Dataflow
Hard Drive Recovery - Dataflow
Dataflow is a software architecture that is based on the idea that a change in the value of a variable should automatically result in recalculation of the values of other variables. Dataflow is also known as reactive programming. A few programming languages are created to support dataflow. For example, many of the visual programming languages are based on the principle of dataflow.
Dataflow programming principle is widely employed in spreadsheets, where the change in the value of one variable will change the value in the referred cells. A single change may sometimes initiate a whole sequence of changes, if the cells are connected to each other in a sequence.
Dataflow reduces the amount of coupling related code in a program. For example, if a variable X depends on a variable Y, then whenever Y is changed X must be explicitly recalculated. This means that Y is coupled to X. Since X is also coupled to Y (because X’s value depends on the Y’s value), the program ends up with a cyclic dependency between the two variables.
This process can be avoided using an observer pattern, but it will result in a non-trivial amount of code. Dataflow is the ideal solution here as it makes the recalculation of X automatic, thereby eliminating the coupling from Y to X. Dataflow makes implicit a significant amount of computation that must be expressed explicitly in other programming paradigms.
