Game Programming Patterns What really happens when you navigate to a URL As a software developer, you certainly have a high-level picture of how web apps work and what kinds of technologies are involved: the browser, HTTP, HTML, web server, request handlers, and so on. In this article, we will take a deeper look at the sequence of events that take place when you visit a URL. 1. You enter a URL into the browser It all starts here: 2. The first step in the navigation is to figure out the IP address for the visited domain. Browser cache – The browser caches DNS records for some time. Here is a diagram of what a recursive DNS search looks like: One worrying thing about DNS is that the entire domain like wikipedia.org or facebook.com seems to map to a single IP address. Round-robin DNS is a solution where the DNS lookup returns multiple IP addresses, rather than just one. Most of the DNS servers themselves use anycast to achieve high availability and low latency of the DNS lookups. 3. So, the browser will send this request to the Facebook server: 4. 5. 6. 7. <! 8. 9.
Home The Memory Management Reference Kit Arduino - iniciante | Multilogica-shop O Kit mais completo do Brasil com tudo que você precisa para começar a desenvolver projetos com a plataforma Arduino sem necessidade de realizar soldas. O que vem incluído: 1 Arduino Uno R3 Original da Itália1 Cabo USB - Para conectar o Arduino ao seu computador.1 Protoboard - Para testar seus primeiros circuitos conectando os outros componentes do kit sem soldas1 Display LCD 2x16 com conector soldado e backlight (preto sobre verde ou branco sobre azul)1 Motor CC 6V com jumpers soldados1 Sensor de temperatura (termistor ntc 1k)1 Sensor de luminosidade (LDR 5mm)1 potenciômetro 10kΩ2 chaves momentâneas (botão)5 LEDs amarelos (1,2 Vdc 20mA)5 LEDs verdes (1,2 Vdc 20mA)5 LEDs vermelhos (1,2 Vdc 20mA)1 LED de alto brilho (2,1 Vdc 20mA, a cor pode variar)15 resistores 330Ω5 resistores 1kΩ5 resistores 10kΩ1 resistor 15Ω1 sensor/atuador piezoelétricoConjunto com 20 Jumpers premium - macho-macho1 Relê de uso geral, bobina de 5V, 40 mA / dois contatos independentes e reversíveis de 1A. Tutoriais:
Learning C/C++ Step-By-Step 01. Step-by-Step C/C++ --- Introduction Many people are really interested in learning and implementing C/C++ programs on their favorite platforms like DOS/Windows or Linux. If you are the one looking for a step-by-step guide to get started, this tutorial is for you. Let me know your comments on my tiny attempt to serve the community. Contents I. What is C ? II. Components of a program Constants Data types Numeric Data Type Non-Numeric Data Type Integer Data Type Real Data Type Logical Data Type Enumerated Data Type Introduction to Language & Expressions What is C? C is a compiler based programming language supports both high level and low level statements to interact directly with the hardware. Development of C Language The C programming language evolved from a succession of programming languages developed at Bell Laboratories in early 1970s. UNIX operating system is written in the C language. C as a general purpose Language History of C Features of C II. Components of a program 1. Constants 1. 1.
Ruby Quiz Best Practices for Speeding Up Your Web Site The Exceptional Performance team has identified a number of best practices for making web pages fast. The list includes 35 best practices divided into 7 categories. Minimize HTTP Requests tag: content 80% of the end-user response time is spent on the front-end. One way to reduce the number of components in the page is to simplify the page's design. Combined files are a way to reduce the number of HTTP requests by combining all scripts into a single script, and similarly combining all CSS into a single stylesheet. CSS Sprites are the preferred method for reducing the number of image requests. Image maps combine multiple images into a single image. Inline images use the data: URL scheme to embed the image data in the actual page. Reducing the number of HTTP requests in your page is the place to start. top | discuss this rule Use a Content Delivery Network tag: server The user's proximity to your web server has an impact on response times. top | discuss this rule top | discuss this rule tag: css
ArticleS.UncleBob.PrinciplesOfOod The Principles of OOD What is object oriented design? What is it all about? What are it's benefits? What are it's costs? It may seem silly to ask these questions in a day and age when virtually every software developer is using an object oriented language of some kind. Of all the revolutions that have occurred in our industry, two have been so successful that they have permeated our mentality to the extent that we take them for granted. Programs written in these languages may look structured and object oriented, but looks can be decieving. In March of 1995, in comp.object, I wrote an article that was the first glimmer of a set of principles for OOD that I have written about many times since. These principles expose the dependency management aspects of OOD as opposed to the conceptualization and modeling aspects. Dependency Management is an issue that most of us have faced. The first five principles are principles of class design. The next six principles are about packages. Robert,