Improved DFA algorithm based on multi-dimensional finite automata

Compiling multiple regular expression signatures into a combined DFA can blowup in state and storage space. Explanations from the prospective of information theory and multi-dimensional mathematical model were proposed focusing on the most serious state explosion. Redundancy states were divided into zero-dimensional ones and one-dimensional ones. The former were compressed by dimension, and the later were dynamically built. The space complexity of the model came to the theoretical lower bound by the above methods. Then the multi-dimensional finite automata (MFA) was proposed with the model. Experiments show that, the construction time taken by MFA is slightly less than XFA and is 2~3 orders of magnitude lower than DFA, STT redundancy compression algorithms and Hybrid-FA; the memory space of MFA is slightly higher than XFA, but is 1~2 orders of magnitude lower than DFA, STT redundancy compression algorithms, mDFA and Hybrid-FA; in the aspect of matching time, MFA ranks after DFA and Hybrid-FA, but ranks before XFA, and it achieves 1~2 orders of magnitude lower than that of STT redundancy compression algorithms and mDFA. ©, 2015, Editorial Board of Journal on Communications. All right reserved.