Matching of complex nested objects by multilevel hashing

A computer-based system using multilevel hashing, in a computer with a physical memory, for lookup of a complex nested object having a plurality of nesting levels, each said level having at least one element, comprising the means for:

• storing representatives of a complex nested object in a data structure at locations determined by multilevel hashing of the complex nested object elements performed recursively for each said nesting level, each said location defined by calculating a position index for each said representative of the nesting level as a modulo of hash values of the elements from the previous nesting level and the data structure size;
• and
• determining a match for an inputted complex nested object by performing the same recursive multilevel hashing on the inputted complex nested object as during storing of the complex nested object, and performing integer comparisons with hash values of the complex nested object, found at the data structure locations determined by the position index calculated from the hash values, by comparing, for each said nesting level, an overall level hash value and, if a match is found, comparing each said element hash value,
• wherein a complex nested object is an access control list having representatives stored in an array of linked lists, wherein a linked list storing a set of access control lists with a same position index, and wherein the access control list having a set of rules′ representatives stored in an array of linked list of rules in the physical memory, where each said rule having a user identifier and a set of attributes.

A computer program product embedded in a computer usable medium of a computer with a physical memory and a database management system, tangibly embodying a program of instructions executable by the computer to perform a computer-based method using multilevel hashing for lookup of a complex nested object having a plurality of nesting levels, each said level having at least one element, compnsing:

• storing representatives of a complex nested object in a data structure at locations determined by multilevel hashing of the complex nested object elements performed recursively for each said nesting level, each said location defined by calculating a position index for each said representative of the nesting level as a modulo of hash values of the elements from the previous nesting level and the data structure size;
• and
• determining a match for an inputted complex nested object by performing the same recursive multilevel hashing on the inputted complex nested object as during storing of the complex nested object, and performing integer comparisons with hash values of the complex nested object, found at the data structure locations determined by the position index calculated from the hash values, by comparing, for each said nesting level, an overall level hash value and, if a match is found, comparing each said element hash value,
• wherein a complex nested object is an access control list having representatives stored in an array of linked lists, wherein a linked list storing a set of access control lists with a same position index, and wherein the access control list having a set of rules′ representatives stored in an array of linked list of rules in the physical memory, where each said rule having a user identifier and a set of attributes.