First commit in tauruslib. Restructure according to SEP10

1 files changed, 57 insertions, 0 deletions

diff --git a/lib/taurus/core/util/decorator/memoize.py b/lib/taurus/core/util/decorator/memoize.py
new file mode 100644
index 00000000..4dbb1d2e
--- /dev/null
+++ b/lib/taurus/core/util/decorator/memoize.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+
+#############################################################################
+##
+## This file is part of Taurus
+##
+## http://taurus-scada.org
+##
+## Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
+##
+## Taurus is free software: you can redistribute it and/or modify
+## it under the terms of the GNU Lesser General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## Taurus is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public License
+## along with Taurus.  If not, see <http://www.gnu.org/licenses/>.
+##
+#############################################################################
+
+import functools
+
+
+class memoized(object):
+    '''Decorator. Caches a function's return value each time it is called.
+    If called later with the same arguments, the cached value is returned
+    (not reevaluated).
+    '''
+
+    def __init__(self, func):
+        self.func = func
+        self.cache = {}
+
+    def __call__(self, *args):
+        try:
+            return self.cache[args]
+        except KeyError:
+            value = self.func(*args)
+            self.cache[args] = value
+            return value
+        except TypeError:
+            # uncachable -- for instance, passing a list as an argument.
+            # Better to not cache than to blow up entirely.
+            return self.func(*args)
+
+    def __repr__(self):
+        '''Return the function's docstring.'''
+        return self.func.__doc__
+
+    def __get__(self, obj, objtype):
+        '''Support instance methods.'''
+        return functools.partial(self.__call__, obj)