Only send updates when necessary.

diff --git a/src/ddns/providers.py b/src/ddns/providers.py
index b0b3bf7ddcab65acbcc813db6c4ab833144b9682..21159727ad989ca297604ed1574af78901d6568d 100644 (file)
--- a/src/ddns/providers.py
+++ b/src/ddns/providers.py
@@ -19,9 +19,16 @@
 #                                                                             #
 ###############################################################################
 
+import logging
+
+from i18n import _
+
 # Import all possible exception types.
 from .errors import *
 
+logger = logging.getLogger("ddns.providers")
+logger.propagate = 1
+
 class DDNSProvider(object):
        INFO = {
                # A short string that uniquely identifies
@@ -104,12 +111,38 @@ class DDNSProvider(object):
                """
                return self.get("password")
 
+       @property
+       def protocols(self):
+               return self.INFO.get("protocols")
+
        def __call__(self):
+               # Check if we actually need to update this host.
+               if self.is_uptodate(self.protocols):
+                       logger.info(_("%s is already up to date") % self.hostname)
+                       return
+
+               # Execute the update.
                self.update()
 
        def update(self):
                raise NotImplementedError
 
+       def is_uptodate(self, protos):
+               """
+                       Returns True if this host is already up to date
+                       and does not need to change the IP address on the
+                       name server.
+               """
+               for proto in protos:
+                       addresses = self.core.system.resolve(self.hostname, proto)
+
+                       current_address = self.get_address(proto)
+
+                       if not current_address in addresses:
+                               return False
+
+               return True
+
        def send_request(self, *args, **kwargs):
                """
                        Proxy connection to the send request