Add a buddy icon cache

services/presence/BuddyIconCache.py

@@ -0,0 +1,61 @@
+import os, time, md5
+from sugar import env
+from sugar import util
+
+class BuddyIconCache(object):
+	"""Caches icons on disk and finds them based on md5 hash."""
+	def __init__(self):
+		ppath = env.get_profile_path()
+		self._cachepath = os.path.join(ppath, "cache", "buddy-icons")
+		if not os.path.exists(self._cachepath):
+			os.makedirs(self._cachepath)
+
+		self._cache = {}
+
+		# Read all cached icons and their sums
+		for fname in os.listdir(self._cachepath):
+			m = md5.new()
+			data = self._get_icon_data(fname)
+			if len(data) == 0:
+				continue
+			m.update(data)
+			printable_hash = util.printable_hash(m.digest())
+			self._cache[printable_hash] = fname
+			del m
+
+	def _get_icon_data(self, fname):
+		fd = open(os.path.join(self._cachepath, fname), "r")
+		data = fd.read()
+		fd.close()
+		del fd
+		return data
+
+	def get_icon(self, printable_hash):
+		if type(printable_hash) != type(u""):
+			raise RuntimeError("printable_hash must be a unicode string.")
+		try:
+			fname = self._cache[printable_hash]
+			return self._get_icon_data(fname)
+		except KeyError:
+			pass
+		return None
+
+	def add_icon(self, icon_data):
+		if len(icon_data) == 0:
+			return
+
+		m = md5.new()
+		m.update(icon_data)
+		printable_hash = util.printable_hash(m.digest())
+		if self._cache.has_key(printable_hash):
+			del m
+			return
+
+		# Write the icon to disk and add an entry to our cache for it
+		m.update(time.asctime())
+		fname = util.printable_hash(m.digest())
+		fd = open(os.path.join(self._cachepath, fname), "w")
+		fd.write(icon_data)
+		fd.close()
+		self._cache[printable_hash] = fname
+		del m

services/presence/Makefile.am

@@ -10,6 +10,7 @@ sugar_PYTHON =				\
 	__init__.py			\
 	Activity.py			\
 	Buddy.py			\
+	BuddyIconCache.py	\
 	PresenceService.py	\
 	Service.py