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Phases in life of a “software developer”–Types of developers! Who am i?

2011-09-12T08:36:00.001-07:00

Do you call yourself developer? If so, where exactly do you stand in the following table? Following table peeks into the “professional” life of a software developer

	Wannabe Developer	Developer, as a profession	Senior developer	Principal developer	Architect	Chief architect
Question	Level 0	Level 1	Level 2	Level 3	Level 4	Level 5
Changes?	Copy pasting code, trying to merge; doesn’t know/care about changes	Very resistant to change; spaghetti code.	Ok to change, but provides no suggestions; tries to follow coding standards.	Ok to change, provide suggestions, brainstorm;, finds alternate solutions;	Accept changes, provide alternate solutions, face mortar board	Brings change
Thought process?	Not available (0:	Doesn’t think	Thinks about how;	Following industry standards and practices.	Provide feedbacks, comments, corrections	Build industry standards
Sticks around		Functional/method level implementation; coding	Available libraries, classes,	Reusable components	Thinking process is more in terms of business strategy; provides solutions; face mortar board, provide alternate solutions, answer any missing questions	Mortar board; business, technology
Inclines toward	Coder; coding	Classes	Modular	how; componentized approach	what; enterprise approach	why; business market
Goal	To go home	Learning	Advancement, participation,	Think around technology	Thinks around scalability, availability, modularity, loose coupling high cohesion, security, etc.	Thinks around business strategy

High light the first row of the table above, to see exactly where you stand.

Btw, no offense to anyone, these are just thoughts out of small experience that I have.

Enjoy! (0:

Are you sure you want to move to gulf? Think again!

2011-07-30T05:58:00.001-07:00

Yep, if you are moving to gulf(Dubai) from Pakistan (Karachi), it(the process) sounds like you are placing an order for a double cheese burger with diet coke!

What is the process?

S. No.	Steps	Duration (Days)	Fee (PKR)	Comment
1	Get passport	7	4200
2	Get attested degrees	5	6700	HEC + UAE Consulate (PKR1200 + ~USD45)
3	Send to employer for visa	1	0
4	Receive passport/visa	20	0	~Keep 3/4 weeks of time; better resign only when you receive your visa
5	Get NICOP	7	1500	USD 25? @PKR86 (PKR 3000 for urgent); besides NIC
6	Obtain ticket with OK-TO-BOARD	2	21000	Get the ticket agent that is close to your place; they usually charge 6% of the ticket charges
7	Get protector stamp	1	6700	Very cumbersome process if you DIY
8	Shop	3	25000	If you must, must you should
9	Prepare to fly	1	0	Checkout the checklist that, if you may need
	TOTAL	47	65100

STEP 1: How to prepare/renew Pakistani passport?

Process:

Day 1: Get bank Challan from the National Bank that is inside Passport office, Saddar (PKR4100 Fee + PKR25 Service Charges = 4125 (as of today) – FastTrack ~5 days)
- Requires:
  1. Old passport
  2. NIC
  3. NIC of one of your parent

Note that, if you are going for a brand new passport, they will ask you for the educational transcripts; so, inquire before you leave your place for passport office

Day 2: Submit application (if you have time, and patience, you can continue this on the Day1 – but trust me, you wouldn’t want to afford that if you are with you family)
Day 7: Collect passport (~next week sometime)
- Requires:
  1. NIC

Location:

Passport office, Saddar, Karachi

References:

Directorate General of Immigration & Passports, Ministry of Interior, Government of Pakistan

STEP 2: How to get the educational documents (degree/transcripts) attested?

Process:

Day 1: Attestation from HEC (Use OCS Courier Service, PKR1200/-) ~5 days. Any OCS close to your place.
- Requires:
  1. HEC requires Matriculation/Intermediate marksheets, and certificates to be attached as well, besides your University degrees
Day 6: Attestation from Foreign Ministry (Submit PKR25/-) ~2 Day process. This is right beside the FTC (Finance and Trade Center), Sharah-e-Faisal road.
- Requires:
  1. Degree attested by HEC
Day 8: Attestation from UAE Embassy (Use Bokhari Travels, USD40/- per document) ~1 day if you are willing to pay USD60/- for urgent service, otherwise USD40/- ~4 working days.
- Requires:
  1. Degrees attested by HEC + Foreign Ministry

Location:

For HEC, use nearest OCS
Foreign Ministry, right beside FTC, Shahrah-e-Faisal
For UAE Consulate, go to Bokhari Travels that is on main Punjab Chowrangi

References:

STEP 3: How to get NICOP (National Identity Card for Overseas Pakistanis)?

Please don’t ask why, it is necessary, because I don’t have the answer to that; I wonder about the reason of having multiple identifications, NIC, NICOP, Passport, and what not – for a single reason!

Process:

Somewhat similar to when filing for an NIC

Issuance of Token
- Requires:
  1. Birth Certificate —OR—
  2. Old NIC —OR—
  3. Matriculation Certificate —OR—
  4. CNICs of immediate relatives —OR—
  5. Passport (mandatory in case of new)
Photo capturing
Thumb and Signatures
Data Acquisition by DEO
Form Printing
Attestation & Form Submission

Location:

Any NADRA office close to your place

References:

National Database & Registration Authority (NADRA)

STEP 4: How to get OK-TO-BOARD stamped on my visa copy?

Process:

Get ticket
Send your ticket/itinerary details to your employer, and ask them to apply for the OK-TO-BOARD message — OR—
- Requires:
  1. Ticket/itinerary details
Give you visa/entry permit copy to your ticket agent, and tell her to provide you with an OK-TO-BOARD stamp.
- Requires:
  1. Visa/entry permit copy

Note: Get ticket from Emirates. OK-TO-BOARD more streamlined; suggested by a friend. It would look something like following(see hand written OK-TO-BOARD in the highlighted red):

References:

STEP 5: How can I get protectorate stamp on my passport?

Who and why in the world would ever want it? This process/explanation might soothe your veins.

Process:

Provide documents on the protectorate counter; s/he will give you a bank challan copy to sign it
- · Requires:
  1. Passport with visa stamped
  2. NICOP or its receipt
  3. Offer letter
  4. Ticket with OK to board —OR—
  5. Attested offer letter by Ministry of foreign affairs in DUBAI

Note: You will need OK-TO-BOARD in any case, but you can’t get it stamped prior to departure.

Submit challan in National Bank, UBL Bank, and Habib Bank
Get photocopy of those challan on single page – not sure why its important, but it was asked with everyone
Attach the challan recepts with other documents, and arrange if you can, otherwise give it to the photocopy guy; he will do that for you.
Hand it over to the counter
If you are lucky, they will tell you collect after 2 hours; meanwhile you roam around the Shahrah-e-Faisal sidewalks, you can enjoy a newly open Biryani shop there. ~PKR60/serving;0)

Catch99: There is a tiny Photostat shop inside the protectorate office; give all of the documents to him, and he will do the job for you, just for PKR100/- no hassle.

I did it on my own, with the help of the people around, and I did all of it. Except for the arrangements of the documents in specific order. I did not know that – and that shop guy was not willing to disclose that to me; under pressure with small amount of time left in that “sarkari (read: government)” office, I decided to let him arrange that for a cost of PKR90/- Money wasn’t the issue, it was just that I wanted to do it myself, because documents were original and I wanted to avoid any last minutes shocks – or – apologies – so to say, that he has lost the documents/etc. Anyway, throw in the money, relax, and enjoy!

Notes

NICOP and protector can be done through the same office
Takes ~1 week to receive the NICOP for urgent service
You can apply for Protectorate based on the receipt of the NICOP

Location:

Protectorate Office is located on the street right behind KFC, Nursery, Shahrah-e-Faisal, Karachi

If you live somewhere near North Nazimabad, there is one more office, which I have not verified, which is near Nagan Chorangi behind Salim Center, PTCL Office; a service lane is going inside, after ~200 meters, you will find the office on the left. A friend pointed out.

References:

Bureau of Emigration & Overseas Employment, Government of Pakistan
WikiHow, Howto

How to think a unified design for multi device architecture?

2011-07-06T04:34:00.001-07:00

Couple of weeks ago, I responded to question of similar sort, and then I thought I must elaborate on this using actual code snips, that may help anyone looking for similar solution.

Problem statement:
Build an internet based application that should be able to:

Process the incoming requests
Get records available in the data store
Perform actions on that data

Most importantly, a non functional requirement is that, the request may come from multiple devices, for instance PC, Handheld device, iPhone, Windows Phone, Android, etc. This means, solution should have one core functional module (Unified Functionality); that would serve multiple device ends.

Simple? It is.

There could be several ways of achieving that; lets discuss couple ways, and then elaborate the implementation.

SOLUTION 1: Use WCF based RESTful service with App_Browser feature

Why? Because it is easy, tidy, and quick.

What is required to achieve that?

Mark the web service methods with WebGet attribute, and set the ResponseFormat parameter to WebMessageFormat.Json.

For instance:

[OperationContract]

[WebGet(UriTemplate = "/DoSomething?intSomeType={intSomeType}", ResponseFormat = WebMessageFormat.Json)]

Response DoSomething (Int32 intSomeType);

When the service is accessed RESTfully, it will return the data using the DataContractJsonSerializer. So you should JSONize(JSON Serialize) your POCO’s by marking it with the [DataContract] attribute and mark each serializable member as [DataMember].
Note that, this assumes that requests will only come from browser based user agent.

Also, the type hinting in WCF can add a lot of unnecessary overhead in the JSON response for large collections. Therefore, if you believe that you might want multiple types of end-points (SOAP, etc.) at some point in the time, then WCF is the way to go.

Easy? See! Let’s go through a demo app code right out of my pilot project.

Step 1: Write an interface that defines the basic operations that a mobile service will provide; and then provide an implementation of the interface:

[ServiceContract(Namespace = "izlooite.blogspot.services")]

public interface IMobileService

[OperationContract]

[WebGet(UriTemplate = "/ListBusinesses?intBusinessType={intBusinessType}", ResponseFormat = WebMessageFormat.Json)]

Response ListBusinesses(Int32 intBusinessType);

Step 2: Create WCF web service that implements IMobileService interface

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class MobileService : IMobileService
    {
        private NameValueCollection _params = null;

        public MobileService()
        {
            _params = null;
            if (HttpContext.Current.Request.HttpMethod == "POST")
            {
                _params = HttpContext.Current.Request.Params;
            }
        }

        public Response ListBusinesses(Int32 intBusinessType)
        {
            return new Response(AcknowledgmentStateSuccess, ConvertToString(Business.List(intBusinessType)));
        }



Step 3: Create a 

DataContract for a generic response:

[DataContract]
    public class Response
    {
        private AcknowledgmentState _ack;//custom types
        private List _errors;
        private Object _result;

        private void Initialize(AcknowledgmentState ack, List errors, object res)
        {
            _ack = ack;
            _errors = (errors == null) ? new List() : errors;
            _result = (res == null) ? "" : res;
        }

        public Response()
        {
            Initialize(AcknowledgmentStateCustom, null, null);
        }

        public Response(object res)
        {
            Initialize(AcknowledgmentStateSuccess, null, res);
        }

        public Response(AcknowledgmentState ack, object res)
        {
            Initialize(ack, null, res);
        }

        public Response(AcknowledgmentState ack, Error error, object res)
        {
            List errors = new List(1);
            errors.Add(error);
            Initialize(ack, errors, res);
        }

        public Response(AcknowledgmentState ack, List errors, object res)
        {
            Initialize(ack, errors, res);
        }

        [DataMember(EmitDefaultValue = true, IsRequired = true)]
        public AcknowledgmentState Ack { get { return _ack; } set { _ack = value; } }

        [DataMember(EmitDefaultValue = false, IsRequired = false)]
        public List Errors { get { return _errors; } set { _errors = value; } }

        [DataMember(EmitDefaultValue = false, IsRequired = true)]
        public Object Result { get { return _result; } set { _result = value; } }
    }

Step 4: Create a business class that takes in the type of business, and respond with a list.

Step 5: Configure and then use the App_Browser, MOBILE.BROWSER class file

private static List List(int? businessType, int count)
        {
            List businessList = new List();

            if (count > 100)
                count = 100;

            EnumBusinessType enumBizType = EnumBusinessType.UNKNOWN;
            try
            {
                if(businessType != null)
                    if(businessType > 0)
                        enumBizType = (EnumBusinessType)Enum.ToObject(typeof(EnumBusinessType), businessType);
            }
            catch { }

            using (NorthwindDataContext dc = new NorthwindDataContext())
            {
                var records = dc.Businesses.Select(b=> b);
                
                if(enumBizType != EnumBusinessType.UNKNOWN)
                    records = records.Where(b=> b.TypeID == businessType);

                if (!string.IsNullOrEmpty(prefix))
                    records = records.Where(b => b.Name.StartsWith(prefix.Trim()));

                records = records
                            .OrderBy(b => b.Name)
                            .Take(count);

                foreach (var rec in records)
                {
                    businessList.Add(new MyBusinessContract(rec.ID, rec.Name));
                }
            }
            return businessList;
        }

Note that App_Browser is a feature that lets you *tweak* the way user interface is rendered based upon different devices. Its an xml based file, that uses xml to format the user interface presentation.

From MSDN:

Browser definition files contain definitions for individual browsers. At run time, ASP.NET uses the information in the request header to determine what type of browser has made the request. Then ASP.NET uses .browser files to determine the capabilities of the browser. ASP.NET control adapters can use this information to adapt the behavior of an ASP.NET Web server control depending on the type of device. For example, a server control might generate different HTML for a graphical browser such as Internet Explorer than it would for a mobile device.

I will add this .SLN on codeplex soon, ping me if I don’t. (0:

SOLUTION 2: WCF RESTful service with customized client applications

This means, separate client apps for separate devices, for instance Objective-C based app for iPhone, Silverlight based app for Windows Mobile. In this case, let’s get inside the core, and come up with a set of core functionality.

Lets decide, what the "Core" is? Or what the Core should be - what will be the functionality that Core will perform. Ideally, when we say Core, it essentially means, a layer that performs basic or atomic operations.

Over that Core you can wrap the device wrapper (IPhone, PC, etc) that builds a query to be sent to core, for instance, coming in from different device channels.

We can use WCF Data Service to constitute a data layer. And your core can perform business operations/etc, and communicate with the Data Service.

For instance:
1. Our core will performs core operations - for instance talking to Datalayer ; the Core will be a "library" that will perform basic operations:

Authentication
Authorization
Select records
Perform Action 1
Perform Action 2

2. A DeviceWrapper(DeviceAndriod, DeviceIPhone, DeviceWeb, etc), that wraps different devices.
The first thing that comes to mind, in this case, is a mixture of Factory and Builder pattern. Think about factory of Devices, and Builder pattern for types of views to be rendered on different devices.

3. TextRenderer, based upon the device settings, renders the text. Therefore, following will be the steps to implement:

Step 1: Write a core that will provide authenticate/authorization; for instance, call the Core.Authenticate(), and .Authorize();
Step 2: Based upon the user agent call ICore.RenderView(agentType, url), this may return you the view/html to be rendered.

User may perform an action, your request may call Core.PerformAction(); which in turn may return the link to the page to be redirected, for instance.

Up till now, we were talking about Server side, which primarily is concerned with:

How the requests from different user agents will be processed by the server.
How the text will be rendered with respect to different devices.

Client ends could be:

A web browser, in this case you don't need any client app to be developed –OR–
A, let’s say, Silverlight app for Windows Phone –OR–
An android app for Android phone –OR–
So on so forth…

Decide what this "client app" will do. For instance:

User shall login
User shall be able to perform certain operations

Note that, these client apps will call the server side smartly (using web services, rather than asp.net web pages) in order to perform operations.

Top 6 ways to parse .CSV? High Performance!

2011-06-29T09:51:00.001-07:00

Sometime back a question was asked to develop a well performant parser– there was no restriction defined in the question whatsoever as to what technology, logic, flow/etc should be applied. Just the input block, and expected output result format, and maximum time that the parser may take.
This may answer questions:

How to query a .CSV and save the result in another CSV?
Custom .CSV Parser?
How to ETL .CSV into a .CSV
High performance .CSV parser

I found the performance requirement interesting, and so is the reason of this post; besides, another reason is to discuss only “some” of the solutions of the problem; therefore, it should be stated clearly in a question as to what exactly is required, just to save the the test’ee and tester from any after shocks. Though can have several solutions, but lets get into the details and see what do we have here. Following are important aspects of the problem.

Business requirement:

Calculate the usage of different country and dial codes for a particular customer, and write result in a separate file.

Functional requirement:

Read from CSV data source
Query for the data (select, group by, sum, count, etc)
Write into a separate .CSV file

Non functional requirement: (Performance)

Data source contains the ~1.2 million records, and the module is required to complete the whole procedure in less than 5 seconds.

Given that:

We have a CustomerData.CSV file already exists, to which we will query.

CustomerData.CSV has the following schema:

Columns	Description
Field 1	This field contains the customer id (sorted in ascending order)
Field 2	Country code
Field 3	Dial Code
Field 4	Start time
Field 5	Call duration

Result.CSV has the following schema:

Columns	Description
Field 1	Country code
Field 2	Dial Code
Field 3	Total duration (in minutes and seconds)

SOLUTION 1: (Use Jet OLE DB Text Driver)

Easiest, quickest, fastest, and very well performant!

Step 1: Define the following schema.ini file in some folder that you like:

If you would like, then look into the Schema.ini File (Text File Driver). Following content goes in schema.ini:

   1: [CustomerData.csv]   2: Format=CSVDelimited   3: CharacterSet=ANSI   4: ColNameHeader=False   5: Col1=customerId Text Width 20   6: Col2=countryCode Short Width 3   7: Col3=dialCode Short Width 3   8: Col4=startTime DateTime Width 15   9: Col5=callDuration Text Width 5  10: [result.csv]  11: ColNameHeader=False  12: CharacterSet=1252  13: Format=CSVDelimited  14: Col1=countryCode Short  15: Col2=dialCode Short  16: Col3=Expr1002 Float

STEP 2: Stub in the backend code in some .cs file

   1: private static void Query(string CustomerID)   2: {   3:     //Pseudo/logic:   4:     //Use jet ole db text driver to select * insert into new table;    5:     //to read-from a .csv, and write-into a .csv   6:     7:     string customerId = CustomerID;   8:     string writeTo = @"result.csv";   9:     string readFrom = @"CustomerData.csv";  10:    11:     //1: SELECT * INTO NEW_TABLE   12:     //2:  FROM SOURCE_TABLE   13:    14:     //dont just read, write as well.  15:     string query = @"  SELECT   16:                     countryCode, dialCode, sum(callDuration) INTO " + writeTo + @"  17:                 FROM   18:                     [" + readFrom + @"]   19:                 WHERE   20:                     customerId='" + customerId + @"'   21:                 GROUP BY countryCode, dialCode";  22:    23:     Stopwatch timer = new Stopwatch();  24:    25:     try  26:     {  27:         Console.WriteLine("Looking for customer: {0}, to export into {1}.", customerId, writeTo);  28:                   29:         string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\MyDocs\Software Test\;Extended Properties='text;HDR=No;FMT=CSVDelimited'";  30:         using (OleDbConnection conn = new OleDbConnection(connectionString))  31:         {  32:             OleDbCommand cmd = new OleDbCommand(query, conn);  33:             conn.Open();  34:             timer.Start();  35:             int nRecordsAffected = cmd.ExecuteNonQuery();  36:             timer.Stop();  37:             conn.Close();  38:         }  39:     }  40:     catch (Exception ex) { Console.Write(ex.ToString()); }  41:     Console.WriteLine("Time taken to read/write (ms):[{0}] ({1} secs)", timer.ElapsedMilliseconds, TimeSpan.FromMilliseconds(timer.ElapsedMilliseconds).Seconds);  42: }

Output:

SOLUTION 2: (Write a custom class, create indexes, and apply bisection search)

For instance, following code performs following operations to achieve the same:

Perform indexing on the selected column
Select specific records from the .CSV file
Perform aggregate function, call SUM() – Use LINQ

Usage:

   1: using (CsvParser parser = new CsvParser(@"E:\CustomerData.csv"))   2: {   3:     parser.PerformIndexing((int)CsvParser.CsvColumns.Col1_CustomerID);//One time only.   4:     5:     timer.Start();   6:     parser.Select("AMANTEL").Sum((int)CsvParser.CsvColumns.CallDuration);   7:     timer.Stop();   8:     9:     foreach (var o in parser.Result)  10:     {  11:         Console.WriteLine(string.Format("CountryCode:{0}, DialCode:{1}, TotalDurationOfCall:{2}",  12:                    o.CountryCode, o.DialCode, o.TotalDurationOfCall));  13:     }  14:    15: }  16: Console.WriteLine("Time taken to read/write (ms):[{0}] ({1} secs)", timer.ElapsedMilliseconds, TimeSpan.FromMilliseconds(timer.ElapsedMilliseconds).Seconds);

Output:

Backend code:

   1: class CsvParser : IDisposable   2: {   3:     4:     public dynamic Result { get; set; }   5:     private string _fileName;   6:     private char _separator = ',';   7:     private Dictionary<string, Bounds> _lstIndex = new Dictionary<string, Bounds>();   8:     private List<string> _Rows = new List<string>();   9:     public enum CsvColumns { Col1_CustomerID = 0, Col2_CountryCode = 1, Col3_DialCode = 2, Col4_StartTime = 3, CallDuration = 5 }  10:    11:     //Simple bound structure to hold start and end index in the file.  12:     class Bounds  13:     {  14:         public int Start { get; set; }  15:         public int End { get; set; }  16:    17:         public Bounds(int start, int stop) { Start = start; End = stop; }  18:     }  19:    20:    21:     //Default constructor  22:     public CsvParser(string file, char seperator = ',')  23:     {  24:         if (string.IsNullOrEmpty(file)) throw new Exception("Invalid file");  25:    26:         this._fileName = file; this._separator = seperator;  27:     }  28:    29:     /// <summary>  30:     /// Should be called once, before using the object;  31:     /// </summary>  32:     /// <param name="nColumn">Column to be indexed</param>  33:     /// <returns>Chained object</returns>  34:     public CsvParser PerformIndexing(int nColumn)  35:     {  36:         using (StreamReader reader = new StreamReader(_fileName))  37:         {  38:             string previousVal = string.Empty; string currentVal = string.Empty;  39:             int nStart = 0;  40:             int nEnd = 0;  41:             int nRowCounter = 0;  42:    43:             do  44:             {  45:                 currentVal = reader.ReadLine().Split(_separator)[nColumn];  46:    47:                 if (previousVal != currentVal)  48:                 {  49:                     if (!string.IsNullOrEmpty(previousVal))  50:                     {  51:                         nEnd = nRowCounter;  52:                         _lstIndex.Add(previousVal, new Bounds(nStart, nEnd)); //Add previous value  53:                         nStart = nEnd + 1;//next line  54:                     }  55:    56:                     previousVal = currentVal;  57:                 }  58:    59:    60:                 nRowCounter++;//next line  61:             } while (!reader.EndOfStream);  62:         }  63:    64:         System.Diagnostics.Trace.WriteLine(string.Format("Done. Total indexed {0}.", _lstIndex.Count));  65:         return this;  66:     }  67:    68:     /// <summary>  69:     /// Select rows where given customer id  70:     /// </summary>  71:     /// <param name="CustomerID">Customer id predicate</param>  72:     /// <returns></returns>  73:     internal CsvParser Select(string CustomerID)  74:     {  75:         using (StreamReader reader = new StreamReader(_fileName))  76:         {  77:             //1. Get location from index; also get the next index id so that we know where to stop.  78:             //2. Jump to that position  79:             //3. Start fetching  80:    81:             Bounds bounds = _lstIndex[CustomerID];  82:    83:             int nRowCounter = 0;  84:             while (!reader.EndOfStream || nRowCounter == bounds.End)  85:             {  86:                 if (nRowCounter >= bounds.Start)  87:                     _Rows.Add(reader.ReadLine());  88:    89:                 nRowCounter++;  90:    91:                 if (nRowCounter > bounds.End) break;  92:             }  93:         }  94:    95:         return this;  96:     }  97:    98:     /// <summary>  99:     /// Binary search 100:     /// </summary> 101:     /// <param name="data"></param> 102:     /// <param name="key"></param> 103:     /// <param name="left"></param> 104:     /// <param name="right"></param> 105:     /// <returns></returns> 106:     [Obsolete("Unused", true)] 107:     internal static int Search(string[] data, string key, int left, int right) 108:     { 109:         if (left <= right) 110:         { 111:             int middle = (left + right) / 2; 112:             if (key == data[middle]) 113:                 return middle; 114:             else if (!key.Equals(data[middle])) 115:                 return Search(data, key, left, middle - 1); 116:             else 117:                 return Search(data, key, middle + 1, right); 118:         } 119:         return -1; 120:     } 121:   122:     /// <summary> 123:     /// Provide SUM aggregate function 124:     /// </summary> 125:     /// <param name="nColumnID">by column</param> 126:     /// <returns>Chained object</returns> 127:     internal CsvParser Sum(int nColumnID) 128:     { 129:         var result = from theRow in _Rows 130:                         let rowItems = theRow.Split(_separator) 131:   132:                         group theRow by new 133:                         { 134:                             countryCode = rowItems[(int)CsvColumns.Col2_CountryCode], 135:                             dialCode = rowItems[(int)CsvColumns.Col3_DialCode] 136:                         } into g 137:   138:                         select new 139:                         { 140:                             CountryCode = g.Key.countryCode, 141:                             DialCode = g.Key.dialCode, 142:                             TotalDurationOfCall = g.Sum(p => p[(int)CsvColumns.CallDuration]), 143:                             selectedRows = g 144:                         }; 145:   146:         Result = result.ToList(); 147:   148:         return this; 149:     } 150:   151:     #region IDisposable Members 152:     public void Dispose() { } 153:     #endregion 154:   155:   156: }

Btw, far more interesting code would have been the following implementation:

parser .Select(Col1, Col2, Col3)
 .Where(Col1,"AMANTEL")
 .Sum(Col3);

Let me know if you can help me with that (0: Note that, I have not applied bisection search, yet; but the method is there.

SOLUTION 3: (Use TextFieldParser class)

Checkout this solution, but its a VB turned into C# solution. Let me know if you enjoy?

   1: using (var parser =   2:     new TextFieldParser(@"c:\CustomerData.CSV")   3:         {   4:             TextFieldType = FieldType.Delimited,   5:             Delimiters = new[] { "," }   6:         })   7: {   8:     while (!parser.EndOfData)   9:     {  10:         string[] fields;  11:         fields = parser.ReadFields();  12:         //Do something with it!  13:     }  14: }

SOLUTION 4: (Using LINQ to CSV)

Here is how.

SOLUTION 5: (Use XmlCSVReader, convert CSV to XML and use XPath to query the data)

How so? Here is the method.

SOLUTION 6: (Load .CSV in a database and use SELECT query to get result)

See Importing CSV Data and saving it in database; I hope you get the idea; ping me if you did not. Another, just as interesting A Fast CSV Reader is also there; this is interesting because it has benchmarks.

SOLUTION 7 (Bonus): (Use Text Driver with DSN)

Just to retrieve data, quick and easy.

   1: OdbcConnection conn = new OdbcConnection("DSN=CustomerData.csv");   2: conn.Open();   3: OdbcCommand foo = new OdbcCommand(@"SELECT * FROM [CustomerData.csv]", conn);   4: IDataReader dr = foo.ExecuteReader();   5: while (dr.Read())   6: {   7:     List<string> data = new List<string>();   8:     int cols = dr.GetSchemaTable().Rows.Count;   9:     for (int i = 0; i < cols; i++)  10:     {  11:         Console.WriteLine(string.Format("Col:{0}", dr[i].ToString()));  12:     }  13: }

Happy parsing!

Crystal Reports for VS2010 (v13.0.1)

2011-06-05T22:58:00.000-07:00

Download here. Also, checkout this discussion.

ASP.NET: Async calls vs threading

2011-05-30T06:43:00.001-07:00

This answers following questions:

How to improve performance?
Should I ever use Threading in ASP.NET?

How to improve performance of an ASP.NET MVC page that calls a database which takes a specific amount of time, and the results are then rendered on to an html page? This means, for instance, if 4 method calls takes 4 seconds, then target is, to improve the performance to 2 seconds for 4 database calls.

   1: string strReturnValue1 = CallDB("SomeStoredProcedureThatTakes1CompleteSecondToProcess1");   2: string strReturnValue2 = CallDB("SomeStoredProcedureThatTakes1CompleteSecondToProcess2");   3: string strReturnValue1 = CallDB("SomeStoredProcedureThatTakes1CompleteSecondToProcess1");

Takes exactly 3 seconds.

Move it inside a web service, and then call:

   1: yourWebServiceObject.CallDB +=  new CallDBCompletedEventHandler(CallDBCompleted); 

Define a handler:

   1: void CallDBCompletedEventHandler(object sender, CallDBCompletedEventArgs e)   2: {   3:     SomeLabel.Text += string.Format("Return value: [{0}]<br/>", e.Result);   4: }

Lets call it async'ly:

   1: yourWebServiceObject.CallDBAsync("SomeStoredProcedureThatTakes1CompleteSecondToProcess2");   2: yourWebServiceObject.CallDBAsync("SomeStoredProcedureThatTakes1CompleteSecondToProcess2");   3: yourWebServiceObject.CallDBAsync("SomeStoredProcedureThatTakes1CompleteSecondToProcess2");

Takes ~1 second.

How so?

The I/O thread(completion ports or IOCPs) use the ThreadPool, but they use IOCP, which do not interfere with ASP.NET requests. Therefore, you can safely use the asynchronous call to a web service, and update the page accordingly; for instance using UpdatePanel.

These web service asynchronous calls, uses IOCP behind the scenes, freeing ASP from essentially all of the burdens.

I could have done it using the thread pool as well?!

Usually, unless we want to parallelize a CPU-intensive operation in order to get it done faster, it is generally *not recommended* to use a worker thread; this eventually will starve the ThreadPool in an ASP.NET process by queuing too many work items.

Don't forget that you also use Reactive Framework in your ASP.NET app to do the job async'ly.

For instance,

   1: var o = Observable.Start(() => { CallDB    2:     3: ("SomeStoredProcedureThatTakes1CompleteSecondToProcess2"); Popup.Message("Done."); Popup.Show (); });   4: o.First();   // subscribe and wait for completion of background operation   5:     6:  

Takes ~1 second.

This and this a very interesting article targeted to performance as well as scalability gains in a web app.

Enjoy!

Is ‘jQuery vs Silverlight’-comparison even possible?

2011-05-20T00:40:00.001-07:00

Some "time" back, I was given a choice to decide between jQuery and Silverlight.

I did not delve into the discussion of what Silverlight is and what jQuery is. I just presented the solution, using jQuery for lightweight UI's, Silverlight if its intranet based.

First, please understand that Silverlight is not Macromedia Flash. It is far more superior, and elegant; -- and -- it has the "capabilities" of Flash.

[Image shamefully stolen from Silverlight/Javascript interop library :0) ]
Silverlight and jQuery "may be" intended for similar things, rich user interface, but Silverlight has a complete framework that utilizes the power of .NET and provide rich feature set.
Actually comparing jQuery and Silverlight feels like comparing a red-apple with one-hundred-acre'd-fruit-farm.

Ok, that may be indigestible example, but that's how it really is.

Silverlight comes with a framework, while jQuery is just a JavaScript library. JavaScript -- that is used to play around with DOM elements; meaning? Find and manipulate the html elements. It is just ~30KB in size.

So, how can you compare the two?
The only way you *can* look into the two is from the UI perspective, both can be used to develop Rich Internet Application(RIA); for instance, the data grid provided by Silverlight, and the data grid provided by jQuery. Obviously in that case, jQuery is lightweight. But then again, you might need to "extend" the jQuery data grid to your custom needs. Its JavaScript, so you've got your length and breadth to play around.
Also, you can use jQuery inside Silverlight app, but you cannot otherwise.

The only problem is that, Silverlight requires to be downloaded, similar to Macromedia Flash plugin, but once you download it, you're good to go. Plus, with MEF(Microsoft Extensibility Framework) it feels cool to "componentize" a Silverlight app and load modules on-the-fly and on-demand.

So, must if you choose between the two, go for jQuery if you are considering a web based line of business - lightweight and simple;

And if its a web application, which means, intranet based application for some corporate customer, you can always play with the Silverlight and its features. It can help providing native windows application on the web.

The questions that may help you reach a decision:

0. What feature set customer is looking for? What domain does it belong to? For instance, for a media company you might choose Silverlight UI for a web based app, rather than a jQuery.

1. Is your customer ok with Silverlight requirement on every pc of the network? This means, application will not work if the user has not installed Silverlight.

2. If your customer wants an extra-ordinary user experience; which includes rich interactive media, games, simulation, etc.

3. jQuery may be easier to get along if you already know Javascript, but Silverlight would require a learning curve, atleast of 4 weeks to "really" get along.

Here is an interesting answer posted; and if you’re a jQuery fan this will soothe your veins.

Enjoy, the silver light (0;

NHibernate – The Good, the Bad, and the Ugly, that it gets!

2011-04-30T13:35:00.001-07:00

A data access layer usually consumes 30% of the development time. A reasonable ORM can save you 90% of that 30% time. One such big hit is NHibernate.
Steps to use NHibernate:

Decide - Model first, Database first, or Code first
Create Mapping
Configuration
Query!

Pros:

Caching
Detached object
Concurrency
Interceptors
Batch processing
Attributes
Fluent Syntax
Database independency
Pretty mature, and large community
Open source
Model classes are POCO

Cons:

No visual modeler
Alot of mapping code that requires to be put into
Classes must have a no-arg constructor
Classes should have a private Long id;
Classes may have private database attributes
Clumsy mapping/configuration files

Note that, to handle mappings/configurations, Fluent NHibernate is there. Fluent NHibernate is not a replacement for NHibernate or LINQ but merely a helper library that helps you configure NHibernate in code rather than using XML files; Fluent NHibernate defines helper classes which significantly facilitate the task of providing the correct configuration.

No good LINQ to NHB! still under development – very, very young!
Stored procedures in NHB; challenging.
Increased startup time due to metadata preparation ( not good for desktop like apps)
Huge learning curve, especially for those having no ORM background.
Pretty challenging to fine-tune the generated sql. For instance, see following SQL:

   1: SELECT    this_.[CHEQUE_ID] as CHEQUE1_0_1_, this_.[CHEQUE_TYPE_ID] as CHEQUE2_0_1_, this_.[BATCH_ID] as BATCH3_0_1_, this_.[ENTRY_DATETIME] as ENTRY4_0_1_, this_.[STATE_ID] as STATE5_0_1_, this_.[MICR_AMOUNT] as MICR6_0_1_,    2:         this_.[CHEQUE_NUMBER] as CHEQUE7_0_1_, this_.[PHEONIX_REFERENCE_NUMBER] as PHEONIX8_0_1_, this_.[ACCOUNT_NUMBER] as ACCOUNT9_0_1_,this_.[ACCOUNT_TITLE] as ACCOUNT10_0_1_, this_.[BRANCH_CODE] as BRANCH11_0_1_, this_.[ENTITY_ID] as ENTITY12_0_1_, this_.[FRONT_IMAGE] as FRONT13_0_1_, this_.[BACK_IMAGE] as BACK14_0_1_, this_.[IS_LINKED] as IS15_0_1_, this_.[CHEQUE_AMOUNT] as CHEQUE16_0_1_,    3:         this_.[LINKED_CHEQUE_NUMBER] as LINKED17_0_1_, this_.[LINKED_ACCOUNT_NUMBER] as LINKED18_0_1_, this_.[LINKED_CHEQUE_AMOUNT] as LINKED19_0_1_, this_.[LINKED_BENEFICIARY_ACCOUNT_NUMBER] as LINKED20_0_1_, this_.[EXCEPTION_DESCRIPTION] as EXCEPTION21_0_1_, this_.[OWNER_VERIFIER] as OWNER22_0_1_, this_.[CUSTOMER_TYPE_CODE] as CUSTOMER23_0_1_, this_.[IS_STOPPED] as IS24_0_1_, this_.[IS_OVERDRAW] as IS25_0_1_, this_.[LOCK_DATETIME] as LOCK26_0_1_, this_.[DEPOSIT_BANK] as DEPOSIT27_0_1_, this_.[AVAILABLE_BALANCE] as AVAILABLE28_0_1_, this_.[LINKED_DEPOSITED_BRANCH] as LINKED29_0_1_, this_.[LINKED_CHEQUE_NAME] as LINKED30_0_1_, b1_.[CHEQUE_ACTIVITY_ID] as CHEQUE1_1_0_   4:         , b1_.[CHEQUE_ID] as CHEQUE2_1_0_, b1_.[ACTIVITY_TYPE_ID] as ACTIVITY3_1_0_, b1_.[Status] as Status4_1_0_, b1_.[REJECTION_REASON_ID] as REJECTION5_1_0_, b1_.[IS_OVERDRAW] as IS6_1_0_, b1_.[TRANSFER_AMOUNT] as TRANSFER7_1_0_, b1_.[Description] as Descript8_1_0_, b1_.[ACTIVITY_DATETIME] as ACTIVITY9_1_0_, b1_.[USER_ID] as USER10_1_0_, b1_.[ACCOUNT_NUMBER] as ACCOUNT11_1_0_   5:         , b1_.[UserId] as UserId12_1_0_ FROM [CPS_CHEQUE] this_ inner join [CPS_CHEQUE_ACTIVITY] b1_ on this_.[CHEQUE_ID]=b1_.[CHEQUE_ID] 

Hard to get session management right if used in non-typical environments ( read non webapps )
Not suited for apps without a clean domain object model ( no all apps in world dont need clean domain object models) .
Have to jump through hoops if you have badly designed ( legacy ) db schema.

You might find this interesting to know that, NHibernate is also marketed by the term “multi-database support”; this means, you *can* move from one engine to another (from SQL Server to Oracle); but this does not mean that you can connect to both the databases at a time. For instance, query from Oracle and save into the SQL Server; for this you will have to create another set of configuration file!

		ADO.NET	Nhibernate
Test #	Operation	Time (ms)	NH
1	100 Reads	000.609	000.859
2	100 Reads - 3 Joins	001.844	Couldnt apply 3 level join in HQL! ツ
3	100 Inserts	000.422	000.516
4	100 Updates	000.109	000.078
5	100 Reads - 1 Join	000.328	000.781

FIG1: ADO.NET vs NHibernate

Happy coding!

Persistent Dictionary

2011-04-19T00:53:00.001-07:00

Key Features:
A data structure implementation similar to Dictionary in .NET.
- Writes objects to file system to preserve the memory
- Hold keys/locations in memory
- Retrieves any object by passing key in less than five milliseconds
Output, with 10000 inserts/updates/deletes:

Memory profiling:

   1: using (CPersistentDictionary lst = new CPersistentDictionary(@"C:\persist.kkhan"))   2: {   3:     Stopwatch timer = new Stopwatch();   4:     5:     //1. Insert/update items   6:     7:     int threshold = 10000;   8:     timer.Start();   9:     for (int i = 0; i < threshold; i++)  10:     {  11:         lst.Add("Counter" + i.ToString(), i.ToString());  12:     }  13:     timer.Stop();  14:     Console.WriteLine("Items processed(add):{0}", threshold);  15:     Console.WriteLine("Time elapsed in (ms):{0}  ({1} secs)", timer.ElapsedMilliseconds, TimeSpan.FromMilliseconds(timer.ElapsedMilliseconds).Seconds);  16:    17:    18:     //2. Read items  19:     timer.Start();  20:     for (int i = 0; i < threshold; i++)  21:     {  22:         var o = lst["Counter" + i.ToString()];  23:     }  24:     timer.Stop();  25:     Console.WriteLine("Items processed(read):{0}", threshold);  26:     Console.WriteLine("Time elapsed in (ms):{0}  ({1} secs)", timer.ElapsedMilliseconds, TimeSpan.FromMilliseconds(timer.ElapsedMilliseconds).Seconds);  27:    28:    29:     //3. Remove items  30:     timer.Start();  31:     for (int i = 0; i < threshold; i++)  32:     {  33:         lst.Remove("Counter" + i.ToString());  34:     }  35:     timer.Stop();  36:     Console.WriteLine("Items processed(Remove):{0}", threshold);  37:     Console.WriteLine("Time elapsed in (ms):{0}  ({1} secs)", timer.ElapsedMilliseconds, TimeSpan.FromMilliseconds(timer.ElapsedMilliseconds).Seconds);  38:    39:    40:    41:     Console.ReadKey();  42: }

http://persistentdictionary.codeplex.com

CREATE TABLE FROM SELECT STAR

2011-04-18T00:46:00.001-07:00

This answers the questions:

How to create a new table(on the fly) out of a query result?
How to copy schema into a new table out of a query result?

SQL Server:

   1: SELECT * INTO NEW_TABLE    2:  FROM SOURCE_TABLE 

mySQL:

   1: CREATE TABLE NEW_TABLE    2:  SELECT * FROM SOURCE_TABLE; 

Oracle:

   1: SELECT * INTO NEW_TABLE   2:  FROM SOURCE_TABLE 

   1: SELECT Col1, Col2, Col_n INTO NEW_TABLE   2:  FROM SOURCE_TABLE 

Postgre SQL:

   1: CREATE TABLE NEW_TABLE   2:  AS SELECT * FROM SOURCE_TABLE;

Note, you can always use WHERE 1=0 if you want to copy only schema.

Enjoy!

Covariance and Contravariance

2011-04-10T23:00:00.001-07:00

Covariance is when an object that is instantiated with a more derived type is assigned to an object that is instantiated with a less derived type.
For instance,

   1: IEnumerable<string> strings = new List<string>(); 

The assignment compatibility is preserved. Know that:

Invariant means, must use the exact type – be ‘in’ or ‘out’

Covariant means, parameter type can be of a derived class type; upcast’able; more specific to more general. Specified as output types: return types, 'out' params, get properties. Array types fall in this category.

Contravariant is opposite of covariance. Parameter type can be a parent class type; downcast'able; more general to specific type. Use base type where a child type was expected. Specified as input types: set, 'in' parameters, etc.

Covariance and contravariance (or simply “variance”) are advanced concepts. The motivation behind introducing and enhancing variance in C# was to allow generic interface and generic types (in particular, those defined in the Framework, such as IEnumerable<T>() to work more as we would expect.

Conventionally, array types are covariant. This means that X can be cast to Y if X subclasses Y. For instance:

   1: Bear[] bears = new Bear[3];   2: Animal[] animals = bears; // OK

The downside of this reusability is that element assignments can fail at runtime:

   1: animals[0] = new Camel(); // Runtime error. Why, because Animal class is    2: //expecting Bears, notCamels!

Covariance (and contra variance) in interfaces is something that you typically consume: it’s less common that you need to write variant interfaces.

See following example:

   1: //Base type   2: class Car { public string name = "Base car"; }    3:     4: //Sub type   5: class Honda : Car { public Honda() { name = "Specific car:    6: Honda"; } }    7:     8: class Program   9: {  10:  delegate T Func<out T>(); /*Covariant; remember? Specified as 'out'put types*/  11:    12: delegate void Action<in T>(T a);/*Contravariant; Specified as 'in'put types!*/  13:  static void Main(string[]   14: args)  15:  {  16:  // Example: Covariance  17:  Func<Honda> child1 = () => new Honda();  18:  Func<Car> parent1 = child1; //Assignment compatibility is preserved   19:    20:  // Example: Contravariance  21:  Action<Car> parent2 = (someArgs) => { Console.WriteLine(someArgs.name); };  22:  Action<Honda> child2 = parent2;//Assignment compatibility is maintained   23:  child2(new Honda());//Prints, Specific car: Honda   24:    25: Console.ReadKey();  26:  }  27: }

The type system is free to allow us to safely upcast and downcast between those interfaces in the direction indicated by the keyword. You might like exploring more here.

It's really not a "save the day" sort of feature. It's more of a "it works the way I expect it to" feature - Eric Lippert

Enjoy, variants in life! (0:

Will I ever be able run windows phone 7 on windows xp machine?

2011-04-07T23:53:00.000-07:00

This post answers the following questions:

How to run Windows Phone Development Tools on Windows XP?
How to run install windows phone developer resources on windows xp?
XDELauncher.EXE vs XDE.exe?

I tried running windows phone 7 development environment from an xp machine. Amazing! the windows phone 7 developer phone would not install on xp machine, in the first place.

When you download a windows phone 7 online installation executable (vm_web.exe) and double click the file, it throws an error saying that a better OS is required, which means a Windows 7 or Vista.

Dint work!

Then I thought that I should download the .ISO (WPDT_RTM_en1.iso); and may be I get lucky to find the exact files that required installation.

This helped digging in more, and was able to find in the extracted files, a folder named WindowsPhone inside WCU folder. Installed XNA Game Studio, and Expression Blend without a glitch. What did not work was WindowsPhoneDeveloperResources_en.msi; it did not install. Same error, a better OS is required.

I was able to see the windows phone templates in visual studio 2010 professional; that kept on throwing the error that it requires windows phone developer resources!

Dint work!

Some how I still was sure that I'd be able to run the windows phone 7 application on a windows xp machine.

I tried installing Visual Studio 2010 Ultimate; and bang! it did the trick (0:

But wait!

I get this compilation error which says, Device Emulator is not detected. Install the Device Emulator.

Woohoo!!!

And this happiness turned in to a nightmare when I tried lauching the WP7 emulator (XDELauncher.exe, found in \Program Files\Microsoft SDKs\Windows Phone\v7.0\Tools\XDE Launcher); and un/fortunately, it did not run. I click on it, it seems that it runs, but it does not. When you click on the file, the program ends, it seems, before it starts!

Dint work!

I still, "had" some hope... so I asked my friend google; but to my surprise it responded me with zero result set.

Ah ha! (made me scratch my skull)

It turned out not many people know about the XDELauncher.exe. And it seems that in Windows 7, XDELauncher.exe is called XDE.exe.

Here, another one like myself tried a different method of installation which "did" work! But, not really worked! (0:

The emulator requires:

DirectX 10
WDDM Driver

Both of which do not exists on Windows XP. Installing DirectX 10 also did not work.

Dint work!

This issue was raised on Microsoft Connect on May/4/2010; currently in "Review" status, with only 1 vote for it! Sounds like windows xp is scrap already. What will those do whos "corporate standard" is still Windows XP.

From another, more into "mobile-dev" says:

"I work for a large mobile silicon vendor with many, many developers working on WP7. Our corporate standard is Windows XP, and I can promise you that a bunch of very bright people have spent a lot of time trying to get this to work."

It seems, even if you are able to install and run the WP7 app successfully, you cannot guarantee that it will run smoothly everywhere. The hacked/cracked environment that you will setup will be full of surprises. (0:

Btw, if you "still" want a workaround while staying on XP - get a VM! I created a virtual (VMWare) environment with windows 7, visual studio 2010 ultimate, and windows phone 7 developer tools - Just need to see if it works!

I'll post an update as soon as I deploy my first app on Windows Phone 7 App Store.

Update 2011/APR/21: (for those who are interested)

"Running Windows Phone developer edition in Virtual Machine is not supported". Yep, damn!

From MSDN Forums:

"Running Windows Phone developer edition in Virtual Machine is not supported. Windows Phone Developer Edition is supported on physical machine"

Emulator during its boot checks whether HW virtualiztion is enabled or not. If enabled and is available, it will enable it for its VM. My guess is that the VMWare VM driver must be tripping when the query is invoked. I will follow up with development team for possible solutions to fix this. For the current drop, please do not have active VM when launching the Emulator.

You might also enjoy this discussion.

Enjoy!

DOS Move command doesn't work on Windows 2003 Server?

2011-04-06T00:23:00.000-07:00

MOVE command doesnt work in Windows 2003 Server; workaround?

To emulate the process, we can create a batch file and:

Copy the file to new folder
Verify the copied file
Delete the file from old folder

@echo off

echo -----------------------------------------
ECHO File Move Utility for Windows 2003 Server
echo -----------------------------------------

set /p loc1= Copy From location 1: 
set /p loc2= Copy To location 2: 

@echo Copying...
copy /b "%loc1%" "%loc2%"

@echo Validating...
fc /b "%loc2%"  "%loc1%" |find /i "Ditto" > nul

@echo Cleaning...
if not errorlevel 1 del /f "%loc1%"

@echo Logging...
if not errorlevel 1 >>"file.log" echo File copied successfully
if errorlevel 1 >>"file.log" echo Error removing file from "%loc1%"

@echo Complete.

A couple of gotchas to keep an eye on:

You could have used the MOVE.EXE command if its available on your OS; move simply alters the folder information, which means it does not move the data. While COPY.EXE may do.
When you compare the file, it most probably compares the contents with disk cache. In order to test, you can copy the file on a flash drive, a pause for a while, pull out the flash drive, and then compare. If it does not look for the flash drive, this means the OS uses the cached version instead.
Copy does not copy files that are 0 bytes long. Use XCOPY.exe to copy these files.

Why go green?

2011-03-29T11:54:00.000-07:00

This is an article that I wrote some time back for a well known Pakistani internet magazine, about green computing.

This answers following questions:

What is Green Computing?
Why go green?
Who is going green?

They say about Nature, the more the need is, the abundant is its quantity. Air is one of such instances.

So, what is it?
To answer the question, it is a "way" to minimize the environmental pollution. But how would a computer harm the environment? You may ask. Well, how did you last dispose off your old 286 desktop pc along with a large 14 inch Cathode Ray Tube (CRT) monitor? I ask.

You will either throw it, sell it to *raddi wala* for as low as 50 rupees, or give it away to your house maid who would "eventually" do the same thing as you did.

And you might well find some garbage collector lads burning your monitor in the chilly mornings to warm their hands.

Have you ever thought about how this pc ends up, and is processed by the Nitrogen Cycle?

Severely dangerous gas is released when the plastic, silicon, mercury, etc is burnt; and to my surprise, some time back when I tried to burn my much fiddled/diddled oldest Cathode Ray Tube (CRT) computer monitor back in 1998, burns with a notable blast - reason being, some parts in the circuitry (specially capacitors) can hold high voltage of charges even when the component is turned off.

Now think about this; you are in-charge of computer labs in a large company having tens of labs equipped with several hundreds of computers and hardware equipments. To maintain a certain level of quality your management decided that you need to replace all; they mean ALL of your hardware with brand new machines.

It may be easy for you to procure another couple of hundred pcs; but How, and where will you dispose off the existing ones?

Try answering this question and you might understand.

Even if you are able to find an online, offshored, Garbage collector; you've only "transferred" the direction of responsibility in question. But really, how do you think that Garbage collector will dispose off the crap. In case if you are thinking that the Garbage collector is going to reuse the workable components - there are three things that you must know:

1. Old components, especially in computing industry, are just worthless from every aspect, selling or reusing. Or downgrade drastically.

2. You may want to recycle those components, but remember not everything can be recycled; you must "produce" recycle'able components in order for them to be recycled.

3. For the sake of making the point, let’s assume that "you must dispose" the hardware.

Some believe that it is better to have passed on your computer to benefit someone else - this helps others.

This avoids the environmental dangers of disposal in landfill or incinerators. But this "could" have been correct if the components could retain its original state of functionality. Many charities have recently imposed minimum system requirements for donated equipment.

So, you might end up digging a hole somewhere near Gavadar so that no one would know. That’s exactly where the Green Computing comes in; it would stop you from doing so.

A Malaysian Multimedia University professor, Dr San Murugesan, in his recent publication 'Harnessing Green IT: Principles and Practices', defines green computing as:

"The study and practice of designing, manufacturing, using, and disposing of computers, servers, and associated subsystems—such as monitors, printers, storage devices, and networking and communications systems—efficiently and effectively with minimal or no impact on the environment."

Who is doing what?
Companies are now producing environment friendly components; even with an extra extensible life cycle or those that could be disposed off easily.

In Pakistan, the concept is relatively "still" new. There are a few technology companies who helped. Students of Karachi University, SZABIST are exploring the idea in their research projects.

A joint venture of Lahore based software house FiveRivers Technologies, and ClearCube Technology provides extensive virtualization services. In India green computing is becoming more prevalent[2], WIPRO was the first company to go green in 2007. Bangladesh is already in the lines and trying to introduce the idea.
PCAdvisor ran a poll[5], that resulted in that, 45% of firms have green computing policy in UK.

Recently people have started adding, you might have noticed, a green colored tree-and-road icon in the footer of email messages, discouraging the printing of email text unless necessary. That is a part of green computing concept.

Several international certification(CompTIA Strata Green IT, for instance) programs have been introduced for managers, which show that they have good knowledge of green IT practices and methods and why it is important to incorporate them into an organization.

According to Microsoft Research Labs the best practices [6] for sustainable architecture design includes:
• Reduced energy consumption
• Reduced operational costs for the data center and business
• Understand energy consumption and environmental impact.
• Build environmental sustainability into change and configuration management processes.

This is where Cloud Computing plays an important part, where environment (including hardware, operating system, etc) is provided by the service (Virtualization, etc) provider; all you have to focus on is business. Cloud Computing was ranked top technology strategy by Gartner[3] for year 2010.

There are quite a couple of companies providing virtualization services in Pakistan; and whole lot more in India.

Government can play a vital role, by introducing laws and regulations to dispose such components. Govt can encourage garbage collector companies to get an international quality certification for waste disposal.
Provide help line 0800 numbers for public and corporate consumers so that they feel encouraged and comfortable disposing off the material.

How can I help?
Just remember the primary goal:

Discourage the make/use of hazardous components, and factory waste.
Encourage the make/use of efficient, energy-aware, durable, recyclable components.

If you are "just a guy" living next door, then don’t throw away the pc or hand it over to "help" someone - well just wait - wait till Mustafa Kamal installs the promised Waste Disposal and Management System.
Just so this may interest you, you better wipe your hard drive clean before disposing off - your data can be restored[4].

Peek More At:
• Going Green [http://www.time.com/time/goinggreen]
• Harnessing Green IT: Principles and Practices [http://www.computer.org/portal/web/csdl/doi/10.1109/MITP.2008.10]
• Green Computing [http://www.computing.co.uk/ctg/special/1814241/green-computing]
• Old Computer Disposal [http://www.intel.com/learn/practical-advice/computer-maintenance/green/old-computer-disposal]
• http://en.wikipedia.org/wiki/Green_computing

References:
[1]: http://jehanara.wordpress.com/2009/08/25/pakistan-tech-sector-helping-companies-to-go-green
[2]: http://www.businessweek.com/globalbiz/content/apr2009/gb20090413_237615.htm
[3]: http://www.gartner.com/it/page.jsp?id=1210613
[4]: http://www.which.co.uk/news/2009/01/smash-up-your-hard-drive-to-avoid-id-theft-166079/
[5]: http://www.pcadvisor.co.uk/news/index.cfm?newsId=3247127
[6]: Microsoft Research Labs [http://research.microsoft.com/pubs/78813/AJ18_EN.pdf]

Find trailing zeros in a factorial number

2011-03-25T05:00:00.000-07:00

How many zeros are at the end of "1000!" (one thousand factorial)?

No cheating... calculator is not allowed! Btw, you cant calculate that, because of the

I hope you are not thinking about multiplying all the numbers, are you?

N! = N x (N-1)!

The trick is around the the number Five(5).

STEP 1: Divide the number by 5, and note down the remainder
STEP 2: If the remainder is greater than 5, goto step 1
STEP 3: Add all remainders

Yep, thats it.

Lets have an example.

Example 1: 6!
=> 6/5 = 1 (This means, expect one (1) trailing zero at the end of 6!)

Example 2: 10!

10/5 = 2 (Expect two zeros)

Example 3: 50!

50/5 = 10
10/5 = 2
=> 10 + 2= 12 (Expect 12 trailing zeros)

Example 4: 100!

100/5 = 20
20/5 = 4
=> 20+4 (Expect 24 zeros)

I am leaving 1000! as an exercise for the reader (0:

Btw, no standard C data type can handle numbers this large. Unless you use some Mathlab library or your own code with some arbitrary data type restricted only to the available memory, you might be able to write a program. So, just find out the number of trailing zeros; and if you want to validate the answer using Calculator, try for 15!, 25!, 35!, etc...

Enjoy!

C++ Refresher Course - Interview Questions and Answers

2011-03-23T09:55:00.000-07:00

Refresh your C++ days! This resource is not only an excellent resource to interview questions, I found the answers interesting enough to float your thoughts upon. Compiled by Dr. Fatih Kocan, Wael Kdouh, and Kathryn Patterson. Though, I am not sure how long this PDF is going to stay there.

My first love "was" and "is" C++ - just that I have been unable to spend time with it since I switched to .NET development stack. The world of dots. While rest of the class was moving into the Java and qualifying for the certifications of UML, the challenge of understanding C++ attracted me more into it. Luckily I got a chance to learn more about C++ from a university senior, now in Microsoft, Haroon Ahmed. He was the inspiration that I wrote multilingual chat server in plain VC++ and made it to the AQ Khan Research Labs, an state level software development competition.

In .NET, the emphasis is more on business, than the mere UI library that you had to create before developing your logic. Or everytime you start your Doc-View architected C++ application, you had to provide everything that would make your business logic work. And then move to business logic. More side-kick code was required to develop an app. And in .NET, seldom - very seldom, we find ourselves implementing the OnPaint, OnDraw, people do not know about the PreTranslateMessage(), yep I'm talking about VC++, WNDPROC, the DispatchMessage method. The power that VC++ brought with it - Absolute - the God Language.

Plus, the concept of CLR; the .NET exe and dll aren't really exe/dll. They are just the intermediate language for the CLR that would JIT the .EXE/DLL and turn that into machine language. How easy it is to disassemble your code! that hurts. (0:

Just so this may interests you, when a managed module is invoked, the OS(windows) "thinks" that its just another "normal"(win32) executable; then it tells the windows loader to load the file; the loader reads the idata section, and when it finds the reference of mscoree.dll, it knows that it now needs to load the managed module in CLR; and then eventually managed module's IL is JIT'ted(Just in time compilation) into native code; which means, MSCorEE.dll compiles IL to native CPU instructions. I wrote about it sometime ago.

But still, if you are to develop a mission critical system, or software that does some real time process, or rendering realtime data, with zero delays, and zero compromise on performance - C++ is the way to go.

Well, also, if you want more, for instance to know about STL, ATL, COM, DCOM development using VC++, check out the CODEGURU.com website. It has excellent, invaluable resources in their VC++ section.

How to get checked values out of a CheckBoxList?

2011-03-16T02:32:00.000-07:00

Have you ever thought of why exactly do you love custom extensions? Roll out one just for this case:

public static class ControlExtensions
{
    public static string GetCheckedValues(this CheckBoxList list)
    {
        return String.Join(",", list.Items.OfType()
                                             .Where(s => s.Selected)
                                             .Select(s => s.Value).ToArray());
    }

}

Usage example, somewhere in ASP.NET MVC:

public ActionResult Index()
{
    CheckBoxList lst = new CheckBoxList();
    lst.Items.Add(new ListItem("one", "1"));
    lst.Items.Add(new ListItem("two", "2"));
    lst.Items.Add(new ListItem("three", "3"));
    lst.Items.Add(new ListItem("four", "4"));

    lst.Items[0].Selected = true;
    lst.Items[1].Selected = true;

    ViewData["Message"] = lst.GetCheckedValues();// Here.

    return View();
}

Enjoy!

Should I ever use Entity Framework 4.0?

2011-03-02T05:31:00.000-08:00

I did a small in-house presentation for the young architects in our company and though of sharing my findings. We compared different ORMs, and discussed more about entity framework vs NHibernate vs performance that ADO.NET provides. I will also post the difference of performance that we found while comparing NHibernate and ADO.NET. You count this in continuum to my previous post that I wrote sometime back, about EF4: ADO.NET Entity Framework v4.0

What is Entity Framework?

Is a data access framework comes with .NET 4.0
Bridges the gap between database and objects(POCO)
Its an evolution of ADO.NET
Uses Entity SQL (eSQL) – Query to entity framework model (.edmx files)
Sits on top of ADO.NET 2.0
Has an out-the-box answer with regard to n-tier development, in "self-tracking entities“ - eventually.

Architecture

FIG 1: ADO.NET Evolution and technology support

FIG 2: Entity Framework mapping to ADO.NET

FIG 3: Entity Framework components

Provides three types of approach:

Database first (the old way – then generate the model, then code)
Model first (the .edmx model – and then generate the database)
Code first (and then generate the model, and then the database)

What does it provide?

Generates strongly-typed entity objects
Customizable beyond 1-1 map
Generates mapping/plumbing code
Translates LINQ queries to database queries (LINQ to Entities)
Materializes objects from db calls
Tracks changes, generates updates/inserts
Giving intellisense, compile-time and debugger support

Where can it help?

Create ER-->Database
Generate ER Model
Quickly provide the CRUD operations, along with lazy/eager loading options.
Data layer (~~Enumerated tables~~, ~~query generation~~, ~~default crud~~, complex joins - reports, data core Wrapper, business logic, etc?) – You may want to utilize the Unit of Work pattern along with the Repository pattern.
Specific modules (UI logic - Handling data/complex grids, cells within cells)

Are there any EF data providers?

The Progress DataDirect 100% managed code ADO.NET data provider eliminates the need for database clients, which boosts .NET application performance and delivers a flexible, secure connection to all major databases, including Oracle, DB2, Sybase, and Microsoft SQL Server.
VistaDB is the only .NET embedded database that allows you to Xcopy a single DLL for both 32 and 64 bit runtime support.
Devart, offers ADO.NET Data Providers supporting access to Oracle, MySQL, SQL Lite, PostgreSQL, and Microsoft SQL Server databases.
OpenLink's Virtuoso ADO.NET Data Provider allows developers to access native Virtuoso data (SQL, XML, and RDF) and any Virtuoso Linked Tables from external ODBC and JDBC accessible data sources. Known-compatible external data sources include Oracle (versions 7.x to 11.x), Microsoft SQL Server (6.x to 2005), IBM DB2 , Sybase (4.2 to 12.x+), IBM Informix (5.x to 11.x), Ingres (6.4 to 9.x), Progress (7.x to 10.x), MySQL, PostgreSQL, and Firebird.
IBM supplies ADO.NET data providers for access to DB2, Informix, and U2 databases.
Sybase SQL Anywhere 11 includes Sybase iAnywhere's ADO.NET Data Provider.
Sample Entity Framework Provider for Oracle - community effort project

Some points to ponder

Primary purpose is providing basic CRUD operations
Not really feasible for reporting.
- eSQL Learning Curve, usually required to learn eSQL(unless generating complex reports?).
- Requires knowledge of eSQL for complex joins/GROUPBY
- Uses traditional string based queries with a more familiar SQL like syntax
- Dynamic queries may be composed in a traditional way at run time using string manipulation
- Projection is not possible; you must always return an ObjectQuery<T>
Develop against a conceptual view(the model, that is, .edmx classes) of your underlying data, not the store itself
Doesn't have a lot of providers for other databases.
Very young
Small community behind it.
Requires workaround for LEFT OUTER JOINs. For instance, see following loc:

   1: var v = from en in context.Entity.Include("PostalAddress").Include("PostalAddressType")   2:     3: let leftouter = (from pa in en.PostalAddress   4:                 select new //Project into a new object   5:                 {   6:                 PA = pa,   7:                 PAT = pa.PostalAddressType   8:                 }).FirstOrDefault()   9:                   10:             select new {  11:             EntityID = en.EntityID,  12:             PostalAddressID = (Guid?)leftouter.PA.PostalAddressID,  13:             PostalTypeID = (Guid?)leftouter.PAT.PostalAddressTypeID  14:             };

Entity Framework problems with SQL IN keyword
…AND D.STATE_NAME IN ('Approved', 'Scanned', 'Returned') is invalid!
eSQL is not SQL!

Cannot access multiple database! Quite rare in our case…

Relationship navigation problem – Learn to navigate!
NAVIGATE operator allows a query to explicitly traverse a relationship; says don’t use joins.

   1: SELECT SalesPersonID, FirstName, LastName, HireDate   2: FROM SalesPerson sp   3:     INNER JOIN Employee e ON sp.SalesPersonID = e.EmployeeID   4:     INNER JOIN Contact c ON e.EmployeeID = c.ContactID   5:     INNER JOIN SalesOrder o ON sp.SalesPersonID = o.SalesPersonID   6: WHERE e.SalariedFlag = 1 AND o.TotalDue > 200000

The above code is like following is eSQL:

   1: SELECT VALUE sp   2:     FROM AdventureWorks.AdventureWorksDB.SalesPeople AS sp   3: WHERE EXISTS(   4:     SELECT VALUE o    5:         FROM NAVIGATE(p, AdventureWorks.SalesPerson_Order) AS o   6:     WHERE o.TotalDue > 200000)

What about EF Logging? Does it provide cool logging features?
Nope. Missing!

Use objectQuery.ToTraceString(); for query logging; yep, thats all.

Output for the above loc: Untraceable!
[SELECT 1 AS [C1], [Extent1].[CHEQUE_ID] AS [CHEQUE_ID], [Extent1].[CHEQUE_NUMBER] AS [CHEQUE_NUMBER], [Extent1].[ACCOUNT_NUMBER] AS [ACCOUNT_NUMBER], [Extent1].[ACCOUNT_TITLE] AS [ACCOUNT_TITLE], [Extent1].[MICR_AMOUNT] AS [MICR_AMOUNT] FROM [dbo].[CHEQUE] AS [Extent1] INNER JOIN [dbo].[CHEQUE_ACTIVITY] AS [Extent2] ON EXISTS (SELECT cast(1 as bit) AS [C1] FROM ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1] INNER JOIN [dbo].[CPS_CHEQUE] AS [Extent3] ON 1 = 1 WHERE ([Extent2].[CHEQUE_ID] = [Extent3].[CHEQUE_ID]) AND ([Extent1].[CHEQUE_ID] = [Extent3].[CHEQUE_ID]) ) INNER JOIN [dbo].[SEC_USER] AS [Extent4] ON EXISTS (SELECT cast(1 as bit) AS [C1] FROM ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable2] INNER JOIN [dbo].[USER] AS [Extent5] ON 1 = 1 WHERE ([Extent2].[USER_ID] = [Extent5].[USER_ID]) AND ([Extent4].[USER_ID] = [Extent5].[USER_ID]) ) INNER JOIN [dbo].[WF_STATE] AS [Extent6] ON ([Extent1].[STATE_ID] = [Extent6].[STATE_ID]) AND (([Extent6].[STATE_NAME] = 'Approved') OR ([Extent6].[STATE_NAME] = 'Scanned') OR ([Extent6].[STATE_NAME] = 'Returned'))]
How in the world will you map Extent1 with the actual database table? think, and leme know.

Vote of no/confidence?
Here is a website, expecting “more” from Microsoft! (0: Signed by the people who doesn’t buy into the vote of confidence on this product. What does this mean? This means, no one, at least no one from the signatories.

So, should I ever use entity framework?
Yes, you should.

B…ut… Why?
Community as well as the online help (tutorials, videos, etc) growing, stabilizing, and expanding fast. Plus, dont forget the LINQ functionalities. EF has the best LINQ providers as compared the NHibernate. NHibernate is far far beyond where LINQ is concerned.

Where should I use it?
Anywhere and everywhere. Except for your production environment! If you still are, then tell your customer to be prepared for surprises. Since EF is growing faster, you may bank upon it after sometime.
Good luck.

References:

Disclaimer: Please understand, the motive behind this post is to understand the pros and cons, this means, there is NO boiler plate answer; and its up to the reader to decide whether they want to use EF or not.

Part II: How to become a consultant , employed, independent or contract - Pricing model

2011-02-25T10:28:00.001-08:00

Related to Part I: How to become a consultant

Part II: What should be the pricing model

So what could be pricing model. Interesting you may find, all across Europe, your services are rented on per hour basis. For instance her in Asian sub continent, one would ask your monthly expected salary. But if you were somewhere in UK, do not wonder if they ask you about hourly charges. You better calculate that before appearing in any interview. Same holds good for USA. Not sure about the eastern region - Singapore, Malaysia, Australia, etc.

Generally there are 250 billable days per year. How so? Lets see a possible breakup for billable hours per year; a breakup that you can also think of, could be as follows:

1 Month = 4 weeks
Now, 4 weeks x 12 months = 48 weeks + the odd days of the month (for instance, not all months are of 30, so add 2 weeks, ~15 days, of variation)

So, 48 weeks + 2 weeks = 50 weeks.

Note that the above 50-weeks includes weekends, holidays, and sickness leaves.

This concludes that your baseline in calculating the work weeks shall be 50 weeks per year.

Now lets calculate the work hours per year:

A usual 9 to 5 job corresponds to 8 working hours. So, working for 8 hours per day(btw, do you work for straight 8 hours?), that makes it:

8 hours x 5 days a week = 40 hours per week; if you are lost, then continue reading - you don't have a choice (0;

This concludes 40 hours x 365 = 14600 hours a year.

Note that, sometimes contractors avoid adding weekends, holidays, leaves/etc, when they quote the price; how would this help them? They tend to charge higher per hour; so either way the actual result is same.

What makes the most difference is how many links are in the chain between the company (who's paying) and you (the resource). In most cases, there's a middle-man or an staffing firm who has the prime contract; and all the resources gets sub-contracted through them.

Gulf is full of such contracting companies. Hiring guys for different large companies, but on their own payroll.

A very well known company that does just that in the Middle Eastern region is the IT People. Btw, a google will tell you that most of these are Indian companies, and they have "Consulting" as a suffix to their company name.

These middlemen come into play because of the liability protection for the company. Which works as a insurance company for the large corporates. But getting a contract directly from a company is actually better for both, the consultant as well as the company; why? Because company will be able to pay less(no middlemen) to you, while you'd be able to see more money pouring in - no middlemen.

There is one more point about hourly vs. daily rate. There are a number of different ways a company can spin it. For instance, now you are a contractor, and you hire a couple-a resources - how would you go about their salaries? You may call it "work-day" rate or they can also call it a cap-on-billing. Like for instance in case of my company, it says "I don't care how many hours you work for, I want to see 8 hours a day across the board.".

Typically the company does a day rate to limit the overtime they would normally have to pay if they're driving hard on a project. It's free labor to them. Also, daily billing usually simplifies the time reporting requirement. Which probably in turn helps management "justify" their management. This is an interesting information.

Enjoy!

And yes, in case this interests you, my friend decided to use the "Consultant" title, and Consulting as a suffix in his company name.

Part I: How to become a consultant , employed, independent or contract

2011-02-25T10:28:00.000-08:00

I have been working over this article, with discussion and research, so the content has gone miles from a single kilometer and has reached to a point of no return (0: So I have broken it up into parts, just so you I may share my experience that can be understood well. Here it goes:

I have been working with some friends - on and off - doing freelance consulting locally and online using rentacoder. Recently a friend asked for some help who decided to leave the job and go-consultant.

We were precisely looking for following two questions:

Question 1: Choosing the title
The type of position-or-title that should be used; as it could range from consultant, architect, to contractor, or simply a freelance. But you cant print that on your card, can you? (0:

Question 2: Pricing model
And the type of pricing model that would benefit the most - not only funds-wise but consulting as well career-wise.

Part I: How and what to choose the title

So, What should you choose? Consultant, Entrepreneur, Freelance, or Architect?

At rentacoder, I saw the term "Freelancer", which is more inclined towards graphics/designing type of role, and seldom is used with freelance-developers. Mostly, the freelance developers go by their own company name.

So if you are working for yourself, who are you? A consultant, a contractor, a freelancer or an entrepreneur? or what would you want to be?

This really boils down to where do you want to see yourself? What words attracts you? What words sound convincing to you. Note that, IMHO, its important that you convince yourself first, and only then you would be able to prove that to the world. So, unless you are sure, unless you "believe" in it - don't buy it.

Many people goes with title of Consultant. You must have seen visiting cards saying Consultant, with a keyword "specialist" as a prefix or suffix to that title.

So, one question that you must ask yourself, what you really like(I meant love) doing?

Consultant:
Job responsibilities may include, proposing the re-engineered IT solution to business people. Turn business requirements into functional requirements. Propose solutions. Either subcontract the work to other company or allocate resources, make the job done ASAP, with quality, timeliness, and with a delighted customer.

Architect:
When you are proposing a solution based upon business requirements, built around specific set of technologies, you may be called architect. This may include, helping with a robust system architecture. Providing all sorts of design artifacts, which includes but not limited to, system design diagram, entity relationship, code/solution files structure; as well as lead and mentor other developers to help finish their project on time, with quality.

Contractor:
Contractor is usually a term used if you are involved in state level projects. So, a government department "subcontracts" you the piece of business to be turned into a technology masterpiece. You can further "subcontract" the project depending upon the revenue and legal agreements that you signed with buyer. Note that, in legal terms, you are called - Seller - the one who is selling the services; and state shall be called Buyer, the one who is buying your services.

Freelancer:
As for freelancer, that's just a general term for anyone not employed by a company - or doing anything in *parallel*. You can be a freelance contractor or consultant.

More in Part II: Pricing Model...

Delegates vs Methods

2011-02-17T21:26:00.000-08:00

You might get into arguments with your peers upon using delegates over method calls.

Delegates have an entirely different purpose in their life, compared to a method call. If you can call a method directly, then you don't need a delegate. Because delegates are mostly useful when a function needs to be invoked in a context where the actual object is not available, such as event callbacks.

Or delegates are used in cases where you want a class to notify you, for instance, upon certain action.

Here is a scenario where you definitely need a delegate.

There is a sample worker class, that does some processing. While processing we require the class to send the updated status of the process.

//Small enumerated work statuses
enum WorkState
{
    Started,
    InProcess,
    AlmostThere,
    Completed
}

//A sample worker class, that uses the 
class Worker
{
    public void SomeWork(TheDelegate callback)
    {
        callback(this, WorkState.Started);

        int count = 0;
        while (count < 100)
        {
            count++;//the usual while counter.
            if(count>80)
                callback(this, WorkState.AlmostThere);
            else
                callback(this, WorkState.InProcess);
        }

        callback(this, WorkState.Completed);
    }
}

How to call the delegate?

//The delegate, that "delegates" the reference to the 
//actual callback method.
delegate void TheDelegate(Worker t, WorkState status);

class Program
{
    static void Main(string[] args)
    {
        Worker t = new Worker();

        //Pass on the reference to the callback method.
        t.SomeWork(new TheDelegate(MyCallbackMethod));

        Console.ReadKey();
    }

    //The call back method.
    static void MyCallbackMethod(Worker t, WorkState status)
    {
        Console.WriteLine("The task status is {0}", status);

        //Can also send it to a different network/pc or write into a file.
        //if (Network.IsConnectedToNetwork)
        //{
        //    Network.Send(IPAddress, t, status);
        //}
    }
}

Quite an interesting part to note that you can send the data anywhere you want, over intranet, internet, shared device, print server, etc.

Now you may question about the performance of delegate over method calls? Just so you may know there is not much of a difference: Performance of calling delegates vs methods?

Since CLR v2, the cost of delegate invocation is very close to that of virtual method invocation, which is used for interface methods.

Jon Skeet has provided his results:

Now I don't have particular faith that that means delegates are really faster than interfaces... but it makes me fairly convinced that they're not an order of magnitude slower. Additionally, this is doing almost nothing within the delegate/interface method. Obviously the invocation cost is going to make less and less difference as you do more and more work per call.

Joel Pobar's blog has some interesting facts about the cost of delegate invocation; it says its somehwat similar to virtual method call invocation for interface methods - or - should I say, our good old pure virtual functions - as we call it.

Enjoy! (0:

Offline - Electronic funds transfer

2011-02-17T20:28:00.000-08:00

Recently, I was involved in the development and implementation of the electronic funds transfer in offline mode. The destination was Dhaka, Bangladesh. The inward processing of EFT was imposed by the central bank, that all banks needed to pass the SIT with the central bank's central server.

Offline-mode meaning, that transaction would settle the next day; contrary to the middleware/switch concept, that a customer is standing on a channel(ATM, for instance) and waiting for the transaction to be processed then and there.The middleware that the central bank was using was called PBM (Participant banking module) server.

The central bank hired a American consulting company to implement the central server; the company had similar experience of implementing the Clearing Houses (CA); somehow that I couldn't understand, the company suggested the central bank to use the twisted format of NACHA format. By *twisted* I mean, they turned the length based format into XML. Now XML is good, but not utilizing the powers of XML is not good. This means, we were provided with the XML format without providing the XSD schema, which the core of an XML, especially when you plan to exchange the data in huge amounts, and with a large customer base.

Btw, in case if you are interested in the consulting company, it is called Radix Consulting, run by "famous-in-the-payment-solutions-industry" George Thomas. He is an nice person with a wealth of clearing house business knowledge.

When I started with the training sessions, users were unable to understand their business process, so I had to come up with following simple visual. This turned out to be very helpful for them.

Usually, the business process of inward clearing would be same in any banking industry, with a plus or minus one. This is for inward clearing, which means processing of credits only, which was made mandatory by the central bank.

This is for those who want to understand the offline electronic funds transfer process; turning business classes into services.

How to OPENROWSET on x64?

2011-02-08T07:50:00.000-08:00

Requirement:
- Load data from csv source file
- Join with an internal table
- Trim a column of csv
- Insert into the target table

Problem statement:
OPENROWSET query works on my dev machine, but doesn't work in test server environment, why?!

Because dev machine:
- Wass x86 machine, having 32bit software installed on it
- 32 bit SQL Server 2008
- and because you cannot run 32bit driver for JET from a 64 bit application;

And test machine:
- Was running on x64 bit, windows server 2008 R2, with SQL Server 2008 R2

There are couple of solutions that you can target according to your workload and required effort:

Solution 1: Use push technique instead of pulling from SQL Server
Write a visual studio app using CPUAll as configuration settings; and run this app on the target machine.

Solution 2: Use Microsoft Access Database Engine 2010 Redistributable

You can download x64 version.

This download will install a set of components that facilitate the transfer of data between existing Microsoft Office files such as Microsoft Office Access 2010 (*.mdb and *.accdb) files and Microsoft Office Excel 2010 (*.xls, *.xlsx, and *.xlsb) files to other data sources such as Microsoft SQL Server. Connectivity to existing text files is also supported.ODBC and OLEDB drivers are installed for application developers to use in developing their applications with connectivity to Office file formats.

SELECT * INTO #tem FROM OPENDATASOURCE('Microsoft.ACE.OLEDB.12.0','Data Source=c:\test.xlsx;Extended Properties=Excel 12.0')...[Sheet1$]

select * from #tem

drop table #tem

Solution 3: Use temp table
- Load the csv in temporary table
- Join and select
- Insert

CREATE TABLE #tmp(a float, b varchar(max), c varchar(max));

BULK INSERT #tmp FROM 'c:\test.csv' 
WITH (FIELDTERMINATOR = ',' , FIRSTROW = 2 );

--If you want to see anything from the temp table, uncomment following loc
--SELECT * FROM #tmp

--Insert into select *
INSERT INTO TARGET_TABLE ([C1],[C2],[C3])

SELECT name=SUBSTRING(A.b,0,30)
,trimmedPhoneNumber= SUBSTRING(CONVERT(VARCHAR, A.c,0), 4,5)
,code=b
FROM #tmp A
 INNER JOIN OTHER_TABLE B ON REPLACE(STR(A.a, 3), SPACE(1), '0') = CONVERT(VARCHAR,B.CODE,0)
ORDER BY B.ID;

TRUNCATE TABLE #tmp;
DROP TABLE #tmp;

Technology | Business | Life | Thoughts | Meta ツ

Phases in life of a “software developer”–Types of developers! Who am i?

Question

Level 0

Level 1

Level 2

Level 3

Level 4

Level 5

Are you sure you want to move to gulf? Think again!

How to think a unified design for multi device architecture?

Top 6 ways to parse .CSV? High Performance!

Crystal Reports for VS2010 (v13.0.1)

ASP.NET: Async calls vs threading

Is ‘jQuery vs Silverlight’-comparison even possible?

NHibernate – The Good, the Bad, and the Ugly, that it gets!

Persistent Dictionary

CREATE TABLE FROM SELECT STAR

Covariance and Contravariance

Will I ever be able run windows phone 7 on windows xp machine?

DOS Move command doesn't work on Windows 2003 Server?

Why go green?

Find trailing zeros in a factorial number

C++ Refresher Course - Interview Questions and Answers

How to get checked values out of a CheckBoxList?

Top 10 answers to top 10 software requirements interview question

Should I ever use Entity Framework 4.0?

Top 10 answers to top 10 Project Management questions that a senior software developer must know

Part II: How to become a consultant , employed, independent or contract - Pricing model

Part I: How to become a consultant , employed, independent or contract

Delegates vs Methods

Offline - Electronic funds transfer

How to OPENROWSET on x64?