Initial commit: Core packages

odoo-bringout-oca-ocb-base/odoo/tools/lru.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+import collections
+import threading
+
+from .func import locked
+
+__all__ = ['LRU']
+
+class LRU(object):
+    """
+    Implementation of a length-limited O(1) LRU map.
+
+    Original Copyright 2003 Josiah Carlson, later rebuilt on OrderedDict.
+    """
+    def __init__(self, count, pairs=()):
+        self._lock = threading.RLock()
+        self.count = max(count, 1)
+        self.d = collections.OrderedDict()
+        for key, value in pairs:
+            self[key] = value
+
+    @locked
+    def __contains__(self, obj):
+        return obj in self.d
+
+    def get(self, obj, val=None):
+        try:
+            return self[obj]
+        except KeyError:
+            return val
+
+    @locked
+    def __getitem__(self, obj):
+        a = self.d[obj]
+        self.d.move_to_end(obj, last=False)
+        return a
+
+    @locked
+    def __setitem__(self, obj, val):
+        self.d[obj] = val
+        self.d.move_to_end(obj, last=False)
+        while len(self.d) > self.count:
+            self.d.popitem(last=True)
+
+    @locked
+    def __delitem__(self, obj):
+        del self.d[obj]
+
+    @locked
+    def __len__(self):
+        return len(self.d)
+
+    @locked
+    def pop(self,key):
+        return self.d.pop(key)
+
+    @locked
+    def clear(self):
+        self.d.clear()