A transparent non-invasive file data model for algorithmic skeletons

A file data model for algorithmic skeletons is proposed, focusing on transparency and efficiency. Algorithmic skeletons correspond to a high-level programming model that takes advantage of nestable programming patterns to hide the complexity of parallell distributed applications. Transparency is achieved using a workspace factory abstraction and the proxy pattern to intercept calls on File type objects. Thus allowing programmers to continue using their accustomed programming libraries, without having the burden of explicitly introducing non-functional code to deal with the distribution aspects of their data. A hybrid file fetching strategy is proposed (instead of lazy or eager), that takes advantage of annotated functions and pipelined multithreaded interpreters to transfer files in-advance or on-demand. Experimentally, using a BLAST skeleton application, it is shown that the hybrid strategy provides a good tradeoff between bandwidth usage and CPU idle time.