The default path formats now include both a "default", which is the same as
before but now uses $albumartist instead of $artist, and a "comp" path, which
uses a Compilations directory. Old paths are supported as-is by letting $artist
refer to either a track artist (when present, as it is in all old library
tracks) or album artist (when the track artist isn't present, as is the case
with most albums imported now).
When computing track destination paths, we now look for album-level values when
they're available. This has the effect of making albums go into a single
directory even when their tracks have heterogeneous metadata. We will need to
revisit this once we start explicitly supporting non-album tracks.
In the end, after all of this, it turns out that we basically need to abandon
the temptation of dealing with unicode paths altogether. The POSIX filesystem
API has no notion of unicode and is very much a bytes-only interface. This
means that undecodable pathnames are a reality we must deal with. This new
approach stores all paths as buffers (blobs) in SQLite and -- as transparently
as possible -- presents them as str objects to the Python code. Legacy
databases will have their paths automatically encoded into str objects, and
will lazily have their unicodes in the database replaced with buffers.
current metadata to be correct if it's complete
Previously, we were using the Munkres algorithm (minimum bipartite matching) to
order tracks intelligently only as a fallback if the current metadata was
paradoxical or incomplete. This was because of a concern about the performance
of the potentially-O(n^3) Munkres solver. However, it was found that (a) the
performance is actually not bad, taking on the order of 0.02 to perform a
matching, and (b) there was no recourse for the tagger to reorder tracks that
were legitimately in the wrong order. Now, we get intelligent reordering of
badly tagged music even when the metadata seems to be complete.
To retain some of the functionality of the old orderer, the track distance
metric was expanded to include a component reflecting the track index.
In doing this, another bug was discovered in the UI that showed the track name
differences based on an arbitrary ordering. Now, the tag_album function returns
a reordered items list with every candidate.
This is especially important for read(), which will assign many times while, in many cases, causing few actual changes. A store() that follows soon after will now be much more lightweight.
--HG--
extra : convert_revision : svn%3A41726ec3-264d-0410-9c23-a9f1637257cc/trunk%4079
