David Woodhouse wrote: > On Fri, 2005-04-01 at 18:57 +0400, Artem B. Bityuckiy wrote: > >>Yes, the compression will be better. But the implementation will be more >>complicated. >>We can try to use the "bound" functions to predict how many bytes to >>pass to the deflate's input, but there is no guarantee they'll fit into >>the output buffer. In this case we'll need to try again. > > > Can we not predict the maximum number of bytes it'll take to flush the > stream when we're not using Z_SYNC_FLUSH?
AFAIU, no. Zlib may eat a lot of input and do not produce much output, but on Z_FINISH it may ask an undetermined amount of additional output space. So, we must even regulate the amount of input we pass to zlib_deflate(). In case of Z_SYNC_FLUSH, things are more determined. Another question, does JFFSx *really* need the peaces of a 4K page to be independently uncompressable? It it wouldn't be required, we would achieve better compression if we have saved the zstream state. :-) But it is too late to change things at least for JFFS2. -- Best Regards, Artem B. Bityuckiy, St.-Petersburg, Russia. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
