From 28d4368c425f8a410735c7b02997cba44f7c704b Mon Sep 17 00:00:00 2001
From: Abhinav Sarkar <abhinav.sarkar@gmail.com>
Date: Tue, 31 Mar 2009 15:48:04 +0000
Subject: [PATCH] * moved object registry and register function to objectcache
 module * changed the cache dict to a WeakReferenceDict for avoiding excessive
 memory usage * added stats method to ObjectCache to get current stats about
 cache

---
 lastfm/mixins/_cacheable.py | 22 ++++--------
 lastfm/objectcache.py       | 68 +++++++++++++++++++++++++------------
 2 files changed, 53 insertions(+), 37 deletions(-)

diff --git a/lastfm/mixins/_cacheable.py b/lastfm/mixins/_cacheable.py
index 6ae87d0..3100cc2 100644
--- a/lastfm/mixins/_cacheable.py
+++ b/lastfm/mixins/_cacheable.py
@@ -9,21 +9,9 @@ try:
     from threading import Lock
 except ImportError:
     from dummy_threading import Lock
-    
-registry = {}
-_lock = Lock()
+from lastfm.objectcache import ObjectCache
 
-def register(ob, key):
-    if not ob.__class__ in registry:
-        registry[ob.__class__] = {}
-    if key in registry[ob.__class__]:
-        ob = registry[ob.__class__][key]
-        #print "already registered: %s" % repr(ob)
-        return (ob, True)
-    else:
-        #print "not already registered: %s" % ob.__class__
-        registry[ob.__class__][key] = ob
-        return (ob, False)
+_lock = Lock()
 
 def cacheable(cls):
     @classmethod
@@ -45,7 +33,7 @@ def cacheable(cls):
             key = (hash(subject), key)
             
         with _lock:
-            inst, already_registered = register(object.__new__(cls), key)
+            inst, already_registered = ObjectCache.register(object.__new__(cls), key)
             if not already_registered:
                 inst.init(*args, **kwds)
         return inst
@@ -58,4 +46,8 @@ def cacheable(cls):
     if not hasattr(cls, '_hash_func'):
         cls._hash_func = _hash_func
         
+    if not hasattr(cls, '_mixins'):
+            cls._mixins = []
+    cls._mixins.append('__new__')
+        
     return cls
diff --git a/lastfm/objectcache.py b/lastfm/objectcache.py
index f57d92d..bb10542 100644
--- a/lastfm/objectcache.py
+++ b/lastfm/objectcache.py
@@ -4,36 +4,60 @@ __author__ = "Abhinav Sarkar <abhinav@abhinavsarkar.net>"
 __version__ = "0.2"
 __license__ = "GNU Lesser General Public License"
 __package__ = "lastfm"
-
-from lastfm.album import Album
-from lastfm.artist import Artist
-from lastfm.mixins import _cacheable
-from lastfm.error import InvalidParametersError
-from lastfm.event import Event
-from lastfm.geo import Location, Country
-from lastfm.group import Group
-from lastfm.playlist import Playlist
-from lastfm.tag import Tag
-from lastfm.track import Track
-from lastfm.user import User
-from lastfm.venue import Venue
-from lastfm.chart import WeeklyAlbumChart, WeeklyArtistChart, WeeklyTrackChart
+    
+_registry = {}
 
 class ObjectCache(object):
     """The registry to contain all the entities"""
-    keys = [c.__name__ for c in [Album, Artist, Event, Location, Country, Group, 
-            Playlist, Tag, Track, User, Venue, WeeklyAlbumChart, WeeklyArtistChart, WeeklyTrackChart]]
+    keys = ['Album', 'Artist', 'Event', 'Location', 'Country', 'Group', 
+            'Playlist', 'Shout', 'Tag', 'Track', 'User', 'Venue',
+            'WeeklyChart',
+            'WeeklyAlbumChart', 'WeeklyArtistChart', 'WeeklyTrackChart', 'WeeklyTagChart',
+            'MonthlyChart',
+            'MonthlyAlbumChart', 'MonthlyArtistChart', 'MonthlyTrackChart', 'MonthlyTagChart',
+            'QuaterlyChart',
+            'QuaterlyAlbumChart', 'QuaterlyArtistChart', 'QuaterlyTrackChart', 'QuaterlyTagChart',
+            'HalfYearlyChart',
+            'HalfYearlyAlbumChart', 'HalfYearlyArtistChart', 'HalfYearlyTrackChart', 'HalfYearlyTagChart',
+            'YearlyChart',
+            'YearlyAlbumChart', 'YearlyArtistChart', 'YearlyTrackChart', 'YearlyTagChart'
+            ]
+    
+    @staticmethod
+    def register(ob, key):
+        cls_name = ob.__class__.__name__
+        if not cls_name in _registry:
+            _registry[cls_name] = WeakValueDictionary()
+        if key in _registry[cls_name]:
+            ob = _registry[cls_name][key]
+            print "already registered: %s" % repr(ob)
+            return (ob, True)
+        else:
+            print "not already registered: %s" % ob.__class__
+            _registry[cls_name][key] = ob
+            return (ob, False)
+
+    @property
+    def stats(self):
+        counts = {}
+        for k in ObjectCache.keys:
+            if k in _registry:
+                counts[k] = len(_registry[k])
+            else:
+                counts[k] = 0
+        return counts
     
     def __getitem__(self, name):
         if name not in ObjectCache.keys:
             raise InvalidParametersError("Key does not correspond to a valid class")
         else:
-            try:
-                vals = _cacheable.registry[eval(name)].values()
-                vals.sort()
-                return vals
-            except KeyError:
+            if name in _registry:
+                return sorted(_registry[name].values())
+            else:
                 return []
             
     def __repr__(self):
-        return "<lastfm.ObjectCache>"
\ No newline at end of file
+        return "<lastfm.ObjectCache>"
+
+from weakref import WeakValueDictionary
+from lastfm.error import InvalidParametersError
\ No newline at end of file