Design And Implement Of The Embedded HTML Parser Based On Automaton

With the rapid development of network technique and the wide application of the embedded system, embedded parser has been one of the most important applications, even the only application which can be supported directly. Used for browsing the information, embedded browser always works on such protocols as HTTP or WAP etc, and can support such language as HTML, XML, XHTML, JavaScript, WML. It has been widely used in such embedded systems as Set Top Box, mobile phone, PDA, car pc, etc.Compared with the common browser used on the PC, embedded browser has the characteristic of diversity. Because different business has different attitudes towards the CPU type, system function definition, display equipment, and electricity limitation, the development must exactly bases on the requirement. Take the different display equipment for example; developer of the embedded browser must use different display optimization such as font identification, font library, graph visualization, page display rule and so on. Moreover embedded browser only has limit memory and storage space, so it is necessary to design special algorithm for the guarantee of the function velocity and efficiency.In this paper we design an embedded browser which is part of an internet model used on the car embedded system of ShenZhen ECLECTRONICS Company. It is programmed with EVC on the WinCE platform, can fully display Chinese words, and bases on the parsing algorithm which only parses a chunk of words which can improve efficiency.The contribution of this thesis are:This paper designs and implements the embedded brower's network transport model. It downloads the page basing on the HTTP protocol with implement by WinInet Class of EVC. In this model we use a thread to carry on it for the multithread.Presents a new DFA algorithm used in embedded brower's parser model, including lexical analysis and syntax analysis. At first we abstract the DFA (Deterministic Finite Automaton) mathematical mode from the HTML parser, then design a minimize DFA algorithm. The key idea of the algorithm is that we separate all the DFA's states into different subsets which do not have same state with each other. So we get different subsets and every state is equal to another in a same subset.In this paper we store the parser result in the structure of DOM tree,which is an important preparation for the next step of displaying HTML document (such as add, delete, remove and so on ).The works presented in this paper have been applied in the car embedded system of ShenZhen SOUND ECLECTRONICS Company, and achieved good academic and practical values.