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Readers of our articles occasionally note that the PVS-Studio static code analyzer detects a large number of errors that are insignificant and don't affect the application. It is really so. For the most part, important bugs have already been fixed due to manual testing, user feedback, and other expensive methods. At the same time, many of these errors could have been found at the code writing stage and corrected with minimal loss of time, reputation and money. This article will provide several examples of real errors, which could have been immediately fixed, if project authors had used static code analysis.

Before reading this article, it is recommended to read the previous one: Audio over Bluetooth: most detailed information about profiles, codecs, and devices / по-русски

Some wireless headphone users note low sound quality and lack of high frequencies when using the standard Bluetooth SBC codec, which is supported by all headphones and other Bluetooth audio devices. A common recommendation to get better sound quality is to buy devices and headphones with aptX or LDAC codecs support. These codecs require licensing fees, that's why devices with them are more expensive.

It turns out that the low quality of SBC is caused by artificial limitations of all current Bluetooth stacks and headphones' configuration, and this limitation can be circumvented on any existing device with software modification only.

MessageBox — useful window for different GUI frameworks, but you can't find it in AvaloniaUI.
Let's try to do it.

Starting from .NET Core 2.0 and .NET Framework 4.5 we can use new data types: Span and Memory. To use them, you just need to install the System.Memory nuget package:

PM> Install-Package System.Memory

These data types are notable because the CLR team has done a great job to implement their special support inside the code of .NET Core 2.1+ JIT compiler by embedding these data types right into the core. What kind of data types are these and why are they worth a whole chapter?

If we talk about problems that made these types appear, I should name three of them. The first one is unmanaged code.

Both the language and the platform have existed for many years along with means to work with unmanaged code. So, why release another API to work with unmanaged code if the former basically existed for many years? To answer this question, we should understand what we lacked before.

This chapter was translated from Russian jointly by author and by professional translators. You can help us with translation from Russian or English into any other language, primarily into Chinese or German.

Also, if you want thank us, the best way you can do that is to give us a star on github or to fork repository github/sidristij/dotnetbook.

If someone of you has tried create angular libraries, he may face the issue with lazy loading Feature Module from node_modules. Let's dive deeper and go thru the dark water.

Creating library tools

It’s More Than You Imagine…

The possibility of acquiring more profit through a chat app solution is gaining popularity than adopting to monthly plans based chat platforms

With the rise of instant conversation among the users, it's not surprising that the global mobile messaging app is estimated to reach around 2.1 billion active users by 2020. When the communication lies as the significant action in nature, then in fact the underlying tool “messaging application” also acquires the same importance. Thus, every chat platforms like WhatsApp demand a great market value according to the features and functionalities listed. Most of the business professionals and enterprises are urged to rely on subscription-based plans to avail such messaging platform.

How’s your work week going? I took some time off publishing new articles and consulting clients to look at «The Hero and the Outlaw» by Carol Pearson and Margaret Mark. It’s a guide to leveraging the power of archetypes for your brand, and I think there’s much to learn from it.

Archetypes are properly defined as «universal constructs of the human psyche». In layman’s terms, these are images we all recognise because they’re built into our subconscious mind. One such example is the archetype of the hero  —  a good guy who triumphs over evil and saves the day.

Every year there are a lot of articles dedicated to Valentine's Day. I also decided to get involved in this topic and create something original and unusual. The idea was to create a simple Android application with hearts that would have their physical models and interact with each other. Then I added text, sounds, particles and some other effects. The resulting app was working and quite original! In this article I will describe the creation process, as well as the capabilities and pitfalls of the libgdx library.

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Source: eeNews Europe

I'm glad that Habr got brand new English version. And my first post in English is about new MIT project. Researchers designed an ultra-low capacitance and ultra-low resistance Schottky diode capable of switching at GHz frequencies. This diode is able rectify and convert random WiFi signals into DC electricity.

MoS₂ «rectenna» (this is how scientists called their invention) could become the main element of roll-to-roll process to cover a huge areas. To be fair antennas capable transform radio signals in to electricity is not a new thing. The main achievement of MIT engineers is creation of soft rectenna made from special alloy.

A long time ago in a galaxy far, far away there was a company grown from a startup to something much bigger, but for a while the IT department was still compact and very efficient. That company hosted on prem hundreds of virtual Windows servers, and of course these servers were monitored. Even before I joined the company, NetIQ had been chosen as a monitoring solution.

One of my new tasks was to support NetIQ. The person, who worked with NetIQ before, said a lot about his experience with NetIQ, unfortunately, if I try to put it here it would be just a long line of ‘****’ characters. Soon I realized why. Steve Jobs is probably spinning in his grave looking at the interface like this:

If you are working with Kubernetes environment then you probably make use of several existing templating tools, some of them being a part of package managers such as Helm or Ksonnet, or just templating languages (Jinja2, Go template etc.). All of them have their own drawbacks as well as advantages and we are going to go through them and write our own tool that will try to combine the best features.

As 2018 has come to an end, now is the time to look towards the future. We typically look out 6 to 12 months and establish topics we want to work on.

As we go we learn and our assessment of some of the topics listed changes. Thus, we may add or drop topics as we go.

We describe some initiatives as «investigations» which means our goal in the next few months is to better understand the problem and potential solutions before scheduling actual feature work. Once an investigation is done, we will update our plan, either deferring the initiative or committing to it.

As always, we will listen to your feedback and adapt our plans if needed.

Back in those times when I just started learning how to code, I trusted the old wise weasels with their “Programming languages don’t matter” mantra. I grew obsessed with the idea of some day becoming a developer who can do just anything. That guy who transfers his experience from one technology to another and transcends the minutia. But that idea failed miserably.

It's a story on how to write a plugin for Unity Asset Store, take a crack at solving the well-known isometric problems in games, and make a little coffee money from that, and also to understand how expandable Unity editor is. Pictures, code, graphs and thoughts inside.

Did you ever think that one day you had got into PHP web programming too quickly?
Several years have passed already, you have gained a lot of experience and can’t think of any other ways to work with web but PHP. Perhaps, you sometimes doubt the choice you have made, but are unable to confirm your doubts here and now. At the same time, you need real examples; you want to understand the changes that may occur in particular aspects of your work.

Today I will try to answer the following question: "What if we use Python instead of PHP?".

I have asked this question myself many times. I have been using PHP for 11 years already and am a certified PHP specialist. I have mastered it so it works just the way I want. I was really puzzled by several articles that criticized PHP severely (PHP: a fractal of bad design). However, when chance came, I switched to Ruby and then to Python. Eventually, I chose the latter. Now I will try to explain how we Python guys live out there.

Hello, my name is Andrey Sergeyev and I work as a Head of IoT Solution Development at Mail.ru Cloud Solutions. We all know there is no such thing as a universal database. Especially when the task is to build an IoT platform that would be capable of processing millions of events from various sensors in near real-time.

Our product Mail.ru IoT Platform started as a Tarantool-based prototype. I’m going to tell you about our journey, the problems we faced and the solutions we found. I will also show you a current architecture for the modern Industrial Internet of Things platform. In this article we will look into:

• our requirements for the database, universal solutions, and the CAP theorem
• whether the database + application server in one approach is a silver bullet
• the evolution of the platform and the databases used in it
• the number of Tarantools we use and how we came to this

“In 1665, Cambridge University closed because of the plague. Issac Newton decided to work from home. He discovered calculus & the laws of motion.”

We live in a truly remarkable moment. With the year 2020 and the COVID-19 outbreak employees all over the world are staying home for quarantine, trying their best to sustain the normal flow of life, which means continue working. And this is something new compared to all the previous infectious pandemics humanity has survived through — this time we have the Internet.

Open Graph protocol is a web standard originally developed by Facebook that turns any webpage into a graph object with title, description, image and so on. Even though there is no direct correlation between OG meta tags and improved SEO rankings, it still drives more traffic to your webpage by making it more “attractive” in social networks (Facebook, Twitter, Linkedin, etc).

An example of a link shared in Twitter that has «og:image» and «og:title».

Adding OG (and not only) meta tags into your React app

Without further due let’s jump into newly created React app with create-react-app and OG meta tags to /public/index.html. It should look like something like this:

<!DOCTYPE html>
<html>
   <head>
      <meta charSet="utf-8"/>
      <meta http-equiv="x-ua-compatible" content="ie=edge"/>
      <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"/>
      <link rel="alternate" type="application/rss+xml" href="/rss.xml"/>
      <title>Awesome App</title>
      <meta property="og:title" content="Awesome app - the best app ever" />
      <meta property="og:type" content="website" />
      <meta property="og:image" content="https://picsum.photos/id/52/1200/600" />
      <meta property="og:description" content="Describe stuff here." />
      <meta property="og:url" content="yourawesomeapp.com" />
   </head>
   <body>
      <noscript>This app works best with JavaScript enabled.</noscript>
      <div id="root"></div>
   </body>
</html>

What's this about

After working on different projects, I've noticed that every one of them had some common problems, regardless of domain, architecture, code convention and so on. Those problems weren't challenging, just a tedious routine: making sure you didn't miss anything stupid and obvious. Instead of doing this routine on a daily basis I became obsessed with seeking solution: some development approach or code convention or whatever that will help me to design a project in a way that will prevent those problems from happening, so I can focus on interesting stuff. That's the goal of this article: to describe those problems and show you that mix of tools and approaches that I found to solve them.

When you run queries in ClickHouse, you might notice that the profiler often shows the LZ_decompress_fast function near the top. What is going on? This question had us wondering how to choose the best compression algorithm.

ClickHouse stores data in compressed form. When running queries, ClickHouse tries to do as little as possible, in order to conserve CPU resources. In many cases, all the potentially time-consuming computations are already well optimized, plus the user wrote a well thought-out query. Then all that's left to do is to perform decompression.



So why does LZ4 decompression becomes a bottleneck? LZ4 seems like an extremely light algorithm: the data decompression rate is usually from 1 to 3 GB/s per processor core, depending on the data. This is much faster than the typical disk subsystem. Moreover, we use all available CPU cores, and decompression scales linearly across all physical cores.