Design Issue: Class Library and State

mcljava

I have an interesting problem that I am looking for some advice on. Basically I have a protocol library, where each PDU is a class. Thus the library is a collection of individual classes that are stateless. Meanwhile, I have a need to aquire some housekeeping info via a one time register function. I'd like for this function to make the housekeeping info persistent or semi-persistent so that thet data would be available to the other classes as they are instantiated. Now, I could use XML to write out persistant data but the overhead in file I/O seems quite underdesirable in a near real time application. I could write a value to the Registry, but again there is a performance hit. Finally I have considered kicking off a thread which the instantiated classes could interrogate but that feels over the top. If only you could create a Shared Memory Region like the good ol' days (just kidding). But if you have tackled a similar problem, or know of an elegant approach please let me know. Thanks in advance! Mike

Colin Angus Mackay

mcljava wrote:

PDU

What's a PDU? If all this is happening in one application then reading an XML file at start up then holding the data internally isn't too bad. The other classes could then query the central housekeeping class. If it needs to write stuff out to persist it then it could do so when the application is shut down or at regular intervals so it doesn't disrupt the flow of the rest of the application. ColinMackay.net "Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucius "If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

J4amieC

PDU usually refers to a Power Distribution Unit, used to switch between main power and backup generator power seamlessly with no loss of power.

mcljava

Sorry for the confusion, PDU means Protocol Data Unit (i.e. a packet) in data communications and in my library.