trackdb: Give TrackAllocators an autoremove() function

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

trackdb/allocator.py

@@ -44,6 +44,15 @@ class TrackAllocator:
         except Exception as e:
             pass
 
+    def autoremove(self, lib):
+        with self.lock:
+            to_rm = [ trak for trak in self.tracks.values() \
+                    if trak.library == lib and not trak.filepath().exists() ]
+            for trak in to_rm:
+                del self.tracks[trak.trackid]
+                self.Removed.publish(trak)
+            return to_rm
+
     def list_tracks(self, lib):
         with self.lock:
             for (id, track) in self.tracks.items():

trackdb/test_allocator.py

@@ -64,6 +64,18 @@ class TestTrackAllocator(unittest.TestCase):
         self.assertEqual(alloc.Added.subscribers, set())
         self.assertEqual(alloc.Removed.subscribers, set())
 
+    def test_allocator_autoremove(self):
+        lib = library.LibraryPath(test_tracks)
+        alloc = allocator.TrackAllocator()
+        alloc.Removed.register(self.on_track_removed)
+
+        track = alloc.allocate(lib, test_tracks / "01 - Test Track.ogg")
+        track2 = alloc.allocate(lib, test_tracks / "02 - Test {Disc 2}.ogg")
+        track2.path = pathlib.Path("No Such File")
+
+        self.assertEqual(alloc.autoremove(lib), [ track2 ])
+        self.assertEqual([ t for t in alloc.list_tracks(lib) ], [ track ])
+
     def test_allocator_state(self):
         lib = library.LibraryPath(test_tracks)
         alloc = allocator.TrackAllocator()