Procedures for managing extendible array files
Gary D. Knott · Software Practice and Experience · 1981
Abstract Varieties of files are reviewed and the notion of a file space is discussed. A number of properties which characterize file spaces are listed. This modest theoretical framework has a clarifying influence on the subject of files. Certain file‐system primitives are introduced which are similar to those in most commonly‐known operating systems, and then these primitives are used in constructing a collection of routines for reading and writing extedible arrays. Extendible arrays are based on fixed page size randomly‐accessible files and they are a useful universal input/output (I/O) structure for many different storage and retrieval schemes. The routines for managing such files are similar to the mechanisms used in handling a paged address space in a virtual memory system. The contribution of this paper lies in the detailed implementation which is presented; these routines are well understood in principle, but tricky to construct in practice. Finally, these routines are used in a practical example which provides for managing a variable blocksize free space list within a extendible array.