This involves yet another new plugin method: album_distance. This leaves as the
last major puzzle piece for lastid the ability to augment the initial search
into MB (i.e., can start a search using fingerprinted metadata).
(I'm not sure why, but the weight for track index mismatches was set to 0.0.
This way, the tagger will be slightly more reluctant to frivolously reorder.)
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.
As part of this, the BaseLibrary class was also adapted to include a notion of
albums. This is reflected by the new BaseAlbum class, which the Album class
(formerly _AlbumInfo) completely replaces in the concrete Library. The BaseAlbum
class just fetches metadata from the underlying items.
In the case that Mutagen throws an exception while trying to read a file, we
throw an UnreadableFileError, which is a new superclass for FileTypeError.
This entailed:
- changing the "flac" storage style option to "etc" to encompass both
flac and vorbis as the tags are very similar
- permitting multiple StorageStyles per field/format, to allow a
read-any/store-all approach to multiple field options
