[discussion] data structures for CS, FIB, PIT?

[cgundogan]

In the current situation there are instances, where the CS, FIB or PIT are accessed directly through a global struct (ccnl_relay_s). Adding support for proper data structures for CS, FIB, PIT can improve access control and allows for thread-safe read and write operations. Further, it is far simpler to provide interchangeable data structure implementaitons (malloc vs. static memory), without using too many #ifdefs or major code restructurings.

Should we put some effort into this topic? How should we organize these data structures?

[mfrey]

Personally, I think this might change how you use CCN-lite, since you don't want to

1. make the free'd data structures parameters of functions, e.g.

226 int
227 ccnl_fwd_handleInterest(struct ccnl_relay_s *relay, struct ccnl_face_s *from,     
228                         struct ccnl_pkt_s **pkt, cMatchFct cMatch)
229 {

becomes

226 int
227 ccnl_fwd_handleInterest(struct ccnl_relay_s *relay, struct ccnl_face_s *from,
228                         struct ccnl_interest_s *pit,  struct ccnl_pkt_s **pkt,
229                         cMatchFct cMatch)
230 {

2. introduce additional global variables which are passed around as functions.

Also, besides having thread-safe functions I'm wondering if we want to support some kind of a generic "interface" which allows you to easily swap implementations. So, you e.g. you would have something like

struct some_data_type get_interest(const char* prefix);

and the function could use a hash map or a double linked list in the background.