db: Improve filtering Tables

I scheduled the filter query with  first=True so it can run without a
long delay during scanning. Additionally, I cancel any pending filter
calls to discard stale arguments that otherwise would be processed.

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

emmental/db/table.py

@@ -227,7 +227,8 @@ class Table(Gtk.FilterListModel):
     def filter(self, glob: str | None, *, now: bool = False) -> None:
         """Filter the displayed Rows."""
         if glob is not None:
-            self.queue.push(self._filter_idle, glob, now=now)
+            self.queue.cancel_task(self._filter_idle)
+            self.queue.push(self._filter_idle, glob, now=now, first=True)
         else:
             self.get_filter().keys = None
 

tests/db/test_table.py

@@ -368,9 +368,13 @@ class TestTableFunctions(tests.util.TestCase):
         """Test filtering Rows in the table."""
         for n in [1, 121, 212,  333]:
             self.table.create(number=n)
+        self.table.queue.push(unittest.mock.Mock())
+
+        self.table.filter("*3*")
+        self.assertIsNone(self.table.get_filter().keys)
+        self.assertEqual(self.table.queue[0], (self.table._filter_idle, "*3*"))
 
         self.table.filter("*2*")
-        self.assertIsNone(self.table.get_filter().keys)
         self.assertEqual(self.table.queue[0], (self.table._filter_idle, "*2*"))
 
         self.table.queue.complete()