Re: big Packages.gz file

[Brian May <bam@debian.org>]

>>>>> "zhaoway" == zhaoway  <zw@debian.org> writes:

    zhaoway> This is only a small part of the whole story, IMHO. See
    zhaoway> my other email replying you. ;)

    >> Maybe there could be another version of Packages.gz without the
    >> extended descriptions -- I imagine they would take something
    >> like 33% of the Packages file, in line count at least.

    zhaoway> Exactly. DIFF or RSYNC method of APT (as Goswin pointed
    zhaoway> out), or just seperate Descriptions out (as I pointed out
    zhaoway> and you got it too), nearly 66% of the bits are
    zhaoway> saved. But this is only a hack, albeit efficient.

At the risk of getting flamed, I investigated the possibility of
writing an apt-get method to support rsync. I would use this to access
an already existing private mirror, and not the main Debian
archive. Hence the server load issue is not a problem. The only
problem I have is downloading several megs of index files every time I
want to install a new package (often under 100kb) from unstable, over
a volume charged 28.8 kbps PPP link, using apt-get[1].

I think (if I understand correctly) that I found three problems with
the design of apt-get:

1. It tries to down-load the compressed Packages file, and has no way
to override it with the uncompressed file. I filed a bug report
against apt-get on this, as I believe this will also
be a problem with protocols like rproxy too.

2. apt-get tries to be smart and passes the method a destination file
name that is only a temporary file, and not the final file. Hence,
rsync cannot make a comparison between local and remote versions of
the file.

3. Instead, rsync creates its own temporary file while downloading, so
apt-get cannot display the progress of the download operation because
as far as it is concerned the destination file is still empty.

I think the only way to fix both 2 and 3 is to allow some coordination
between apt-get and rsync where to put the temporary file and where to
find the previous version of the file.

Note:
[1] Normally I try to find the files manually via lynx, but right
at the moment this is rather difficult, as I seem to try numerous
directories but not get the expected result. Some packages
-- 
Brian May <bam@debian.org>