|
Publish–subscribe Pattern
In software architecture, the publish–subscribe pattern (pub/sub) is a messaging pattern in which message senders, called publishers, categorize messages into classes (or ''topics''), and send them without needing to know which components will receive them. Message recipients, called subscribers, express interest in one or more classes and only receive messages in those classes, without needing to know the identity of the publishers. This pattern decouples the components that produce messages from those that consume them, and supports asynchronous, many-to-many communication. The publish–subscribe model is commonly contrasted with message queue-based and point-to-point messaging models, where producers send messages directly to consumers. Publish–subscribe is a sibling of the message queue paradigm, and is typically a component of larger message-oriented middleware systems. Many modern messaging frameworks and protocols, such as the Java Message Service (JMS), Apac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Architecture
Software architecture is the set of structures needed to reason about a software system and the discipline of creating such structures and systems. Each structure comprises software elements, relations among them, and properties of both elements and relations. The ''architecture'' of a software system is a metaphor, analogous to the architecture of a building. It functions as the blueprints for the system and the development project, which project management can later use to extrapolate the tasks necessary to be executed by the teams and people involved. Software architecture is about making fundamental structural choices that are costly to change once implemented. Software architecture choices include specific structural options from possibilities in Software design, the design of the software. There are two fundamental laws in software architecture: # Everything is a trade-off # "Why is more important than how" "Architectural Kata" is a teamwork which can be used to produce an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Queue
In computer science, a priority queue is an abstract data type similar to a regular queue (abstract data type), queue or stack (abstract data type), stack abstract data type. In a priority queue, each element has an associated ''priority'', which determines its order of service. Priority queue serves highest priority items first. Priority values have to be instances of an ordered data type, and higher priority can be given either to the lesser or to the greater values with respect to the given order relation. For example, in Java (programming language), Java standard library, ''PriorityQueues the least elements with respect to the order have the highest priority. This implementation detail is without much practical significance, since passing to the converse relation, opposite order relation turns the least values into the greatest, and vice versa. While priority queues are often implemented using Heap (data structure) , heaps, they are conceptually distinct. A priority queue can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loose Coupling
In computing and systems design, a loosely coupled system is one # in which components are weakly associated (have breakable relationships) with each other, and thus changes in one component least affect existence or performance of another component. # in which each of its components has, or makes use of, little or no knowledge of the definitions of other separate components. Subareas include the coupling of classes, interfaces, data, and services. Loose coupling is the opposite of tight coupling. Advantages and disadvantages Components in a loosely coupled system can be replaced with alternative implementations that provide the same services. Components in a loosely coupled system are less constrained to the same platform, language, operating system, or build environment. If systems are decoupled in time, it is difficult to also provide transactional integrity; additional coordination protocols are required. Data replication across different systems provides loose coupling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Google Books
Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google that searches the full text of books and magazines that Google has scanned, converted to text using optical character recognition (OCR), and stored in its digital database.The basic Google book link is found at: https://books.google.com/ . The "advanced" interface allowing more specific searches is found at: https://books.google.com/advanced_book_search Books are provided either by publishers and authors through the Google Books Partner Program, or by Google's library partners through the Library Project. Additionally, Google has partnered with a number of magazine publishers to digitize their archives. The Publisher Program was first known as Google Print when it was introduced at the Frankfurt Book Fair in October 2004. The Google Books Library Project, which scans works in the collections of library partners and adds them to the digital inventory, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Petzold
Charles Petzold (born February 2, 1953) is an American programmer and technical author on Microsoft Windows applications. He is also a Microsoft Most Valuable Professional and was named one of Microsoft's seven Windows Pioneers. Biography Petzold graduated with a Master of Science in Mathematics from Stevens Institute of Technology in 1975. Aside from writing books about Windows programming, he has contributed to various magazines about computers. He had an interest in electronic music and in 1977 started building electronic music instruments out of CMOS chips. In 1979, Petzold started building a computer-controlled digital electronic music synthesizer based on the Zilog Z80 microprocessor. This experience of digital circuitry and assembly language programming formed the basis of his book ''Code: The Hidden Language of Computer Hardware and Software''. Petzold purchased a two-diskette IBM PC in 1984 for $5,000. This debt encouraged him to use the PC to earn some revenue so he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observer Pattern
In software design and software engineering, the observer pattern is a software design pattern in which an object, called the ''subject'' (also known as ''event source'' or ''event stream''), maintains a list of its dependents, called observers (also known as ''event sinks''), and automatically notifies them of any state (computer science), state changes, typically by calling one of their method (computer science), methods. The subject knows its observers through a standardized interface and manages the subscription list directly. This pattern creates a one-to-many dependency where multiple observers can listen to a single subject, but the coupling is typically synchronous and direct—the subject calls observer methods when changes occur, though asynchronous implementations using event queues are possible. Unlike the publish-subscribe pattern, there is no intermediary broker; the subject and observers have direct references to each other. It is commonly used to implement event ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association For Computing Machinery
The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional membership group, reporting nearly 110,000 student and professional members . Its headquarters are in New York City. The ACM is an umbrella organization for academic and scholarly interests in computer science (informatics). Its motto is "Advancing Computing as a Science & Profession". History In 1947, a notice was sent to various people: On January 10, 1947, at the Symposium on Large-Scale Digital Calculating Machinery at the Harvard computation Laboratory, Professor Samuel H. Caldwell of Massachusetts Institute of Technology spoke of the need for an association of those interested in computing machinery, and of the need for communication between them. ..After making some inquiries during May and June, we believe there is ample interest to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isis Toolkit
Isis was a major goddess in ancient Egyptian religion whose worship spread throughout the Greco-Roman world. Isis was first mentioned in the Old Kingdom () as one of the main characters of the Osiris myth, in which she resurrects her slain brother and husband, the divine king Osiris, and produces and protects his heir, Horus. She was believed to help the dead enter the afterlife as she had helped Osiris, and she was considered the divine mother of the pharaoh, who was likened to Horus. Her maternal aid was invoked in healing spells to benefit ordinary people. Originally, she played a limited role in royal rituals and temple rites, although she was more prominent in funerary practices and magical texts. She was usually portrayed in art as a human woman wearing a throne-like hieroglyph on her head. During the New Kingdom (), as she took on traits that originally belonged to Hathor, the preeminent goddess of earlier times, Isis was portrayed wearing Hathor's headdress: a sun di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
