[MERGE]

bzr revid: nch@tinyerp.com-20091208041517-n8932hvnsprkcme8

1 files changed, 39 insertions, 0 deletions

diff --git a/addons/document_webdav/cache.py b/addons/document_webdav/cache.py
new file mode 100644
index 00000000000..bc75114c4ae
--- /dev/null
+++ b/addons/document_webdav/cache.py
@@ -0,0 +1,39 @@
+import time
+import heapq
+
+def memoize(maxsize):
+	"""decorator to 'memoize' a function - caching its results"""
+	def decorating_function(f):
+		cache = {}  # map from key to value
+		heap = []   # list of keys, in LRU heap
+		cursize = 0 # because len() is slow
+		def wrapper(*args):
+			key = repr(args)
+			# performance crap
+			_cache=cache
+			_heap=heap
+			_heappop = heapq.heappop
+			_heappush = heapq.heappush
+			_time = time.time
+			_cursize = cursize
+			_maxsize = maxsize
+			if not _cache.has_key(key):
+				if _cursize == _maxsize:
+					# pop oldest element
+					(_,oldkey) = _heappop(_heap)
+					_cache.pop(oldkey)
+				else:
+					_cursize += 1
+				# insert this element
+				_cache[key] = f(*args)
+				_heappush(_heap,(_time(),key))
+				wrapper.misses += 1
+			else:
+				wrapper.hits += 1
+			return cache[key]
+		wrapper.__doc__ = f.__doc__
+		wrapper.__name__ = f.__name__
+		wrapper.hits = wrapper.misses = 0
+		return wrapper 
+	return decorating_function
+