Zanedlouho, konkrétně 28.5.-29.5., se uskuteční zajímavá konference nazvaná ”Update Days: Legacy aplikace“. Proč zajímavá? Protože často se na konferencích řeší novinky, fičurky atp., ale ne na každém projektu je čas a prostředky na implementaci posledních výstřelků (které ještě případně po dvou letech upadnou v zapomnění) a tato konference není o novinkách; je o tom co dělat s existující aplikací, jak ji posunout dál, co funguje a má smysl.
I was listening to DotNetRocks podcast episode yesterday and while the talk went bit off-topic (which is fine for me), one interesting question popped up. How many curved monitors you’d need to make a full circle? And I immediately thought: “That should be easy to calculate, no?".
In less than a month (22nd-24th of May 2018) the biggest Slovenian conference – NT konferenca 2018 – will happen. It is the 23rd edition, amazing. And I’m so stoked to be part of it with my session about Entity Framework Core 2.0 and 2.1.
Web hlásí vyprodáno, takže budu asi lákat především ty, kteří si vstup už urvali. Na letošní TechEd jsem připravil dvě přednášky:
My house has a load management switch (we call it HDO here), which means the company managing the electricity grid can turn on and off some devices, like water heater, when the demand is low or high. And in exchange I get cheaper electricity (when switched on). And although the schedule is known in advance, I was interested whether the switching happens also at unscheduled times (aka to get a little peek into what’s happening in the grid) and maybe also switch automatically other devices I have when the electricity is cheap. I could ask an electrician to install another contactor on my fuse board and connect “something” to it, but I was not into doing anything permanent and expensive, in case I’d change my mind about all of this in the future etc. I also wanted to get this information into my home automation system (Domoticz). Here’s my cheap solution I hacked together.
Máte rádi C#? A ztrácíte se v aktuální rychlé kadenci verzí? Mám pro vás řešení – WUG 2.5.2018 od 17:00 v Olomouci. Všechno dáme do kupy a srovnáme si to v hlavě.
C# v poslední době velmi rychle přidává nové funkce. Malé funkce v minor verzích, ale připravuji se i velké změny do major verze (verzí). Co je tedy dostupné v C# 7, 7.1, 7.2 a jak to začít používat. A co nás ceká v 7.3 a hlavně ve verzi 8.0?
I needed to cache value from method. Simple. I know there’s at least dozen of ready-made solutions, but I eventually decided to write my own interceptor, because the whole project is already using Castle Windsor and it seemed like a fun stuff to explore. There isn’t really anything special about this code and I originally didn’t want to blog about it, but people on Twitter changed my mind.
I was speaking about new features in C# 7.x and 8 some days ago and as the questions came in, some were really good small brainstorming, basically trying where C# compiler limits are. And that’s always interesting to me.
From this brainstorming I have two interesting pieces. This is the other one and the first one is here.
I was speaking about new features in C# 7.x and 8 some days ago and as the questions came in, some were really good small brainstorming, basically trying where C# compiler limits are. And that’s always interesting to me.
From this brainstorming I have two interesting pieces. This is the first one and the other one is here.
Global Azure Bootcamp 2018. Jeden den, Azure po celém světě. A taky v Čechách, v Praze. I já přispěju svojí troškou do mlýna a povím vám něco o Azure CDN v přednášce “Azure CDN a jak ji začít rozumně používat”.
Fíha, to byl ale hektický závěr týdne. Ve čtvrtek, ještě před WUGem, jsem stihl promluvit o Entity Frameworku a Entity Frameworku Core v .NET.CZ Podcastu ve 24. epizodě. A o Entity Frameworku Core jsem, kromě jiného, mluvil i na WUG Days (nyní už máte šanci podívat se jen na záznam). Entity Framework (Core) otázky? Sem s nimi.
I was testing dimmer during the weekend and I used halogen lamp in my garage. The dimmer worked great, but that’s not what I want to talk about now. When I played with the dimming I realized I can dim the 8000-9000 lumens halogen bulb down to one percent and see the glowing filament with my own eyes. So I did.
Víkend 7.-8.4. se v Brně koná nabitá konference WUG Days 2018. Celkem je připraveno 48 přednášek. Na dva dny masakr.
Hlasováním byly vybrány 3 moje přednášky. A sice:
Máte rádi C#? A ztrácíte se v aktuální rychlé kadenci verzí? Mám pro vás řešení – WUG 5.4.2018 od 18:00 v Praze. Všechno dáme do kupy a srovnáme si to v hlavě.
C# v poslední době velmi rychle přidává nové funkce. Malé funkce v minor verzích, ale připravuji se i velké změny do major verze (verzí). Co je tedy dostupné v C# 7, 7.1, 7.2 a jak to začít používat. A co nás ceká v 7.3 a hlavně ve verzi 8.0?
In February I wrote Custom encryption of field with Entity Framework Core post, which in turn was building on idea for Entity Framework 6. Both are easy, but not absolutely straightforward. And another problem is that the encrypted value needs to fit into the datatype of unencrypted value. Finally, the querying is inconvenient. Luckily Entity Framework Core 2.1 (currently in preview) has a solution.
Few days ago, I learned new thing about C#. Apparently, there are “true” and “false” operators and you can overload these. But I also wanted to know what are these good for, given I’ve never heard about these.
As I was on the .NET.CZ podcast I realized there’s maybe a one specific behavior of digit separators in C# 7 people might not be aware of.
Na světlo světa se dostala další epizoda (22) .NET.CZ Podcastu, kde jsem byl vyzpovídán nejen o C#, novinkách v C# 7, 7.1, 7.2 a 8, ale také o programovacích jazycích obecně a jejich vývoji. Máte-li otázky, sem s nimi.
One thing remaining from last week’s exploration of named locks is performance. My personal preference was and still is ConcurrentDictionary<TKey, TValue>, but what if the string interning is 10 times faster? That would convince me to thing about it for usage.
The Monitor class in .NET might be the most often used “locking” mechanism in C#, mostly because the lock keyword is making it so easy. One thing you might face is unknown number of locks you’re going to need and how to solve this. This is often called named locks or named Monitors, because the lock is bound to some name (or similar value).
I’m sad. I’m sad because I bought myself a chair. It sounds probably confusing, why buying yourself a chair would make you sad. Stay with me.
At the moment, one of my explorations is how the system (Windows) handles more-than-number-of-CPUs threads (all ready to run) under full load (from these threads). And because I’m out of office, I access my workstation remotely (using TeamViewer, in case you’re wondering).
Almost exactly 5 years ago (yes, that’s 2013) I wrote about Custom encryption of field with Entity Framework. At that time, it was using few tricks to make it work and although it might have looked like magic first time you saw it, it was actually very easy. With Entity Framework Core nowadays we have far more options how the entity can look like and hence how the whole solution can be plugged together. Let’s revisit the topic.
I was teaching my Entity Framework Core course last two days and question about priority of attributes’ and configurations’ priority came. Let’s test it, shall we?
Příští týden se konají po roce opět konference ShowIT (Bratislava) a G2B•TechEd (Brno) a myslím, že ještě nějaké místo urvat můžete. Aby se ani jedno město necítilo ochuzené, budu mít na stejné přednášky na obou. Povíme si něco o Azure CosmosDB.
Azure CosmosDB je databáze s globálním škálováním a dostupností. Podporuje několik modelů ukládání a konzistence. Má garantovanou dobu odezvy bez ohledu na data. A to vše jako služba v Azure. Wow! Je to opravdu tak přímočaré? Nebo je nadšení třeba krotit? Vysvětlím vám, jak CosmosDB funguje, na co se dá použít a uvidíme jestli je nadšení podloženo daty (třeba i těmi uvnitř DB 😉).
One of the few things I was missing when tuples were introduced was some way to generically work with unknown tuples. Mostly to be able to identify tuples, instead of using plain object and also work with items using index of some sort. Luckily, I was probably not the only one and starting .NET 4.7.1 new interesting interface – ITuple – was added (also available in .NET Core 2.0).
Recently in my social bubble, mostly on Twitter, there has been a lot of talking about mentoring. Senior developers mentoring juniors and so on. Although I’m not, by any means, saying mentoring is bad and juniors should leave seniors alone, I’d like to also share my opinion. Shedding some light into this seemingly black-and-white problem.
New version 5.12.1.0 of ADO.NET provider for Firebird is ready for download. This is a regular bug-fix release.
As I’m sweeping the corners, the work is less glamorous (read: close to zero outside contributions) and every move is harder and harder. But despite all of that, I’m glad to move one step closer to the RTM version of Entity Framework Core 2.0 provider for Firebird and jump to the beta phase.
WUGy v Olomouci opět oživly a můžeme se tedy podívat společně na Entity Framework Core 2.0.
Entity Framework Core 2.0 byl představen nedávno společně s .NET Core 2 a ASP.NET Core 2. Co nového přináší? Jaké jsou změny oproti verzi 1.0 / 1.1? Má smysl verzi 2.0 používat? Jaké jsou pokročilejší features, jaká jsou její omezení… A co například použití s jinými databázemi než jen MS SQL Server?
Těším se na vás 12.12.2017 od 17:00 v Olomouci.
Although you can disable PDB files generation altogether, it’s good idea to have these. Debugging without PDB files later is so much harder, like if debugging isn’t hard enough already. One thing that might be bothering you, is the source files location that is stored in PDB files. You might want to change these paths – build servers often use random directory names or you might want to simply hide that the project directory on your hard drive has some weird name. 😃
In previous post I measured execution speed of static and instance methods. Here I’ll dig deeper and I’ll try to find where the difference comes from. Bear in mind, I don’t have a deep knowledge of processors, JIT or assembly. I’m just thinking out loud, poking and observing.
Couple days ago, fellow MVP and colleague @RobertHaken tweeted from frustration about a refactoring (in this case not a good refactoring) into static methods. And I immediately started thinking about scenario where the static method might have some tangible benefits compared to instance method. What a better way to improve method execution than speeding it up? Could this be the case?
As the usage of await seeps more and more into general C# code, I’m finding some small “leaks” that make me sad sometimes. This one is pretty simple. Looks like that every time somebody uses XxxAsync method, he or she also awaits it. Makes sense, or does it?
New version 5.12.0.0 of ADO.NET provider for Firebird is ready for download. Although I’m focusing mainly on version 6 of FirebirdClient now, immediate fixes and small improvements are still landing in 5.x version(s). This is a collection of these.
The Multisensor 6 from Aeotec is a nice little device. I have three of these in my house at the moment (and I’m sure I’m not done yet 😉). Being data geek I always calibrate the temperature (and humidity) sensor to match my own “calibration” devices (ESP-8266 with Si-7021). The steps described in official documentation are correct, but because I use OpenZWave (in Domoticz) I had to do some specific steps to make it work.
C# 7.1 comes with option to use asynchronous Main method. That means now the Main can have async modifier and return Task or Task<int>. But how it works under the hood? Let’s find out.
If you read the documentation etc. for Azure CDN, it often expects that you’re going to use it on parts of your website and rest will be served directly from the original location. But if you have completely static (and currently running) website, like for example this blog, which is using the Azure CDN actually, you need to take a few specific steps to start using Azure CDN in such setup and without downtime.
Stejně jako .NET, Microsoft a techonologie kolem mají výbornou Gopas TechEd konferenci, má i Java svět svoji – JavaDays. Letos se uskuteční 13. – 14. listopadu a já jsem si připravil několik přednášek, které vás doufám zaujmou. Především kolem tématu databází, které je mi velmi blízké.
Just before the end of the week I have a toy for you for the weekend. Yes you see it correctly – Entity Framework Core 2.0 support for Firebird. And together with that preview of FirebirdClient 6.0, which contains heaps of changes as well.
Few months back I decided to play a little with asyncio in Python. Explore a little bit how “they did it” and align that in my mind with what I know about the implementation in .NET. Because at that time I needed some HTTP probing I decided to test the async IO together with regular HTTP (aka network) requests. And I used aiohttp. Not that I did some big research. I did quick search and looked at some demos to see whether I like how it’s structured or not. And aiohttp felt fine.
Creating script for migrations in command line is easy. Just execute dotnet ef migrations script and you’re done. But what if you want to do this in the code?
If you want to use any national characters set (i.e. windows-1250) on .NET Core, thus also with FirebirdClient, you need to do some extra steps.
I hate seeing Count > 0 when doing code reviews. And I always recommend using Any instead. It shows the intention, hence makes the code more readable, I think.
Although I would always choose readability over performance – unless in some very specific cases, with well-defined numbers – at one point I wondered whether there’s a cost in using Any. Speed? Allocations?
Letošní CORESTART 2.0 (2. – 3. listopadu) naváže na loňskou “edici”, tentokrát samozřejmě se zaměřením na .NET Core 2.0 a všeho okolo něj. Verze 2.0 už opravdu něco umí a jde na ní solidně stavět. Kromě zahraničních speakerů, přispěji i já svou troškou do mlýna dvěma přednáškami – jedna kolem Entity Frameworku Core 2.0 a druhá kolem novinek v C# 7 a dál. Novinek je hodně a program stojí za to. Přijďte, nebudete litovat.
Yesterday I was rewriting some code from Entity Framework 6 to Entity Framework 2 for testing and discovered unexpected behavior. Luckily, the code fails, so it’s easy to detect.
I’m pretty sure you know what the red squiggle in Visual Studio means (correct, it’s the error). Very likely you know green squiggle (correct, it’s the warning). Maybe you know blue squiggle (correct, it’s the message). But do you know what purple squiggle means? By the way the official name for squiggle in Visual Studio is wavy underline.
Today I found a great new feature for debugging in Visual Studio. Maybe you know the Run to Cursor feature (if not, I’ll explain it in next paragraph), but did you know you can use the same feature from Call Stack as well?
During a break of my user group talk yesterday I got a question about how Entity Framework translates Contains into an IN clause. Whether it uses parameters and how it handles limits that SQL Server has around the parameter count.
Last couple of years I published this blog using Jekyll. Static pages are hard to beat in performance and security. Initially on GitHub pages, then GitLab Pages and eventually moving to Azure. Mainly because thanks to web.config I have more control over the webserver (IIS) and I can do bit more (in fact quite a lot). But lately I started to be more and more tired of Jekyll. It was slow for me and given it’s a Ruby application and me not being fan nor fluent of Ruby it started to add up. For maybe a year I looked multiple times at Hugo, because it was an obvious choice and didn’t liked the templating structure. Also Pelican, because it’s written in Python and I like Python. Not sure why, but I didn’t convert to it. And I also played multiple times with the idea of writing something myself, just to dismiss that idea hundred times because I knew I would trap myself in constantly fiddling with it and burning my free time.
New version 5.11.0.0 of ADO.NET provider for Firebird is ready for download. This release is about .NET Standard 2.0. Now the .NET Standard 2.0, with all the new APIs supported, version is available (this work, together with upcoming Entity Framework Core 2.0 support, is sponsored by Integrative9).
Another new feature is support for passing key over the wire for encrypted databases (you need to have server side plugin for this feature, i.e. this from IBPhoenix). New connection string property crypt key is available for that. The value is base64 encoded data representing the key. You can find small example in tests.
New version 5.10.0.0 of ADO.NET provider for Firebird is ready for download. Apart from regular bugfixes some new features are available. Notably, FbTrace now supports new format of Firebird 3 and then DefaultFbMigrationSqlGeneratorBehavior allows easier customization in case you want specific behavior for Entity Framework Migrations.
I was reading the announcement about Entity Framework Core 2 the other morning and saw “String interpolation in raw SQL methods” paragraph. This was already in preview(s) and I kind of took it as granted, not thinking about how it’s done or what it is doing. Not this time. Somehow my curiosity kicked in and I decided to create same feature and maybe do something with it.
Of course, I could peek into sources, but I decided to use the idea, but build it myself from scratch. I like the idea of using already existing feature from C# and then using for different, but reasonable, purpose. String interpolation and SQL parameters are exactly this.
Asynchronous stuff with async/await in C# is great. But as with any other great tool, there are some gotchas that might cost you something (performance, memory, etc.). Today I’m going to talk about FileStream.
I was profiling FbNetExternalEngine to squeeze a bit more performance from the code and as I was going through stack traces, hot paths and allocations, I realized (again), how geeky I am. I was looking into a stack trace and found it fascinating.
As I said in previous post I had to drop AppDomains from my solution to allow replacing assembly while the FbNetExternalEngine is running. Calls across AppDomains are simply too slow (read: I can’t make it fast enough. 😉) for this kind of project. Why I even needed AppDomains? The specs are simple: Allow assembly replacing (rewrite) while it’s loaded in Firebird via my FbNetExternalEngine. Can it be solved without AppDomains?
Over the last few days I was working on performance of FbNetExternalEngine. Basically doing all I can to make it execute the code quickly as possible. OK, maybe not all I can, but something that gives biggest gain while being able to program it in a reasonable timeframe, because there’s always room for more.
I completely missed some handy methods on Entity Framework Core’s DbContext. Maybe you did too. And that would be a pity.
When I was writing the original post I knew the code was right on the edge. It worked on 2.5 and that mattered at that time. My hope was that it will eventually work forever, because why would you change such thing… Nope.
While writing previous post I realized the deconstruction to tuple can be added to any type. As far as compiler is concerned the Deconstruct method needs to exist, doesn’t matter whether it’s an extension method or instance one. That means I can write a Head- and Tail-like methods in C# with nice syntax. I also dusted off my Haskell knowledge and wrote the same logic there for comparison. And then I did it in Python and F# as well. Brace yourself for a true polyglot post.