KUKURUKU HUB

Lock-free Data Structures. Basics: Atomicity and Atomic Primitives

Written by khizmax

Lock-free data structures are based on two things – atomic operations and methods of memory access regulation. In this article I will refer to atomicity and atomic primitives. To begin with, I would like to thank you for a warm welcome of Lock-free Data Structures. 1 — Introduction . I can see that lock-free topic is interesting and it makes me glad. I planned to build a series according to academic concept, flowing from basics to algorithms, at the same time illustrating the text with the code from libcds. But part of the readers wants me to show them, without any delays and rambling on, how to use the library. I agree that there is some reason in it. After all, it’s not interesting for me either to know what is inside the boost , — and how to apply it! So I will divide my epic series into three

Benchmarks: 14 Sorting Algorithms and PHP Arrays

Written by ahwoobachairiesaas

In this article I will tell you about the benchmark of sorting algorithms, written on PHP. There are 14 algorithms presented: quickSort countingSort combSort heapSort mergeSort shellSort selectionSort insertSort gnomeSort combinedBubbleSort cocktailSort bubbleSort oddEvenSort bubbleSortWithFlag Algorithms are not alphabetically ordered, but in order of their performance speed descending when sorting an array of 8 thousand elements. The following arrays dimensions, used for sorting, are presented: 1 100 200 400 600 800 1000 5000 10000 15000 20000 25000 30000 Each measurement was performed with different array filling, which is passed to sorting function. In the first case the array has been filled by random values with a (1, n) interval, in which n — is an array dimension. In the second case the array has been filled by random values with a (1, PHP_INT_MAX) interval, in which PHP_INT_MAX — is maximum variable value of INT type in the current system. In

Browser Extension to Extract the Text from Images

Written by alizar

Naptha — is a very useful Chrome extension. It automatically recognizes text of all the images that are downloaded by the browser. With the help of this extension you can edit images text, select, copy and translate it. This extension is indispensable for copying the text from the document scans, photographs, posters, diagrams, charts, screenshots and even memes. The idea to create this extension was born on the basis of xkcd meme. It showed the websites, which didn’t allow selecting the text at their web-pages. Ironically, xkcd website can also be referred to “violators” as it doesn’t allow selecting the text inside the memes. Naptha extension fixes this drawback. Developers say that the Stroke Width Transform algorithm, which is used in the extension, can recognize a text even of incoherent flourishes. This peculiarity can be considered as a bug or a feature. By the way, Naptha works for any

Mobile Responsive Design

Written by muhurov

When designing a mobile version of the site, the core question is still what resolution to choose and which ones are the most popular. By reference to statistics we will consider five the most popular resolutions of mobile screens resolutions. And five the most popular tablet resolutions. And then media queries are entering the game. For instance, if we add the following code to the style sheet, it will define the site background, provided that a certain device will have 480 or less pixels screen. @media screen and (max-device-width: 480px) and (orientation: portrait) { #background { width: 480px; background:url(/img/background.jpg); } } We can also use CSS-rule @import for the conditional loading of stylesheets into the current stylesheet. For example, the following code imports the phone.css, provided that a certain device will have the screen and the display area of maximum width 480 pixels. @import url("phone.css") screen and (max-width:480px); When creating

Lytro Company Announced a Plenoptic Camera of the Second Generation

Written by ilya42

Lytro Company, founded by Ren Ng from Stanford University, is commercializing plenoptic photography. It’s a photo of the light field when matrix with the help of micro lens system fixes not a 2D image but full information of the scene light field — you can focus such images right after the shooting, and photos taken by this camera allow you to get a stereo image. The first Lytro camera looked more like a cute toy and shots quality was not that high. After rendering it into a 2D image its resolution was just a few mega pixels. The second generation camera, named Lytro Illym , looks much more like a real camera in both appearance and features. The size of the sensor has been increased from 1/3" to 1", images resolution is 40 Megaray (it’s the measurement for plenoptic cameras) compared to 11 in the first Lytro. 2D images

Leonardo da Vinci: Daily Routine

Written by kal1sha

Few people know that Leonardo da Vinci invented a way to spend little time for sleep, but not suffer from doing so. He slept only an hour and a half per day! Many people say that it was the exact secret of his efficiency. Today it is called a polyphasic sleep. Genius Leonardo decided that he spent too much time on sleep and invented his own sleep method. It lies in sleeping for 15 minutes every 4 hours. And he lived like that during not a week, but many years. Why does it work? Psychologists say that after sleep our working capacity increases from 6 to 10 times as much. And wise Leonardo used it to the fullest extent. Other psychologists say that polyphasic sleep doesn’t match all the people and they should read the literature about: sleep nature relaxation eutrophy healthy living P.S. I think this sleep method will

Yogurt making machine powered by Arduino

Written by Shrim

Everyone knows that yogurt is a very better-for-you product, plus it’s delicious. There is a short story under the cut about how I decided to create a yogurt maker, some pictures and a sketch. Wandering in the vast expanses of the Internet I came across such an interesting thing as a yogurt maker. My wife likes yogurt and fairly often buys it. Having read the specialized website, I was inspired. I was inspired by the very thought of easily making yogurt at home, plus it will be more health-giving than the store-brought one. Having read a few reviews and comparisons, my wife and I decided to buy “Moulinex YG230 YOGURTEO”. But oops, we couldn’t find where to buy it in our town. We were just going to place an order when it dawned upon me. What is a yogurt maker? Roughly speaking, it’s a device for keeping some definite temperature

LibreSSL: clean version of OpenSSL (OpenBSD project)

Written by Kukuruku Hub

Participants of the OpenBSD project, that have developed the system of the same name and also different tools such as OpenSSH, OpenBGPD, OpenNTPD and OpenSMTPD, began a LibreSSL project. It is a cleared from odd codes, easier version of OpenSSL. Theo de Raadt, the founder and the manager of OpenBSD and OpenSSH projects said that they have managed to get rid of approximately 90 000 code lines at C and 150 000 lines of the content on the whole. MacOS, Netware, OS/2, VMS and Windows support is deleted as few people need it. ”We are trying to make code more clean. 99.99% community representatives don’t need VMS support and 98% don’t need Windows support, — says Theo de Raadt. – They need POSIX support so that Unix and Unix-derivatives could start. People don’t care about FIPS. Code should be simple. Even after all the changes, the code base is still

Marionette.js. Drag&Drop model sorting in the collection

Written by pharrell

Swapping elements in a list is a common task. But as a rule it is often made in a thorny way, especially if it’s Drag&Drop. And now I am going to tell you about a very easy and flexible way to do it using Marionette.js and jQuery UI Sortable. Installing jQuery UI We will need part of Sortable only, so in order to save the traffic, I cleared all the ticks for you here . You just need to download it. Pay attention We are using a reference to Marionette in the code below: var Marionette=Backbone.Marionette; Creating Behavior template This functionality will be implemented with Behaviors. Here’s the behavior code that will be in charge of capacity to sort models inside the collection: Behaviors.Sortable=Marionette.Behavior.extend({ onRender:function(){ var collection=this.view.collection // Close the collection ,items=this.view.children._views // Get the list of child elements ,view ; for(var v in items){ view=items[v] // Hook the element