The Research Of The Key Methods Of The RTCOM-based Component Repository Management

The success of software reuse heavily depends on a good component management system. Meanwhile, the mature distributed real-time system is bound to the precise real-time component model. Facing current development of distributed real-time software engineering, the management system of real-time components becomes an unavoidable research topic.The PCCM, which is short for the Component Model with performance constraints, is a logic model which can describe both the functional logic and performance constraints at the same time. RTCOM is the implemental model of PCCM. While it is language independent, it has precise semantics and can satisfy the functional and performance requirements of the distributed real-time components. The RTCOM-based distributed real-time component management system mainly solves the following three problems: management, retrieval and reusability.The RTCOM-based component management system adopts the strategy of combining file systems and XML files to store components, resulting that it can not only support the complex structures of components, but also can set up the logic relationships between components quickly and effectively. The component entity library is used to store the binary executable components, while the component information library is used to hold the structural and deployment information of components themselves. Complementing each other, those two libraries will greatly support the maintenance of consistency between components.The RTCOM-based component repository uses the method of combining the facet retrieval and key-word retrieval together as its retrieving strategy. The system adopts the three-level application domain to describe the facets, and it uses those component register information such as GUID and those deployment information such as detail description as its key-words. With the optimized Boyer-Moore algorithm, it can use the HebmBc and HebmGs table to carry on quick string match, making the system can both support the retrieval of Chinese characters and support multiple words retrieval. What's more, compared with the old BM algorithm, the system achieves both lower time and lower space cost.Keeping to the principle of"Best effort to support reuse"and trying to design the"intellectual"component repository, the RTCOM-based component repository will not only support those components which totally match the user requirements, but also it can supply the users with extra candidate components and adaptation patterns. From those perspective of sequence, parallel and recursion, the adaptation methods in the system are able to guide the component adaptation, which will improve the reusability of existing components in the component repository.