[gnome-music/wip/mschraal/grltracker-batch-initial-fill: 10/10] grltrackerwrapper: Batch listmodel updates

[Marinus Schraal <mschraal src gnome org>]

commit 4ed89f9e1525455bfbb2ce73f32ee92cec6ebdc7
Author: Marinus Schraal <mschraal gnome org>
Date:   Mon Nov 4 14:13:53 2019 +0100

    grltrackerwrapper: Batch listmodel updates
    
    Grilo provides Music query results one at a time, this results in a lot
    of signal traffic adding songs, albums and artists to the different
    listmodels.
    
    This patch adds batch update functionality to the initial fill queries,
    reducing the amount of signals and hopefully improve loading times.

 gnomemusic/grilowrappers/grltrackerwrapper.py | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)
---
diff --git a/gnomemusic/grilowrappers/grltrackerwrapper.py b/gnomemusic/grilowrappers/grltrackerwrapper.py
index ceb8242e..52f68148 100644
--- a/gnomemusic/grilowrappers/grltrackerwrapper.py
+++ b/gnomemusic/grilowrappers/grltrackerwrapper.py
@@ -38,6 +38,8 @@ class GrlTrackerWrapper(GObject.GObject):
     """Wrapper for the Grilo Tracker source.
     """
 
+    _SPLICE_SIZE = 100
+
     METADATA_KEYS = [
         Grl.METADATA_KEY_ALBUM,
         Grl.METADATA_KEY_ALBUM_ARTIST,
@@ -341,6 +343,7 @@ class GrlTrackerWrapper(GObject.GObject):
 
     def _initial_songs_fill(self, source):
         self._window.notifications_popup.push_loading()
+        songs_added = []
 
         def _add_to_model(source, op_id, media, user_data, error):
             if error:
@@ -349,12 +352,16 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             if not media:
+                self._model.splice(self._model.get_n_items(), 0, songs_added)
                 self._window.notifications_popup.pop_loading()
                 return
 
             song = CoreSong(media, self._coreselection, self._grilo)
-            self._model.append(song)
+            songs_added.append(song)
             self._hash[media.get_id()] = song
+            if len(songs_added) == self._SPLICE_SIZE:
+                self._model.splice(self._model.get_n_items(), 0, songs_added)
+                del songs_added[:]
 
         query = """
         SELECT
@@ -390,6 +397,7 @@ class GrlTrackerWrapper(GObject.GObject):
 
     def _initial_albums_fill(self, source):
         self._window.notifications_popup.push_loading()
+        albums_added = []
 
         def _add_to_albums_model(source, op_id, media, user_data, error):
             if error:
@@ -398,12 +406,18 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             if not media:
+                self._albums_model.splice(
+                    self._albums_model.get_n_items(), 0, albums_added)
                 self._window.notifications_popup.pop_loading()
                 return
 
             album = CoreAlbum(media, self._coremodel)
-            self._albums_model.append(album)
             self._album_ids[media.get_id()] = album
+            albums_added.append(album)
+            if len(albums_added) == self._SPLICE_SIZE:
+                self._albums_model.splice(
+                    self._albums_model.get_n_items(), 0, albums_added)
+                del albums_added[:]
 
         query = """
         SELECT
@@ -437,6 +451,7 @@ class GrlTrackerWrapper(GObject.GObject):
 
     def _initial_artists_fill(self, source):
         self._window.notifications_popup.push_loading()
+        artists_added = []
 
         def _add_to_artists_model(source, op_id, media, user_data, error):
             if error:
@@ -445,13 +460,19 @@ class GrlTrackerWrapper(GObject.GObject):
                 return
 
             if not media:
+                self._artists_model.splice(
+                    self._artists_model.get_n_items(), 0, artists_added)
                 self._coremodel.emit("artists-loaded")
                 self._window.notifications_popup.pop_loading()
                 return
 
             artist = CoreArtist(media, self._coremodel)
-            self._artists_model.append(artist)
             self._artist_ids[media.get_id()] = artist
+            artists_added.append(artist)
+            if len(artists_added) == self._SPLICE_SIZE:
+                self._artists_model.splice(
+                    self._artists_model.get_n_items(), 0, artists_added)
+                del artists_added[:]
 
         query = """
         SELECT