Implement __hash__ method for custom classes (close #45)

Implement a reasonable __hash__ method() for the classes MCGAlbum and
MCGTrack and use a separate id for referencing albums.

mcg/client.py

@@ -12,9 +12,8 @@ import sys
 import threading
 import urllib.request
 
-from hashlib import md5
-
 from mcg.utils import SortOrder
+from mcg.utils import Utils
 
 
 
@@ -519,7 +518,7 @@ class Client(Base):
             self._logger.debug("track: %r", track)
             # Album
             album = self._extract_album(song, lookup=False)
-            if len(self._playlist) == 0 or self._playlist[len(self._playlist)-1].get_hash() != album.get_hash():
+            if len(self._playlist) == 0 or self._playlist[len(self._playlist)-1] != album:
                 self._playlist.append(album)
             else:
                 album = self._playlist[len(self._playlist)-1]
@@ -736,13 +735,13 @@ class Client(Base):
         album = None
         if 'album' not in song:
             song['album'] = MCGAlbum.DEFAULT_ALBUM
-        hash = MCGAlbum.hash(song['album'])
+        id = Utils.generate_id(song['album'])
-        if lookup and hash in self._albums.keys():
+        if lookup and id in self._albums.keys():
-            album = self._albums[hash]
+            album = self._albums[id]
         else:
             album = MCGAlbum(song['album'], self._host, self._image_dir)
         if lookup:
-            self._albums[hash] = album
+            self._albums[id] = album
         return album
 
 
@@ -822,11 +821,19 @@ class MCGAlbum:
         self._length = 0
         self._cover = None
         self._cover_searched = False
-        self._set_hash()
+        self._id = Utils.generate_id(title)
 
 
     def __eq__(self, other):
-        return self._hash == other.get_hash()
+        return (other and self.get_id() == other.get_id())
+
+
+    def __hash__(self):
+        return hash(self._title)
+
+
+    def get_id(self):
+        return self._id
 
 
     def get_artists(self):
@@ -889,16 +896,6 @@ class MCGAlbum:
         return self._cover
 
 
-    def hash(title):
-        if type(title) is list:
-            title = title[0]
-        return md5(title.encode('utf-8')).hexdigest()
-
-
-    def get_hash(self):
-        return self._hash
-
-
     def filter(self, filter_string):
         if len(filter_string) == 0:
             return True
@@ -951,10 +948,6 @@ class MCGAlbum:
             return 1
 
 
-    def _set_hash(self):
-        self._hash = MCGAlbum.hash(self._title)
-
-
     def _find_cover(self):
         names = list(MCGAlbum._FILE_NAMES)
         names.append(self._title)
@@ -1028,6 +1021,10 @@ class MCGTrack:
         return self._file == other.get_file()
 
 
+    def __hash__(self):
+        return hash(self._file)
+
+
     def get_artists(self):
         if self._albumartists:
             return [artist for artist in self._artists if artist not in self._albumartists]
@@ -1161,7 +1158,7 @@ class MCGCache():
 
 
     def create_filename(self, album):
-        return os.path.join(self._dirname, '-'.join([album.get_hash()]))
+        return os.path.join(self._dirname, '-'.join([album.get_id()]))
 
 
     def _read_size(self):

mcg/utils.py

@@ -3,6 +3,7 @@
 
 import gi
 gi.require_version('Gtk', '3.0')
+import hashlib
 import locale
 import os
 import urllib
@@ -75,6 +76,15 @@ class Utils:
         return title
 
 
+    def generate_id(values):
+        if type(values) is not list:
+            values = [values]
+        m = hashlib.md5()
+        for value in values:
+            m.update(value.encode('utf-8'))
+        return m.hexdigest()
+
+
 
 
 class SortOrder:

mcg/widgets.py

@@ -1088,9 +1088,7 @@ class CoverPanel(GObject.GObject):
     def _set_cover(self, current_album, new_album):
         self._cover_stack.set_visible_child(self._cover_spinner)
         self._cover_spinner.start()
-        current_hash = current_album.get_hash() if current_album else None
+        if not current_album or not new_album or current_album != new_album:
-        new_hash = new_album.get_hash() if new_album else None
-        if not current_hash or not new_hash or current_hash != new_hash:
             url = new_album.get_cover() if new_album else None
             if url and url is not "":
                 # Load image and draw it
@@ -1365,7 +1363,7 @@ class PlaylistPanel(GObject.GObject):
         self._playlist = playlist
         self._playlist_albums = {}
         for album in playlist:
-            self._playlist_albums[album.get_hash()] = album
+            self._playlist_albums[album.get_id()] = album
         self._playlist_grid.set_model(None)
         self._playlist_grid.freeze_child_notify()
         self._playlist_grid_model.clear()
@@ -1393,7 +1391,7 @@ class PlaylistPanel(GObject.GObject):
                         ', '.join(album.get_dates()),
                         Utils.create_artists_label(album)
                     ])),
-                    album.get_hash()
+                    album.get_id()
                 ])
 
             if self._playlist_stop.is_set():
@@ -1690,8 +1688,8 @@ class LibraryPanel(GObject.GObject):
         # Get selected album
         path = self._library_grid_filter.convert_path_to_child_path(path)
         iter = self._library_grid_model.get_iter(path)
-        hash = self._library_grid_model.get_value(iter, 2)
+        id = self._library_grid_model.get_value(iter, 2)
-        album = self._albums[hash]
+        album = self._albums[id]
         self._selected_albums = [album]
 
         # Show standalone album
@@ -1712,15 +1710,15 @@ class LibraryPanel(GObject.GObject):
         for path in widget.get_selected_items():
             path = self._library_grid_filter.convert_path_to_child_path(path)
             iter = self._library_grid_model.get_iter(path)
-            hash = self._library_grid_model.get_value(iter, 2)
+            id = self._library_grid_model.get_value(iter, 2)
-            self._selected_albums.insert(0, self._albums[hash])
+            self._selected_albums.insert(0, self._albums[id])
 
 
     def on_filter_visible(self, model, iter, data):
-        hash = model.get_value(iter, 2)
+        id = model.get_value(iter, 2)
-        if not hash in self._albums.keys():
+        if not id in self._albums.keys():
             return
-        album = self._albums[hash]
+        album = self._albums[id]
         return album.filter(self._filter_string)
 
 
@@ -1729,8 +1727,8 @@ class LibraryPanel(GObject.GObject):
 
 
     def on_selection_add_clicked(self, widget):
-        hashes = [album.get_hash() for album in self._selected_albums]
+        ids = [album.get_id() for album in self._selected_albums]
-        self.emit('queue-multiple', hashes)
+        self.emit('queue-multiple', ids)
         self._select_button.set_active(False)
 
 
@@ -1739,12 +1737,12 @@ class LibraryPanel(GObject.GObject):
 
 
     def on_standalone_play_clicked(self, widget):
-        self.emit('play', self._selected_albums[0].get_hash())
+        self.emit('play', self._selected_albums[0].get_id())
         self._close_standalone()
 
 
     def on_standalone_queue_clicked(self, widget):
-        self.emit('queue', self._selected_albums[0].get_hash())
+        self.emit('queue', self._selected_albums[0].get_id())
         self._close_standalone()
 
 
@@ -1800,12 +1798,12 @@ class LibraryPanel(GObject.GObject):
 
 
     def compare_albums(self, model, row1, row2, criterion):
-        hash1 = model.get_value(row1, 2)
+        id1 = model.get_value(row1, 2)
-        hash2 = model.get_value(row2, 2)
+        id2 = model.get_value(row2, 2)
 
-        if hash1 == "" or hash2 == "":
+        if not id1 or not id2:
             return
-        return client.MCGAlbum.compare(self._albums[hash1], self._albums[hash2], criterion)
+        return client.MCGAlbum.compare(self._albums[id1], self._albums[id2], criterion)
 
 
     def stop_threads(self):
@@ -1833,8 +1831,8 @@ class LibraryPanel(GObject.GObject):
         n = len(albums)
         cache = client.MCGCache(host, size)
         self._grid_pixbufs.clear()
-        for hash in albums.keys():
+        for album_id in albums.keys():
-            album = albums[hash]
+            album = albums[album_id]
             pixbuf = None
             try:
                 pixbuf = Utils.load_thumbnail(cache, album, size)
@@ -1847,7 +1845,7 @@ class LibraryPanel(GObject.GObject):
                     Gtk.IconLookupFlags.FORCE_SVG & Gtk.IconLookupFlags.FORCE_SIZE
                 )
             if pixbuf is not None:
-                self._grid_pixbufs[album.get_hash()] = pixbuf
+                self._grid_pixbufs[album.get_id()] = pixbuf
                 self._library_grid_model.append([
                     pixbuf,
                     GObject.markup_escape_text("\n".join([
@@ -1855,7 +1853,7 @@ class LibraryPanel(GObject.GObject):
                         ', '.join(album.get_dates()),
                         Utils.create_artists_label(album)
                     ])),
-                    hash
+                    album_id
                 ])
 
             i += 1
@@ -1910,8 +1908,8 @@ class LibraryPanel(GObject.GObject):
         for index in cur_range:
             iter = grid_filter.convert_iter_to_child_iter(grid_filter[index].iter)
             if index in vis_range:
-                hash = grid_model.get_value(iter, 2)
+                album_id = grid_model.get_value(iter, 2)
-                pixbuf = self._grid_pixbufs[hash]
+                pixbuf = self._grid_pixbufs[album_id]
                 pixbuf = pixbuf.scale_simple(size, size, GdkPixbuf.InterpType.NEAREST)
             else:
                 pixbuf = GdkPixbuf.Pixbuf.new(GdkPixbuf.Colorspace.RGB, False, 8, 1, 1)