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by Jiří {x2} Činčura

Gopas TechEd 2022

9 May 2022 1 mins Presentations & Speaking

Příští týden se bude konat Gopas TechEd. Po několika letech online verzí, tentokrát v hybridním provedení. Letos si z mé strany můžete poslechnout jednu in-person i online přednášku a dvě čistě online.

Ask Jiri: Ukládání IP adres do databáze, plus IPv6

28 Apr 2022 1 mins Ask Jiri

Sometimes people ask me a question where the answer requires some kind of dialogue or follow-up questions and/or is too long to type. Thus, I’m trying new way of recording the conversation and then posting it for anybody to watch.

Sometimes it is in Czech (like this one), sometimes in English. Sometimes one person (and me), sometimes multiple.

Do you have an interesting question? Send me an email and let’s chat about it.

Now, here’s the recording:

Ask Jiri: Python očima .NETáka

14 Apr 2022 1 mins Ask Jiri

Sometimes people ask me a question where the answer requires some kind of dialogue or follow-up questions and/or is too long to type. Thus, I’m trying new way of recording the conversation and then posting it for anybody to watch.

Sometimes it is in Czech (like this one), sometimes in English. Sometimes one person (and me), sometimes multiple.

Do you have an interesting question? Send me an email and let’s chat about it.

Now, here’s the recording:

Techorama 2022

13 Apr 2022 1 mins Presentations & Speaking

I’ll be speaking at Techorama 2022 happening May 23-25. And I’m very excited about it. Over the last decade or so I was working with/for Belgium based company on and off, so Belgium has somewhat special place in my heart.

Two of my sessions were selected. First is C# Source Generators – let the machine do the programming and other is Performance with Span<T> for dummies (should I care?).

MS Stage conference

18 Feb 2022 1 mins Presentations & Speaking

I’ll be speaking on MS Stage (online) February 25th April 1st. I’ll show you what Source Generators are and how to create one yourself.

Attribute on attribute itself

10 Feb 2022 1 mins C#

Today I learned that you could use attribute, in C#, on itself. 🤯 Not sure why would I do that, but it’s cool.

What is the cost of casting in .NET (C#)?

8 Feb 2022 4 mins .NET, C#, Performance

As I was (at that moment) running out of ideas about optimizations in hot paths in FbNetExternalEngine, I turned my attention into other parts of code. And one piece that was doing casting on every call caught my attention. Could I make the casting faster? What is actually the cost of casting? Does it matter? I had to dive into it.

Pure magic in C# using tuples and relational patterns

2 Feb 2022 1 mins C#

As I was writing bunch of ifs today, I was thinking whether it would be possible to use pattern matching from recent versions of C#. To make things more interesting, I was comparing multiple values and it was not a simple equality. Blindly typing the code, I was very surprised Roslyn didn’t complain.

Simple WebSocket client and server application using .NET

24 Jan 2022 2 mins .NET, ASP.NET Core, WebSocket

Couple months back when teaching a course in Gopas, colleague William Ischanoe came to me and asked me, whether it would be possible to create a simple WebSocket server (and later client) in .NET. As far as I understood he wanted to use it to command process on victim’s computer (as he’s an expert in hacking and security). Might be useful for others as well, therefore I’m posting it here.

New Task.WaitAsync method in .NET 6

21 Jan 2022 1 mins Multithreading/Parallelism/Asynchronous/Concurrency

.NET 6 has this new handy method on Task called WaitAsync. It might not look like a big deal. Basically, the asynchronous version of Wait, right? Yes, but also it closes one gap that was often implemented poorly.

.NET Developer Conference ’21

1 Dec 2021 1 mins Presentations & Speaking

Few moments ago I finished my session on .NET Developer Conference ’21 (yeah, I forgot to make the post sooner). My session was C# Source Generators – let the machine do the programming. It was recorded and demos are attached below.

Operators with different color in Visual Studio

24 Sep 2021 1 mins C#, Visual Studio

When writing some code day or two ago I noticed one operator color in Visual Studio being different color than it usually is. I initially thought it’s a fluke in syntax highlighting that will eventually go away. When it didn’t, I decided to investigate.

.NET DeveloperDays 2021

15 Sep 2021 3 mins Presentations & Speaking

It’s again that time of the year when my favorite conference is about to happen. Yep, it’s .NET DeveloperDays time (and planned as in-person, yay!). You still have about a month to register and you should. I’ll have both the workshop and two sessions in main conference.

C# static constructor called multiple times

7 Sep 2021 2 mins .NET, .NET Core

Few days ago, I had a behavior I couldn’t believe. Static constructor of my C# class was clearly called two times. For no reason! Even the static variable it was initializing was null during second call. How is that even possible?

ADO.NET provider 8.5.0.0 for Firebird is ready

17 Aug 2021 1 mins .NET, C#, Databases in general, Entity Framework, Entity Framework Core, Entity SQL, Firebird, LINQ, SQL, Visual Studio

New version 8.5.0.0 of ADO.NET provider for Firebird is ready for download. This release contains, among other small improvements and fixes, support for Srp256 (and quite a few related changes, like support for SPB version 3) and fix for performance regression for synchronous code paths introduced in 8.0.0.0.

Live: How to start with FbNetExternalEngine

2 Aug 2021 1 mins Livestream

After a lot of live and pre-recorded conference talks, I decided to try also livestreaming myself. Being a beginner, I forgot to properly announce it beforehand and hence although still livestream, for most people it will be a recording. I’ll get better next time.

Developer Week ’21

7 Jun 2021 1 mins Presentations & Speaking

Developer Week ’21, a new conference for me, is happening from 28 June to 2 July and I’m lucky to be speaking there, although only via the power of the Internet. I’ll have two sessions.

Introducing FirebirdMonitorTool – tool for processing Firebird’s trace output

20 May 2021 3 mins .NET, .NET Core, Databases in general, Firebird

Last few weeks, on and off, I was reviving, finishing and improving a library, or now a tool if you will, that allows processing of trace output from Firebird. The library started its life probably sometime around 2014, and after a minimal working piece was done, it was briefly, yet successfully, used. Then it was left rusting up until last few weeks. What can it do?

Gopas TechEd 2021 (online)

7 May 2021 1 mins Presentations & Speaking

Už za pár týdnů se bude konat Gopas TechEd, tento rok také online. Já jsem připravil dvě přednášky. Obě plné kódu.

I replaced jQuery on this blog with vanilla JavaScript

26 Apr 2021 2 mins Blog, JavaScript, jQuery

Over maybe last two years or so, I’ve been reading with interest primarily @alesroubicek’s tweets, where he disregarded (with good arguments) all the all-encompassing JavaScript frameworks and libraries. And then out of nowhere last week, I decided to try to remove jQuery from this blog. Simply to have a personal experience with doing stuff in vanilla JavaScript.

My new AC has built-in Wi-Fi and that brings dilemma into my home automation hacking

5 Apr 2021 3 mins Home Automation, IoT

Last week I had AC installed into my house and the unit has Wi-Fi module as a standard option. That brings dilemma to my inner geekiness. As you might expect from me, I want to control the unit remotely my own way. Would the unit have only infrared remote control I would take some ESP8266 board (Wemos D1 Mini Pro is my favorite) and hack together my own infrared remote with simple API over the Wi-Fi. Because that would be the only way. But now I have two options. Oh my.

Fusing await using and await foreach and await

22 Mar 2021 2 mins C#

As I’m thinking about the await using and various usage patterns, my mind sometimes starts to wander into pieces like Task<IAsyncDisposable>, Task<IAsyncEnumerable<T>> and Task<IAsyncEnumerable<IAsyncDisposable>>. And how to wrap that into await using and await foreach making some confusing combinations. This is what I was playing with, don’t expect anything specific.

Migrated from Disqus to utteranc.es

10 Mar 2021 2 mins Blog

In last 24 hours I migrated from Disqus to utteranc.es because I’m done with Disqus. I didn’t mind it initially, but last few years I was more and more unhappy about it. Here’s why and how I migrated.

WUG: (Ne)Známé vlastnosti Azure Storage (online)

19 Feb 2021 1 mins Presentations & Speaking

Azure Storage je tak nějak moje oblíbená služba. A za ty roky co existuje jsem nasbíral a taky náhodou objevil hromadu zajimavých vlastností, o kterých možná nevíte nebo nevíte jak je použít. No a tak se na ně podíváme na WUGu 18.3.2021 od 17:00.

Home automation is heavily stateful and that sucks

11 Jan 2021 3 mins Home Automation, IoT, Z-Wave, Zigbee

In programming we like stateless pieces of code, immutable data structures, functional composition, etc. and we value languages, libraries and environments designed with this in mind. Home automation is complete opposite.

My new PC (and why I chose the components I chose)

5 Jan 2021 4 mins AMD, ASUS, Hardware, Kingston, Noctua, Nvidia, PC, Samsung, SSD

During December I finished building my new PC. My previous PC was not terribly dated or slow (and continues to be used by my wife), but I felt it’s favorable time for update. It’s not balls to wall build, rather something I think is good for my workflow – mostly development and related tasks. I don’t edit movies, stream (or play for that matter) games, etc. I describe each component (in no particular order) and my reasoning why I chose it, your mileage may obviously vary.

DevDay 2020: Using Roslyn to improve your codebase

9 Nov 2020 1 mins Presentations & Speaking

I have to say, Belgium has a special place in my heart, so when my session for DevDay.be was accepted, I was happy. I would be happier if the conference would be in-person, but 2020 is what it is. Anyway. I’ll be talking about Using Roslyn to improve your codebase. Basically taking advantage of Roslyn’s open design where you can use various pieces of the whole compiler platform and create your own tools with the full power of “compiler” i.e. sematic analysis.

New Environment.ProcessId in .NET 5

4 Nov 2020 1 mins .NET

While reading some code in .NET runtime, I found Environment.ProcessId property, which surprised me a bit, because I had no idea it existed. Quick look into the documentation and no wonder I had no idea. It’s new in .NET 5.

How Entity Framework Core’s query cache works

27 Oct 2020 3 mins Entity Framework Core

Last week, when speaking at .NET Developer Days, I got a question about the query cache in Entity Framework Core – is it shared across DbContexts or is it per instance? With this question I realized I know how the cache work(ed) in Entity Framework 6, but I’m not entirely sure how it’s done in Entity Framework Core. Time to explore! And you can go with me.