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EAccelerator
eAccelerator was a PHP accelerator derived from the MMCache extension for the PHP programming language. eAccelerator provides a bytecode cache. eAccelerator is open source and thereby free to use and distribute. Old and unmaintained versions also provided an encoder. Every time a PHP script is accessed, PHP usually parses and compiles scripts to bytecode. Once installed, eAccelerator optimizes the compiled bytecode and caches this to shared memory or disk or both. Upon subsequent accesses to a script, eAccelerator will access cached bytecode if it is available instead of the script being compiled. This avoids the performance overhead of repeated parsing and compilation. Previous eAccelerator versions also provided functions for use in PHP scripts that allow access to shared memory, automatic web (content) caching, and other related tasks. These were removed as of version 0.9.6rc1. Old eAccelerator versions had an encoder component that creates a file that cannot be as easil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternative PHP Cache
This is a list of PHP accelerators. Alternative PHP Cache (APC) Alternative PHP Cache is a free and open (PHP license) framework that caches the output of the PHP bytecode compiler in shared memory, thus reducing parsing and disk I/O overhead for later requests; and a shared memory cache for user data. For an application consisting of a large source code base such as Drupal, a 3x increase in page generation speed is possible as a result. It has been used at Facebook and has a mature codebase thanks to numerous contributors, including Facebook itself. APC was originally scheduled for inclusion into the PHP core no later than PHP 6. While multiple accelerator projects were considered desirable, the focus has since moved to Optimizer Plus, and, later, Zend OPcache that is included in the core distribution as of PHP 5.5. Since March 2013, a beta version of APCu (APC User Cache) is available, in which all opcode caching abilities have been removed to support user caches in share ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PHP Accelerator
A PHP accelerator is a PHP extension designed to improve the performance of software applications written in the PHP programming language. Operation Most PHP accelerators work by caching the compiled opcode/bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normal ... of PHP representation of php files to avoid the overhead of parsing and compiling source code on each request (some or even most of which may never be executed). To further improve performance, the cached code is stored in shared memory and directly executed from there, minimizing the amount of slow disk reads and memory copying at runtime. Practical benefits PHP accelerators substantially increase the speed of PHP applications. Improvements of web page generation throughput by factors of two to seven have been o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fork (software)
In software development, a fork is a codebase that is created by duplicating an existing codebase and, generally, is subsequently modified independently of the original. Software built from a fork initially has identical behavior as software built from the original code, but as the source code is increasingly modified, the resulting software tends to have increasingly different behavior compared to the original. A fork is a form of branching, but generally involves storing the forked files separately from the original; not in the repository. Reasons for forking a codebase include user preference, stagnated or discontinued development of the original software or a schism in the developer community. Forking proprietary software (such as Unix) is prohibited by copyright law without explicit permission, but free and open-source software, by definition, may be forked without permission. Etymology The word ''fork'' has been used to mean "to divide in branches, go separate ways" as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Extension
In computing, a plug-in (also spelled plugin) or add-in (also addin, add-on, or addon) is a software component that extends the functionality of an existing software system without requiring the system to be re-built. A plug-in feature is one way that a system can be customizable. Applications support plug-ins for a variety of reasons including: * Enable third-party developers to extend an application * Support easily adding new features * Reduce the size of an application by not loading unused features * Separate source code from an application because of incompatible software licenses Examples Examples of plug-in use for various categories of applications: * Digital audio workstations and audio editing software use audio plug-ins to generate, process or analyze sound. Ardour, Audacity, Cubase, FL Studio, Logic Pro X and Pro Tools are examples of such systems. * Email clients use plug-ins to decrypt and encrypt email. Pretty Good Privacy is an example of such plug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language
A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually defined by a formal language. Languages usually provide features such as a type system, Variable (computer science), variables, and mechanisms for Exception handling (programming), error handling. An Programming language implementation, implementation of a programming language is required in order to Execution (computing), execute programs, namely an Interpreter (computing), interpreter or a compiler. An interpreter directly executes the source code, while a compiler produces an executable program. Computer architecture has strongly influenced the design of programming languages, with the most common type (imperative languages—which implement operations in a specified order) developed to perform well on the popular von Neumann architecture. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bytecode
Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normally numeric addresses) that encode the result of compiler parsing and performing semantic analysis of things like type, scope, and nesting depths of program objects. The name ''bytecode'' stems from instruction sets that have one- byte opcodes followed by optional parameters. Intermediate representations such as bytecode may be output by programming language implementations to ease interpretation, or it may be used to reduce hardware and operating system dependence by allowing the same code to run cross-platform, on different devices. Bytecode may often be either directly executed on a virtual machine (a p-code machine, i.e., interpreter), or it may be further compiled into machine code for better performance. Since bytecode instruct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cache (computing)
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A cache hit occurs when the requested data can be found in a cache, while a cache miss occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs. To be cost-effective, caches must be relatively small. Nevertheless, caches are effective in many areas of computing because typical Application software, computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested, and spatial locality, where data is requested that is stored near dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source License
Open-source licenses are software licenses that allow content to be used, modified, and shared. They facilitate free and open-source software (FOSS) development. Intellectual property (IP) laws restrict the modification and sharing of creative works. Free and open-source licenses use these existing legal structures for an inverse purpose. They Grant (law), grant the recipient the rights to use the software, examine the source code, modify it, and distribute the modifications. These criteria are outlined in the Open Source Definition. After 1980, the United States began to treat software as a literary work covered by copyright law. Richard Stallman founded the free software movement in response to the rise of proprietary software. The term "open source" was used by the Open Source Initiative (OSI), founded by free software developers Bruce Perens and Eric S. Raymond. "Open source" emphasizes the strengths of the Open-source software development, open development model rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Web Caching
A web cache (or HTTP cache) is a system for optimizing the World Wide Web. It is implemented both client-side and server-side. The caching of multimedia and other files can result in less overall delay when browsing the Web. Parts of the system Forward and reverse A forward cache is a cache outside the web server's network, e.g. in the client's web browser, in an ISP, or within a corporate network. A network-aware forward cache only caches heavily accessed items. A proxy server sitting between the client and web server can evaluate HTTP headers and choose whether to store web content. A reverse cache sits in front of one or more web servers, accelerating requests from the Internet and reducing peak server load. This is usually a content delivery network (CDN) that retains copies of web content at various points throughout a network. HTTP options The Hypertext Transfer Protocol (HTTP) defines three basic mechanisms for controlling caches: freshness, validation, and invalidation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Software
Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribute it and any adapted versions. Free software is a matter of liberty, not price; all users are legally free to do what they want with their copies of a free software (including profiting from them) regardless of how much is paid to obtain the program.Selling Free Software (GNU) Computer programs are deemed "free" if they give end-users (not just the developer) ultimate control over the software and, subsequently, over their devices. The right to study and modify a computer program entails that the source code—the preferred ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU GPL
The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first copyleft license available for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. The GPL is more restrictive than the GNU Lesser General Public License, and even more distinct from the more widely used permissive software licenses such as BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domain. Promi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
