Pre-processing before precise pattern matching

Abstract

A method for pattern matching finds a target pattern from a stream of patterns, both of the stream of patterns and the target pattern being comprised of elements. The method includes acquiring occurrence numbers of target elements in the target pattern, initializing the buffer, the buffer indicating a section in the stream of patterns, determining whether occurrence numbers of the target elements in the buffer reach the occurrence numbers of the target elements in the target pattern, updating the buffer and then returning to the determining step, in response to determining that the occurrence numbers of the target elements in the buffer do not reach the occurrence numbers of the target elements in the target pattern, and outputting the elements in the buffer for subsequent processing, in response to determining that the occurrence numbers of the target elements in the buffer reach the occurrence numbers of the target elements in the target pattern. A device and a circuit for pattern matching are also provided to increase the speed for pattern matching.