Required packages
-----------------

    aptitude install python python-debian python-lzma curl python-jinja2 python-werkzeug sqlite3 python-imaging

Create a database
-----------------
The database name is currently hardcoded as `test.sqlite3`. So copy the SQL
statements from `schema.sql` into `sqlite3 test.sqlite3`. In addition it is
highly recommended to put the database into WAL mode. Otherwise all your
reading queries will block forever when doing an import. This setting is
permanent.

    PRAGMA journal_mode = WAL;

Import packages
---------------
Import individual packages by feeding them to importpkg.py:

    ls -t /var/cache/apt/archives/*.deb | while read f; do echo $f; ./importpkg.py < $f || break; done

Import a full mirror::

    ./autoimport.py http://your.mirror.example/debian

Viewing the results
-------------------
Run `./webapp.py` and enjoy a webinterface at `0.0.0.0:8800` or inspect the
SQL database by hand. Here are some example queries.

Finding the 100 largest files shared with multiple packages.

    SELECT a.package, a.filename, b.package, b.filename, a.size FROM content AS a JOIN hash AS ha ON a.id = ha.cid JOIN hash AS hb ON ha.hash = hb.hash JOIN content AS b ON b.id = hb.cid WHERE (a.package != b.package OR a.filename != b.filename) ORDER BY a.size DESC LIMIT 100;

Finding those top 100 files that save most space when being reduced to only
one copy in the archive.

    SELECT hash, sum(size)-min(size), count(*), count(distinct package) FROM content JOIN hash ON content.id = hash.cid WHERE hash.function = "sha512" GROUP BY hash ORDER BY sum(size)-min(size) DESC LIMIT 100;

Finding PNG images that do not carry a .png file extension.

    SELECT package, filename, size FROM content JOIN hash ON content.id = hash.cid WHERE function = "image_sha512" AND filename NOT LIKE "%.png";

Finding .gz files which either are not gziped or contain errors.

    SELECT a.package, a.filename FROM content AS a JOIN hash AS ha ON a.id = ha.cid WHERE ha.function = "sha512" AND a.filename LIKE "%.gz" AND (SELECT count(*) FROM content AS b JOIN hash AS hb ON b.id = hb.cid WHERE b.package = a.package AND b.filename = a.filename AND hb.function = "gzip_sha512") = 0;