Make generic named objects collection instead of separate for each type

There will be more:
 - labels
 - storage pools
 - storage volumes

qubesmgmt/app.py

@@ -113,7 +113,8 @@ class QubesBase(qubesmgmt.base.PropertyHolder):
     def __init__(self):
         super(QubesBase, self).__init__(self, 'mgmt.property.', 'dom0')
         self.domains = VMCollection(self)
-        self.labels = qubesmgmt.label.LabelsCollection(self)
+        self.labels = qubesmgmt.base.WrapperObjectsCollection(
+            self, 'mgmt.label.List', qubesmgmt.label.Label)
 
 
 class QubesLocal(QubesBase):

qubesmgmt/base.py

@@ -224,3 +224,63 @@ class PropertyHolder(object):
             )
         except qubesmgmt.exc.QubesDaemonNoResponseError:
             raise qubesmgmt.exc.QubesPropertyAccessError(name)
+
+
+class WrapperObjectsCollection(object):
+    '''Collection of simple named objects'''
+    def __init__(self, app, list_method, object_class):
+        '''
+        Construct manager of named wrapper objects.
+
+        :param app: Qubes() object
+        :param list_method: name of API method used to list objects,
+            must return simple "one name per line" list
+        :param object_class: object class (callable) for wrapper objects,
+            will be called with just two arguments: app and a name
+        '''
+        self.app = app
+        self._list_method = list_method
+        self._object_class = object_class
+        #: names cache
+        self._names_list = None
+        #: returned objects cache
+        self._objects = {}
+
+    def clear_cache(self):
+        '''Clear cached list of names'''
+        self._names_list = None
+
+    def refresh_cache(self, force=False):
+        '''Refresh cached list of names'''
+        if not force and self._names_list is not None:
+            return
+        list_data = self.app.qubesd_call('dom0', self._list_method)
+        list_data = list_data.decode('ascii')
+        assert list_data[-1] == '\n'
+        self._names_list = list_data[:-1].splitlines()
+
+        for name, obj in list(self._objects.items()):
+            if obj.name not in self._names_list:
+                # Object no longer exists
+                del self._objects[name]
+
+    def __getitem__(self, item):
+        if item not in self:
+            raise KeyError(item)
+        if item not in self._objects:
+            self._objects[item] = self._object_class(self.app, item)
+        return self._objects[item]
+
+    def __contains__(self, item):
+        self.refresh_cache()
+        return item in self._names_list
+
+    def __iter__(self):
+        self.refresh_cache()
+        for obj in self._names_list:
+            yield self[obj]
+
+    def keys(self):
+        '''Get list of names.'''
+        self.refresh_cache()
+        return self._names_list.copy()

qubesmgmt/label.py

@@ -55,50 +55,3 @@ class Label(object):
 
     def __str__(self):
         return self._name
-
-
-class LabelsCollection(object):
-    '''Collection of VMs objects'''
-    def __init__(self, app):
-        self.app = app
-        self._label_list = None
-        self._label_objects = {}
-
-    def clear_cache(self):
-        '''Clear cached list of labels'''
-        self._label_list = None
-
-    def refresh_cache(self, force=False):
-        '''Refresh cached list of VMs'''
-        if not force and self._label_list is not None:
-            return
-        label_list_data = self.app.qubesd_call('dom0', 'mgmt.label.List')
-        label_list_data = label_list_data.decode('ascii')
-        assert label_list_data[-1] == '\n'
-        self._label_list = label_list_data[:-1].splitlines()
-
-        for name, label in list(self._label_objects.items()):
-            if label.name not in self._label_list:
-                # Label no longer exists
-                del self._label_objects[name]
-
-    def __getitem__(self, item):
-        if item not in self:
-            raise KeyError(item)
-        if item not in self._label_objects:
-            self._label_objects[item] = Label(self.app, item)
-        return self._label_objects[item]
-
-    def __contains__(self, item):
-        self.refresh_cache()
-        return item in self._label_list
-
-    def __iter__(self):
-        self.refresh_cache()
-        for vm in self._label_list:
-            yield self[vm]
-
-    def keys(self):
-        '''Get list of label names.'''
-        self.refresh_cache()
-        return self._label_list.keys()