A Table Compression Method for Extended Aho-Corasick Automaton

The Aho-Corasick algorithm is a classic method for matching a set of strings. However, the huge memory usage of Aho-Corasick antomaton prevents it from being applied to large-scale pattern sets. Here we present a simple but efficient table compression method to reduce the automaton's space. The basic idea of our method is based on equivalent rows elimination, which groups state rows into equivalent classes and eliminates the duplicates. Experiments demonstrate that the proposed method significantly reduces the memory usage and still runs at linear searching time comparable to that of extended Aho-Corasick algorithm. Our method provides good trade-off between memory usage and searching time.