In an attempt to finally address the longstanding SQLite locking issues, I'm
introducing a way to explicitly, lexically scope transactions. The Transaction
class is a context manager that always fully fetches after SELECTs and
automatically commits on exit. No direct access to the library is allowed, so
all changes will eventually be committed and all queries will be completed. This
will also provide a debugging mechanism to show where concurrent transactions
are beginning and ending.
To support composition (transaction reentrancy), an internal, per-Library stack
of transactions is maintained. Commits only happen when the outermost
transaction exits. This means that, while it's possible to introduce atomicity
bugs by invoking Library methods outside of a transaction, you can conveniently
call them *without* a currently-active transaction to get a single atomic
action.
Note that this "transaction stack" concepts assumes a single Library object per
thread. Because we need to duplicate Library objects for concurrent access due
to sqlite3 limitation already, this is fine for now. Later, the interface should
provide one transaction stack per thread for shared Library objects.
Previously, all files would be moved/copied/deleted before the corresponding
Items and Albums were added to the database. Now, the in-place items are added
to the database; the files are moved; and then the new paths are saved to the
DB. The apply_choices coroutine now executes two database transactions per task.
This has a couple of benefits:
- %aunique{} requires album structures to be in place before the destination()
call, so this now works as expected.
- As an added bonus, the "in_album" parameter to move() and destination() --
along with its associated ugly hacks -- is no longer required.
- Copying and moving are mutually exclusive. Moving overrides copying so the
user only has to add one line ("import_move: true") to disable copying and
enable moving in its place.
- Deleting is only possible when copying.
- Deprecating the "delete" option (moving is almost always better).
- Removed command-line switch for moving. It's somewhat "unsafe", so this
removes some potential for accidental irreversible changes.
- Changelog & thanks.
- Update docs to refer to import_move instead of import_delete as the
correct solution for ending up with only one copy of the file.
The new fields are:
ALBUM: mb_releasegroupid asin catalognum script language country albumstatus
media albumdisambig
TRACK: disctitle encoder
These are not yet parsed from MusicBrainz responses (just added to MediaFile
and the database).
There's no longer a distinction between Unix and Windows substitutions. Enough
users reported problems with Windows-forbidden characters on Samba shares that
it seems appropriate to make all filenames Windows-safe, even on Unix. Users who
really want those additional characters (<>:"?*|\) can re-enable them via the
"replace" option. Nobody has complained about beets being *too* conservative.
This also adds sanitization of control characters, which is an all-around good
idea, and the substitution now runs in the Unicode (rather than byte) domain.
This is accomplished via a new event, "import_task_apply", which is called
right after metadata is applied to newly-imported items.
This change makes chroma REQUIRE a new version (0.6) of pyacoustid. Users with
older versions installed will see complaints about a missing method
"fingerprint_file".
The old "caching"-based approach to fingerprinting was kinda hacky to begin
with. Now, the chroma plugin has an explicit opportunity (in the form of a new
event) to perform its initial fingerprinting and lookup for all tracks. Then,
this information is used explicitly during the autotagging phase rather than
being used transparently through memoization of the lookup function.
Previously, there was just an "artist sort name" field -- now there's a
corresponding sort name for both track artists and album artists. I also made
the names shorter (artist_sort and albumartist_sort).
