Added properties to configure MaxMessageSize and MaxChunkCount (#517)

* Added properties to configure MaxMessageSize and MaxChunkCount

* improved properties to configure MaxMessageSize and MaxChunkCount

opcua/client/client.py

@@ -114,6 +114,9 @@ class Client(object):
         self._session_counter = 1
         self.keepalive = None
         self.nodes = Shortcuts(self.uaclient)
+        self.max_messagesize = 0 # No limits
+        self.max_chunkcount = 0 # No limits
+
 
     def __enter__(self):
         self.connect()
@@ -146,7 +149,7 @@ class Client(object):
         Set user password for the connection.
         initial password from the URL will be overwritten
         """
-        self._password = pwd
+        self._password = pwd   
 
     def set_security_string(self, string):
         """
@@ -270,7 +273,7 @@ class Client(object):
         """
         Send OPC-UA hello to server
         """
-        ack = self.uaclient.send_hello(self.server_url.geturl())
+        ack = self.uaclient.send_hello(self.server_url.geturl(), self.max_messagesize, self.max_chunkcount)
         # FIXME check ack
 
     def open_secure_channel(self, renew=False):

opcua/client/ua_client.py

@@ -144,9 +144,11 @@ class UASocketClient(object):
         self._socket.socket.shutdown(socket.SHUT_RDWR)
         self._socket.socket.close()
 
-    def send_hello(self, url):
+    def send_hello(self, url, max_messagesize = 0, max_chunkcount = 0):
         hello = ua.Hello()
         hello.EndpointUrl = url
+        hello.MaxMessageSize = max_messagesize
+        hello.MaxChunkCount = max_chunkcount
         future = Future()
         with self._lock:
             self._callbackmap[0] = future
@@ -218,8 +220,8 @@ class UaClient(object):
     def disconnect_socket(self):
         return self._uasocket.disconnect_socket()
 
-    def send_hello(self, url):
-        return self._uasocket.send_hello(url)
+    def send_hello(self, url, max_messagesize = 0, max_chunkcount = 0):
+        return self._uasocket.send_hello(url, max_messagesize, max_chunkcount)
 
     def open_secure_channel(self, params):
         return self._uasocket.open_secure_channel(params)

opcua/ua/uaprotocol_hand.py

@@ -17,8 +17,8 @@ class Hello(uatypes.FrozenClass):
         self.ProtocolVersion = 0
         self.ReceiveBufferSize = 65536
         self.SendBufferSize = 65536
-        self.MaxMessageSize = 0
-        self.MaxChunkCount = 0
+        self.MaxMessageSize = 0 # No limits
+        self.MaxChunkCount = 0 # No limits
         self.EndpointUrl = ""
         self._freeze = True