1. A method of managing associations between keys and values within a computer processing system, comprising: inputting requests to store associations between keys and data values corresponding to the keys; storing the associations in entry nodes within a data structure represented as a hash-based directed acyclic graph (HDAG); and upon receipt of a data value request that includes a specified function of the request key, together with satisfaction of any additional access criterion, automatically providing a return data value corresponding to the request key, wherein the return data value has been generated based on at least one of the associations that involve the request key.