support deleting all nodes on server side. Needed by opcua-modeler

opcua/server/address_space.py

@@ -473,6 +473,13 @@ class AddressSpace(object):
         with self._lock:
             return self._nodes.keys()
 
+    def empty(self):
+        """
+        Delete all nodes in address space
+        """
+        with self._lock:
+            self._nodes = {}
+
     def dump(self, path):
         """
         dump address space as binary to file

opcua/server/internal_server.py

@@ -64,18 +64,7 @@ class InternalServer(object):
         self.method_service = MethodService(self.aspace)
         self.node_mgt_service = NodeManagementService(self.aspace)
 
-        if cacheFile and path.isfile(cacheFile):
-            # import address space from shelve
-            self.aspace.load(cacheFile)
-        else:
-            # import address space from code generated from xml
-            standard_address_space.fill_address_space(self.node_mgt_service)
-            # import address space directly from xml, this has preformance impact so disabled
-            # importer = xmlimporter.XmlImporter(self.node_mgt_service)
-            # importer.import_xml("/path/to/python-opcua/schemas/Opc.Ua.NodeSet2.xml", self)
-
-            if cacheFile:
-                self.aspace.dump(cacheFile)
+        self.load_standard_address_space(cacheFile)
 
         self.loop = utils.ThreadLoop()
         self.asyncio_transports = []
@@ -85,15 +74,39 @@ class InternalServer(object):
 
         # create a session to use on server side
         self.isession = InternalSession(self, self.aspace, self.subscription_service, "Internal", user=User.Admin)
+
         self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
+        self.setup_nodes()
+
+    def setup_nodes(self):
+        """
+        Set up some nodes as defined by spec
+        """
         uries = ["http://opcfoundation.org/UA/"]
         ns_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
         ns_node.set_value(uries)
 
+    def load_standard_address_space(self, cacheFile=None):
+        if cacheFile and path.isfile(cacheFile):
+            # import address space from shelve
+            self.aspace.load(cacheFile)
+        else:
+            # import address space from code generated from xml
+            standard_address_space.fill_address_space(self.node_mgt_service)
+            # import address space directly from xml, this has preformance impact so disabled
+            # importer = xmlimporter.XmlImporter(self.node_mgt_service)
+            # importer.import_xml("/path/to/python-opcua/schemas/Opc.Ua.NodeSet2.xml", self)
+
     def load_address_space(self, path):
+        """
+        Load address space frfrom path
+        """
         self.aspace.load(path)
 
     def dump_address_space(self, path):
+        """
+        Dump current address space to path
+        """
         self.aspace.dump(path)
 
     def start(self):