Re: [NNTP] NNTP Compression
Julien ÉLIE <[email protected]> Sun, 24 Jan 2010 01:23:06 +0100
| Newsgroups | gmane.ietf.nntp |
|---|---|
| Organization | TrigoFACILE -- http://www.trigofacile.com/ |
| Message-ID | <BA44B2D466D34E26B07FEEDCC78DD940@Iulius> |
Hi Ken, > I'd have to look at the zlib docs and the actual Diablo code (which I have no > desire to do), but tt looks like MODE COMPRESS is actually putting a gzip header > on each chunk of compressed data. The COMPRESS command as standardized by > IMAP/NNTP COMPRESS doesn't bother putting an unnecessary header on the data. > That's why IMAP/NNTP COMPRESS uses [de|in]flatInit2() calls rather than the > simpler [de|in]flateInit(), so it can specify more params rather than using > defaults. OK, then it is better not to use what Diablo implemented. >> When you say: >> >> > A very simple strategy is to change the level to 0 at the start of >> > a multi-line data block provided the first two bytes are either >> > 0x1F 0x8B (as in deflate-compressed files) or 0xFF 0xD8 (JPEG), >> > and to keep it at 1-5 the rest of the time. >> >> It would apply to BODY only (at the start of a multi-line data block). > > It would also apply to ARTICLE, POST, IHAVE, TAKETHIS. My point was that only BODY was concerned by the strategy to check the first two bytes at the start of a multi-line data block. Because ARTICLE, HEAD, POST, IHAVE, and TAKETHIS all begin with headers and headers are not binaries! >> Why couldn't we define several algorithms (some are more efficient than >> DEFLATE, for instance LZMA or LZMA2) and say that DEFLATE *MUST* be >> implemented when COMPRESS is implemented? > > Well, IMAP/NNTP COMPRESS are really just stop-gaps until existing TLS > implementations support compression. As mentioned in the text TLS really should > be the preferred way to negotiate compression. So I don't see the need to add > more algorithms to NNTP COMPRESS. So it would imply that peers also use TLS in order to compress articles. That's not usual practice at all... While a better algorithm like LZMA2 could be worthwile for peers to send articles. They do not need TLS and its overhead. >> Second [...] Third >> independent of the order >> >> Isn't it better to use "Secondly", "Thirdly"/"Finally", "independently of"? > > This text was already approved by the LEMONADE WG and the RFC editor, so I don't > see any need to change it. OK, if both of these expressions are equivalent, I'm fine with that. I thought "secondly" and "independently of" were more fluent than "second" and "independent of", but as you know, I am not an example in English :) > TLS is the preferred method for negotiating compression. All right. -- Julien ÉLIE « -- Maintenant les Romains sont alertés. -- En tout cas, ceux-là ne sont plus très alertes ! » (Astérix)