db: Occasionally optimize the database

I do this whenever we commit during scanning, and during application
shutdown.

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

db/sql.py

@@ -9,3 +9,7 @@ Connection.row_factory = sqlite3.Row
 
 commit = Connection.commit
 execute = Connection.execute
+
+def optimize():
+    Connection.execute("PRAGMA analysis_limit=1000")
+    Connection.execute("PRAGMA optimize")

scanner/task.py

@@ -9,7 +9,9 @@ class Task(GObject.GObject):
 
 
 class CommitTask(Task):
-    def run_task(self): db.sql.commit()
+    def run_task(self):
+        db.sql.commit()
+        db.sql.optimize()
 
 
 class FileTask(Task):

ui/__init__.py

@@ -3,6 +3,7 @@ from . import icons
 from . import window
 from gi.repository import Gtk
 import audio
+import db
 
 class EmmentalApplication(Gtk.Application):
     def __init__(self, *args, **kwargs):
@@ -16,4 +17,8 @@ class EmmentalApplication(Gtk.Application):
         Gtk.Application.do_startup(self)
         self.add_window(self.window)
 
+    def do_shutdown(self):
+        db.sql.optimize()
+        Gtk.Application.do_shutdown(self)
+
 Application = EmmentalApplication()