[core] Add util.store for store-like get/set

util/store.py

@@ -0,0 +1,26 @@
+"""Store interface
+
+Allows arbitrary classes to offer a simple get/set
+store interface by deriving from the Store class in
+this module
+"""
+
+class Store(object):
+    """Interface for storing and retrieving simple values"""
+    def __init__(self):
+        self._data = {}
+
+    def set(self, key, value):
+        """Set 'key' to 'value', overwriting 'key' if it exists already"""
+        self._data[key] = { 'value': value, 'used': False }
+
+    def unused_keys(self):
+        return [ key for key, value in self._data.items() if value['used'] == False ]
+
+    def get(self, key, default=None):
+        """Return the current value of 'key', or 'default' if 'key' is not set"""
+        if key in self._data:
+            self._data[key]['used'] = True
+        return self._data.get(key, { 'value': default })['value']
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4