From mboxrd@z Thu Jan 1 00:00:00 1970 From: Loic Dachary Subject: Re: Mojette Transform implementation Date: Thu, 30 May 2013 17:56:32 +0200 Message-ID: <51A776B0.7060209@dachary.org> References: <51A5E408.6070104@dachary.org> <51A77516.2040306@dachary.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigB3D479AC3330EF76E7D06E30" Return-path: Received: from smtp.dmail.dachary.org ([86.65.39.20]:32815 "EHLO smtp.dmail.dachary.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933966Ab3E3P4g (ORCPT ); Thu, 30 May 2013 11:56:36 -0400 In-Reply-To: <51A77516.2040306@dachary.org> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Pierre Evenou Cc: Ceph Development This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB3D479AC3330EF76E7D06E30 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Pierre, Thanks for the pointer to https://github.com/rozofs/rozofs/blob/master/rozofs/common/transform.c https://github.com/rozofs/rozofs/blob/master/rozofs/common/transform.h If I understand correctly these are the core functions implementing the a= lgorithm. Would you advise to expose these three functions so that a thir= d party software such as ceph use it ? Or are there more high level funct= ions that are easier to use to do something like: encode(char* buffer_in, char* buffer_out[]) decode(char* buffer_in[], char* buffer_out)=20 repair(char* buffer_in[], char* buffer_out, int indices_of_damaged_buffe= rs[]) Cheers On 05/30/2013 05:49 PM, Loic Dachary wrote: > Hi Pierre, >=20 > I took a look at https://github.com/rozofs/rozofs/blob/master/src/rozof= smount/rozofsmount.c#L1557 > and it gave me a high level view of the fuse bindings of rozofs, thanks= for this :-) >=20 > I'm now looking into the functions that could be wrapped into a library= implementing Mojette Transform so that it could be used by rozofs and ce= ph. Which file would you recommend I study for bootstraping this effort ?= >=20 > Cheers >=20 >=20 > On 05/29/2013 05:23 PM, Pierre Evenou wrote: >> 2013/5/29 Loic Dachary > >> >> Hi Pierre, >> >> As discussed today over the phone, I'm very much interested in try= ing to reuse the Mojette Transform implementation in the context of the w= ork related to the implementation of an erasure coded backend in Ceph. Th= e progress can be tracked from http://tracker.ceph.com/issues/5046 and th= e sub-tickets and the original discussion from the last Ceph summit is at= http://wiki.ceph.com/01Planning/02Blueprints/Dumpling/Erasure_encoding_a= s_a_storage_backend >> >> >> Thanks for the links. >> =20 >> >> I was reading the code of rbs_restore_one_rb_entry at >> https://github.com/rozofs/rozofs/blob/master/src/storaged/rbs.c#L1= 04 >> and assumed the implementation is in >> https://github.com/rozofs/rozofs/blob/master/src/storaged/rbs_tran= sform.h >> https://github.com/rozofs/rozofs/blob/master/src/storaged/rbs_tran= sform.cc >> >> And also tried to understand http://en.wikipedia.org/wiki/Mojette_= Transform and bought "The Mojette Transform: Theory and Applications" htt= p://eu.wiley.com/WileyCDA/WileyTitle/productCd-1848210809.html in the hop= e to get more sense out of it ;-) >> >> Is there a part of the rozofs code you would advise me to read fir= st in order to understand how it works ? >> >> >> I would recommend to have a look to rozofsmount.c witch is a key part = in RozoFS. >> =20 >> >> Cheers >> >> -- >> Lo=C3=AFc Dachary, Artisan Logiciel Libre >> All that is necessary for the triumph of evil is that good people = do nothing. >> >> >> >> >> --=20 >> Pierre Evenou=E2=94=82+33.7.60.09.08.80=E2=94=82pierre.evenou@rozofs.c= om =E2=94=82www.rozofs.com >=20 --=20 Lo=C3=AFc Dachary, Artisan Logiciel Libre All that is necessary for the triumph of evil is that good people do noth= ing. --------------enigB3D479AC3330EF76E7D06E30 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlGndrEACgkQ8dLMyEl6F22rWQCfV9rjgBJgz8rZc+usmfq3wmux x7sAoLaiObes/jAnny/7EJujs53lQs9S =TVDL -----END PGP SIGNATURE----- --------------enigB3D479AC3330EF76E7D06E30--