Tue 23 Feb 2010 11:51:27 AM UTC, comment #3:
> > Manual pages are typically so small
> > that the compression method
> > you use really doesn't matter much;
>
> Size isn't the only benefit: it decompresser faster.
http://tukaani.org/lzma/benchmarks.html, on the upstream author's own web site, shows substantially slower decompression using lzma than using gzip. In case you object that this was with LZMA1, http://fedoratux.blogspot.com/2009/05/xz-compression.html is quite recent and supports this with XZ.
But, even if it were faster, it would be of fractional benefit at most. Manual pages are not big enough to exhibit substantial benefit from decompression time.
> > compressing them further usually means
> > that they still take up the same number of blocks
> > and thus the same effective disk space.
>
> Even if the same number of blocks are used,
> the decompression will process less data flow.
> Moreover lzma decompresses faster than gzip.
See above. Also, lzma uses more memory to decompress; again, it's probably fractional at the file sizes we're talking about, but it's honest to mention it given that man is a program often used even on low-memory systems.
> > Yes, there is some small benefit,
> > but it's not worth extra complexity
>
> This could be a long term feature only.
I'm not going to lie. If I don't think something should be done, I'm not going to put it on a "long-term wishlist" and then bury it; I'll just say that I don't think it should be done. This is more honest to you, and better for me in terms of managing my bug list.
> > and certainly not worth extra run-time linkage.
>
> You could provide alternative configuration:
> either gzip or lzma (not both).
This has a cost to me as the maintainer, which I don't want to bear, and a cost to users in terms of additional complexity. Since your interest appears to be Ubuntu, this wouldn't benefit you anyway as there's no way I would turn off zlib linkage there; it would not make sense to do so.
For casual use of lzma, using the external program is sufficient, and I consider this an acceptable level of support. I don't think it's appropriate, wise, or necessary for distributions to compress all or most of their manual pages using lzma, and so I don't think it's necessary to have man-db link against liblzma to make it faster. Sorry.
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