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Active Restore: Beginning UEFI development

Reading time12 min
Views2.5K

This is a translation with minor changes from the original post according to advice from comments.


Hello, folks! We have studied the boot sequence of the Windows operating system as part of a project from Acronis with students of Innopolis University. You can find more about the project here and there. There was an idea to execute the logic even before the boot sequence of the OS. Therefore, we tried to write something just to try, for a smooth immersion in UEFI. In this article, we will go through the theory and practice to read and write to disk in a pre-OS environment.


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Android interop with SWIG (a guide). From simple to weird. Part 1 — simple

Reading time18 min
Views5K

SWIG is a tool for generating cross-language interfaces - it provides interoperability of C++ and other languages (C++ and Java in our case). SWIG just simplifies and automizes cross-language interaction; otherwise, you may end up with thousands of lines of handwritten JNI code - but SWIG covers this for you.

This guide is for newbies (Part 1) and for those who experienced in SWIG (part 2). I'm starting from basic setup and usage and ending with complex & weird cases encountered in development. The latter cases are not so complex, rather usual for modern languages, which SWIG doesn't support yet (as lambdas).

This guide is practical. In opposition to overcomplicated huge-volume SWIG documentation, this guide is showing the cases practically. The bits developed by myself while working on the different projects or taken from StackOverflow. This guide allows you to quick-start an Android Studio project and giving practical examples of using SWIG. The link to the Android Studio project is here.

This guide is Android-first. The goal was to make it simple to onboard for Android developers. There are many articles about SWIG, but they are mainly for desktop Java applications, and it is quite an overhead to just try them on Android to check if the solution for the particular problem is working. While this guide includes an Android Studio project, with which you can play around instantly. Of course, all the information given here applies to any Java application.

Warning! I should warn you, that nowadays cross-platform development offers powerful tools. If you are developing a new application it is much more cost-efficient in practice to use ReactNative, Flutter of Kotlin-Native than the SWIG. While SWIG is more suitable to connect the C++ library or existing C++ application core.

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GTK: The First Analyzer Run in Figures

Reading time5 min
Views1K

For some people, the introduction of a static analyzer into a project seems like an insurmountable obstacle. It is widely believed that the amount of analysis results issued after the first run is so large that only two options seem reasonable: do not mess with it at all or refocus all people on fixing warnings. In this article, we will try to dispel this myth by implementing and configuring the analyzer on a GTK project.

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Tarantool: an analyst's view

Reading time8 min
Views2K
Hi all! I'm Andrey Kapustin. I work as a system analyst at Mail.ru Group. Our products form a unified ecosystem. Many independent infrastructures generate data in it: taxi and food delivery services, email services, social networks, etc. The faster and more precise we can predict a client's needs, the sooner and more correctly we can offer our products. 

Many system analysts and engineers are keen to know: 

  1. How to design the architecture of a trigger platform for real-time marketing?
  2. How to arrange a data structure that would be in line with the requirements of a marketing strategy for interacting with clients?
  3. How to ensure the stable operations of the  system under very heavy workloads? 

Such systems are based on technologies of high-load processing and Big Data analysis. We have accumulated considerable experience in these areas. Our expertise is in high demand on the market.  I'm going to show how we help our customers to switch from off-line to on-line in their interactions with clients using Real-Time Marketing solutions based on Tarantool.
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React Native: The First Choice of Mobile App Developers and Businesses

Reading time5 min
Views2.7K
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Let’s discuss why mobile app developers select React Native for application development over other cross-platform frameworks.

While few users continue to work with the Native development approach, those who want to succeed in their business have started exploring new opportunities. One such occasion in this technically advanced world is to turn toward cross-platform frameworks.

Out of 2.8 million apps available on the Google play store and 2.2 million apps in Apple App Store, there is a growing need for cross-platform applications. The significant advantage of a cross-platform mobile application is that it helps businesses save development costs. This is where React Native comes into action.

In the middle of this, if you are a businessman and thinking of hiring mobile app developers and there is a continuously running debate in your mind “React Native vs Native” then this post is for you.
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9 Reasons Why Students Don’t Want You as a Teacher

Reading time1 min
Views1.5K
Teaching is hard! Finding a way to explain ideas and concepts, finding an approach to each individual among your students, each having a unique mind and learning capabilities. Being patient and creative, friendly but respective, kind but fair. You have to understand complex stuff and be able to present them in the simplest of ways. There are so many things that you must balance and consider in your work. Teachers, you are heroes, the every-day heroes! With this heroic work comes a responsibility. A responsibility of keeping yourself accountable for your student’s education. Some teachers forget about that and stay oblivious to the mistakes they are making. We’ve compiled a list of 9 Reasons Why Students Don’t Want You as a Teacher. We sincerely hope that it will help you to self-reflect, better connect with your students and achieve better results during your lessons.

Tutorial. Deploying Django project to Heroku and storing static content on AWS S3: basic scenario from start to finish

Reading time12 min
Views8.7K

This tutorial is aimed to help Django beginners who want to run a project on Heroku while storing static files on AWS S3. While being a major help for web developers, both services can be hard for beginners to set up correctly. I’ll admit these topics can be found covered separately elsewhere, but there are also some unaccountable nuances if you are trying to make both work in a single project.

Personally I couldn’t find a source which would not only cover Heroku deployment or S3 usage, but would address those nuances as well. Reading the manuals trying to figure out what do you have to do to deploy a project correctly might be an important part of learning, but it can also make you lose focus on what you are currently trying to study or, even worse, discourage you altogether. If this is your story, look no further. I hope instructions below will help you to deploy your project in a single track without having to consult with other resources.

The text is broken down into 3 logically distinct chapters: prerequisites for local Django app (a mini-chapter), integrating  AWS S3 into your app for storing static files, and finally deploying to Heroku. You might not want to go through the entire process in one sitting. In the beginning of each chapter an approximate time required to complete chapter’s instructions will be noted so it is possible for the reader to plan ahead. I would advise not to break down a single chapter into multiple sittings, but if it is not possible, at least try to complete all work covered by a single sub-chapter section in a single go.

Links to official documentation will be provided in text in case you might need extra details on particular actions.

Text highlighted in yellow needs to be replaced in accordance with your settings/paths/accounts.

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Visualizing Network Topologies: Zero to Hero in Two Days

Reading time49 min
Views34K

Hey everyone! This is a follow-up article on a local Cisco Russia DevNet Marathon online event I attended in May 2020. It was a series of educational webinars on network automation followed by daily challenges based on the discussed topics.
On a final day, the participants were challenged to automate a topology analysis and visualization of an arbitrary network segment and, optionally, track and visualize the changes.


The task was definitely not trivial and not widely covered in public blog posts. In this article, I would like to break down my own solution that finally took first place and describe the selected toolset and considerations.

Let's get started.


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Top-10 Bugs Found in C# Projects in 2020

Reading time10 min
Views1.3K
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This tough year, 2020, will soon be over at last, which means it's time to look back at our accomplishments! Over the year, the PVS-Studio team has written quite a number of articles covering a large variety of bugs found in open-source projects with the help of PVS-Studio. This 2020 Top-10 list of bugs in C# projects presents the most interesting specimens. Enjoy the reading!
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Did It Have to Take So Long to Find a Bug?

Reading time2 min
Views1.8K
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Have you ever wondered which type of project demonstrates higher code quality – open-source or proprietary? Our blog posts may seem to suggest that bugs tend to concentrate in open-source projects. But that's not quite true. Bugs can be found in any project, no matter the manner of storage. As for the code quality, it tends to be higher in those projects where developers care about and work on it. In this small post, you will learn about a bug that took two years to fix, although it could have been done in just five minutes.
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Rich text editors from backend perspective

Reading time7 min
Views5K
Welcome everyone, in this article I’m going to overview the most popular types of rich text editors, tradeoffs of their use from a backend perspective. By that I mean:

  • Streaming of content from the rich text editor to other infrastructure tools like full-text search, warehouses, etc.
  • Retrieving of content to clients: mobile, web, desktop.
  • Storing of content in some kind of storage (SQL database in my case)
  • Analyzing of content, which includes point 1, but also analyzing it from the perspective of our application
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ONLYOFFICE Community Server: how bugs contribute to the emergence of security problems

Reading time12 min
Views964
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Server-side network applications rarely get the chance to join the ranks of our reviews of errors found in open source software. This is probably due to their popularity. After all, we try to pay attention to the projects that readers themselves offer us. At the same time, servers often perform very important functions, but their performance and benefits remain invisible to most users. So, by chance, the code of ONLYOFFICE Community Server was checked. It turned out to be a very fun review.
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Big Data Tools EAP 12 Is Out: Experimental Python Support and Search Function in Zeppelin Notebooks

Reading time3 min
Views1.2K

Update 12 of the Big Data Tools plugin for IntelliJ IDEA Ultimate, PyCharm Professional Edition, and DataGrip has been released. You can install it from the JetBrains Plugin Repository or from inside your IDE. The plugin allows you to edit Zeppelin notebooks, upload files to cloud filesystems, and monitor Hadoop and Spark clusters.


In this release, we've added experimental Python support and global search inside Zeppelin notebooks. We’ve also addressed a variety of bugs. Let's talk about the details.


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Russian microcontroller K1986BK025 based on the RISC-V processor core for smart electricity meters

Reading time10 min
Views7.2K
Welcome to RISC-V era!

Solutions based on the open standard instruction set architecture RISC-V are currently increasing their presence on the market. Microcontrollers from Chinese colleagues are already in serial production; Microchip is offering interesting solutions with FPGA on board. The ecosystem of software and design tools for this architecture are also growing. Seeming previously unshaken leaders have more often found themselves in resale ads, while young startups attract multi-million investments. Milandr also got involved in this race and today began supplying interested companies with samples of its new K1986BK025 microcontroller based on the RISC-V processor core for electricity meters. Well here we go, pictures, characteristics and other information, as well as a little bit of hype under the cut.


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Big / Bug Data: Analyzing the Apache Flink Source Code

Reading time11 min
Views909
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Applications used in the field of Big Data process huge amounts of information, and this often happens in real time. Naturally, such applications must be highly reliable so that no error in the code can interfere with data processing. To achieve high reliability, one needs to keep a wary eye on the code quality of projects developed for this area. The PVS-Studio static analyzer is one of the solutions to this problem. Today, the Apache Flink project developed by the Apache Software Foundation, one of the leaders in the Big Data software market, was chosen as a test subject for the analyzer.
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A Book on the API Design

Reading time1 min
Views1.9K

This year, each of us seeks a special way to pass the time. I am writing a book, for example. A book about one thing I love dearly: the API. (You may read who am I and what expertise got in APIs in my LinkedIn profile.)


I've just finished the first large section dedicated to the API design. You may read it online, or download either pdf or epub version, or take a look at the source code on Github.


The book is distributed for free under a CC-BY-NC license. Enjoy!

Algorithms in Go: Sliding Window Pattern (Part II)

Reading time4 min
Views7.3K

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/adf4f836-dc81-4a3d-8a84-9c1d9c81fd66/algo_-_Starting_Picture.jpg


This is the second part of the article covering the Sliding Window Pattern and its implementation in Go, the first part can be found here.


Let's have a look at the following problem: we have an array of words, and we want to check whether a concatenation of these words is present in the given string. The length of all words is the same, and the concatenation must include all the words without any overlapping. Would it be possible to solve the problem with linear time complexity?


Let's start with string catdogcat and target words cat and dog.


https://s3-us-west-2.amazonaws.com/secure.notion-static.com/a49a78c7-5177-401b-9d30-3f02d3d8db49/algo_-_Input_string.jpg


two concat


How can we handle this problem?

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