On Fri, Oct 18, 2002 at 08:12:29PM -0500, Edgar Friendly wrote: > Matthew Toseland <toad at amphibian.dyndns.org> writes: > > > Hmm. If I remember correctly, it is possible to parse the CHK key > > without having the data, and tell approximately how big it is from > > that... If we require that all but the last chunk are full, then this > > gives you your filesize (CHKs are power of two sizes, plus some > > metadata/fields stuff). > > It may be possible, but it's quite undesirable to parse the CHK to > find the size. It's not sufficient that all chunks but the last be > full, because they could be different power-of-2 sizes. Huh? CHKs are power of two sizes. You can take the CHK URI and without fetching anything find out which power of two it is. And if all but the last CHK are required to be full and sans metadata, you know how big everything is and can reconstruct in situ. OTOH, it's pointless to reconstruct in situ because everyone should be using redundant splitfiles, which are more complex. If we are using rsplits, all the chunks will probably be the same size. > > We could require that everyone follow the obviously optimal strategy > of splitting with all chunks the same power of 2 size, excepting the > last. But I'm against having that as part of a specification. I will > definitely recommend that people do things this way, but there may > very well be a good reason not to. Clients should be able to work > with as many ways to split files up as possible. > > Thelema > -- > E-mail: thelema314 at bigfoot.com Raabu and Piisu > GPG 1024D/36352AAB fpr:756D F615 B4F3 BFFC 02C7 84B7 D8D7 6ECE 3635 2AAB > > _______________________________________________ > devl mailing list > devl at freenetproject.org > http://hawk.freenetproject.org/cgi-bin/mailman/listinfo/devl >
-- Matthew Toseland toad at amphibian.dyndns.org amphibian at users.sourceforge.net Freenet/Coldstore open source hacker. Employed full time by Freenet Project Inc. from 11/9/02 to 11/11/02. http://freenetproject.org/ -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <https://emu.freenetproject.org/pipermail/devl/attachments/20021019/344a38f6/attachment.pgp>
