The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Software Development’ Category

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The cloud has no walls: cache-based jamming agreement to communicate over the CPU cache even without rights

Posted by jpluimers on 2017/10/12

Oh boy: [WayBack] Alles kaputt: In der Cloud gibt es keine Wände.  – Kristian Köhntopp – Google+:

Two Amazon EC2 instances communicating over the CPU cache without the need of a network in-between them.

Open sourced foundations: IAIK/CJAG: CJAG is an open-source implementation of our cache-based jamming agreement.

In our BlackHat Asia 2017 Talk we show that the cache covert channel we built is so fast and reliable that we can do much more than tunneling SSH over it: We show that we can even stream a music video in decent quality through the cache – on the Amazon EC2 cloud.

See the BlackHat Asia Briefings Information here: https://www.blackhat.com/asia-17/brie…

See a video of the Live Demo here: https://www.youtube.com/watch?v=yPZmi…

Find our NDSS 2017 paper here: https://gruss.cc/files/hello.pdf

–jeroen

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Posted in Development, Hardware Development, Security, Software Development | Leave a Comment »

ThreadBarrier/ThreadBarrier.pas at master · lordcrc/ThreadBarrier

Posted by jpluimers on 2017/10/12

I mentioned Asbjørn Heid on wiert.me before. While prepping for the Deadlock Empire workshop at EKON20, I needed a Delphi equivalent for the .NET [Way: Barrier Class (System.Threading)

The game uses that in level deadlockempire.github.io/#H4-Barrier [WayBack].

Edwin van der Kraan found the ThreadBarrier/ThreadBarrier.pas at master · lordcrc/ThreadBarrier implementation via [WayBack] Is there a way to create memory barriers in Delphi? Something like .NET’s System.Threading.Barrier class, java.util.concurrent.CyclicBarrier… – Horácio Filho – Google+

It’s from Asbjoørn who is known as lordcrc on GitHub. Cool stuff!

So yes, there is a Delphi version of If you thought you could do multi-threading, then play “The Deadlock Empire” games. You can find it at https://deadlockempire.4delphi.com/ There are two deadlockempire implementations there:

The workshop was great fun!

This is about a web game focussing on the concurrency issues in multi-threading environments. By the conference there will be a Delphi version of it. At the workshop we will play each round interactively: all attendees play the round followed by a short discussion. This is about collective learning, so the speakers will probably learn… Read More

Source: [Archive.is] If you thought you could do multi-threading, then play “The Deadlock Empire” games – Entwickler Konferenz

–jeroen

Posted in .NET, C#, Delphi, Delphi 10 Seattle, Delphi 10.1 Berlin (BigBen), Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Delphi XE6, Delphi XE7, Delphi XE8, Development, Software Development | 1 Comment »

HTML indentation: 2 spaces

Posted by jpluimers on 2017/10/12

Using too many editors in too many environments, tabbed files usually kills my productivity.

Not just because the structure of the indented code, also because most editors are stupid enough to also use tabs beyond the indentation, for instance for carefully aligned initialisation statements.

Changing the tab-size effectively waves good bye to those.

It’s weird (Wiert loves that word) that HTML peeps even argue about tabs versus spaces:

Most people still use HTML for pixel perfect rendering and spaces help getting character perfect rendering of the source code.

I was glad to bump into [WayBack] Jefferson Lima answering this on Stack Overflow:

The Google HTML/CSS Style Guide and the W3School HTML(5) Style Guide recommend 2 spaces.

This article also brings an analysis of the effect of tabs vs spaces in the resulting file size.

Source: [WayBack] html5 – html indenting standard, tab or two spaces? – Stack Overflow

So: use 2 spacec for HTML indent.

It doesn’t really matter in transmitted size (minified compressed transfer difference is ~0% and the usual image bloat is way larger than the HTML anyway – just try www.webbloatscore.com and watch).

References:

  • Indent by 2 spaces at a time.
  • Don’t use tabs or mix tabs and spaces for indentation.

Source: [WayBack] Google HTML/CSS Style Guide

  • Do not add blank lines without a reason.
  • For readability, add blank lines to separate large or logical code blocks.
  • For readability, add two spaces of indentation. Do not use the tab key.
  • Do not use unnecessary blank lines and indentation. It is not necessary to indent every element.

Source: [WayBack] HTML5 Style Guide

Tabs Spaces Saving
Raw file size 1403 bytes 1703 bytes 300 bytes/18%
Raw file GZipped   327 bytes   332 bytes      5 bytes/1.5%
Raw file minified 1199 bytes 1199 bytes      0 bytes/0%
Minified & GZipped   312 bytes   312 bytes      0 bytes/0%

When minified, it doesn’t matter if tabs or spaces are used, since they are all stripped away.

Source: [WayBack] Effect of tabs vs. spaces in HTML files

–jeroen

Posted in Development, HTML, Software Development, Web Development | Leave a Comment »

Is there a standard function to check for null, undefined, or blank variables in JavaScript? – Stack Overflow

Posted by jpluimers on 2017/10/11

Yes there is; it’s the answer below. Note I needed to exclude false by adding a check value === false to the code below as that was a valid value for me.

You can just check if the variable has a truthy value or not. That means

if( value ) {
}

will evaluate to true if value is not:

  • null
  • undefined
  • NaN
  • empty string (“”)
  • 0
  • false

The above list represents all possible falsy values in ECMA-/Javascript. Find it in the specification at the ToBoolean section.

Furthermore, if you do not know whether a variable exists (that means, if it was declared) you should check with the typeof operator. For instance

if( typeof foo !== 'undefined' ) {
    // foo could get resolved and it's defined
}

If you can be sure that a variable is declared at least, you should directly check if it has a truthyvalue like shown above.

Further read: http://typeofnan.blogspot.com/2011/01/typeof-is-fast.html

Thanks to [WayBack] User jAndy – Stack Overflow who answered the above at [WayBack] Is there a standard function to check for null, undefined, or blank variables in JavaScript? – Stack Overflow.

–jeroen

Posted in Development, JavaScript/ECMAScript, Scripting, Software Development | Leave a Comment »

How do I make the first letter of a string uppercase in JavaScript? – Stack Overflow

Posted by jpluimers on 2017/10/11

I’m a JavaScript n00b, so I like solutions like these:

Another solution:

function capitalizeFirstLetter(string) {
    return string.charAt(0).toUpperCase() + string.slice(1);
}

You could also add it to the String.prototype so you could chain it with other methods:

String.prototype.capitalizeFirstLetter = function() {
    return this.charAt(0).toUpperCase() + this.slice(1);
}

and use it like this:

'string'.capitalizeFirstLetter() // String

Thanks [WayBack] Hutch Moore and [WayBack] Deviljho for answering at [WayBack] How do I make the first letter of a string uppercase in JavaScript? – Stack Overflow!

Note you can do it in CSS too as explained by [WayBack] sam6ber:

In CSS:

p:first-letter {
    text-transform:capitalize;
}

–jeroen

Posted in CSS, Development, JavaScript/ECMAScript, Scripting, Software Development, Web Development | Leave a Comment »

`Inc(I)` versus `I := I + 1;` in Delphi – they’re the same, but not atomic per se.

Posted by jpluimers on 2017/10/10

Given a variable I: Integer, some people like Inc(I); others like I := I + 1;.

You might think that part of that discussion nowadays should be multithreading.

In practice this does not matter: the compiler will use the same instructions for both statements.

TL;DR: This might make you think they are always atomic. But that’s not always true, as the below differences show. In addition, it can also depend on your processor archicture.

In the Win32 Delphi Compiler, this is how they look:

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Posted in Delphi, Delphi 10 Seattle, Delphi 10.1 Berlin (BigBen), Delphi XE3, Delphi XE4, Delphi XE5, Delphi XE6, Delphi XE7, Delphi XE8, Development, Software Development | 5 Comments »

Multithreading in C# .NET 4.5 (Part 2) – CodeProject

Posted by jpluimers on 2017/10/10

Always good having a reference article at hand: [WayBack] Multithreading in C# .NET 4.5 (Part 2) – CodeProject

via: [WayBack] Best C# Article of September 2016 PureNsanity – Multithreading in C# .NET 4.5 (Part 2)Runner UpSnesh Prajapati – Factory Patterns – Simple Factory … – CodeProject – Google+

–jeroen

Posted in .NET, .NET 4.5, C#, C# 4.0, C# 5.0, C# 6 (Roslyn), Development, Software Development | 1 Comment »

Comparison of Common markup for Markdown and reStructuredText · GitHub

Posted by jpluimers on 2017/10/09

This is a very good comparison of how to use reStructuredText and Markdown well for rendering at GitHub: [WayBack] Common markup for Markdown and reStructuredText · GitHub.

It is being updated by Alex Dupuy over time at https://gist.github.com/dupuy/1855764 and has two sections:

And it refers to http://pandoc.org/try/ which I had missed when starting with reStructuredText a long time ago.

Examples in there are actually more useful to me than these reStructuredText ones:

–jeroen

Posted in Development, Lightweight markup language, MarkDown, Power User, reStructuredText, Software Development | 2 Comments »

nojhan/liquidprompt: A full-featured & carefully designed adaptive prompt for Bash & Zsh

Posted by jpluimers on 2017/10/05

Wow: nojhan/liquidprompt: A full-featured & carefully designed adaptive prompt for Bash & Zsh

This is really useful!

via:

Sort of tanslated from the first “via” (note that “mit Alles und Scharf” is hard to translate; it’s somewhere between “everything but the kitchen sink, but done right” and “right on the money”):

Bash Prompt Overkill: https://github.com/nojhan/liquidprompt is a Bash “Prompt doing it all right”-extension, which doesn’t care how much any feature costs as we have cores, gigabytes and SSD.

Liquid Prompt automagically recognises context and enables a plethora of features in the prompt when needed based on that context.

It’s like pixie dust for your prompt.

You can configure everything, but you don’t have to: the out of the box experience is already like pixie dust for your prompt.

It works on OS X too and is part of homebrew:

$ brew install liquidprompt
==> Using the sandbox
==> Downloading https://github.com/nojhan/liquidprompt/archive/v_1.11.tar.gz
==> Downloading from https://codeload.github.com/nojhan/liquidprompt/tar.gz/v_1.11
######################################################################## 100.0%
==> Caveats
Add the following lines to your bash or zsh config (e.g. ~/.bash_profile):
  if [ -f /usr/local/share/liquidprompt ]; then
    . /usr/local/share/liquidprompt
  fi
If you'd like to reconfigure options, you may do so in ~/.liquidpromptrc.
A sample file you may copy and modify has been installed to
  /usr/local/share/liquidpromptrc-dist
Don't modify the PROMPT_COMMAND variable elsewhere in your shell config;
that will break things.
==> Summary
🍺  /usr/local/Cellar/liquidprompt/1.11: 7 files, 125.6K, built in 3 seconds
[jeroenp:~/Versioned] 10s $

–jeroen

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Posted in *nix, *nix-tools, Apple, bash, bash, Development, Mac OS X / OS X / MacOS, Power User, Scripting, Software Development | Leave a Comment »

Visual Studio Code – getting started – some links

Posted by jpluimers on 2017/10/05

It might sound like I’m late in the game, but remember that blog posts are usually scheduled like a year in advance.

So I found out a long time ago (I think it’s Matthijs ter Woord who attended me) about Visual Studio Code.

At the start [WayBack] it was more limited (from memory something like C#, TypeScript, Java Script languages and frameworks Node.js and ASP.NET 5) than my other development environments but now it’s much richer.

It’s based on the Electron framework which I kew from the Atom.io editor and Koush‘s framework Electron Chrome that wraps Chrome Apps in Electron so he ensured Vysor would live after Google will kill Chrome Apps.

Oh it’s free and runs multi-platform which I like a lot (and was one of the reasons to start using Atom.io): Mac OS X, Windows and Linux are supported.

So here are a few links to get started:

I got reminded a while back** that it is now supported by OmniPascal [WayBack] which I like because of my Turbo Pascal -> VAX/VMS -> csh -> Delphi -> AS/400 -> .NET background.

Like Visual Studio Code is updated often, the Omni Pascal blog [WayBack] shows regular updates and I like it a lot better than the Lazarus IDE (I’m not a visual RAD person: I’m a RAD code person) especially the refactorings.

So start playing with it. I will post more about my Visual Studio Code experience in due time.

–jeroen

** via [WayBack] Finally: OmniPascal 0.11.0 released – Implement an interface via key stroke …

Posted in .NET, ASP.NET, C#, Delphi, Development, JavaScript/ECMAScript, Node.js, Omni Pascal, Pascal, Scripting, Software Development, TypeScript, Visual Studio and tools, vscode Visual Studio Code | 1 Comment »

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