- From: <noah_mendelsohn@us.ibm.com>
- Date: Tue, 17 Feb 2009 20:52:26 -0500
- To: "Taki Kamiya" <tkamiya@us.fujitsu.com>
- Cc: "'Henry S. Thompson'" <ht@inf.ed.ac.uk>, public-exi@w3.org, www-tag@w3.org, "David Orchard" <orchard@pacificspirit.com>
You sent this note many months ago, but I am (finally) moved to respond now. Please accept my apologies for the delay. In particular, I would like to inquire as to whether the EXI working group is currently waiting on or expecting any particular response from the TAG in relation to the attached email? The reason I ask is that the TAG has for some months been tracking an action assigned to me and to Dave Orchard, though since he's graduated from the TAG it now falls just to me. Anyway, our ACTION-176 [1] asks that Dave and I "send comments on exi w.r.t. evaluation and efficiency" to you. When I was reminded of this issue a few months ago, my intuition was that it had in fact been assigned before TPAC, and that whatever interaction was at the time required between the TAG and the EXI group indeed happened at TPAC, if not before, and that the action should probably have been closed after TPAC. Just when I was about to revisit this, I was appointed TAG chair, which not surprisingly proved a bit of a distraction for awhile. Anyway, with great embarassment for the delay, I am now revisiting the history of this action, and I find that it indeed was originally assigned ahead of TPAC [2]. This somewhat supports, but does not completely confirm, my intuition that in fact that action should have been marked CLOSED at that time. FWIW, I see in the minutes of our session at TPAC [3] my mentioning some existing TAG actions, presumably including 176. Though I doubt there's anything tremendously sensitive, I see that your WG minutes are member-only, so I won't quote them here. They do include some mention by me of the fact that further details on speed (as opposed to compression) would be helpful, and my impression is that there was agreement that you would work on those. Anyway, I'd like to propose a reset, on the following basis. 1) My recollection is that, at TPAC, you made the case that suitably well documented compression results had been provided for EXI, and we in the TAG agreed, at least informally. So, unless something changes, the TAG does not expect to again raise questions about the compactness achievable with EXI. 2) As noted above, my recollection is that you were intending to write a more careful analysis of speed results, and that we on the TAG expressed at least an informal interest in seeing them. Please let us know whether such a document has indeed been produced, if not whether you still intend to produce it, whether my recollection of the history is flawed, etc.. 3) If you are waiting on any other feedback from the TAG right now, please clarify what it is. Once you confirm that you are not, I will close TAG action 176. This is just a proposal from me, not a formal proposal from the TAG, but if you agree that the above is appropriate I will confirm with other TAG members that it is acceptable to them. If not, please suggest what might be a better approach. Of course, if you wish to consult us on some matter in the future, we will be glad to try and help, and we reserve the right to raise new questions should we become aware of them in the future. That said, when last we discussed this, the TAG felt that you and the community were in general aware of our concerns regarding the analysis of EXI speed, and at least informally, I can say that we have no expectation at this point of doing anything that would impede your progress toward Recommendation. Thank you very much Noah Mendelsohn [1] http://www.w3.org/2001/tag/group/track/actions/176 [2] http://www.w3.org/2001/tag/group/track/actions/176?changelog [3] http://www.w3.org/2008/10/20-exi-minutes.html#item02 -------------------------------------- Noah Mendelsohn IBM Corporation One Rogers Street Cambridge, MA 02142 1-617-693-4036 -------------------------------------- "Taki Kamiya" <tkamiya@us.fujitsu.com> Sent by: www-tag-request@w3.org 10/29/2008 07:50 PM To: "'Henry S. Thompson'" <ht@inf.ed.ac.uk>, <www-tag@w3.org> cc: <public-exi@w3.org>, (bcc: Noah Mendelsohn/Cambridge/IBM) Subject: RE: TAG review of EXI Best Practices Dear TAG members, Per the resolution in the joint meeting in TPAC last week, we have updated the working copy of the EXI format specification to add a caveat regarding the use of content-coding in EXI, clarifying that it is applicable only to XML documents and it is neither byte- nor character-preserving. Note that, since EXI Best Practices document was last updated, the EXI specification has described its use of content coding and internet media type in the appendix. We believe that the above mentioned caveat fits best into this appendix section. We appreciate TAG's continued attention, guidance and support for our activity, which are all valuable to us. Thank you, Taki Kamiya for the EXI Working Group -----Original Message----- From: public-exi-request@w3.org [mailto:public-exi-request@w3.org] On Behalf Of Henry S. Thompson Sent: Thursday, October 02, 2008 6:43 AM To: public-exi@w3.org Cc: www-tag@w3.org Subject: TAG review of EXI Best Practices -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On behalf of the TAG, we welcome the expression of the outcome of the discussions at TPAC last year in this document [1]. Presuming this now 10-month-old draft continues to represent the WG's position on the matter, we endorse the commitment to the 'Content Encoding' route as the least-bad alternative available. We would encourage you, however, to devote a bit more space to explaining the details of what this amounts to, in particular the way in which EXI as specified cannot literally take the place of a Content Encoding: 1) It doesn't map text to text; 2) Even if a version of it were specified that did, it is not universal, that is, it _only_ maps XML to XML. Compare this to for example gzip: gzip maps text to encoded text, and back again, whereas EXI as spec'ed maps infosets to encoded text and back again, so a message which says "Content-Encoding: gzip; Content-Type: application/svg+xml" can be understood as saying "Unzip this byte-stream and you'll get a message body to which normal application/svg+xml processing can be applied", whereas a message which says "Content-Encoding: x-gzip; Content-Type: application/svg+xml" cannot be interpreted as saying "EXI-decode this byte-stream, and you'll get a message to which normal application/svg+xml processing can be applied", because the result of the EXI decoding algorithm is not a message body, it's an Infoset. And of course you can gzip anything, whereas you can only EXI-encode XML. ht, on behalf of the TAG [2] [1] http://www.w3.org/TR/2007/WD-exi-best-practices-20071219/ [2] http://www.w3.org/2001/tag/group/track/actions/180 - -- Henry S. Thompson, School of Informatics, University of Edinburgh Half-time member of W3C Team 10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440 Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk URL: http://www.ltg.ed.ac.uk/~ht/ [mail really from me _always_ has this .sig -- mail without it is forged spam] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) iD8DBQFI5M/skjnJixAXWBoRAvGFAJ4yANHqyS6U4zvngnEuetypoS1kGgCdGetr Ftund8ggscvGfmzgqNQ833U= =etF8 -----END PGP SIGNATURE-----
Received on Wednesday, 18 February 2009 01:51:26 UTC