Multiple-mode-string matching method and device

Abstract

The invention discloses a multiple-mode-string matching method and device. The method includes that a plurality of mode strings are sequenced according to their respective characters, each character is written into a node along a root node of a tree structure downwards to generate a decision tree structure, and main strings to be matched are matched downwards along the decision tree. By means of the method and device, accurate matching of multiple mode strings can be achieved, meanwhile sub nodes are searched according to the Hash values that the sub nodes correspond to, the width change of the decision tree cannot affect time expense of a central processing unit (CPU) matched with the strings, and the time expense of the algorithm depends on the average depth of the decision tree and is unrelated to the number of the mode strings. For string matching with a large number of mode strings, the algorithm can greatly reduce the time expense of the CPU and improve application response speed.

Description

technical field [0001] The invention relates to the field of computer technology, in particular to a multi-pattern character string matching method and device. Background technique [0002] In the computer field, string matching is a relatively common topic. For example, in applications such as search operations and sensitive word filtering, string matching will be involved. A good string matching method can help applications reduce CPU usage time and improve application response time. [0003] Multi-pattern string matching means that there are more than one matching pattern strings. The matching method of multi-pattern strings is: there are n pattern strings P1, P2, ..., Pn and a main text string T, and n pattern strings are searched in T Whether any of them appear in T, the match is successful. [0004] For the matching of multiple pattern strings, the idea of ​​the existing scheme is to match according to a single pattern string, and then traverse all the pattern string...

AI Technical Summary

Problems solved by technology

Assuming that the time complexity of a single pattern string is O(m) and the number of pattern strings is n, then the time complexity of the multi-pattern string matching of the existing scheme is nO(m)

It can be seen that the time complexity of this type of algorithm will increase linearly with the increase of the number of pattern strings. Even if the time complexity of a single pattern is very low, when the number of pattern strings reaches a certain level, the algorithm's CPU time overhead will be substantial

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