--- Andy Ross <[EMAIL PROTECTED]> wrote: > Christian Mayer wrote: > > The missing functionality is the ability to figure out if the tile > has > > changed IIRC. > > > > But that'n no problem - HTTP already supports that. IIRC it send's > a > > status code of 302 if the reqested data didn't change... > > There seems to be some confusion about what rsync is and what it > does. > Unlike FTP and HTTP, it does more than a date stamp and file size > check to determine whether or not to resend a file. Rsync is > essentially a binary "diff" utility. It is capable of finding > continguous unchanged sections in otherwise-modified files and > sending > *only* the sections that change. And it does it in time linear in > the > size of the file and network bandwidth linear in the size of the > changes, without either side needing to see both copies to do it.
Ahh, might it be reasonable, then to offer ftp or http as a fall back protocol (if rsync is not available) and provide only new scenery (not updated) in those cases? > > It's a very, very cool program. There is a (amazingly readable!) > paper on how it works available at http://www.rsync.org for those > interested. > > For some applications, this is critically important. Simply > downloading new scenery underneath your airplane won't be any > different, but *updating* preexisting scenery will (probably) work > much better with rsync than with any other web protocol. This is > likely to be the more important feature, IMHO. In the future, you > won't need to do anything to get access to new runway lighting, large > building models, new elevation data, etc... > > Now, whether rsync is really a win for terrasync depends on the > details of the data files and whether or not they'll have contiguous > unchanged sections after typical updates. I don't know enough about > it to say. The only point is that rsync is most definitely *not* a > new and incompatible file transfer protocol. It solves a much harder > problem. > > About the windows binary: is anyone really opposed to shipping a > rsync.exe and cygwin.dll with the rest of the binaries? I'm not a > windows guy, but this really doesn't seem to awful to me. > > Andy > > -- > Andrew J. Ross NextBus Information Systems > Senior Software Engineer Emeryville, CA > [EMAIL PROTECTED] http://www.nextbus.com > "Men go crazy in conflagrations. They only get better one by one." > - Sting (misquoted) > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > > __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
