Thursday, March 31, 2016

Few C# Terms

An accessor is a method which provides access to the value managed within a class. Effectively the access is read only, in that the data is held securely in the class but code in other classes may need to have access to the value itself. An accessor is implemented as a public method which will return a value to the caller. Note that if the thing being given access to is managed by reference the programmer must make sure that it is OK for a reference to the object is passed out. If the object is not to be changed it may be necessary to make a copy of the object to return to the caller.

If a class is dependent on another the two classes are said to be coupled. Generally speaking a programmer should strive to have as little coupling in their designs as possible, since it makes it harder to update the system. Coupling is often discussed alongside cohesion, in that you should aim for high cohesion and low coupling.

A mutator is a method which is called to change the value of a member inside an object. The change will hopefully be managed, in that invalid values will be rejected in some way. This is implemented in the form of a public method which is supplied with a new value and may return an error code.

A stream is an object which represents a connection to something which is going to move data for us. The movement might be to a disk file, to a network port or even to the system console. Streams remove the need to modify a program depending on where the output is to be sent or input received from.

This is a value which is used to identify the element in an array. It must be an integer value. Subscripts in C# always start at 0 (this locates, the first element of the array) and extend up to the size of the array minus 1. This means that if you create a four element array you get hold of elements in the array by subscript values of 0,1,2 or 3. The best way to regard a subscript is the distance down the array you are going to move to get the element that you want. This means that the first element in the array must have a subscript value of 0.

Type-safe code accesses only the memory locations it is authorized to access. For example, type-safe code cannot read values from another object's private fields. It accesses types only in well-defined, allowable ways. When code is type safe, the common language runtime can completely isolate assemblies from each other. This isolation helps ensure that assemblies cannot adversely affect each other and it increases application reliability. Type-safe components can execute safely in the same process even if they are trusted at different levels.

Continuous Delivery

Continuous delivery (CD) is a software engineering approach in which teams produce software in short cycles, ensuring that the software can be reliably released at any time. It aims at building, testing, and releasing software faster and more frequently. The approach helps reduce the cost, time, and risk of delivering changes by allowing for more incremental updates to applications in production. A straightforward and repeatable deployment process is important for continuous delivery.
"Continuous Delivery is a software development discipline where you build software in such a way that the software can be released to production at any time" — Martin Fowler
Continuous integration (CI) is the practice, in software engineering, of merging all developer working copies to a shared mainline several times a day. Continuous Integration provides a framework for efficiently validating software in a predictable way. But to get the most out of it, you need to look at how it fits into the overall process of delivering software. In an agile project, you want to deliver working software at every iteration. Unfortunately, this is easier said than done; it often turns out that even if you implement CI and get the build process to produce a new installation package in a few minutes, it takes several days to get a new piece of software tested and released into production. To make this work better, the key is process. In order to deliver working software faster, you need a good cohesive set of tools and practices. So you need to add planning, environment management, deployment, and automated validation to get a great solution for your product, and this is just what Continuous Delivery is about.
Continuous Deployment is the practice of continuously pushing to production new versions of software under development. So Continuous Integration is all about quick feedback and validation of the commit phase, and Continuous Delivery is about establishing a mindset where you can deliver features at customer demand. Continuous Deployment is a third term that’s sometimes confused with both Continuous Integration and Continuous Delivery. Continuous Deployment can be viewed as the next level of Continuous Delivery. Where Continuous Delivery provides a process to create frequent releases but not necessarily deploy them, Continuous Deployment means that every change you make automatically gets deployed through the deployment pipeline. When you have established a Continuous Delivery solution, you are ready to move to Continuous Deployment if that’s something your business would benefit from.

Continuous Integration is a software development practice in which you build and unit-test software every time a developer checks in new code.
Continuous Delivery (CD) is a software development practice in which continuous integration, automated testing, and automated deployment capabilities allow software to be developed and deployed rapidly, reliably and repeatedly with minimal manual overhead.
Continuous Deployment is a software development practice in which every code change goes through the entire pipeline and is put into production, automatically, resulting in many production deployments every day.