[2018] Make diff an internal member as well

We'll need to create it early to make sure the finds done in the prerequisite section are taken from the finder that comes from the same updater (which is the next step to implement)

src/lib/python/isc/ddns/session.py

@@ -243,6 +243,10 @@ class UpdateSession:
         zclass = zrecord.get_class()
         zone_type, datasrc_client = self.__zone_config.find_zone(zname, zclass)
         if zone_type == isc.ddns.zone_config.ZONE_PRIMARY:
+            # create an ixfr-out-friendly diff structure to work on
+            self.__diff = isc.xfrin.diff.Diff(datasrc_client, zname,
+                                              journaling=True,
+                                              single_update_mode=True)
             _, self.__finder = datasrc_client.find_zone(zname)
             self.__zname = zname
             self.__zclass = zclass
@@ -552,20 +556,20 @@ class UpdateSession:
                 return Rcode.FORMERR()
         return Rcode.NOERROR()
 
-    def __do_update_add_single_rr(self, diff, rr, existing_rrset):
+    def __do_update_add_single_rr(self, rr, existing_rrset):
         '''Helper for __do_update_add_rrs_to_rrset: only add the
            rr if it is not present yet
            (note that rr here should already be a single-rr rrset)
         '''
         if existing_rrset is None:
-            diff.add_data(rr)
+            self.__diff.add_data(rr)
         else:
             rr_rdata = rr.get_rdata()[0]
             if not rr_rdata in existing_rrset.get_rdata():
-                diff.add_data(rr)
+                self.__diff.add_data(rr)
 
-    def __do_update_add_rrs_to_rrset(self, diff, rrset):
-        '''Add the rrs from the given rrset to the diff.
+    def __do_update_add_rrs_to_rrset(self, rrset):
+        '''Add the rrs from the given rrset to the internal diff.
            There is handling for a number of special cases mentioned
            in RFC2136;
            - If the addition is a CNAME, but existing data at its
@@ -597,7 +601,7 @@ class UpdateSession:
             if rrset.get_type() == RRType.CNAME():
                 # Remove original CNAME record (the new one
                 # is added below)
-                diff.delete_data(orig_rrset)
+                self.__diff.delete_data(orig_rrset)
             # We do not have WKS support at this time, but if there
             # are special Update equality rules such as for WKS, and
             # we do have support for the type, this is where the check
@@ -608,12 +612,12 @@ class UpdateSession:
             if rrset.get_type() == RRType.CNAME():
                 return
         for rr in foreach_rr(rrset):
-            self.__do_update_add_single_rr(diff, rr, orig_rrset)
+            self.__do_update_add_single_rr(rr, orig_rrset)
 
-    def __do_update_delete_rrset(self, diff, rrset):
+    def __do_update_delete_rrset(self, rrset):
         '''Deletes the rrset with the name and type of the given
            rrset from the zone data (by putting all existing data
-           in the given diff as delete statements).
+           in the internal diff as delete statements).
            Special cases: if the delete statement is for the
            zone's apex, and the type is either SOA or NS, it
            is ignored.'''
@@ -628,9 +632,9 @@ class UpdateSession:
                 # ignore
                 return
             for rr in foreach_rr(to_delete):
-                diff.delete_data(rr)
+                self.__diff.delete_data(rr)
 
-    def __ns_deleter_helper(self, diff, rrset):
+    def __ns_deleter_helper(self, rrset):
         '''Special case helper for deleting NS resource records
            at the zone apex. In that scenario, the last NS record
            may never be removed (and any action that would do so
@@ -666,12 +670,12 @@ class UpdateSession:
                                           rrset.get_ttl())
                 to_delete.add_rdata(rdata)
                 orig_rrset_rdata.remove(rdata)
-                diff.delete_data(to_delete)
+                self.__diff.delete_data(to_delete)
 
-    def __do_update_delete_name(self, diff, rrset):
+    def __do_update_delete_name(self, rrset):
         '''Delete all data at the name of the given rrset,
            by adding all data found by find_all as delete statements
-           to the given diff.
+           to the internal diff.
            Special case: if the name is the zone's apex, SOA and
            NS records are kept.
         '''
@@ -688,9 +692,9 @@ class UpdateSession:
                     continue
                 else:
                     for rr in foreach_rr(to_delete):
-                        diff.delete_data(rr)
+                        self.__diff.delete_data(rr)
 
-    def __do_update_delete_rrs_from_rrset(self, diff, rrset):
+    def __do_update_delete_rrs_from_rrset(self, rrset):
         '''Deletes all resource records in the given rrset from the
            zone. Resource records that do not exist are ignored.
            If the rrset if of type SOA, it is ignored.
@@ -711,17 +715,17 @@ class UpdateSession:
             elif rrset.get_type() == RRType.NS():
                 # hmm. okay. annoying. There must be at least one left,
                 # delegate to helper method
-                self.__ns_deleter_helper(diff, to_delete)
+                self.__ns_deleter_helper(to_delete)
                 return
         for rr in foreach_rr(to_delete):
-            diff.delete_data(rr)
+            self.__diff.delete_data(rr)
 
-    def __update_soa(self, diff):
+    def __update_soa(self):
         '''Checks the member value __added_soa, and depending on
            whether it has been set and what its value is, creates
            a new SOA if necessary.
            Then removes the original SOA and adds the new one,
-           by adding the needed operations to the given diff.'''
+           by adding the needed operations to the internal diff.'''
         # Get the existing SOA
         # if a new soa was specified, add that one, otherwise, do the
         # serial magic and add the newly created one
@@ -738,8 +742,8 @@ class UpdateSession:
             new_soa = old_soa
             # increment goes here
 
-        diff.delete_data(old_soa)
-        diff.add_data(new_soa)
+        self.__diff.delete_data(old_soa)
+        self.__diff.add_data(new_soa)
 
     def __do_update(self):
         '''Scan, check, and execute the Update section in the
@@ -754,12 +758,8 @@ class UpdateSession:
 
         # update
         try:
-            # create an ixfr-out-friendly diff structure to work on
-            diff = isc.xfrin.diff.Diff(self.__datasrc_client, self.__zname,
-                                       journaling=True, single_update_mode=True)
-
             # Do special handling for SOA first
-            self.__update_soa(diff)
+            self.__update_soa()
 
             # Algorithm from RFC2136 Section 3.4
             # Note that this works on full rrsets, not individual RRs.
@@ -773,16 +773,16 @@ class UpdateSession:
             # do_update statements)
             for rrset in self.__message.get_section(SECTION_UPDATE):
                 if rrset.get_class() == self.__zclass:
-                    self.__do_update_add_rrs_to_rrset(diff, rrset)
+                    self.__do_update_add_rrs_to_rrset(rrset)
                 elif rrset.get_class() == RRClass.ANY():
                     if rrset.get_type() == RRType.ANY():
-                        self.__do_update_delete_name(diff, rrset)
+                        self.__do_update_delete_name(rrset)
                     else:
-                        self.__do_update_delete_rrset(diff, rrset)
+                        self.__do_update_delete_rrset(rrset)
                 elif rrset.get_class() == RRClass.NONE():
-                    self.__do_update_delete_rrs_from_rrset(diff, rrset)
+                    self.__do_update_delete_rrs_from_rrset(rrset)
 
-            diff.commit()
+            self.__diff.commit()
             return Rcode.NOERROR()
         except isc.datasrc.Error as dse:
             logger.info(LIBDDNS_UPDATE_DATASRC_ERROR, dse)