A Dictionary-Based Compressed Pattern Matching Algorithm

Compressed pattern matching refers to the process of, given a text in a compressed form and a pattern, finding all the occurrences of the pattern in the text without decompression. To utilize bandwidth more effectively in the Internet environment, it is highly desirable that data be kept and sent over the Internet in the compressed form. In order to support information retrieval for compressed data, compressed pattern matching has been gaining increasing attention from both theoretical and practical viewpoints. In this article, we design and implement a dictionary-based compressed pattern matching algorithm. Our algorithm takes advantage of the dictionary structure common in the LZ78 family. With the help of a slightly modified dictionary structure, we are able to do ‘block decompression’ (a key in many existing compressed pattern matching schemes) as well as pattern matching on-the-fly, resulting in performance improvement as our experimental results indicate.