Precompute the whole comparision key for song sorting.

openlp/core/utils/__init__.py

@@ -398,25 +398,18 @@ def get_local_key(string):
 
 def get_natural_key(string):
     """
-    Generate a key for locale aware natural string sorting. Returns a list of strings and integers.
-
-    ``string``
-        A string, list or tuple which represents the item string.
+    Generate a key for locale aware natural string sorting.
+    Returns a list of string compare keys and integers.
     """
-    if isinstance(string, basestring):
-        string = re.findall(r'(\d+|\D+)', string)
-        if len(string) == 1:
-            return list(get_local_key(string[0]))
-    elif isinstance(string, tuple):
-        string = list(string)
-    if isinstance(string, list):
-        for index, part in enumerate(string):
-            if isinstance(part, basestring):
-                if part.isdigit():
-                    string[index] = int(part)
-                else:
-                    string[index] = get_local_key(part)
-    return string
+    key = re.findall(r'(\d+|\D+)', string)
+    if len(key) == 1:
+        return list(get_local_key(string))
+    for index, part in enumerate(key):
+        if part.isdigit():
+            key[index] = int(part)
+        else:
+            key[index] = get_local_key(part)
+    return key
 
 
 from applocation import AppLocation

openlp/plugins/songs/forms/songexportform.py

@@ -37,7 +37,6 @@ from PyQt4 import QtCore, QtGui
 from openlp.core.lib import Registry, UiStrings, create_separated_list, build_icon, translate
 from openlp.core.lib.ui import critical_error_message_box
 from openlp.core.ui.wizard import OpenLPWizard, WizardStrings
-from openlp.core.utils import get_natural_key
 from openlp.plugins.songs.lib.db import Song
 from openlp.plugins.songs.lib.openlyricsexport import OpenLyricsExport
 
@@ -222,7 +221,7 @@ class SongExportForm(OpenLPWizard):
         # Load the list of songs.
         self.application.set_busy_cursor()
         songs = self.plugin.manager.get_all_objects(Song)
-        songs.sort(key=lambda song: get_natural_key(song.sort_key))
+        songs.sort(key=lambda song: song.sort_key)
         for song in songs:
             # No need to export temporary songs.
             if song.temporary:

openlp/plugins/songs/lib/db.py

@@ -38,6 +38,7 @@ from sqlalchemy.orm import mapper, relation, reconstructor
 from sqlalchemy.sql.expression import func
 
 from openlp.core.lib.db import BaseModel, init_db
+from openlp.core.utils import get_natural_key
 
 
 class Author(BaseModel):
@@ -69,36 +70,15 @@ class Song(BaseModel):
     def __init__(self):
         self.sort_key = ()
 
-    def _try_int(self, s):
-        """
-        Convert to integer if possible.
-        """
-        try:
-            return int(s)
-        except:
-            return s.lower()
-
-    def _natsort_key(self, s):
-        """
-        Used internally to get a tuple by which s is sorted.
-        """
-        return map(self._try_int, re.findall(r'(\d+|\D+)', s))
-
-    # This decorator tells sqlalchemy to call this method everytime
-    # any data on this object is updated.
-
     @reconstructor
     def init_on_load(self):
         """
-        Precompute a tuple to be used for sorting.
+        Precompute a natural sorting, locale aware sorting key.
 
         Song sorting is performance sensitive operation.
-        To get maximum speed lets precompute the string
-        used for comparison.
+        To get maximum speed lets precompute the sorting key.
         """
-        # Avoid the overhead of converting string to lowercase and to QString
-        # with every call to sort().
-        self.sort_key = self._natsort_key(self.title)
+        self.sort_key = get_natural_key(self.title)
 
 
 class Topic(BaseModel):

openlp/plugins/songs/lib/mediaitem.py

@@ -38,7 +38,7 @@ from sqlalchemy.sql import or_
 from openlp.core.lib import Registry, MediaManagerItem, ItemCapabilities, PluginStatus, ServiceItemContext, Settings, \
     UiStrings, translate, check_item_selected, create_separated_list, check_directory_exists
 from openlp.core.lib.ui import create_widget_action
-from openlp.core.utils import AppLocation, get_natural_key
+from openlp.core.utils import AppLocation
 from openlp.plugins.songs.forms.editsongform import EditSongForm
 from openlp.plugins.songs.forms.songmaintenanceform import SongMaintenanceForm
 from openlp.plugins.songs.forms.songimportform import SongImportForm
@@ -225,7 +225,7 @@ class SongMediaItem(MediaManagerItem):
         log.debug(u'display results Song')
         self.save_auto_select_id()
         self.list_view.clear()
-        searchresults.sort(key=lambda song: get_natural_key(song.sort_key))
+        searchresults.sort(key=lambda song: song.sort_key)
         for song in searchresults:
             # Do not display temporary songs
             if song.temporary: