On Mar 2, 2008, at 2:30 AM, Ben Hood wrote: > Scott, > > On 1 Mar 2008, at 17:09, Scott Ferguson wrote: >> I'd think you'd see the same benefits if the types were handled >> lazily, just by making the transmission scope explicit and extending >> it beyond the call/reply. > > I was just thinking about a variant which uses the current > transmission scope as it is now, but instead of sending the type > information, you send a small hash of the type information. > > The receiver would then query the sender for the key that that created > that hash value.
But adding extra requests complicates the protocol tremendously. In particular, a HTTP server doesn't necessarily have the ability to query the client. So it's best to treat Hessian as a single unidirectional stream, which also has the advantage that it works for different call or messaging styles. -- Scott > > > That way the sender doesn't need to maintain any state of the keys he > sent to a particular receiver at all because the hash function is > idempotent. > > This relieves the sender of ever having to maintain coherence of the > type keys he sends out over time to multiple destinations. > > The hash wouldn't necessary need to be cryptographically secure, it > could just be a 32-bit hash like a bloom filter. > > This is a small trade-off to the variant where you just widen the > transmission scope, because you would probably be resending a 3 to 4 > byte hash per type per request/response cycle, whereas with the > widened scope you could implement it so that it averages 1 byte per > type per cycle. > > So you lose 2-3 bytes per type per cycle on average. > > But you gain more simplicity overall, because the type keys will be > idempotent thus making the protocol more robust. > > Thoughts? > > Ben > > > _______________________________________________ > hessian-interest mailing list > [email protected] > http://maillist.caucho.com/mailman/listinfo/hessian-interest _______________________________________________ hessian-interest mailing list [email protected] http://maillist.caucho.com/mailman/listinfo/hessian-interest
