.HTML, .HTM, etc) to dynamism with server scripts (.asp, .jsp, etc) to OO enabled server scripts (ASP.NET) to powerful client applications (ASP.NET + AJAX), THE web has already stepped into rich model of first class web applications delivery to end users.

Making the client rich alone will not work. And that is where .NET RIA services comes into play. There is a nice introductory page released recently, which will clear all your questions and give very good understanding of overall picture.

Getting started with the .NET RIA Services

Thanks!
Dhananjay

Refactoring catalog

2009-07-01T02:05:00.001-07:00

Refactoring is important part of Agile methodology. As they say no code is ever complete and there is a good scope of improvement. As most of my work experience include traditional SDLC models, I always refrain myself from accepting changes and if it becomes mandatory that goes as Requirement bug or Design bug if not change in requirement.

That was horrible.

That was painful too.

Now with Agile practice, you would say – well, I am open for any changes because my design supports that and importantly my mind too! Does that sound interesting to you?

OK, then there are people (Uncle bob, Martin fowler, etc…) who are ready to solve your problems. Being late in the Agile game, it is glad to see that there are tested patterns and practices that you can follow to ensure success in your software projects.

One of such practice they follow is Refactoring – continuous code improvement. Though it is de-facto in Agile, there is no wrong to practice it in other software execution models.

Definition of Refactoring as per martin fowler’s dedicated site:

Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. Its heart is a series of small behavior preserving transformations. Each transformation (called a 'refactoring') does little, but a sequence of transformations can produce a significant restructuring. Since each refactoring is small, it's less likely to go wrong. The system is also kept fully working after each small refactoring, reducing the chances that a system can get seriously broken during the restructuring.

Click on below links to find well researched articles to dig more.

Refactoring home page

Refactoring catalog page

Thanks!

Dhananjay

Stepping into Silverlight

2009-06-30T04:44:00.001-07:00

Recently, I have started exploring Silverlight 2 to replace existing ASP.NET traditional console to some extent with Silverlight. Well, actually I was going through many articles and web pages, but none other served me well than the below book. I am half way to complete the book and would like to recommend to anybody want to jump in the “expressive world of Silverlight”.

Title: Pro Silverlight 2 in C# 2008
Author: Matthew MacDonald

Thanks!
Dhananjay

Want to modify Active Directory objects?

2009-04-02T23:50:00.000-07:00

I can't believe I developed a full AD based application without using any tool as such. Recently I got to know about ADSI Edit tool from Microsoft. I would have solved lot of problems quickly with the help of this tool.

This simple utility can be heaven for anybody who wants to...

develop something using Active Directory; to find attributes and values.
test some of functionalities which are highly based on AD objects.
manage/edit AD objects, especially for IT professionals.

Check the link and get started.
http://technet.microsoft.com/en-us/library/cc773354.aspx

Thanks!
Dhananjay

SQL Server 2005 Error: Insufficient result space to convert uniqueidentifier value to char.

2007-10-27T00:14:00.001-07:00

I was trying to convert a uniqueidentifier column into varchar and stuck up with the "Insufficient result space to convert uniqueidentifier value to char." error message. The cause of the problem is I guess default size of varchar. The uniqueidentifier value which when converted to varchar needs atleast 36 characters which includes 32 characters and 4 dashes.

To come out of the error make sure to specify size of the varchar in convert function. Please see the below code for more details.

declare @var uniqueidentifier
set @var = '1D53379D-C97F-46C2-A22A-0003FA380460'
select convert(varchar(36), @var)
-- select cast(@var as varchar(36))

Thanks!
Dhananjay

C# look at IL - .NET disassembler

2005-09-26T23:58:00.000-07:00

While googling came across Lutz Roeder's .NET Reflector - truely .NET disassembler and thought to share it with you. Have a look at the below link for all tools by Lutz.

http://www.aisto.com/roeder/dotnet/

Thanks!

Dhananjay

Using SQL Cache Dependency in ASP.NET

2005-09-26T05:19:00.000-07:00

ASP.NET Cache is used to store static data across web sessions. But what to do when you want to update the Cache as and when SQL/Data changes. The below two articles focus on the same, have a look.

ondotnet.com
msdn.microsoft.com

Thanks!

Dhananjay

Effective way to expand data tree in SQL Server

2005-09-26T04:33:00.000-07:00

There are possibly many ways to expand nodes which are in parent - child relationship. This post focus on the most effective way to do it along with other possible solutions.

# Multiple round trip to server (worst case)
- Make an SP which returns all parent/child (whatever required) IDs
- From code call SP recursively untill you reach the end.

# Single round trip to server (thats what a better option - again not the best one)
- Make an SP which returns everything from the table.
- Just make your recurssion process in Business logic (.NET/Java) rather than T-SQL

# Without recursion (hopefully, the best)
Let's dig it out, Here is the story. I tried to solve the problem in most effective way using many ways including the above two. But no way could end up into success. I was looking for some logical way at SP end. Below is the table structure and the SP. SP comments would help you to understand it well. Just go through it, it's very easy. Also I would appreciate if you have the solution in some other way.

Thanks!
Dhananjay

Sample Table
CREATE TABLE [_Test_Hierarchy] (
[ID] [numeric](10, 0) IDENTITY (1, 1) NOT NULL ,
[ParentID] [numeric](10, 0) NOT NULL ,
[Name] [varchar] (255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL
) ON [PRIMARY]
GO

Stored Procedure
CREATE PROCEDURE Test_Expand -- Creates an stored procedure
(
@current NUMERIC -- The ID of which all childs are required
)
AS
DECLARE @LinesUpdated INT, @Level INT

SET NOCOUNT ON

SET @LinesUpdated = 1 -- It holds the value indicating number of rows inserted into temp table.
SET @Level = 1 -- used to identify the nodes for which we have already added childs.

CREATE TABLE #stack -- temporary table, you can add more columns as per your comfort.
(
ID NUMERIC,
Lvl INT
)

INSERT INTO #stack -- Insert the current node and set it's level to 1.
VALUES (@current, @Level)

WHILE @LinesUpdated > 0
BEGIN
SET @Level = @Level + 1 -- Every loop iteratation increast one level.

-- Here we need to focus on two criteria while shortlisting.
-- 1. Check all child nodes of the parents already stored into temp table - #stack
-- 2. A node already in the list, must not be repetated. That is why we kept Lvl = @Level - 1 condition. It always search for fresh nodes.
INSERT INTO #stack
SELECT t1.ID, @Level
FROM
_Test_Hierarchy t1,
(SELECT * FROM #stack WHERE Lvl = @Level - 1) s1
WHERE 1 = 1
AND s1.ID = t1.ParentID

SET @LinesUpdated = @@ROWCOUNT -- @@ROWCOUNT always holds last count of selection. Terminate the loop when no row added.
END

-- Its very simpe, you must be knowing...
SELECT t1.ID, t1.Name
FROM
#stack s1,
_Test_Hierarchy t1
WHERE 1 = 1
AND s1.ID = t1.ID

GO

Handeling server control event from page itself in .NET

2005-09-21T01:25:00.000-07:00

Let me define the problem statement. Say, we have address control having address1, address2, city, state and some other fields. This post answers to handle "save" button click event from page itself. You already have the event handler on control code behind, but to handle it from main page (where your control resides) is a bit tricky. Here is a step by step guide for a newbie who want to create server control and would like to wire events.

> Declare an public event in to your control, like...
public event CommandEventHandler SaveCommand;

> Add btnSave click event handler, and also the defination...
btnSave.Click += new EventHandler(btnSave_Click);
private void btnSave_Click(object sender, EventArgs e)
{
Button button = sender as Button;
if (button != null)
{
CommandEventArgs args = new CommandEventArgs(button.CommandName, button.CommandArgument);
OnSaveCommand(args);
}
}

> Add OnSaveCommand function...
protected virtual void OnSaveCommand(CommandEventArgs e)
{
if (SaveCommand != null)
SaveCommand(this, e);
}

> Now you can have the event handler in your page. Just click on control from page, add your code...
private void AddressControl1_SaveCommand(object sender, System.Web.UI.WebControls.CommandEventArgs e)
{
// my code..
}

Thanks!

Dhananjay

Refrencing the Root Path/URL in .NET

2005-09-16T05:12:00.000-07:00

A common question from newbies is "How can I reference the root path of my application from controls?". It is common for many server side controls to have properties such as src (source) and hyperlinks/URL etc. ASP.NET has a neat syntax that you can use to reference the root of the applications directory in any server-side controls URL property. This syntax will relief you of having to place relative pathis in your apps directory hierachy.

Simply prefix the path with the ~ (tilda) character. During the compilation process of the server-side control, ASP.NET will translate that ~ into Request.ApplicationPath.

An example would look like img src="~/images/logo.gif" runat="server". Keep in mind that this will work for SERVER-SIDE controls only!

Thanks!

Dhananjay

Skip prerequisite while installing .NET 2003

2005-07-26T21:46:00.000-07:00

Many times .NET 2003 installation fails due to some known / unknown reasons. And while installing it again it might ask you to install prerequisite first even though you have already installed it. You would become confused why it asks me again and again to install prerequisite. Possibly because of installation failure it might have updated wrong registry entries.
The possible solution is...

Go to Start > Run. And write following command line to run the setup file.
G:\setup\setup.exe /NO_BSLN_CHECK

And you are done! It won’t ask you to install prerequisite any more...

Thanks!
Dhananjay

How to retrieve the identity-id of last inserted record in ms sql server ?

2005-06-03T23:43:00.000-07:00

In many cases you might require to read back auto-generated id after insertion, specially when you want to use the id as foreign key into other table.

Let's have an example to understand it well.
Table: Users ( UserID - Autogenerate id, UserName, LastName, Address )
Composite key = UserName, LastName, Address

Now, after an insert statement you would like to know the value of UserID. Have a look at the solutions

Method: 1
insert into Users(UserName, LastName, Address) values('Hello', 'world', 'Blabla !')
select userid from users where UserName = 'Hello' and LastName='world' and Address='Blabla !'

Method: 2
MS SQL Server provides set of global variables for different users. Instead of method 1, i would go for the one below...
insert into Users(UserName, LastName, Address) values('Hello', 'world', 'Blabla !')
[ select @@identity ]
[ select * from Users where id = @@identity]
[ set @localVarible = @@identity ]
[ return @@identity ]

@@identity holds last inserted record's unique auto-generated id. If your insert statement fails to execute, @@identity holds null.

Thanks!

Dhananjay