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'])
-        if lookup and hash in self._albums.keys():
-            album = self._albums[hash]
+        id = Utils.generate_id(song['album'])
+        if lookup and id in self._albums.keys():
+            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):