The Vigilant Zephyr

Minify Javascript using PHP

2012-09-24T13:17:00.000-07:00

All those newbie web developers out there might have noticed that javascripts are often written in minified forms. When you try and debug the pages you Google, Facebook etc. It can be noticed that the javascript written there is nowhere close to be understood. This is done deliberately by these tech giants to make it difficult for the developers to decipher their code. Also, it makes the process of fetching the javascript from the server faster.

When there are a number of javascripts to be loaded, the individual calls to the javascripts are combined so that a fewer number of server requests can serve the purpose. All this is done by minification of the javascript. There are several ways to minify a javascript. One of them is a two step process to achieve the awesomeness of Google or Facebook like minified javascripts.

1) Minification : In this step, all the line breaks, tabs and white spaces are removed and the javascript is converted into a one line code without any sort of formatting to make the server respond faster to any request for the javascript.

2) Obfuscation : In this step, the minified javascript from the above step is obfuscated so as to hide the actual javascript and make it really confusing,ambiguous and harder to interpret for any person.

So here is a quick tutorial to minify it on the fly using PHP so that the original javascript code remains intact.

1) Download the JSMin PHP file from : https://github.com/rgrove/jsmin-php/blob/master/jsmin.php for minification of your javascript.
2) Download the Packer PHP file from : http://joliclic.free.fr/php/javascript-packer/en/ for obfuscation of your javascript. (Just need the JavascriptPacker.php from the complete zip)

Now save these files into your codebase library or any other suitable place and using these two masterpieces, a javascript can be easily minified using the following PHP code.

//Using the two files and including them onto the PHP page (i.e. JSMin and JavascriptPacker).
require_once('jsmin.php');
require_once('jspacker.php');

//Minification using jsmin.php
$js = file_get_contents('my_javascript.js');
$js = JSMin::minify($js);

//Obfuscation using jspacker.php
$myPacker = new JavaScriptPacker($js, 62, true, false);
$js = $myPacker->pack();

//Display the final ouput wherever it is required.

echo $js;

Now, wherever you want your javascript my_javascript.js to be loaded, in the script tag, just add the 'src' attribute to the PHP file where your above code is put up.

<script type="text/javascript" src="minify.php"></script>

So easy to get the awesomeness. Get amazed with the minified javascript. Even the person who wrote the javascript won't be able to decipher it from the minified form. Hope this helps some of the web developers !!

Pre-Order Tree Traversal Without Recursion : Pseudo Code

2011-11-01T15:14:00.000-07:00

We very well know how to traverse a binary search tree using the concept of recursion. If you don't, click on this link. Now, the challenge is to traversal the same tree in pre-order without the use of recursion. It can be done easily by the use of a stack. The following pseudo code shows us how to do it. The push and pop of the stacks are the basic push and pop operations used in any stack implementation.

Pseudo Code :

typedef struct _node
{
   int data;
   struct _node * left;
   struct _node * right;
} Node;

void PreOrderTraversalNonRecursive(Node * root)
{
   Stack nodeStack;
   nodeStack.Push(root);

   //While stack is not empty
   while(nodeStack.Count > 0)
   {
      Node * currentNode = nodeStack.Pop();
      print (currentNode->data);
      nodeStack.Push(currentNode->right);
      nodeStack.Push(currentNode->left);
   }
}

Heap as a Priority Queue : Pseudo Code

2011-11-01T15:01:00.001-07:00

An important use of heap sort is to implement a priority queue. A priority queue is a collection of elements that each element has been assigned a priority and such that order in which elements are deleted and processed comes from the following rules:

1) An element of higher priority is processed before any element of lower priority.
2) Two element with the same priority are processed according to the order in which they were added to the queue.

Pseudo Code :

HeapExtractMax(A){
    if(heap-size[A] < 1){
        //Underflow
    }
    max = A[1];
    A[1] = A[heap-size[A]];
    heap-size[A]--;
    Heapify(A, 1);
    return max;
}

HeapInsert(A, key){     heap-size[A]++;
    i = heap-size[A];
    while(i > 1 && A[Parent(i)] < key){
        A[i] = A[Parent(i)];
        i = Parent(i);
    }
    A[i] = key;
}

Run-Time for HeapExtractMax : O(log n)
Run-Time for HeapInsert : O(log n)

Heap Sort : Algorithm and Pseudo Code

2011-11-01T15:01:00.000-07:00

Heap sort is a comparison-based sorting algorithm to create a sorted array (or list), and is part of the selection sort family. Although somewhat slower in practice on most machines than a well implemented quick sort, it has the advantage of a more favorable worst-case O(n log n) run-time. Heap sort is an in-place algorithm, but is not a stable sort.

For any array A to be a heap, the following heap property should be satisfied : A[Parent(i)] >= A[i], for any element present at index i in the array A.

The height of any heap consisting of n elements is given as h = O(log n)

Heap sort begins by building a heap out of the data set, and then removing the largest item and placing it at the end of the partially sorted array. After removing the largest item, it reconstructs the heap, removes the largest remaining item, and places it in the next open position from the end of the partially sorted array. This is repeated until there are no items left in the heap and the sorted array is full. Elementary implementations require two arrays - one to hold the heap and the other to hold the sorted elements.

Heap sort inserts the input list elements into a binary heap data structure. The largest value (in a max-heap) or the smallest value (in a min-heap) are extracted until none remain, the values having been extracted in sorted order. The heap's invariant is preserved after each extraction, so the only cost is that of extraction.

During extraction, the only space required is that needed to store the heap. To achieve constant space overhead, the heap is stored in the part of the input array not yet sorted.

Heap sort uses two heap operations: insertion and root deletion. Each extraction places an element in the last empty location of the array. The remaining prefix of the array stores the unsorted elements.

Because of the O(n log n) upper bound on heap sort's running time and constant upper bound on its auxiliary storage, embedded systems with real-time constraints or systems concerned with security often use heap sort. Heap sort also competes with merge sort, which has the same time bounds, but requires Ω(n) auxiliary space, whereas heap sort requires only a constant amount. Heap sort also typically runs more quickly in practice on machines with small or slow data caches. On the other hand, merge sort has several advantages over heap sort:

1) Like quick sort, merge sort on arrays has considerably better data cache performance, often outperforming heap sort on a modern desktop PC, because it accesses the elements in order.

2) Merge sort is a stable sort.

3) Merge sort parallelizes better; the most trivial way of parallelizing merge sort achieves close to linear speedup, while there is no obvious way to parallelize heap sort at all.

4) Merge sort can be easily adapted to operate on linked lists (with O(1) extra space) and very large lists stored on slow-to-access media such as disk storage or network attached storage. Heapsort relies strongly on random access, and its poor locality of reference makes it very slow on media with long access times. (Note: Heapsort can also be applied to doubly linked lists with only O(1) extra space overhead)

Assumptions Made :

Parent(i) = floor(i/2);
Left(i) = 2i;
Right(i) = 2i +1;

Pseudo Code :

Heapify(A, i){
    l = Left(i);
    r = Right(i);
    if( l <= heap-size[A] && A[l] > A[i]){
        largest = l;
    } else {
        largest = i;
    }
    if(r <= heap-size[A] && A[r] > A[largest]){
        largest = r;
    }
    if(largest != i){
        exchange (A[i], A[largest]);
Heapify(A, largest);
}
}

BuildHeap(A){
    heap-size[A] = length[A];
    for i = floor(length[A]/2) to 1{
        Heapify(A, i);
    }
}

HeapSort(A){
    BuildHeap(A);
    for i = length[A] to 2{
        exchange(A[1], A[i]);
        heap-size[A]--;
        Heapify(A, 1);
    }
}

Run-time for Heapify : O(log n) = O(h); T(n) = T(2n/3) + O(1);
Run-time for BuildHeap : O(n)
Run-time for HeapSort : O(n log n)

Worst case performance	$: O(n log n)$
Best case performance	$: Ω(n), O(n log n)$
Average case performance	$: O(n log n)$
Worst case space complexity	$: O(n)$ total, $O(1)$ auxiliary

Insertion Sort : Algorithm and Pseudo Code

2011-10-29T15:46:00.000-07:00

Insertion sort is a simple sorting algorithm: a comparison sort in which the sorted array (or list) is built one entry at a time. Every repetition of insertion sort removes an element from the input data, inserting it into the correct position in the already-sorted list, until no input elements remain. The choice of which element to remove from the input is arbitrary, and can be made using almost any choice algorithm.

Sorting is typically done in-place. The resulting array after k iterations has the property where the first k + 1 entries are sorted. In each iteration the first remaining entry of the input is removed, inserted into the result at the correct position, thus extending the result.

The best case input is an array that is already sorted. In this case insertion sort has a linear running time (i.e., O(n)). The worst case input is an array sorted in reverse order. In this case every iteration of the inner loop will scan and shift the entire sorted subsection of the array before inserting the next element. For this case insertion sort has a quadratic running time (i.e., O(n²)). The average case is also quadratic, which makes insertion sort impractical for sorting large arrays.

However, insertion sort is one of the fastest algorithms for sorting very small arrays, even faster than quicksort; indeed, good quicksort implementations use insertion sort for arrays smaller than a certain threshold, also when arising as sub-problems; the exact threshold must be determined experimentally and depends on the machine, but is commonly around ten.

Insertion sort is very similar to selection sort. As in selection sort, after k passes through the array, the first k elements are in sorted order. For selection sort these are the k smallest elements, while in insertion sort they are whatever the first k elements were in the unsorted array. Insertion sort's advantage is that it only scans as many elements as needed to determine the correct location of the k+1st element, while selection sort must scan all remaining elements to find the absolute smallest element.

Calculations show that insertion sort will usually perform about half as many comparisons as selection sort. Assuming the k+1st element's rank is random, insertion sort will on average require shifting half of the previous k elements, while selection sort always requires scanning all unplaced elements. If the input array is reverse-sorted, insertion sort performs as many comparisons as selection sort. If the input array is already sorted, insertion sort performs as few as n-1 comparisons, thus making insertion sort more efficient when given sorted or "nearly-sorted" arrays.

While insertion sort typically makes fewer comparisons than selection sort, it requires more writes because the inner loop can require shifting large sections of the sorted portion of the array. In general, insertion sort will write to the array O(n²) times, whereas selection sort will write only O(n) times. For this reason selection sort may be preferable in cases where writing to memory is significantly more expensive than reading, such as with EEPROM or flash memory.

Pseudo Code :

InsertionSort(A){
    for j = 2 to length(A){
        key = A[j];
        // Insert A[j] into sorted sequence A[1..j-1]
        i = j-1;
        while(i > 0 && A[i] > key){
            A[i+1] = A[i];
            i--;
        }
        A[i+1] = key;
    }
}

Worst case performance	: О(n²)
Best case performance	: O(n)
Average case performance	: О(n²)
Worst case space complexity	: О(n) total, O(1) auxiliary

LAST_INSERT_ID() : SQL Informative Function

2011-10-09T15:30:00.000-07:00

It returns the the most recently generated ID that is maintained in the server on a per-connection basis.
It is not changed by another client. It is not even changed if you update another AUTO_INCREMENT column with a nonmagic value (that is, a value that is not NULL and not 0).
Using LAST_INSERT_ID() and AUTO_INCREMENT columns simultaneously from multiple clients is perfectly valid as each client will receive the last inserted ID for the last statement that client executed.

If you want to use the ID that was generated for one table and insert it into a second table, you can use SQL statements like this:

INSERT INTO foo (auto,text) VALUES (NULL,'text'); // generate ID by inserting NULL
INSERT INTO foo2 (id,text) VALUES (LAST_INSERT_ID(),'text'); // use ID in second table

BEWARE !!

1) However, you might be getting incorrect output if you try these SQL commands on a browser based SQL interface like phpMyadmin or MySQL Query Browser. This is because these interfaces create a separate connection every time a query is created. So, every time you will see that LAST_INSERT_ID() returns 0 (zero). To, avoid this, you should execute both the queries in a single line, separated by semicolons.

INSERT INTO foo (auto,text) VALUES (NULL,'text'); INSERT INTO foo2 (id,text) VALUES (LAST_INSERT_ID(),'text');

2) Also, LAST_INSERT_ID() returns 0 in a case where you do not have an AUTO_INCREMENT column in your database. So, before executing this query, make sure that you do have one in your database.

For more information, visit :
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html

Web Development Setup on a PC

2011-07-09T14:17:00.000-07:00

Being a developer, and doing the pathetic task of setting up my laptop for web development due to the poor quality of laptops provided in my company which crash or fail due to some hardware problems, I thought about writing up this blog post to help all those web developers who face problems in setting up their computers for web development. This is not a post for developers who want to work on Windows. So, only developers who prefer Linux may read further.

1) Install Linux :

This is the first step towards setting up your machine. I used Ubuntu 11.04 as the Linux OS. I downloaded it from the internet and then installed on my machine after creating a bootable USB using the application provided in the OS download.

2) Install Netbeans :

I prefer Netbeans IDE for my development. Its upto you whatever IDE you want to install but I have listed the steps to install Netbeans. I installed Netbeans IDE 7.0 with all the possible language support like C, C++, Java, PHP etc. along with the bundled servers.

i) Download the Netbeans installation file from http://netbeans.org/downloads/. Its entirely up to you to select and download what all language support you want in your IDE and what suits you best.

ii) Meanwhile, the Netbeans installation file gets downloaded, you can install JVM on your machine, which is required by the Netbeans installer.

iii) Go to the Synaptic Package Manager and search for the JVM packages. Once you find them, mark them for installation and click on apply. The JVM packages would start downloading.

iv) Once you complete with JVM installation and complete downloading the Netbeans installation file. You need to install Netbeans. The downloaded file would be an .sh extension file. So, to run this file, you need to execute the following command in the terminal after you move to the downloaded file's folder:

sudo sh <Name of the Downloaded File>

v) Now, follow the instructions shown by the installer to the install the Netbeans IDE.

3) Install LAMP Server :

This is the most important installation as far as web development is concerned. LAMP stands for (L)inux (A)pache (M)ySQL (P)HP. Its similar to WAMP server provided in Windows. So, to install LAMP, go to the terminal and type the following command:
sudo apt-get install lamp-server^

Now, to check if the LAMP was setup properly, hit the url:

http://localhost

If the url givres you a response, "It Works !", then you can be sure of the correct installation of the Apache web server.

Now, if you want to install PHPMyAdmin for your machine, run the following command in the terminal.

sudo apt-get install phpmyadmin

During this installation, you will be asked to choose an administrator account along with a password. Also, when it asks for a choice of configuration, select 'Apache' and then select 'Yes' for dbconfig-common.

Once, you complete with the PHPMyAdmin, don't forget to restart the Apache server. Without this, PHPMyAdmin won't work properly. To restart the Apache server, run the following command in the terminal.

sudo service apache2 restart

If it still does not work, run the following command and then again restart the server.

sudo ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf.d/phpmyadmin.conf

That's it for installing the LAMP Server.

4) Install RabbitVCS :

If you are working in a team over a project, you will definitely need a Version Control System. I installed RabbitVCS on my machine for this purpose. Run the commands given below in the order to complete RabbitVCS installation.

i) sudo add-apt-repository ppa:rabbitvcs/ppa

ii) sudo apt-get update

iii) sudo apt-get install rabbitvcs-core

iv) sudo apt-get install rabbitvcs-nautilus rabbitvcs-thunar rabbitvcs-gedit rabbitvcs-cli

After running all these commands successfully, you need to restart your machine to completely integrate RabbitVCS into your system.

5) Install xDebug :

This is an essential tool for any developer. For PHP debugging, I preferred xDebug. Its really easy to install. Just open the terminal and run the command given below.

sudo apt-get install php5-xdebug

Once you have installed it, go to the xdebug.ini file. You can go to the file using this command and open it in edit mode.

sudo gedit /etc/php5/apache2/conf.d/xdebug.ini

Now, change the file so it looks like this:

zend_extension="/usr/lib/php5/20090626/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=127.0.0.1
xdebug.remote_port=9000

The zend_extension will already be set. So, you need not change it. But if you don't have it. Find the file xdebug.so in php5 folder and copy its path to zend_extension.

Now you can check if your debugger is installed correctly with phpinfo(). You should see the text something like the one given below:

This program makes use of the Zend Scripting Language Engine:
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with Xdebug v2.0.5, Copyright (c) 2002-2008, by Derick Rethans
with Suhosin v0.9.29, Copyright (c) 2007, by SektionEins GmbH

Hope that this blog post will help you in setting up your machine easily !! Your comments and feedbacks are highly welcomed on this post. If you find any thing or tool installation that I have missed regarding Web Development Setup, please feel free to write back.

How To Setup PEAR Mail On Linux

2011-05-29T07:51:00.000-07:00

PEAR mail is a package that you can to install to set up a mailing system for your website or application. Its really easy to install. I work on a Linux PC. So, for all the Linux developers out there, I can give you out the commands which you need to execute on the command line or the terminal. This will install PEAR mail on your system.

1) sudo apt-get install php-pear

2) sudo pear install mail

3) sudo pear install Net_SMTP

4) sudo pear install Auth_SASL

5) sudo pear install mail_mime

You might find some errors reported during the installation. But don't worry about them. It will work fine.

Now, once you have got your packages installed, you would be itching to see how the mailing system works. As for PHP, its really simple. The code snippets given below explain you how it actually works. If you have a little knowledge in PHP, it will not be hard to understand as to what is happening.

<?php

// This is bundled with the mail package and comes with the above installation.

require_once "Mail.php";

// The sender email address needs to be here.

$from = "sender@example.com";

// The recipient email address needs to be here.

$to = "recipient@example.com";

// The subject of the email is given here.

$subject = "<Your Subject>";

// The body of the email message to be conveyed is written here.

$body = "<Body of the Email message>";

// The SMTP server that you will use to send the emails.

$host = "mail.example.com";

// The username for the SMTP server.

$username = "smtp_username";

// The password for the SMTP server.

$password = "smtp_password";

// The headers are formed as an array here.

$headers = array ('From' => $from, 'To' => $to, 'Subject' => $subject);

// This creates an instance of the Mail Factory with the required login credentials for the SMTP server.

// The first argument tells the factory that the server is an SMTP server.

$smtp = Mail::factory('smtp', array ('host' => $host, 'auth' => true, 'username' => $username, 'password' => $password));

// This sends the mail to the intended recipient with the required headers and the body of the message.

$mail = $smtp->send($to, $headers, $body);

// If an error is reported during the mailing, the appropriate error message will be displayed.

if (PEAR::isError($mail)) {
echo("<p>" . $mail->getMessage() . "</p>");

}

// If the mail is successfully sent, the success message will be shown.

else {
echo("<p>Message successfully sent!</p>");

}

Please make sure to read the comments given in the lines to ensure that your mail service works absolutely fine. I have put up comments at every possible place to guide you through. Hope, this would help you acheive your task.

Blackberry Application Development : Introduction

2011-02-07T23:31:00.000-08:00

Recently, I got a chance to work on Blackberry Application Development. It was a nice learning curve for me. So, I thought to share some experience with the people as well. Just an introduction of how things work and what are the requirements.

Java Basics:

BlackBerry development for all recent models is done exclusively in Java. So if you're not a strong Java programmer, now's the time to brush up on your Java programming skills. (C# programmers will find the transition to Java fairly simple, the languages are very close in most respects.) Don't learn about the newest Java features, however, because the BlackBerry platform is built on top of Java Micro Edition (Java ME), which is itself a derivative of Java version 1.3. So forget all the fancy (but useful) language features introduced in Java 1.5 -- generics, enumerations, and so on -- you can't use these in BlackBerry programming. You can't also use most of the library classes you're familiar with -- they're just not there. A small subset of the Java Standard Edition (Java SE) classes are supported, as well as a number of BlackBerry-specific classes.

Java Micro Edition:

Once you've brushed up on your Java, you need to spend a bit of time understanding the Java ME platform, which was formerly known as Java 2 Micro Edition, or J2ME for short. You need to understand the concepts of configurations and profiles, and in particular the CLDC and MIDP standards. You'll find lots of information about these in various books and on Sun's Java development site.

Blackberry JDE:

After learning about Java ME, it's time to explore the BlackBerry platform. The BlackBerry platform is based on the CLDC and includes support for MIDP 2.0. However, a large number of BlackBerry-specific classes are also provided. Which brings you to the first question you'll face: are you going to write a BlackBerry application or a MIDP application? In a MIDP application you're constrained to only use the APIs exposed by the CLDC and MIDP standards. Your application will run on the BlackBerry and on most cellphones, but it won't be able to use any of the BlackBerry's special features. You can use any MIDP-compatible development tool, such as the Sun Java Wireless Toolkit for CLDC (formerly known as the J2ME Wireless Toolkit), to create your applications.

Most application developers opt to build BlackBerry-specific applications. This means learning the BlackBerry-specific APIs -- including new user interface classes -- and using the BlackBerry Java Development Environment (JDE) to develop your applications. The JDE, which is free to download, works with the standard Java Software Development Kit and provides you with all the tools necessary to create, package, test and debug BlackBerry applications. You don't even need a BlackBerry handheld, because the JDE includes a full-featured BlackBerry device simulator. A complete set of JavaDocs is provided that describes all the classes and interfaces available to programmers.

After downloading and installing the JDE, you'll want to read the developer's guides that come with the JDE and look at the sample applications that are shipped with it. Then start your development by writing a few simple applications to get a feel for the BlackBerry APIs and the tools.

Blackberry Device:

Although you can develop and test your applications for free, at some point you'll need to run the application on an actual BlackBerry handheld. This will cost you money, of course, and so it's not something you'll want to do until you're serious about writing BlackBerry applications. On-device testing is crucial to ensuring that the application works correctly, because the simulator is not a perfect emulation system.

If you're truly serious about BlackBerry application development, consider also joining one of the BlackBerry developer programs for additional support and early access to new devices and APIs. You should also explore RIM's other BlackBerry developer resources. There are also third-party forums and books available to help you learn the BlackBerry platform.

To get more on this stuff, you can go through the documents and sample applications provided by the Blackberry developers. It offers a wide range of sample applications. You can easily learn application develeopment going through the documents provided.

Happy Developing !!

Web Service : Introduction

2011-01-23T11:43:00.000-08:00

Web Service describes a standardized way of integrating Web-based applications using the XML, SOAP, WSDL and UDDI open standards over an Internet protocol backbone.

* XML (eXtensible Mark-up Language) is used to tag the data.
* SOAP (Simple Object Access Protocol) is used to transfer the data.
* WSDL (Web Services Description Language) is used for describing the services available.
* UDDI (Universal Description, Discovery and Integration) is used for listing what services are available.

Used primarily as a means for businesses to communicate with each other and with clients, Web services allow organizations to communicate data without intimate knowledge of each other's IT systems behind the firewall

Unlike traditional client/server models, such as a Web server/Web page system, Web services do not provide the user with a GUI. Web services instead share business logic, data and processes through a programmatic interface across a network. The applications interface, not the users. Developers can then add the Web service to a GUI (such as a Web page or an executable program) to offer specific functionality to users.

Web services allow different applications from different sources to communicate with each other without time-consuming custom coding, and because all communication is in XML, Web services are not tied to any one operating system or programming language. For example, Java can talk with Perl, Windows applications can talk with UNIX applications.

Web services do not require the use of browsers or HTML. Web services are sometimes called Application Services.

Google App Engine (GAE) : Components

2011-01-19T04:42:00.000-08:00

The GAE comprises of the following components that have been given below. All of them help the developers to free themselves of all the headaches involved in hosting a web application and to run the application efficiently. The Google servers take up these time-consuming tasks so that you can concentrate on your application. Below are the components of the Google App Engine :

1) The Application Environment

Google App Engine makes it easy to build an application that runs reliably, even under heavy load and with large amounts of data. App Engine includes the following features:

i) dynamic web serving, with full support for common web technologies
ii) persistent storage with queries, sorting and transactions
iii) automatic scaling and load balancing
iv) APIs for authenticating users and sending email using Google Accounts
v) a fully featured local development environment that simulates Google App Engine on your computer
vi) task queues for performing work outside of the scope of a web request
vii) scheduled tasks for triggering events at specified times and regular intervals

Your application can run in one of two runtime environments: the Java environment, and the Python environment. Each environment provides standard protocols and common technologies for web application development.

2) The Sandbox

Applications run in a secure environment that provides limited access to the underlying operating system. These limitations allow App Engine to distribute web requests for the application across multiple servers, and start and stop servers to meet traffic demands. The sandbox isolates your application in its own secure, reliable environment that is independent of the hardware, operating system and physical location of the web server.

Examples of the limitations of the secure sandbox environment include:

i) An application can only access other computers on the Internet through the provided URL fetch and email services. Other computers can only connect to the application by making HTTP (or HTTPS) requests on the standard ports.

ii) An application cannot write to the file system. An app can read files, but only files uploaded with the application code. The app must use the App Engine datastore, memcache or other services for all data that persists between requests.

iii) Application code only runs in response to a web request, a queued task, or a scheduled task, and must return response data within 30 seconds in any case. A request handler cannot spawn a sub-process or execute code after the response has been sent.

3) The Java Runtime Environment

You can develop your application for the Java runtime environment using common Java web development tools and API standards. Your app interacts with the environment using the Java Servlet standard, and can use common web application technologies such as JavaServer Pages (JSPs).

The Java runtime environment uses Java 6. The App Engine Java SDK supports developing apps using either Java 5 or 6.

The environment includes the Java SE Runtime Environment (JRE) 6 platform and libraries. The restrictions of the sandbox environment are implemented in the JVM. An app can use any JVM bytecode or library feature, as long as it does not exceed the sandbox restrictions. For instance, bytecode that attempts to open a socket or write to a file will throw a runtime exception.

Your app accesses most App Engine services using Java standard APIs. For the App Engine datastore, the Java SDK includes implementations of the Java Data Objects (JDO) and Java Persistence API (JPA) interfaces. Your app can use the JavaMail API to send email messages with the App Engine Mail service. The java.net HTTP APIs access the App Engine URL fetch service. App Engine also includes low-level APIs for its services to implement additional adapters, or to use directly from the application. See the documentation for the datastore, memcache, URL fetch, mail, images and Google Accounts APIs.

Typically, Java developers use the Java programming language and APIs to implement web applications for the JVM. With the use of JVM-compatible compilers or interpreters, you can also use other languages to develop web applications, such as JavaScript, Ruby, or Scala.

4) The Python Runtime Environment

With App Engine's Python runtime environment, you can implement your app using the Python programming language, and run it on an optimized Python interpreter. App Engine includes rich APIs and tools for Python web application development, including a feature rich data modeling API, an easy-to-use web application framework, and tools for managing and accessing your app's data. You can also take advantage of a wide variety of mature libraries and frameworks for Python web application development, such as Django.

The Python runtime environment uses Python version 2.5.2. Additional support for Python 3 is being considered for a future release.

The Python environment includes the Python standard library. Of course, not all of the library's features can run in the sandbox environment. For instance, a call to a method that attempts to open a socket or write to a file will raise an exception. For convenience, several modules in the standard library whose core features are not supported by the runtime environment have been disabled, and code that imports them will raise an error.

Application code written for the Python environment must be written exclusively in Python. Extensions written in the C language are not supported.

The Python environment provides rich Python APIs for the datastore, Google Accounts, URL fetch, and email services. App Engine also provides a simple Python web application framework called webapp to make it easy to start building applications.

You can upload other third-party libraries with your application, as long as they are implemented in pure Python and do not require any unsupported standard library modules.

5) The Datastore

App Engine provides a distributed data storage service that features a query engine and transactions. Just as the distributed web server grows with your traffic, the distributed datastore grows with your data. You have the choice between two different data storage options differentiated by their availability and consistency guarantees.

The App Engine datastore is not like a traditional relational database. Data objects, or "entities," have a kind and a set of properties. Queries can retrieve entities of a given kind filtered and sorted by the values of the properties. Property values can be of any of the supported property value types.

Datastore entities are "schemaless." The structure of data entities is provided by and enforced by your application code. The Java JDO/JPA interfaces and the Python datastore interface include features for applying and enforcing structure within your app. Your app can also access the datastore directly to apply as much or as little structure as it needs.

The datastore is strongly consistent and uses optimistic concurrency control. An update of a entity occurs in a transaction that is retried a fixed number of times if other processes are trying to update the same entity simultaneously. Your application can execute multiple datastore operations in a single transaction which either all succeed or all fail, ensuring the integrity of your data.

The datastore implements transactions across its distributed network using "entity groups." A transaction manipulates entities within a single group. Entities of the same group are stored together for efficient execution of transactions. Your application can assign entities to groups when the entities are created.

6) Google Accounts

App Engine supports integrating an app with Google Accounts for user authentication. Your application can allow a user to sign in with a Google account, and access the email address and displayable name associated with the account. Using Google Accounts lets the user start using your application faster, because the user may not need to create a new account. It also saves you the effort of implementing a user account system just for your application.

If your application is running under Google Apps, it can use the same features with members of your organization and Google Apps accounts.

The Users API can also tell the application whether the current user is a registered administrator for the application. This makes it easy to implement admin-only areas of your site.

7) App Engine Services

App Engine provides a variety of services that enable you to perform common operations when managing your application. The following APIs are provided to access these services:

i) URL Fetch : Applications can access resources on the Internet, such as web services or other data, using App Engine's URL fetch service. The URL fetch service retrieves web resources using the same high-speed Google infrastructure that retrieves web pages for many other Google products.

ii) Mail : Applications can send email messages using App Engine's mail service. The mail service uses Google infrastructure to send email messages.

iii) Memcache : The Memcache service provides your application with a high performance in-memory key-value cache that is accessible by multiple instances of your application. Memcache is useful for data that does not need the persistence and transactional features of the datastore, such as temporary data or data copied from the datastore to the cache for high speed access.

iv) Image Manipulation : The Image service lets your application manipulate images. With this API, you can resize, crop, rotate and flip images in JPEG and PNG formats.

8) Scheduled Tasks and Task Queues

An application can perform tasks outside of responding to web requests. Your application can perform these tasks on a schedule that you configure, such as on a daily or hourly basis. Or, the application can perform tasks added to a queue by the application itself, such as a background task created while handling a request.

Scheduled tasks are also known as "cron jobs," handled by the Cron service. For more information on using the Cron service, see the Python or Java cron documentation.

Task queues are currently released as an experimental feature. At this time, only the Python runtime environment can use task queues. A task queue interface for Java applications will be released in the near future.

9) Development Workflow

The App Engine software development kits (SDKs) for Java and Python each include a web server application that emulates all of the App Engine services on your local computer. Each SDK includes all of the APIs and libraries available on App Engine. The web server also simulates the secure sandbox environment, including checks for attempts to access system resources disallowed in the App Engine runtime environment.

Each SDK also includes a tool to upload your application to App Engine. Once you have created your application's code, static files and configuration files, you run the tool to upload the data. The tool prompts you for your Google account email address and password.

When you build a new major release of an application that is already running on App Engine, you can upload the new release as a new version. The old version will continue to serve users until you switch to the new version. You can test the new version on App Engine while the old version is still running.

The Java SDK runs on any platform with Java 5 or Java 6. The SDK is available as a Zip file. If you use the Eclipse development environment, you can use the Google Plugin for Eclipse to create, test and upload App Engine applications. The SDK also includes command-line tools for running the development server and uploading your app.

The Python SDK is implemented in pure Python, and runs on any platform with Python 2.5, including Windows, Mac OS X and Linux. The SDK is available as a Zip file, and installers are available for Windows and Mac OS X.

The Administration Console is the web-based interface for managing your applications running on App Engine. You can use it to create new applications, configure domain names, change which version of your application is live, examine access and error logs, and browse an application's datastore.

10) Quotas and Limits

Not only is creating an App Engine application easy, it's free! You can create an account and publish an application that people can use right away at no charge, and with no obligation. An application on a free account can use up to 500MB of storage and up to 5 million page views a month. When you are ready for more, you can enable billing, set a maximum daily budget, and allocate your budget for each resource according to your needs.

You can register up to 10 applications per developer account.

Each app is allocated resources within limits, or "quotas." A quota determines how much of a given resource an app can use during a calendar day. In the near future, you will be able to adjust some of these quotas by purchasing additional resources.

Some features impose limits unrelated to quotas to protect the stability of the system. For example, when an application is called to serve a web request, it must issue a response within 30 seconds. If the application takes too long, the process is terminated and the server returns an error code to the user. The request timeout is dynamic, and may be shortened if a request handler reaches its timeout frequently to conserve resources.

Attempts to subvert or abuse quotas, such as by operating applications on multiple accounts that work in tandem, are a violation of the Terms of Service, and could result in apps being disabled or accounts being closed.

Google App Engine (GAE) : Introduction

2011-01-19T04:26:00.000-08:00

This is a really cool technology that Google has come up with. The developers need to have a look at this innovative stuff brought up by Google.

Google App Engine lets you run your web applications on Google's infrastructure. App Engine applications are easy to build, easy to maintain, and easy to scale as your traffic and data storage needs grow. With App Engine, there are no servers to maintain: You just upload your application, and it's ready to serve your users.

You can serve your app from your own domain name (such as http://www.example.com/) using Google Apps. Or, you can serve your app using a free name on the appspot.com domain. You can share your application with the world, or limit access to members of your organization.

Google App Engine supports apps written in several programming languages. With App Engine's Java runtime environment, you can build your app using standard Java technologies, including the JVM, Java servlets, and the Java programming language—or any other language using a JVM-based interpreter or compiler, such as JavaScript or Ruby. App Engine also features a dedicated Python runtime environment, which includes a fast Python interpreter and the Python standard library. The Java and Python runtime environments are built to ensure that your application runs quickly, securely, and without interference from other apps on the system.

With App Engine, you only pay for what you use. There are no set-up costs and no recurring fees. The resources your application uses, such as storage and bandwidth, are measured by the gigabyte, and billed at competitive rates. You control the maximum amounts of resources your app can consume, so it always stays within your budget.

App Engine costs nothing to get started. All applications can use up to 500 MB of storage and enough CPU and bandwidth to support an efficient app serving around 5 million page views a month, absolutely free. When you enable billing for your application, your free limits are raised, and you only pay for resources you use above the free levels.

To know more about it :

Google Web Toolkit (GWT) : Introduction

2011-01-19T04:17:00.000-08:00

Recently, I got to work on a project that involved developing a web application and deploy it on the Google App Engine. The software used were Eclipse IDE and Google Web Toolkit. I found the toolkit interesting. So thought to share an overview of what it is. Application developers can check this out.

Introduction :

Google Web Toolkit (GWT) is a development toolkit for building and optimizing complex browser-based applications. Its goal is to enable productive development of high-performance web applications without the developer having to be an expert in browser quirks, XMLHttpRequest, and JavaScript. GWT is used by many products at Google, including Google Wave and the new version of AdWords. It's open source, completely free, and used by thousands of developers around the world.

Developing using the GWT :

1) Write

The GWT SDK provides a set of core Java APIs and Widgets. These allow you to write AJAX applications in Java and then compile the source to highly optimized JavaScript that runs across all browsers, including mobile browsers for Android and the iPhone.

Constructing AJAX applications in this manner is more productive thanks to a higher level of abstraction on top of common concepts like DOM manipulation and XHR communication.

You aren't limited to pre-canned widgets either. Anything you can do with the browser's DOM and JavaScript can be done in GWT, including interacting with hand-written JavaScript.

2) Debug

You can debug AJAX applications in your favorite IDE just like you would a desktop application, and in your favorite browser just like you would if you were coding JavaScript. The GWT developer plugin spans the gap between Java bytecode in the debugger and the browser's JavaScript.

Thanks to the GWT developer plugin, there's no compiling of code to JavaScript to view it in the browser. You can use the same edit-refresh-view cycle you're used to with JavaScript, while at the same time inspect variables, set breakpoints, and utilize all the other debugger tools available to you with Java. And because GWT's development mode is now in the browser itself, you can use tools like Firebug and Inspector as you code in Java.

3) Optimize

Google Web Toolkit contains two powerful tools for creating optimized web applications. The GWT compiler performs comprehensive optimizations across your codebase — in-lining methods, removing dead code, optimizing strings, and more. By setting split-points in the code, it can also segment your download into multiple JavaScript fragments, splitting up large applications for faster startup time.

Performance bottlenecks aren't limited to JavaScript. Browser layout and CSS often behave in strange ways that are hard to diagnose. Speed Tracer is a new Chrome Extension in Google Web Toolkit that enables you to diagnose performance problems in the browser.

4) Run

When you're ready to deploy, GWT compiles your Java source code into optimized, stand-alone JavaScript files that automatically run on all major browsers, as well as mobile browsers for Android and the iPhone.

Source : http://code.google.com/webtoolkit/overview.html

Team India : A transition from 1996 to 2010

2010-12-30T01:58:00.000-08:00

Going through an article on the web, I was delighted to read how the mentality of the Indian Cricket team has changed over the last 15 years. And I was glad to see that the team hasn't taken a step backwards and are growing strong year by year. Here is the article.

The year 1996 was a completely different world. It was a time when grass courts were fast, photographers shot on reel, computers were yet to beat chess grandmasters, a time when the Indian cricket team developed cold feet the moment they left the subcontinent. Fourteen years and a day before one of their most special wins away from home, at the same venue, in similar conditions, India put in perhaps their worst performance with the bat: bowled out for 100 and 66, lasting 73.2 overs in two innings put. Durban 1996 to Durban 2010 shows how far this team has come.

Allan Donald, who took nine wickets in that match and left India rattled, says the single biggest difference he sees in the team is the mental strength. And Donald could spot a weak opponent from a mile. "One thing that stands out for me vis-à-vis that team is that they haven't taken a backward step," he says. "They have shown a lot more character than they ever have away from home. I always looked forward to playing India away from home because I just didn't think they had enough fight, but they have shown it here. Character, mental toughness."

Talking to some of the Indian players from that team shows how unimaginably different things were back then. WV Raman, who just about managed to avoid a pair against Donald and Shaun Pollock in 1996, played in a world when the meek were supposed to inherit the earth. "Going into the series the batsmen were told to leave as much as possible outside the off stump," Raman remembers. "The team management had strictly told us not to hook or pull. I don't see how you can avoid that against the short-pitched bowling. That probably was one reason we fared badly. Now, that is not the case. Players are free to play their natural game.

"Take this second Test, when South Africa were 62 for no loss in no time chasing the target, our bowlers were relentless. Sreesanth went after Graeme Smith, and Smith fell for the bait and was egotistic enough to be influenced. Back in 1996, [Javagal] Srinath never exchanged any words. [Venkatesh] Prasad, you can forget it. That is the change in attitude and approach of the players then and now. That sums up the difference between the teams."

It is not as if sledging or hooking has won India away Tests, but it shows they have the confidence to stand up to aggressive teams. Donald has seen earlier Indian teams taking backward steps. On the 1992 tour, in the Port Elizabeth Test, "you could see that they just didn't fancy it. We had [Brett] Schultz and me bowling on a wicket that was nice and bouncy, and it seemed like they didn't like it at all. They capitulated in the second innings [except for Kapil Dev]. Not here. In the years gone by, green wicket, put into bat, it would have been a totally different story. Here they kept fighting, kept hanging in there. And then they bowled like champions."

Back in 1996, the bowlers started off well, bowling the hosts out for 235, but that wasn't a result of any plan. "I had no planning as a bowler in 1996," Prasad, who took a 10-for in Durban 1996, says. "We didn't have any videos, so whatever we watched of the opponents playing, we absorbed that. I would always, whichever game it was, sit in my room, draw an image of the field in my notebook and set down the field placements according to my strengths. So I was on my own. I would not like to blame the coaches then because even they were not exposed to these new innovations."

Nor did the likes of Prasad or Srinath have any support on or off the field. "The opposition were trained to perform their role to the best of their ability and they had physical trainers," Prasad says. "We didn't have one. Normally, what we used to do was run a lap, and stretch. We didn't have the professional physio that the other teams had. Our support staff was not well equipped and all that mattered. There's always going to be some niggle or the other and you cannot give your 100%. It's because that niggle tends to develop even into an injury sometimes, and therefore you were always hesitant to give your 100%. It affects your mindset. And add to that the backing from the board in terms of contracts, all that also mattered."

On the field they lacked the third bowler. "Back then, Srinath and I missed the support bowler," Prasad says. "Anil [Kumble] only later got the knack, but in 1996 he was playing more of a supporting role to create pressure. It was Srinath and I who used to get the wickets. I had got a lot of wickets because Srinath used to make things difficult for the batsmen. In this team, everyone is capable of getting wickets, capable of changing the course of the match."

To Donald, Zaheer Khan is the big difference in the bowling line-up. "Having this guy lifts everybody else. He brings another dimension to the attack. He is skilful, and every one bowls around him." Another important point Donald makes is the catching. "They have caught well, fantastically well," he says. "The catching just stood out. Those three magnificent catches in the first innings swung the game."

Raman talks of the batting line-up. "I still remember the delivery that Allan Donald bowled Sachin Tendulkar with in the first Innings," Raman says. "Tendulkar was not offering any shot, covering his off stump but the ball came back a long way and clipped the off bail. Of course, the batsmen were still working out the lengths, which were so different to back home. Nowadays our top six have a phenomenal experience, and they have been together as a unit for a long time. So there is somebody to stand up if everybody else fails. Back in 1996 the dressing room was not such a positive place."

It was the batting that convinced Donald that India wouldn't roll over and die this time around. "The response in Centurion in the second innings, following on, scoring 450-plus, just showed to me that India were not going to take a backward step. They were going to keep fighting."

Raman added: "The other paradigm shift is that they only look at the positive aspects of the day's game. Back then they would sit and brood about why something went wrong. They did not work on what better could be done tomorrow, which probably needed more attention."

It has taken them 14 years to erase the horrible memory, but when India come to Durban for another Boxing Day Test, people will have something else to talk about. About a team that was going to keep fighting.

Courtesy : www.espncricinfo.com

Pascal's Triangle : Awesome Code

2010-12-30T01:47:00.000-08:00

For the newbies, who don't know what a pascal's triangle is, here is a small explanation to guide you.

Pascal's triangle is a triangular array of the binomial coefficients in a triangle. It is named after the French mathematician Blaise Pascal in much of the Western world, although other mathematicians studied it centuries before him in Greece, India, Persia, China, and Italy.

Pascal's Triangle

The rows of Pascal's triangle are conventionally enumerated starting with row n = 0 at the top. The entries in each row are numbered from the left beginning with k = 0 and are usually staggered relative to the numbers in the adjacent rows. A simple construction of the triangle proceeds in the following manner. On row 0, write only the number 1. Then, to construct the elements of following rows, add the number directly above and to the left with the number directly above and to the right to find the new value. If either the number to the right or left is not present, substitute a zero in its place. For example, the first number in the first row is 0 + 1 = 1, whereas the numbers 1 and 3 in the third row are added to produce the number 4 in the fourth row.

Just when I was going through some programming codes for this Pascal's triangle, I found one which was really amazing. No multi-dimension arrays, no space compexity and minimal time complexity.

#include <iostream>
using namespace std;
int main()
{
   int n,k,i,x;
   cout << "Enter a row number for Pascal's Triangle: ";
   cin >> n;
   for(i=0;i<=n;i++)
   {
   x=1;
   for(k=0;k<=i;k++)
   {
   cout << x << " ";
   x = x * (i - k) / (k + 1);
   }
   cout << endl;
   }
   return 0;
}

Hats off to the programmer who came up with this code !!

Cloud Computing : Applications

2010-12-25T05:47:00.000-08:00

The applications of cloud computing are practically limitless. With the right middleware, a cloud computing system could execute all the programs a normal computer could run. Potentially, everything from generic word processing software to customized computer programs designed for a specific company could work on a cloud computing system.

Why would anyone want to rely on another computer system to run programs and store data? Here are just a few reasons:

1) Clients would be able to access their applications and data from anywhere at any time. They could access the cloud computing system using any computer linked to the Internet. Data wouldn't be confined to a hard drive on one user's computer or even a corporation's internal network.

2) It could bring hardware costs down. Cloud computing systems would reduce the need for advanced hardware on the client side. You wouldn't need to buy the fastest computer with the most memory, because the cloud system would take care of those needs for you. Instead, you could buy an inexpensive computer terminal. The terminal could include a monitor, input devices like a keyboard and mouse and just enough processing power to run the middleware necessary to connect to the cloud system. You wouldn't need a large hard drive because you'd store all your information on a remote computer.

3) Corporations that rely on computers have to make sure they have the right software in place to achieve goals. Cloud computing systems give these organizations company-wide access to computer applications. The companies don't have to buy a set of software or software licenses for every employee. Instead, the company could pay a metered fee to a cloud computing company.

4) Servers and digital storage devices take up space. Some companies rent physical space to store servers and databases because they don't have it available on site. Cloud computing gives these companies the option of storing data on someone else's hardware, removing the need for physical space on the front end.

5) Corporations might save money on IT support. Streamlined hardware would, in theory, have fewer problems than a network of heterogeneous machines and operating systems.

6) If the cloud computing system's back end is a grid computing system, then the client could take advantage of the entire network's processing power. Often, scientists and researchers work with calculations so complex that it would take years for individual computers to complete them. On a grid computing system, the client could send the calculation to the cloud for processing. The cloud system would tap into the processing power of all available computers on the back end, significantly speeding up the calculation.

Some of the companies researching cloud computing are big names in the computer industry. Microsoft, IBM and Google are investing millions of dollars into research. Some people think Apple might investigate the possibility of producing interface hardware for cloud computing systems.

Cloud Computing : Architecture

2010-12-25T05:41:00.000-08:00

When talking about a cloud computing system, it's helpful to divide it into two sections: the front end and the back end. They connect to each other through a network, usually the Internet. The front end is the side the computer user, or client, sees. The back end is the "cloud" section of the system.


Cloud Computing Stack

The front end includes the client's computer (or computer network) and the application required to access the cloud computing system. Not all cloud computing systems have the same user interface. Services like Web-based e-mail programs leverage existing Web browsers like Internet Explorer or Firefox. Other systems have unique applications that provide network access to clients.

On the back end of the system are the various computers (infrastructure and platforms), servers and data storage systems that create the "cloud" of computing services. In theory, a cloud computing system could include practically any computer program you can imagine, from data processing to video games. Usually, each application will have its own dedicated server.

Cloud Computing Architecture

A central server administers the system, monitoring traffic and client demands to ensure everything runs smoothly. It follows a set of rules called protocols and uses a special kind of software called middleware. Middleware allows networked computers to communicate with each other.

If a cloud computing company has a lot of clients, there's likely to be a high demand for a lot of storage space. Some companies require hundreds of digital storage devices. Cloud computing systems need at least twice the number of storage devices it requires to keep all its clients' information stored. That's because these devices, like all computers, occasionally break down. A cloud computing system must make a copy of all its clients' information and store it on other devices. The copies enable the central server to access backup machines to retrieve data that otherwise would be unreachable. Making copies of data as a backup is called redundancy.

Cloud computing is closely related to grid computing and utility computing. In a grid computing system, networked computers are able to access and use the resources of every other computer on the network. In cloud computing systems, that usually only applies to the back end. Utility computing is a business model where one company pays another company for access to computer applications or data storage.

Cloud Computing : Introduction

2010-12-25T05:26:00.000-08:00

Cloud computing is Internet-based computing, whereby shared servers provide resources, software, and data to computers and other devices on demand, as with the electricity grid. Cloud computing is a natural evolution of the widespread adoption of virtualization, service-oriented architecture and utility computing.

Let's say you're an executive at a large corporation. Your particular responsibilities include making sure that all of your employees have the right hardware and software they need to do their jobs. Buying computers for everyone isn't enough -- you also have to purchase software or software licenses to give employees the tools they require. Whenever you have a new hire, you have to buy more software or make sure your current software license allows another user. It's so stressful that you find it difficult to go to sleep on your huge pile of money every night.

Soon, there may be an alternative for executives like you. Instead of installing a suite of software for each computer, you'd only have to load one application. That application would allow workers to log into a Web-based service which hosts all the programs the user would need for his or her job. Remote machines owned by another company would run everything from e-mail to word processing to complex data analysis programs. It's called cloud computing, and it could change the entire computer industry.

In a cloud computing system, there's a significant workload shift. Local computers no longer have to do all the heavy lifting when it comes to running applications. The network of computers that make up the cloud handles them instead. Hardware and software demands on the user's side decrease. The only thing the user's computer needs to be able to run is the cloud computing system's interface software which can be as simple as a Web browser, and the cloud's network takes care of the rest.

There's a good chance you've already used some form of cloud computing. If you have an e-mail account with a Web-based e-mail service like Hotmail, Yahoo! Mail or Gmail, then you've had some experience with cloud computing. Instead of running an e-mail program on your computer, you log in to a Web e-mail account remotely. The software and storage for your account doesn't exist on your computer -- it's on the service's computer cloud.

Wikileaks

2010-12-25T05:01:00.000-08:00

There are a lot of talks going about Wikileaks recently and a has faced a lot of criticism all over the world by the governements. Here is a post that will tell you about what it is.

WikiLeaks is an international non-profit organisation that publishes submissions of private, secret, and classified media from anonymous news sources and news leaks.

Its website, launched in 2006 and run by The Sunshine Press, claimed a database of more than 1.2 million documents within a year of its launch. The organisation describes its founders as a mix of Chinese dissidents, journalists, mathematicians, and start-up company technologists from the United States, Taiwan, Europe, Australia, and South Africa. Julian Assange, an Australian Internet activist, is generally described as its director.

WikiLeaks was originally launched as a user-editable wiki site, but has progressively moved towards a more traditional publication model, and no longer accepts either user comments or edits. In April 2010, WikiLeaks posted video from a 2007 incident in which Iraqi civilians and journalists were killed by US forces, on a website called Collateral Murder. In July of the same year, WikiLeaks released Afghan War Diary, a compilation of more than 76,900 documents about the War in Afghanistan not previously available for public review. In October 2010, the group released a package of almost 400,000 documents called the Iraq War Logs in coordination with major commercial media organisations. In November 2010, WikiLeaks began releasing U.S. State department diplomatic cables.

WikiLeaks has received praise as well as criticism. The organisation won a number of awards, including The Economist's New Media Award in 2008 and Amnesty International's UK Media Award in 2009. Daily News listed WikiLeaks first among websites "that could totally change the news", and Julian Assange was named the Readers' Choice for TIME's Person of the Year in 2010. In 2010, the New York City Supporters of Wikileaks in the media have commended it for exposing state and corporate secrets, increasing transparency, supporting freedom of the press, and enhancing democratic discourse while challenging powerful institutions.

At the same time, several U.S. government officials have criticised WikiLeaks for exposing classified information, harming national security, and compromising international diplomacy. Several human rights organisations have criticised WikiLeaks for not adequately redacting the names of civilians working with international forces.

Some journalists have likewise criticised a perceived lack of editorial discretion when releasing thousands of documents at once and without sufficient analysis. Among negative public reactions in the United States, people have characterised the organisation as irresponsible, immoral, and illegal.

Website: www.wikileaks.ch

Citation from the Website:

"Could become as important a journalistic tool as the Freedom of Information Act." - Time Magazine

WikiLeaks is a non-profit media organization dedicated to bringing important news and information to the public. We provide an innovative, secure and anonymous way for independent sources around the world to leak information to our journalists. We publish material of ethical, political and historical significance while keeping the identity of our sources anonymous, thus providing a universal way for the revealing of suppressed and censored injustices.

WikiLeaks relies on its supporters in order to stay strong. Please keep us at the forefront of anti-censorship and support us today.

Sachin Tendulkar : A Tribute

2010-11-25T14:27:00.000-08:00

I consider him above Sir Don Bradman because when Bradman played, there was not so competitive cricket played. Also, during those times, Sir Don Bradman would sometimes keep on batting for 3-4 days in a test match. It didnt matter whether their team was winning or not. The teams would just try to bat till they get out. But, today the scenario is entirely different. The players need to deliver the goods within the given time. And given this situation, Sachin is far better than Sir Donald Bradman. Check out what the cricketers from all over the world have to say about the greatest batsman of all time. This is a tribute to this living legend. Hats off to The Maestro, The Little Master, The Master Blaster, The God of Cricket.

Matthew Hayden:

"I have seen GOD, he bats at no.4 for India in Tests."

Ravi Shashtri:

"He is someone sent from up there to play cricket and go back."

Andy Flower:

"There are 2 kind of batsmen in the world. One Sachin Tendulkar. Two all the others."

Matthew Hayden:

"His life seems to be a stillness in a frantic world. When he goes out to bat, it is beyond chaos - it is a frantic appeal by a nation to one man. The people see him as a God."

Michael Kasprowicz:

"Don't bowl him bad balls, he hits the good ones for fours."

Shane Warne:

"I'll be going to bed having nightmares of Sachin just running down the wicket and belting me back over the head for six. He was unstoppable. I don't think anyone, apart from Don Bradman, is in the same class as Sachin Tendulkar. He is just an amazing player."

Brett Lee:

"You might pitch a ball on the off stump and think you have bowled a good ball and he walks across and hits it for two behind midwicket. His bat looks so heavy but he just waves it around like it's a toothpick."

BBC Sports:

"Beneath the helmet, under that unruly curly hair, inside the cranium, there is something we don't know, something beyond scientific measure. Something that allows him to soar, to roam a territory of sport that, forget us, even those who are gifted enough to play alongside him cannot even fathom. When he goes out to bat, people switch on their television sets and switch off their lives."

Abdul Qadir:

"I was fielding in the covers Tendulkar came out to bat in his debut Test at Karachi. I still remember Waqar Younis was at his peak form at that time. Tendulkar tried to drive Waqar through the covers off his very first ball in Test cricket but was beaten all ends up. But I walked to captain Imran Khan and told him 'this kid looks very good and Imran agree with me."

Shane Warne:

"Sachin Tendulkar is, in my time, the best player without doubt - daylight second, Brian Lara third."

Time Magazine:

"When Sachin Tendulkar travelled to Pakistan to face one of the finest bowling attacks ever assembled in cricket, Michael Schumacher was yet to race a F1 car, Lance Armstrong had never been to the Tour de France, Diego Maradona was still the captain of a world champion Argentina team, Pete Sampras had never won a Grand Slam. When Tendulkar embarked on a glorious career taming Imran and company, Roger Federer was a name unheard of; Lionel Messi was in his nappies, Usain Bolt was an unknown kid in the Jamaican backwaters. The Berlin Wall was still intact, USSR was one big, big country, Dr Manmohan Singh was yet to "open" the Nehruvian economy. It seems while Time was having his toll on every individual on the face of this planet, he excused one man. Time stands frozen in front of Sachin Tendulkar. We have had champions, we have had legends, but we have never had another Sachin Tendulkar and we never will."

And just have a look at the newspapers all across the country, the day after he became the first on this planet to score a double hundred in a one-day internationals on 24th February, 2010, against a team called South Africa which boasted of being one of the most formidable bowling line-up.

Its Sachin Tendulkar for you,
"Reducing the number of atheists worldwide since 1989"

Indian Owner for an EPL Club (Venky's for Blackburn Rovers)

2010-11-22T22:38:00.000-08:00

Poultry giant Venky's became the first Indian company to own an English Premier League club on Friday when it completed the takeover of former champion Blackburn.

A newly established British subsidiary called Venky's London Limited paid 23 million pounds (C$37.5 million) for a 99.9 per cent stake in the northwest England side and will make an unconditional offer for the remaining shares.

Blackburn would not comment on whether the new owners would pay off the club's debt that stood at 21 million pounds (C$34.2 million), according to its last full-year results.

But the Indian company's managing director, B. Venkatesh Rao, previously valued the takeover at 46 million pounds (C$74.9 million), which is close to the combined value of the shares and debt.

"We see real sustainable growth for the club moving forward, both within the UK and also internationally," Venky's director Balaji Rao said. "We intend to exploit our in-depth knowledge of the Indian market in particular, and beyond that, the whole of Asia.

"The immediate future will be spent with the key figures at the club from the chairman and the management team right through to the players and club staff working with them to ensure that we move forward as a team."

As one of seven assurances in its offer document, Venky's said it would provide regular funds to buy new players but did not say how much and how often. Fans hoping to see their team competing for star players with foreign-owned Manchester City and Chelsea are likely to be disappointed.

Venky's previously said it will spend five million pounds (C$8.1 million) in the January transfer window and concentrate on loan signings to help the club finish between 10th and 12th in the 20-team league.

Blackburn's record signing was the eight million pounds (C$13 million) it paid Manchester United for striker Andy Cole in December 2001. While City and Chelsea have each spent 30 million pounds (C$48.8 million) on players, Blackburn has since spent more than five million pounds only twice.

But the takeover could give Blackburn some financial muscle. Venky's, which is short for Venkateshwara Hatcheries, employs more than 7,500 people and has an 85 per cent share of the Indian poultry market.

"It would be very disappointing if it wasn't somebody that wanted to take over the club and try to improve it as quickly as possible," Blackburn manager Sam Allardyce said. "The best way to improve a football club in the early stages is the first-team results.

VH chairperson Anuradha J. Desai said in October that the company was buying Blackburn, which has been mostly mediocre since winning the 1995 Premier League, to promote its image overseas. The company has now given contractual commitments as part of the takeover that include promises not to change the name of the stadium stand bearing the name of former owner Jack Walker and to maintain the club's principal activity as a professional football club.

"We plan to focus on leveraging the global influence in establishing Blackburn Rovers as a truly global brand," Desai said Friday. "We will absolutely respect the Jack Walker legacy and will be actively supporting the organization to ensure that Blackburn Rovers remains one of the best run clubs within the Premier League."

The club was relegated in 1999 and, aside from promotion in 2001 and a League Cup title in 2002, Blackburn has mostly occupied mid-table in the Premier League since. Venky's has promised to maintain the statue of Walker outside Ewood Park stadium and to let President K.C. Lee and his three Vice-Presidents keep their present roles until at least the end of the season.

"We have been impressed with their enthusiasm for the club and their plans and ideas for future investment to develop it further as well as their wish and commitment to preserve the legacy of Jack Walker," said Paul Egerton-Vernon, chairman of the Jack Walker Settlement Trustees who previously owned the club.

"Over the last 10 years, the global appeal of the Premier League has grown significantly and it is only natural that, as we have seen at other clubs, international ownership and investment should increase."

India is on the EPL scene now. Something to cheer and support for the Indian Football fans too. Just hoping to see a revival of football in India. Thanks to Venky's for taking such an initiative. Let's see where it leads upto in the coming times. Hope for a brighter future for football in India.

Different Types Of Sorting Algorithms

2010-11-06T15:46:00.000-07:00

1) Exchange sorts :

1.1 Bubble sort

1.2 Cocktail sort

1.3 Odd-even sort

1.4 Comb sort

1.5 Gnome sort

1.6 Quick sort

2) Selection sorts :

2.1 Selection sort

2.2 Heapsort

2.3 Smoothsort

2.4 Cartesian tree sort

2.5 Tournament sort

2.6 Cycle sort

3) Insertion sorts :

3.1 Insertion sort

3.2 Shell sort

3.3 Tree sort

3.4 Library sort

3.5 Patience sort

4) Merge sorts :

4.1 Merge sort

4.2 Polyphase merge sort

4.3 Strand sort

4.4 Tim sort

5) Non-comparison sorts :

5.1 Radix sort

5.2 Bucket sort

5.3 Counting sort

5.4 Pigeon Hole sort

5.5 Burst sort

5.6 Bead sort

5.7 Bucket sort

6) Others :

6.1 Topological sorting

6.2 Sorting network

6.3 Bitonic sorter

6.4 Batcher odd-even mergesort

6.5 Pancake sorting

7) Ineffective/humorous sorts :

7.1 Bogo sort

7.2 Stooge sort

Hope that this list of sorting algorithms will help you.

Feel free to post comments and your opinions.

People Who Changed The Internet

2010-11-04T13:50:00.000-07:00

1) Bob Kahn and Vint Cerf (The Father Of Intenet)

The Father of Internet, Vint Cerf, together with Bob Kahn created the TCP/IP suite of communication protocols. a language used by computers to talk to each other in a network. Vint Cerf once said that the internet is just a mirror of the population and spam is a side effect of a free service.

2) Tim Berners-Lee (Inventor of WWW)

Tim Berners-Lee invented the World Wide Web. He wrote the first web client and server and designed a way to create links, or hypertext, amid different pieces of online information. He now maintains standards for the web and continues to refine its design as a director of the World Wide Web Consortium (W3C).

3) Ray Tomlinson (Father of Email)

Programmer Ray Tomlinson, the Father of Email made it possible to exchange messages between machines in diverse locations; between universities, across continents, and oceans. He came up with the “@” symbol format for e-mail addresses. Today, more than a billion people around the world type @ sign every day.

4) Michael Hart (Founder of eBooks)

Michael Hart started the birth of eBooks and breaks down the bars of ignorance and illiteracy. He created the Project Gutenberg and was considered world’s first electronic library that changed the way we read. The collection includes public domain works and copyrighted works with express permission.

5) Gary Thuerk (The First Email Spam)

Spamming is an old marketing technique. Gary Thuerk, sent his first mass e-mailing to customers over the Arpanet for Digital’s new T-series of VAX systems. What he didn’t realize at the time was that he had sent the world’s first spam.

6) Scott Fahlman (The First Emoticon)

Scott Fahlman is credited with originating the first ASCII-based smiley emoticon, which he thought would help to distinguish between posts that should be taken humorously and those of a more serious nature. Now, everybody uses them in messenger programs, chat rooms, and e-mail.

7) Marc Andreessen (Netscape Navigator)

Marc Andreessen revolutionized Internet navigation. He came up with first widely used Web browser called Mosaic which was later commercialised as the Netscape Navigator. Marc Andreessen is also co-founder and chairman of Ning and an investor in several startups including Digg, Plazes, and Twitter.

8) Jarkko Oikarinen (Internet Relay Chat, IRC)

Jarkko Oikarinen developed the first real-time online chat tool in Finland known as Internet Relay Chat. IRC’s fame took off in 1991. When Iraq invaded Kuwait and radio and TV signals were shut down, thanks to IRC though up-to-date information was able to be distribute.

9) Robert Tappan Morris (The First Worm Virus)

The concept of a worm virus is unique compare to the conventional hacking. Instead of getting into a network themselves, they send a small program they have coded to do the job. From this concept, Robert Tappan Morris created the Morris Worm. It’s one of the very first worm viruses to be sent out over the internet that inadvertently caused many thousands of dollars worth of damage and “loss of productivity” when it was released in the late 80s.

10) David Bohnett (Geocities)

David Bohnett founded GeoCities in 1994, together with John Rezner. It grew to become the largest community on the Internet. He pioneered and championed the concept of providing free home pages to everyone on the web. The company shut down the service on October 27, 2009.

11) Ward Cunningham (The First Wiki)

American programmer Ward Cunningham developed the first wiki as a way to let people collaborate, create and edit online pages together. Cunningham named the wiki after the Hawaiian word for “quick.”

12) Sabeer Bhatia (Hotmail)

Sabeer Bhatia founded Hotmail in which the uppercase letters spelling out HTML-the language used to write the base of a webpage. He got in the news when he sold the free e-mailing service , Hotmail to Microsoft for $400 million. He was awarded the “Entrepreneur of the Year” by Draper Fisher Jurvertson in 1998 and was noted by TIME as one of the “People to Watch” in international business in 2002. His most exciting acquisition of 2009 was Jaxtyr which he believes is set to overtake Skype in terms of free global calling.

13) Matt Drudge (The Drudge Report)

Matt Drudge started the news aggregation website The Drudge Report. It gained popularity when he was the first outlet to break the news that later became the Monica Lewinsky scandal.

14) Larry Page and Sergey Brin (Google)

Larry Page and Sergey Brin changed the way we search and use the Internet. They worked as a seamless team at the top of the search giant. Their company grew rapidly every year since it began. Page and Brin started with their own funds, but the site quickly outgrew their own existing resources. They later obtain private investments through Stanford. Larry Page, Sergey Brin and their company Google, continue to favor engineering over business.

15) Bill Gates (Microsoft)

Bill Gates founded the software company called “Micro-Soft”. a combination of “microcomputer software.” Later on, Bill Gates developed a new GUI (Graphical User Interface) for a disk operating system. He called this new style Windows. He has all but accomplished his famous mission statement, to put “a computer on every desk and in every home”. at least in developed countries.

16) Steve Jobs (Apple)

Steve Jobs innovative idea of a personal computer led him into revolutionizing the computer hardware and software industry. The Apple founder changed the way we work, play and communicate. He made simple and uncluttered web design stylish. The story of Apple and Steve Jobs is aboutf determination, creative genius, pursuit of innovation with passion and purpose.

17) David Filo and Jerry Yang (Yahoo)

David Filo and Jerry Yang started Yahoo! as a pastime and evolved into a universal brand that has changed the way people communicate with each other, find and access information and purchase things. The name Yahoo! is an acronym for “Yet Another Hierarchical Officious Oracle,” but Filo and Yang insist they selected the name because they liked the general definition of a yahoo: “rude, unsophisticated, uncouth.”

18) Brad Fitzpatrick (LiveJournal)

Brad Fitzpatrick created LiveJournal, one of the earliest blogging platforms. He is seen on the Internet under the nickname bradfitz. He is also the author of a variety of free software projects such as memcached, used on LiveJournal, Facebook and YouTube. LiveJournal continues today as an online community where people can share updates on their lives via diaries and blogs. Members connect by creating a “friends list” that links to their pals’ recent entries.

19) Shawn Fanning (Napster)

Shawn Fanning developed Napster, a peer-to-peer file-sharing program designed to let music fans find and trade music. Users put whatever files they were willing to share with others into special directories on their hard drives. The service had more than 25 million users at its peak in 2001, and was shut down after a series of high-profile lawsuits, not before helping to spark the digital music revolution now dominated by Apple. Napster has since been rebranded and acquired by Roxio.

20) Peter Thiel (Paypal)

Peter Thiel is one of many Web luminaries associated with PayPal. PayPal had enabled people to transfer money to each other instantly. PayPal began giving a small group of developers access to its code, allowing them to work with its super-sophisticated transaction framework. Peter Thiel cofounded PayPal at age 31 and sold it to eBay four years later for $1.5 billion.

21) Pierre Morad Omidyar (Ebay)

Pierre Omidyar set up an online marketplace that brought buyers and sellers together as never before, and pioneered the concept of quantifying the trustworthiness of an anonymous user. In building his auction empire, Omidyar counted on the power of the individual. Omidyar’s greatest strength is his insight into human nature. He understood that people would buy just about anything. one man’s junk is, in fact, another’s treasure.

22) Jimmy Wales (Wikipedia)

Jimmy Wales founded the world’s largest encyclopaedia which carries articles that can easily be edited by anyone who can access the website. It was launched in 2001 and is currently the most popular general reference work on the Internet.

23) Stewart Butterfield and Caterina Fake (Flickr)

Photosharing website has become a part of everyday online life for millions of people. Stewart Butterfield, who with his wife Caterina Fake created Flickr that was born out of an online multi-player game that seemed to sum up everything the Web 2.0 people were trying to do. Flickr came along with an idea that you no longer had an album. Instead, you had a photo stream. Yahoo later on acquired Flickr in 2005.

24) Jonathan Abrams (Friendster)

Jonathan Abrams built Friendster, together with Cris Emmanuel, offering many tools to help members find dates. He took the idea from Match.com. It’s the first social network to hit the big time and go mainstream. Members create profiles listing favorite movies and books (and dating status) and link up to friends, who linked to their friends, and so on.

25) Niklas Zennstrom (Skype)

Niklas Zennstrom co-founded the fastest growing communications trend in history called Skype. It offered consumers worldwide a free software for making superior-quality calls using their computer and expanded its offering for Linux, MAC & PC and mobile/ handheld devices.

26) Bram Cohen (Bit Torrent)

If Napster started the first generation of file sharing , Bram Cohen changed the face of file sharing by developing BitTorrent which has a massive following of users almost instantly. It uses the Golden Rule principle: the faster you upload, the faster you are allowed to download. BitTorrent breaks up files into many little portions, and as soon as a user has a piece, they instantly start uploading that part to other users. So almost everybody who is sharing a given file is simultaneously uploading and downloading pieces of the same file.

27) Reid Hoffman (LinkedIn)

Reid Hoffman, a former executive vice president at PayPal, created LinkedIn as a professional social network allowing registered users to maintain a list of contact details of people they know and trust in business. Members can search for jobs, trade resumes, find new hires and keep up with the competition.

28) Matt Mullenweg (WordPress)

Matt Mullenweg founded the world’s most used open source blogging and the greatest boon to freedom of expression known as WordPress. Some of the most popular websites run on WordPress are Techcrunch, Huffingtonpost, Mashable and more.

29) Chad Hurley, Steve Chen and Jawed Karim (Youtube)

Chad Hurley, Steve Chen and Jawed Karim met as early employees at PayPal. They later started the internet’s most popular video-sharing site YouTube which is broadcasting more than 100 million short videos daily on myriad subjects. When creating YouTube, the three divided work based on skills: Chad Hurley designed the site’s interface and logo. Steve Chen and Jawed Karim divide technical duties making the site work. They later split management tasks, based on strengths and interests: Chad Hurley became CEO; Steve Chen, Chief Technology Officer. A year and a half later, Google acquired YouTube for a deal worth $1.65 billion in stock.

30) Craig Newmark (Craigslist)

Craig Newmark started a site that dramatically altered the classified advertising universe called Craiglist. It was an object of fear for newspapers who felt threatened by the free-for-all classified advertising site. It began as an e-mail list for Newmark’s friends in the Bay Area. Since then, it has grown into an online database for classified ads for those seeking everything from housing to romance.

31) Julian Assange (WikiLeaks)

Julian Assange founded a website dedicated to publishing classified documents stolen from around the world. He designed an advanced software for the Wikileaks shielding the identities of the thieves who steal these documents by completely erasing their identities before spreading the stolen documents to servers ‘all over the world’. As a result, no one can trace who’s given him what or when. The site depicts itself as the “uncensorable Wikipedia for untraceable mass document leaking and analysis” and has developed to be regarded as the most extensive and safest stage for whistleblowers to leak to.

32) Dick Costolo (FeedBurner)

People generally check their preferred sites every now and then to see if there’s anything new. FeedBurner founder Dick Costolo created a news aggregator that automatically downloads an update that is visible in the places that interest you. An RSS feed, short for Really Simple Syndication, delivers those latest bits of media from their creator’s website to your computer. FeedBurner was later acquired by Google in 2007. Currently, Dick Costolo is Twitter’s Chief Operating Officer making twitter the next generation RSS.

33) Mark Zuckerberg (Facebook)

Mark Zuckerberg founded Facebook to help students in universities keep in touch with friends. The “status update” started its rebirth in Facebook, where user after user tell their extended network of trusted friends what they’re doing. They also show off photos, upload videos, chat, make friends, meet old ones, join causes, groups, have fun and throw virtual sheep at one another. The site, which is believed to have 500 million registered users worldwide, has only four remaining countries left to conquer: Russia, Japan, China and Korea, according to Zuckerberg. Facebook is now twice as huge as Rupert Murdoch’s MySpace.

34) Jack Dorsey (Twitter)

Jack Dorsey created Twitter to allow friends and family know what he was doing. The world’s fastest-growing communications medium let users broadcast their thoughts in 140 characters or less and repost someone else’s informative or amusing message to their own Twitter followers by Retweeting. No one thought people would want to follow strangers, or that celebrities would use Twitter to tell fans of their activities, or that businesses would use Twitter to announce discounts or launch new products.

35) Christopher Poole (4chan message board)

Christopher Poole, known online as “Moot,” started a message board called 4chan where people are free to be wrong. Unlike most web forums, 4chan does not have a registration system, allowing users to post anonymously. Moot believes in the value of multiple identities, including anonymity, in contrast to the merge of online and real-world identities occurring on Facebook and many other social networking sites.

36) Joshua Schachter (Delicious)

Del.icio.us is a more sophisticated multiuser version of Muxway, wherein his first implementation of tags. Joshua Schachter began del.icio.us as a way for people to store and share their favorite Web-browsing bookmarks online. Instead of organizing them himself, or even creating a standard taxonomy of categories, Schachter used something called user tagging-people simply labeled the bookmarks by any name they wanted, and eventually the group as a whole effectively voted on them by either adopting those tags themselves or rejecting them. And now del.icio.us has been gobbled up by Yahoo, which hopes to extend the tagging principle to all sorts of its services.

37) Jeff Bezos (Amazon)

Jeff Bezos founded the world’s biggest online store known as Amazon, which was originally named Cadabra Inc. He made online shopping faster and more personal than a trip to the local store. The company now introduced Kindle allowing readers to download books and other written materials and read them on this handheld device.