Method for compressing search tree structures used in rule classification is provided. The method includes classifying packets based on filter rules, compressing a tree structure comprising multiple levels of single bit test nodes and leaf nodes, storing the compressed tree structure in a first memory structure of a storage such that the multiple levels of single bit test nodes and leaf nodes can be accessed from the first memory structure through a single memory access of the storage, collecting single bit test nodes of the tree structure that are in a lowest level of the tree structure, storing only the collected single bit test nodes within a second memory structure of the storage that is contiguous to the first memory structure, collecting leaf nodes of the tree structure, and storing only the collected leaf nodes within a third memory structure of the storage that is contiguous to second memory structure.