Method for transforming a hash bucket number to a control interval to identify the physical location of information in a mass memory

摘要

A method for addressing mass memory in which information is stored in control intervals of physically contiguous disk segments subject to irregularities in the mapping is disclosed. Such irregularities may include discontinuities at some regular interval, which may or may not be 2'', and/or offset from zero with respect to a virtual address employed by a user. Within the method, a unique hashing algorithm is employed to convert a virtual address to a physical address taking into account such irregularities in the mapping. This algorithm is particularly characterized by its use of integer binary arithmetic which results in high speed and complete accuracy. For the special and common condition in which discontinuities appearing at some regular interval of 2'', a similar disclosed algorithm may be employed to achieve even greater speed of address transformation.