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Objective-C Qiqiao technology-underlying forced calling of high-level interfaces, objective-c high-level Technical lust refers to technologies and products that are too clever and useless. Let's take a look at a piece of code. //. H-(void) funa {[B funB];} // B. h-(void) funB {// How can I obtain object a of call object B here} Sometimes the bottom layer is to know the top layer, so don't worry about when,

Writing high-quality code-basics: structure and style, separation of behavior, and high quality --To implement high-quality code, we need to separate the structure, style, and behavior to simplify, reuse, and order. Streamline: Minimize the file size and increase the page loading speed. Reuse: Improves code reusability, reduces redundant code, and increases devel

High-performance Mysql -- Schema and data type optimization; high-performance Mysql Schema Good logical design and the foundation of High Performance for physical designers1. Select an Optimized Data TypeSmaller is usually betterCPU cycle required for smaller disk, memory, CPU cache, and processingEasy to useThe operation requires less CPU cycles. For example, a

completed by the hardware. High cost. Software balancing forwards various requests through software, which makes it easier to define forwarding rules and has many open-source product options. Layer 4 and Layer 7 The terms Layer 4 and Layer 7 are often seen in Server Load balancer. They actually refer to the number of layers (using the ISO model) of the network protocols they process when they work ). The fourth layer is the data transmission layer, i

the data persistence layer, and so on, reduce the system coupling, improve the system operation efficiency and maintainability. All levels of the common code are abstracted out (such as adding and removing changes), so that the hierarchy of other classes inherit, greatly reducing code redundancy. High system security, add anti-SQL injection mechanism and so on. All the code is formatted, comments are comprehensive, beautiful and easy to read.We provi

PhenomenonToday, when doing a project, the maxthreads of Tomcat was added to the 1024x768, and Tomcat provides services primarily to do some arithmetic, then insert Redis, query Redis, and finally return the task to the clientAt the time of the pressure test, 1000 threads were opened concurrently, and the HTTP request was initiated to access the Tomcat service, resulting in a series of Redis query timeouts on the first visit to Tomcat, such as 1000 concurrent initiates 10W requests, and possibly

Chapter 8 high-performance Server programming in Linux (high-performance server program framework)8. High-performance server program frameworkThe server is reconstructed into three main modules:IO processing unit. Four IO models and two efficient event processing modes.Logical unit. Two Efficient concurrency modes.Storage unit. (Not discussed for the moment)IO mo

Unity3d playback high-quality video solution, unity3d high-quality Unity3d playback high-quality video solution ~ A video game is being played recently. It is really a video game. The main background of the game is a large video. Three or four videos may be switched, and seamless switching is required. The platform is Android, and the movie is rockclip. Various

the largest real-time interaction tool on the planet. Twitter mainly distributes messages, rather than producing messages. 300 k qps is read, and only 6000 requests are written per second. Asymmetry, with a large number of fans, is now a common situation. Messages sent by a single user can be seen by many followers. This is a large fan output, which may be very slow in delivery. Twitter tries to ensure that it is within five seconds, but it cannot always achieve this goal, this situation is m

. The actual requirement is to check the hardware resource utilization of this tier server. For example, CPU, memory, disk read/write, and so on. If it is very high, you must add a new server to deploy the same application of this tier to the new server. So that new servers can share some pressure. In fact, this is to enable applications to support high scalability. There is a hardware load balancing betwee

Question B: "High precision" simple high-precision addition time limit: 1 Sec memory limit: up to MBSubmitted by: 94 resolution: 27Submitted State [Discussion Version] Topic description Asura King solved the computer's memory limit problem, finally can use the computer for a large magic operation, he handed the Wolf's first task is to calculate two nonnegative integers a, b and, where A and b in th

Optimization of PHP-FPM parameters under high concurrency and high load Optimization of PHP-FPM parameters under high concurrency and high load Mainly for parameter tuning of PHP in Linux Adjust file descriptor limits # Ulimit-n 1000000 # Vi/etc/security/limits. conf # Setting Shell Limits for File Descriptor

Javascript is your high-level function (advanced application), javascript high-level In common programming languages, function parameters can only be basic types or object references, and return values are only basic data types or object references. However, in Javascript, a function can be passed as a parameter or returned as a return value. A high-order functio

Mysql-High-Performance Index policy, mysql-High-Performance IndexIndependent index: An independent index means that an index Column cannot be part of an expression or a function parameter. 　　Example 1:SELECT actor_id FROM actor WHERE actor_id + 1 = 5 -- this method does not work even if an index is created on actor_id. 　　Example 2:SELECT... WHERE TO_DAYS (CURRENT_DATE)-TO_DAYS (date_col) Multi-column index

59 effective methods for writing high-quality Python code and high-quality python59 The author Brett Slatkin is a senior software engineer at Google. He is the Engineering director and co-founder of the Google consumer survey project. He once worked on the Python infrastructure of Google App Engine and used Python to manage a large number of Google servers. Slatkin is also the co-founder of the PubSubHubbub

Python 3 Study Notes (5) ---- variables, recursion and high-level functions, python high-level functions I. Variables 1. the variables defined in the subroutine are called local variables, and the variables defined at the beginning of the program are called global variables.2. The global variable scope is the whole program, and the local variable scope is the subroutine that defines the variable.3. When a g

N suggestions for writing high-performance Javascript code, high-performance javascript Javascript has been playing an important role in web application development for many years, but many developers tend to ignore some performance knowledge, especially with the continuous upgrade of computer hardware, developers feel that the performance optimization of Javascript does not significantly affect the executi

Configuring HTTP+MYSQL+NFS high-availability clusters based on the Crm+hb_gui interface Configuring Ipvs high-availability clusters based on the crm+hb_gui+ldirectored interface This article is from the "Ccschan" blog, make sure to keep this source http://ccschan.blog.51cto.com/11854461/1925394Configuration of the Linux High Availability cluster Sch

. For example, the UI Tier can be dozens of servers, hundreds of servers, or even thousands of servers. The number of servers required for each Tier is configured based on actual needs. The actual requirement is to check the hardware resource utilization of this Tier server. For example, CPU, memory, disk read/write, and so on. If it is very high, you must add a new server to deploy the same application of this Tier to the new server. So that new serv

The network is filled with a lot of information every day for novice webmaster analysis, to do high-quality original content of various skills, which is also mainly for the daily update of the website of soft writing. Soft writing itself does have the skill to say, however, each soft writer's route is different, and the article writing its own skills is also limited things, the distance between the webmaster and webmaster is a matter of perseverance,