Experiences with integrating persistence into an IMAP server

This paper discusses work in progress in integrating persistence into the University of Washington IMAP (Internet Mail Access Protocol) server to take advantage of the benefits provided by persistence over the flat file storage model. The traditional flat file storage model involves complicated and error prone locking mechanisms (due mainly to legacy UNIX file locking protocols) and does not easily support indexing operations. We have replaced the flat file back end of the IMAP server with a module that uses C++ data structures, thereby allowing the programmer a much easier way to implement searching/storage algorithms and data structures. It is also hoped that it will provide insights into the application development cycle of a real persistent application.