Category: Uncategorized

Continuous integration

Continuous integration (CI) is the practice of automating the integration of code changes from multiple contributors into a single software project. It’s a primary DevOps best practice, allowing developers to frequently merge code changes into a central repository where builds and tests then run. Automated tools are used to assert the new code’s correctness before integration.

A source code version control system is the crux of the CI process. The version control system is also supplemented with other checks like automated code quality tests, syntax style review tools, and more.  

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In this blog post, you will witness how multi-core CPU executes different processes and do context switching.

We will use the following program, this program merely takes input from the user and prints input string after some time periodically.

	using System;
	using System.Diagnostics;
	using System.Runtime.InteropServices;
	using System.Security;
	using System.Threading;
	internal class Program
	{
	[DllImport("Kernel32.dll"), SuppressUnmanagedCodeSecurity]
	public static extern int GetCurrentProcessorNumber();
	private static void Main()
	{
	var currentProcess = Process.GetCurrentProcess();
	Console.WriteLine($"Please enter any string for process {currentProcess.Id} which is executed by {GetCurrentProcessorNumber()}: ");
	var readline = Console.ReadLine();
	var i = 0;
	while (i++ < 12)
	{
	Console.WriteLine($"For process {currentProcess.Id} which is executed by {GetCurrentProcessorNumber()}, you have entered: {readline}");
	Thread.Sleep(1000);
	}
	}
	}

view raw SampleForRunningManyProgramsAtOnce.cs hosted with ❤ by GitHub

I presume after compiling the above file, we get the output file: ‘OSPlayground.exe’.

Now open a command prompt and navigate to the path that contains the above binary. Run the following command and witness the magic.

Command to use: start /b OSPlayground && OSPlayground

Output:

The command prompt will ask you to enter the string a couple of times since we executed the program twice.
I had inputted EARTH! for the first process from the command prompt and MARS! for another one.

The above program is executed on a multicore processor.

• https://nodejs.org/dist/v8.12.0/node-v8.12.0-x64.msi
• https://www.python.org/download/releases/2.7/

npm install --global --production windows-build-tools --vs2015

Tell Node to use the 2015 build tools.

npm config set msvs_version 2015 –global

 Set your Node config to use Python 2.7.

npm config set python python2.7

npm install –no-optional

When getting data from a file

• Verify that if it has valid extensions/file type
• Verify that it does not exceeds certain file size

When getting data from a a user, the network, or some other external interface

• Check to be sure that the data falls within the allowable range.
• Make sure that numeric values are within tolerances
• Strings are short enough to handle.
• If a string is intended to represent a restricted range of values.
• Be sure that the string is valid for its intended purpose;

Otherwise reject it.

Functions in JavaScript are objects.

How to know in the browser?

Navigate to the console of the browser near you and type this simple function Person shown below and hit enter. Next, type Person followed by dot (.) see the methods on Person function. Pretty simple.

Thus the function is an object and has the methods as other objects in JavaScript.

We can call functions on function. Let’s invoke call function and see the output.

Prototype object:

Objects are keyed collection/associative array that has a hidden link to the prototype object. Try the following code in any browser console and understand it.

We can access the prototype object using Object.prototype.

We can get an original object back from the prototype object using constructor (Object.prototype.constructor) property.

Pictorial representation of Object and it’s prototype object.

Oh, wait! We were talking about Function.

Like Object, Function is linked to Function.prototype.

Let me show you using Person function, it’s prototype object and their linking in the browser console.

Pictorial representation of Person function and it’s prototype object.