Airtel 3G Signal on Air

Though Airtel, the biggest private mobile operator in India has not commercially introduced 3G services yet, my 3G USB modem detects Airtel’s 3G signal already in my work city! Looks like they are too close to launch and I really look forward to it! :-)

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CellOne is the national operator BSNL which launched 3G last year 2009.

Google Chrome Cloud Printing – Test Drive

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After I watched yesterday’s webcast by Google on Chrome OS, I got a bit curious about their cloud printing thing and thought would give it a test to see if it really works. So, I took the Chrome Browser Dev Channel 9.0.597.10 and setup/enabled Cloud Printing on my home laptop (Windows 7, 64bit) which is connected to my Canon PIXMA printer (via Wi-Fi). The Cloud Print Connector nicely recognized the printer and showed it on the printer management page:

Chrome Cloud Printer Management

Then from my Mac Book I went to the Cloud Print test page (http://www.google.com/landing/cloudprint/win-enable.html) and fired up a test page to the Canon printer:

Cloud Print Test Page

When you click Print a test page button, you get to select a printer available on the Cloud Printing enabled PC (in my case in was my home laptop):

Select Cloud Printer

The job gets queued, which can be seen back at the printer management page:

Job Queued

After a couple of minutes, Chrome browser on my laptop automatically picks up the test page job and feeds to the selected printer, the job goes to the Completed print jobs list (refresh the above page after a minute or two):

Job Completed

And the test page is this!!

Chrome Cloud Print Test Page

As Google claims, cloud printing is still in early stages and the above UI all subject to change.

Google Chrome OS

I am sure by the time this post appears on my blog site, many around the world would have talked about it, but here are my observations after watching the webcast yesterday by Google.


  1. 3S ‘that drive Chrome (OS and the browser) are: Speed, Simplicity & Security
    • Sundar (VP, Product Development of Google) compared the performance of Chrome browser’s JavaScript engine performance with IE and how Chrome outperforms IE by 100x in JS performance. But, the world also uses Firefox and Opera? How does it compare with these two browsers? No mention of it.
    • Chrome extensively uses GPU to render desktop app-like graphics
    • Update: Same user experience wherever you use Chrome: All your browser settings, installed extensions, themes, etc. all synced on whichever machine you use Chrome browser when synchronization enabled. Indeed, this is one of my very favorite features too. Firefox also has the same feature but not many know about it.
  2. Web Store
    • Update: A web “application” in Chrome’s world is a web application that runs inside a browser (hosted or packaged) with optional offline capability (for packaged only). There is no local Windows app-like install.
    • Primarily a channel for Google partners to sell their web applications targeting Chrome OS & browser
    • Web applications may work offline too so that you can still use them when you are offline
    • Amazon, New York Times and few other partners demonstrated their web applications for Chrome
    • Update: The web store was opened for public with more than 500 web applications already (Check out http://chrome.google.com/webstore).
    • Update: An interesting demo was given by Citrix. As you know, Citrix specializes in application virtualization and run applications with zero local foot print. Citrix Receiver now supports Chrome OS and they showed launching various Microsoft Office apps via Chrome OS. This I believe will be beneficial for the field staff that can carry a slim light-weight Chrome notebook but access applications via Chrome itself. Given the offline capabilities, this can prove even more useful if do not have any connectivity. 
  3. Chrome OS
    • Fully web-oriented with Google’s philosophy that applications in future will reside on the web (cloud based) and browsers are simply a gateway to use them. Example: Google Office applications
    • ISV/Developers can develop & add more applications and downloaded via Web Store
    • When you buy a Chrome notebook, all it requires is a 3-step setup process to go up and running
    • Web apps and Chrome OS are always up-to-date and “feel fresh”!
    • All the in-built apps in Chrome OS are Google’s web-based applications with offline capability (but Google feels that we all connected one way or the other: WiFi, LAN, 3G, EDGE/GPRS, etc.)
    • Instant sleep/resume when you close/open the Chrome notebook lid – demonstrated well! :-)
    • Chrome notebooks will not have function keys and Caps Lock!
    • Samsung and Acer will release Chrome notebooks mid 2011; prices are still being worked out
    • Powered by Intel processors (no mention what type of processor)
    • Update: Inbuilt guest mode: Hand your notebook to your friends without worrying about whether he/she will have access to your browser data. First, all data is encrypted; second, the guest mode opens the browser interface in “Incognito” mode.
    • Update: No user-accessible hard disk! Yet whatever Chrome OS stores (local or cloud) will all be encrypted 
    • Update: First consumer OS to have “Verified Boot” feature. A minimal version of Chrome OS is stored in an EPROM (firmware) chip with no developer-accessible API (Chrome extension APIs) access. On powering on, this firmware OS starts and verifies the rest of the Chrome OS code is not tampered with and came only from Google code base. Only after this verification, the regular boot process kicks off. If any attack or modification is found, the firmware OS initiates recovery process. As secured as possible unless someone replaces the EPROM chip itself! ;-)  
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Less Known Things in C#

There are quite a many gems hidden in C# and .NET Framework. Here are some:


?? operator

C# 2 introduced the concept of nullable value types. If you assign a nullable value type to a non-nullable variable and if the former is null, you will get a runtime error. Meet ?? operator, also known as null-coalescing operator. The operator simply returns a default value when the nullable value type is null otherwise the actual value itself. You can think of it as a specialized ternary operator for nullable-value types.


Null-coalescing Operator


Partial Methods

Again, C# 2 introduced the concept of partial classes, primarily to separate designer-generated code from user-written code so that the designer (Visual Studio’s) can regenerate the code without affecting user’s part. There is one side-benefit too: multiple developers can work on the same class split across multiple files. C# 3 introduced partial methods as an evolvement of partial classes. In short, partial method is one that is declared (without body) but its actual implementation is left to the developer and the implementation is optional. The former aspect may look very similar to abstract methods but the latter is how partial methods differ from abstract methods.


Say you are implementing a business component that performs complex processing. At key stages of this process you want to give the developer an option to do detailed logging or tracing on how the actual logic is running or monitor the code’s performance. In order to do this, you can interleave logging method calls but you do not care how the actual logging is done, if at all it is done. Here is a sample of how the business component class may look like:


Partial Methods


The MortgageCore class defines a partial method named TraceMessage which is actually implemented in the subsequent partial class definition. The following shows the reverse-engineered definition of the MortgageCore.IsMortgateRequestValid() method from the compiled output:



Without the partial method implementation, the method looks like:



As you can see, the compiler has removed all the invocations to the partial method after the partial method implementation has been removed. Partial methods may look like delegates too: unless any handlers are hooked, calling a delegate doesn’t have any effect, which is similar to partial method behavior. But again, the C# complier hard-wires delegate calls into assembly while empty partial methods are optimized away without leaving any traces of their existence. Keep in mind the following:


  • They can only exist inside a partial class
  • They are implicitly private
  • No multiple definitions for partial methods
  • Can accept parameters including ref types but not out types
  • Cannot have a return type; only void

As you might have probably guessed, most of the restrictions are due to the fact that the complier removes partial method references if they are not defined.


Duck Typing

Quite popular in dynamic languages like Ruby, duck typing allows the C# compiler to treat a type with characteristics of another type like that type itself (confusing, I know! :-)). Take a look at the sample below:



The class DuckType doesn’t implement IEnumerabe or IEnumerator but has members with the same name as that of those interfaces. This lets the DuckType class to be treated like one that actually implemented these two interfaces and hence can be used in foreach loop:



Produces the output:


Duck Typing Example


Obvious, right?


 


Well, I have a laundry list of items to cover under this topic and so it might become a multi-part series.