store contacts in a separate file, shared between wallets

lib/util.py

@@ -397,3 +397,33 @@ class QueuePipe:
     def send_all(self, requests):
         for request in requests:
             self.send(request)
+
+
+
+class StoreDict(dict):
+
+    def __init__(self, config, name):
+        self.config = config
+        self.path = os.path.join(self.config.path, name)
+        self.load()
+
+    def load(self):
+        try:
+            with open(self.path, 'r') as f:
+                self.update(json.loads(f.read()))
+        except:
+            pass
+
+    def save(self):
+        with open(self.path, 'w') as f:
+            s = json.dumps(self, indent=4, sort_keys=True)
+            r = f.write(s)
+
+    def __setitem__(self, key, value):
+        dict.__setitem__(self, key, value)
+        self.save()
+
+    def pop(self, key):
+        if key in self.keys():
+            dict.pop(self, key)
+            self.save()