SPECTA: A formal specification language for content transfer algorithms

When data is transferred between nodes in a network, it is often transferred in-order. However, in distributed systems, such as peer-to-peer networks and cloud-based systems, transferring data out-of-order can be advantageous, for instance by improving transfer speed, availability and reliability. With the intent of creating a reusable formalism that can describe the complexities of out-of-order content transfer in a simple manner, while being powerful enough to support as large a variety of distributed content transfer algorithms as possible, we introduce the Specification for Content Transfer Algorithms (SPECTA) language. In this article, we also show how algorithms written in this language can be translated into other formalisms such as Event-B for analysis, verification or code generation.