Addressing in a Persistent Environment

Abstract

An addressing scheme is proposed, called a structured addressing scheme, that will provide a consistent addressing structure for a persistent environment. A structured address is the internal analogue of a qualified name in a programming language (e.g. x.y.z) where each component of the address identifies a special kind of data item, called a memory, whose basic purpose is to hold/store possibly many objects. Memories are organized in a hierarchical fashion. Some memories correspond to physical storage media, but others exist for organizational reasons. Each component of a structured address is not defined by the hardware, but by the memory in which the object is contained. Hence, a component can be encoded by a memory (so it is not a direct displacement) to reduce the length of an address. The component can point indirectly to the next component or object in the memory, making it a handle. This indirection permits the object to be moved around within its memory for storage management reasons and yet still maintain a fixed address. Finally, the structured address has the advantage that it accommodates new memories easily.