--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wsgraph/model.py	Sun Dec 09 10:21:43 2012 -0800
@@ -0,0 +1,54 @@
+from abc import abstractmethod
+
+class GraphModel(object):
+
+    @abstractmethod
+    def node(self, name, **values):
+        """get or set a node"""
+
+    @abstractmethod
+    def nodes(self):
+        """returns a list of all nodes"""
+
+    @abstractmethod
+    def edges(self):
+        """returns a list of all edges"""
+
+    @abstractmethod
+    def edge(self, node1, node2, **values):
+        """returns edge from node1 to node2"""
+
+    def __getitem__(self, key):
+        """
+        if key is a basestring, return the node of that name;
+        if key is a 2-tuple/list, return the edge of that name
+        """
+
+
+class MemoryCache(GraphModel):
+
+    def __init__(self):
+        self._edges = {}
+        self._nodes = {}
+
+    def node(self, name, **values):
+        if values:
+            # setter
+            self._nodes[name] = values
+        else:
+            # getter
+            return self._nodes.get(name, None)
+
+    def nodes(self):
+        return self._nodes.keys()
+
+    def edge(self, node1, node2, **values):
+        if values:
+            # setter
+            self._edges[(node1, node2)] = values
+        else:
+            # getter
+            return self._edges.get((node1, node2), None)
+
+    def edges(self):
+        return self._edges.keys()