Persistent State Services And Psdl Compiler Design And Implementation

The computer technology has come the era of the calculation of network centric. As we all know, Common Object Request Broker Architecture of OMG has become one of the main standards of the distributed applications .On the other hand, with the expansion of the fields and the deepen of the degree, the object persistence become more and more important. If using the conventional applications stored the persistent objects by the RDBMS, it needs us program too many codes, and the mistakes will take place more easily. What is more, it can't meet the requests of the distributed object-oriented technology. So, OMG has defined PSS(Persistence State Service) to make users pay no attentions to details of the storage systems, so the problem of the storage of the persistent objects.In this paper, I will analyze the specification of Persistence State Service on the basis of the technology of object persistence, including the model of the structure of PSS, the language of PSDL, the procedure of developing the applications using PSDL. What is more, I will especially discuss the design and the realization of the compiler of PSDL basing on the profound understanding of the specification of Persistence State Service and the grammar and syntax of PSDL. Then, I will give a flexible and efficient realization of the compiler of PSDL on the base of the middleware product StarBusS.O which conforms to the standard of CORBA, and I will introduce the pretreatment, the analysis of syntax, the analysis of grammar and the codes generation. The feature of our compiler is the using of the structure of distributed objects in the tree of syntax, and by using this structure we can get dynamic description of persistence state in run. So, we can provide support to the description of meta-information for the future dynamic mechinism of accessing persistence state.