Slightly less than the fastest, portable, 64-bit hash function, with decent quality.
Yes, in the air and in the king, about like that. Read on?
Instead of Disclaimer We drop the definition of hash functions along with a detailed listing of properties and requirements for their cryptographic application, assuming that the reader either owns the necessary knowledge minimums, or will make up for them . Also we agree that here and further we mean non-cryptographic (cryptographically non-persistent) hash functions, unless otherwise specified.
In fact, it's been two days already, but no one has yet written an article on Habr, so I will have to eliminate this omission, which I do with pleasure.
So, what's new in this version of PostgreSQL?
First, the versioning itself has changed. Prior to the "dozens", we observed a lot of minor versions of 9.x that came out about once a year and at the same time introduced serious, far from minor changes. Therefore, since version 10, it has been decided to number 10, 11, 12, etc. By the way, MySQL seems to have gone the same way, jumped from 5.7 to 8.0
Okay, it's all trivia, let's move on to the essence of the question
As a continuation of the research publications of our company on the internal mechanisms of the world's largest messengers. Today we will look at WhatsApp in its current state. In fact, the insides have not changed much over the past three years, the changes there are rather cosmetic.
In this article we will look in detail how to study the protocol of the messenger, answer the question "Can WhatsApp read our correspondence?" And I will attach all the necessary code in PHP.
I really liked the discussion thread on Quora.com: What is the hardest part about learning to program? All 87 responses I did not read, but liked, I singled out a separate article of 10 items. It's a free retelling of the opinions of many different people. If readers are interested, I will continue.
1. The difference between high standards and their low skillsIn the article "No one talks about it to newcomers" tells about the common problem of people engaged in creative or intellectual work. Programming is a complex subject, and usually for it are capable, ambitious and prone to perfectionism people. At the initial stage, they will not work well. Accustomed to a high bar, they will be upset. The inner voice will constantly whisper: "You never will, it's better to leave this matter." At such moments, think that your self-criticism is a sign of your extraordinary nature, and believe that you will overcome this "incompetent period".
As for the extraordinary advantages of programming, here they are:
<i> Whatever your dragon told you, he lied. Dragons are deceitful. You do not know what awaits you on the other side. <Tgsri>Not so long ago on Habr a post was published under the name "<a href="https://habrahabr.ru/company/infopulse/blog/338812/"> How can the function never called be called? <Tgsrcut>". The conclusion from the article is simple: in the case of undefined behaviour, the compiler has the right to take any actions, even if they are completely unexpected. However, I was interested in the very mechanism of this optimization. The result of my small research I want to share with the distinguished community of the hubra.
Michael Swanvik. "The daughter of an iron dragon"
In the code id Software sometimes there are unmatched pearls. The most famous is, of course, 0x5f3759df , which even got comics on xkcd . Here we are talking about filling the screen: pixels are colored one at a time in random order, without repetition. How is this done?
On November 23, 2011 id Software supported its own tradition and published the source code of its previous engine.
This time, it's time idTech4 , which was used in Prey, in Quake 4 and, of course, in Doom 3. In just a few hours more than 400 forks of the repository on GitHub were created, people began to explore the internal mechanisms of the game or port it to other platforms. I also decided to participate and created a Intel version for Mac OS X , which John Carmack kindly advertised .
From the point of view of cleanliness and comments, this is the best release of the id Software code since the code base Doom iPhone (which was released later, and therefore commented better). I highly recommend that everyone learn this engine, collect it and experiment.
Here are my notes about what I understood. As usual, I cleaned them, I hope they save someone a couple of hours and encourage someone to study the code to improve their programming skills.
"Something is missing here." I bet you, this idea will come first to your head, if you see my workplace in the office. There is no monitor and mouse. There is only a guy who threshes on the keyboard, looking as if into emptiness.
It's just me, and my colleagues guarantee you that I'm usually not dangerous. I'm a programmer at the Vincit office in Tampere (Finland). And I'm blind. In this article I want to tell you a little about how I work.
One of the most important factors affecting the speed of development and the success of the project launch is the correct decomposition of the product manager idea into tasks for programming directly. How to do it right? Take the script of the new feature from the product and immediately start coding? First, write the acceptance tests, and then code that will provide their passing? And, maybe, shift everything to the shoulders of developers - and let them decide during the spam poker themselves?
Let's think about it and identify the problems that can arise in the process of separation of tasks, and the ways to solve them. In this post, we will discuss the basic principles of decomposition of tasks when working in a team. My name is Ilya Ageyev, I'm the head of QA in Badoo. Today I'll tell you how workflow affects decomposition, how different are testing and laying out tasks that arise as a result of decomposition, and what rules should be followed to ensure that the development process goes smoothly for all participants.
The meeting of the ISO WG21 C ++ Committee, which was held in Toronto from 10 to 15 July, ended today. Soon we will surely be waiting for detailed report from WP21 , and today the respected public is offered a post- "Warming up" with a discussion of the most interesting.
The results of the meeting are as follows: C ++ standard 17 is completed and will be published at the next meeting in November this year; the standard C ++ 20 has already acquired the first serious features - concepts ( concepts ), explicit generic lambda functions (explicit explicit lambdas < / i>) - and this is just the beginning.
The possibilities of the new C ++ standard 17 have been discussed more than once, about innovations written on Habr , conducted reports at conferences , so I will not bring them here again. It's no secret that the key feature of this release of C ++ was carrying the most "delicious" options into an uncertain future. Well, now we can say with certainty that many of the long-awaited "features" have moved to C ++ 20. The course taken for the stdlib extension has not gone away, so a much larger and rich set of functions can be expected from C ++ 20.