libsaria: Began new cache functions

I think the new cache will be more generic, and should work for just
about anything.  We'll see.

libsaria/path/lastfm.py

@@ -6,6 +6,7 @@ from libsaria import web
 from libsaria import xm
 from libsaria import callbacks
 from libsaria import threads
+from libsaria import storage
 
 file_id   = libsaria.path.file_id
 cache     = libsaria.cache
@@ -47,7 +48,7 @@ class LastFmRequest(dict):
 		else:
 			return None
 
-def lfm_cache_album(file, artist, album):
+def lfm_cache_album(file, artist, album, title):
 	req = LastFmRequest("album.getInfo")
 	req["album"]  = album
 	req["artist"] = artist
@@ -76,9 +77,10 @@ def set_art_from_file(file, path):
 		return False
 	return True
 
-def get_artwork_tags(artist, album):
+def get_artwork_tags(artist, album, title):
+	storage.cache.get_item(artist, album, title, "Folder.jpg", lfm_cache_album)
 	cached = cache[artist]
-	file = cached.get("%s.jpg" % album, lfm_cache_album, artist, album)
+	file = cached.get("%s.jpg" % album, lfm_cache_album, artist, album, title)
 	return file
 
 def set_artwork_tags(artist, album, path):
@@ -87,8 +89,8 @@ def set_artwork_tags(artist, album, path):
 	file = cached.get("%s.jpg" % album, set_art_from_file, path)
 
 def get_artwork_id(id):
-	artist, album = sources.get_attrs("artist", "album")
-	return get_artwork_tags(artist, album)
+	artist, album, title = sources.get_attrs("artist", "album", "title")
+	return get_artwork_tags(artist, album, title)
 
 def get_artwork_bg(file):
 	id = sources.get_attrs("id")

libsaria/storage/__init__.py

@@ -4,6 +4,7 @@ import os
 from os import path
 import cPickle as pickle
 from libsaria import version
+import cache
 
 USER_DIR  = path.expanduser("~")
 PROTO     = pickle.HIGHEST_PROTOCOL

libsaria/storage/cache.py

@@ -0,0 +1,34 @@
+# Bryan Schumaker (5 / 6 / 2011)
+
+import os
+import libsaria
+
+join    = os.path.join
+sep     = os.path.sep
+isfile  = os.path.isfile
+isdir   = os.path.isdir
+getsize = os.path.getsize
+
+def file_exists(cache_path):
+	if not isfile(cache_path):
+		return False
+	return getsize(cache_path) != 0
+
+def make_cache_path(artist, album, file):
+	cache_dir  = libsaria.storage.full_path("cache")
+	cache_file = "%s%s%s%s" % (artist, sep, album, sep)
+	cache_path = join(cache_dir, cache_file)
+	if not isdir(cache_path):
+		os.makedirs(cache_path)
+	return join(cache_path, file)
+
+def get_item(artist, album, title, file, cache_func):
+	cache_path = make_cache_path(artist, album, file)
+	if not file_exists(cache_path):
+		f = open(cache_path, 'w')
+		cache_func(f, artist, album, title)
+		f.close()
+		if not file_exists(cache_path):
+			os.remove(cache_path)
+			print "File doesn't exist!"
+	return cache_path