def test_create(self):
"""
This test the case when the diff is successfuly created. It just
tries it does not throw and gets the updater.
"""
diff = Diff(self, Name('example.org.'))
self.assertTrue(self.__updater_requested)
self.assertEqual([], diff.get_buffer())
# By default journaling is disabled
self.assertFalse(self.__journaling_enabled)
def test_commit(self):
"""
If we call a commit, it should first apply whatever changes are
left (we hook into that instead of checking the effect) and then
the commit on the updater should have been called.
Then we check it raises value error for whatever operation we try.
"""
diff = Diff(self, Name('example.org.'))
diff.add_data(self.__rrset1)
orig_apply = diff.apply
diff.apply = self.__mock_apply
diff.commit()
self.assertTrue(self.__apply_called)
self.assertTrue(self.__commit_called)
# The data should be handled by apply which we replaced.
self.assertEqual([], self.__data_operations)
# Now check all range of other methods raise ValueError
self.assertRaises(ValueError, diff.commit)
self.assertRaises(ValueError, diff.add_data, self.__rrset2)
self.assertRaises(ValueError, diff.delete_data, self.__rrset1)
self.assertRaises(ValueError, diff.find, Name('foo.example.org.'),
RRType.A())
self.assertRaises(ValueError, diff.find_all, Name('foo.example.org.'))
diff.apply = orig_apply
self.assertRaises(ValueError, diff.apply)
# This one does not state it should raise, so check it doesn't
# But it is NOP in this situation anyway
diff.compact()
def test_find_all_other_results(self):
'''
Any result code other than SUCCESS and NXDOMAIN should cause
the results to be passed on directly
'''
diff = Diff(self, Name('example.org'), single_update_mode=True)
# Add and delete some data to make sure it's not used
diff.add_data(self.__rrset_soa)
diff.add_data(self.__rrset3)
diff.delete_data(self.__rrset_soa)
diff.delete_data(self.__rrset2)
for rcode in [ ZoneFinder.NXRRSET,
ZoneFinder.DELEGATION,
ZoneFinder.CNAME,
ZoneFinder.DNAME ]:
# override the actual find method
self.__create_find_all(rcode, [], 0)
self.__check_find_all_call(diff.find_all_updated, self.__rrset2,
rcode)
self.__check_find_all_call(diff.find_all_updated, self.__rrset3,
rcode)
self.__check_find_all_call(diff.find_all, self.__rrset2,
rcode)
self.__check_find_all_call(diff.find_all, self.__rrset3,
rcode)
def test_get_buffer(self):
'''
Test that the getters raise when used in the wrong mode
'''
diff_multi = Diff(self, Name('example.org.'), single_update_mode=False)
self.assertRaises(ValueError, diff_multi.get_single_update_buffers)
self.assertEqual([], diff_multi.get_buffer())
diff_single = Diff(self, Name('example.org.'), single_update_mode=True)
self.assertRaises(ValueError, diff_single.get_buffer)
self.assertEqual(([], []), diff_single.get_single_update_buffers())
def test_find_options(self):
diff = Diff(self, Name('example.org.'))
name = Name('foo.example.org.')
rrtype = RRType.TXT()
options = ZoneFinder.NO_WILDCARD
self.assertEqual("find_return", diff.find(name, rrtype, options))
self.assertTrue(self.__find_called)
self.assertEqual(name, self.__find_name)
self.assertEqual(rrtype, self.__find_type)
self.assertEqual(options, self.__find_options)
def test_find_all(self):
diff = Diff(self, Name('example.org.'))
name = Name('www.example.org.')
self.assertFalse(self.__find_all_called)
self.assertEqual(None, self.__find_all_name)
self.assertEqual(None, self.__find_all_options)
self.assertEqual("find_all_return", diff.find_all(name))
self.assertTrue(self.__find_all_called)
self.assertEqual(name, self.__find_all_name)
self.assertEqual(ZoneFinder.NO_WILDCARD | ZoneFinder.FIND_GLUE_OK,
self.__find_all_options)
def __do_raise_test(self):
"""
Do a raise test. Expects that one of the operations is exchanged for
broken version.
"""
diff = Diff(self, Name('example.org.'))
diff.add_data(self.__rrset1)
diff.delete_data(self.__rrset2)
self.assertRaises(TestError, diff.commit)
self.assertTrue(self.__broken_called)
self.assertRaises(ValueError, diff.add_data, self.__rrset1)
self.assertRaises(ValueError, diff.delete_data, self.__rrset2)
self.assertRaises(ValueError, diff.commit)
self.assertRaises(ValueError, diff.apply)
def test_find_all_options(self):
diff = Diff(self, Name('example.org.'))
name = Name('www.example.org.')
options = isc.datasrc.ZoneFinder.NO_WILDCARD
self.assertFalse(self.__find_all_called)
self.assertEqual(None, self.__find_all_name)
self.assertEqual(None, self.__find_all_options)
self.assertEqual("find_all_return", diff.find_all(name, options))
self.assertTrue(self.__find_all_called)
self.assertEqual(name, self.__find_all_name)
self.assertEqual(options, self.__find_all_options)
def test_get_rrset_collection(self):
'''
Test the diff can return corresponding rrset collection. Test
it applies the data first.
'''
diff = Diff(self, Name('example.org'), single_update_mode=True)
diff.add_data(self.__rrset_soa)
collection = diff.get_rrset_collection()
# Check it is applied
self.assertEqual(1, len(self.__data_operations))
self.assertEqual('add', self.__data_operations[0][0])
# Check the returned one is actually RRsetCollection
self.assertTrue(isinstance(collection, self.Collection))
# The collection is just the mock from above, so this doesn't do much
# testing, but we check that the mock got through and didn't get hurt.
self.assertIsNone(collection.find(Name('example.org'), RRClass.IN,
RRType.SOA))
def test_apply(self):
"""
Schedule few additions and check the apply works by passing the
data into the updater.
"""
# Prepare the diff
diff = Diff(self, Name('example.org.'))
diff.add_data(self.__rrset1)
diff.delete_data(self.__rrset2)
dlist = [('add', self.__rrset1), ('delete', self.__rrset2)]
self.assertEqual(dlist, diff.get_buffer())
# Do the apply, hook the compact method
diff.compact = self.__mock_compact
diff.apply()
# It should call the compact
self.assertTrue(self.__compact_called)
# And pass the data. Our local history of what happened is the same
# format, so we can check the same way
self.assertEqual(dlist, self.__data_operations)
# And the buffer in diff should become empty, as everything
# got inside.
self.assertEqual([], diff.get_buffer())
def test_find_updated_other(self):
'''
Test that any other ZoneFinder.result code is directly
passed on.
'''
diff = Diff(self, Name('example.org'), single_update_mode=True)
# Add and delete some data to make sure it's not used
diff.add_data(self.__rrset_soa)
diff.add_data(self.__rrset3)
diff.delete_data(self.__rrset_soa)
diff.delete_data(self.__rrset2)
for rcode in [ ZoneFinder.DELEGATION,
ZoneFinder.CNAME,
ZoneFinder.DNAME ]:
# override the actual find method
self.__create_find(rcode, None, 0)
self.__check_find_call(diff.find, self.__rrset3, rcode)
self.__check_find_call(diff.find_updated, self.__rrset3, rcode)
def test_rrsig_ttl(self):
'''Similar to the previous test, but for RRSIGs of different covered
types.
They shouldn't be compacted.
'''
diff = Diff(self, Name('example.org.'))
rrsig1 = RRset(Name('example.org'), self.__rrclass,
RRType.RRSIG(), RRTTL(3600))
rrsig1.add_rdata(Rdata(RRType.RRSIG(), self.__rrclass,
'A 5 3 3600 20000101000000 20000201000000 ' +
'0 example.org. FAKEFAKEFAKE'))
diff.add_data(rrsig1)
rrsig2 = RRset(Name('example.org'), self.__rrclass,
RRType.RRSIG(), RRTTL(1800))
rrsig2.add_rdata(Rdata(RRType.RRSIG(), self.__rrclass,
'AAAA 5 3 3600 20000101000000 20000201000000 ' +
'1 example.org. FAKEFAKEFAKE'))
diff.add_data(rrsig2)
diff.compact()
self.assertEqual(2, len(diff.get_buffer()))
def test_autoapply(self):
"""
Test the apply is called all by itself after 100 tasks are added.
"""
diff = Diff(self, Name('example.org.'))
# A method to check the apply is called _after_ the 100th element
# is added. We don't use it anywhere else, so we define it locally
# as lambda function
def check():
self.assertEqual(100, len(diff.get_buffer()))
self.__mock_apply()
orig_apply = diff.apply
diff.apply = check
# If we put 99, nothing happens yet
for i in range(0, 99):
diff.add_data(self.__rrset1)
expected = [('add', self.__rrset1)] * 99
self.assertEqual(expected, diff.get_buffer())
self.assertFalse(self.__apply_called)
# Now we push the 100th and it should call the apply method
# This will _not_ flush the data yet, as we replaced the method.
# It, however, would in the real life.
diff.add_data(self.__rrset1)
# Now the apply method (which is replaced by our check) should
# have been called. If it wasn't, this is false. If it was, but
# still with 99 elements, the check would complain
self.assertTrue(self.__apply_called)
# Reset the buffer by calling the original apply.
orig_apply()
self.assertEqual([], diff.get_buffer())
# Similar with delete
self.__apply_called = False
for i in range(0, 99):
diff.delete_data(self.__rrset2)
expected = [('delete', self.__rrset2)] * 99
self.assertEqual(expected, diff.get_buffer())
self.assertFalse(self.__apply_called)
diff.delete_data(self.__rrset2)
self.assertTrue(self.__apply_called)
def test_find_all_existing_data(self):
diff = Diff(self, Name('example.org'), single_update_mode=True)
diff.add_data(self.__rrset_soa)
diff.delete_data(self.__rrset_soa)
# override the actual find method
self.__create_find_all(ZoneFinder.SUCCESS, [ self.__rrset3 ], 0)
# Sanity check
result, rrsets, _ = diff.find_all_updated(self.__rrset3.get_name())
self.assertEqual(ZoneFinder.SUCCESS, result)
self.assertEqual([self.__rrset3], rrsets)
self.__check_find_all_call(diff.find_all_updated, self.__rrset3,
ZoneFinder.SUCCESS, [self.__rrset3])
self.__check_find_all_call(diff.find_all, self.__rrset3,
ZoneFinder.SUCCESS, [self.__rrset3])
# Add a second rr with different type at same name
add_rrset = RRset(self.__rrset3.get_name(), self.__rrclass,
RRType.A(), self.__ttl)
add_rrset.add_rdata(Rdata(RRType.A(), self.__rrclass, "192.0.2.2"))
diff.add_data(add_rrset)
self.__check_find_all_call(diff.find_all_updated, self.__rrset3,
ZoneFinder.SUCCESS,
[self.__rrset3, add_rrset])
self.__check_find_all_call(diff.find_all, self.__rrset3,
ZoneFinder.SUCCESS, [self.__rrset3])
# Remove original one
diff.delete_data(self.__rrset3)
self.__check_find_all_call(diff.find_all_updated, self.__rrset3,
ZoneFinder.SUCCESS, [add_rrset])
self.__check_find_all_call(diff.find_all, self.__rrset3,
ZoneFinder.SUCCESS, [self.__rrset3])
# And remove new one, result should then become NXDOMAIN
diff.delete_data(add_rrset)
result, rrsets, _ = diff.find_all_updated(self.__rrset3.get_name())
self.assertEqual(ZoneFinder.NXDOMAIN, result)
self.assertEqual([ ], rrsets)
self.__check_find_all_call(diff.find_all_updated, self.__rrset3,
ZoneFinder.NXDOMAIN)
self.__check_find_all_call(diff.find_all, self.__rrset3,
ZoneFinder.SUCCESS, [self.__rrset3])
def test_find_updated_existing_data(self):
'''
Tests whether existent data is updated with the additions and
deletions from the Diff
'''
diff = Diff(self, Name('example.org'), single_update_mode=True)
diff.add_data(self.__rrset_soa)
diff.delete_data(self.__rrset_soa)
# override the actual find method
self.__create_find(ZoneFinder.SUCCESS, self.__rrset3, 0)
# sanity check
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
# check that normal find also returns the original data
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
# Adding another should have it returned in the find_updated
diff.add_data(self.__rrset4)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata() +
self.__rrset4.get_rdata())
# check that normal find still returns the original data
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
# Adding a different type should have no effect
diff.add_data(self.__rrset2)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata() +
self.__rrset4.get_rdata())
# check that normal find still returns the original data
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
# Deleting 3 now should result in only 4 being updated
diff.delete_data(self.__rrset3)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset4.get_rdata())
# check that normal find still returns the original data
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
# Deleting 4 now should result in empty rrset
diff.delete_data(self.__rrset4)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.NXRRSET)
# check that normal find still returns the original data
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
def test_find_updated_nonexistent_data(self):
'''
Test whether added data for a query that would originally result
in NXDOMAIN works
'''
diff = Diff(self, Name('example.org'), single_update_mode=True)
diff.add_data(self.__rrset_soa)
diff.delete_data(self.__rrset_soa)
# override the actual find method
self.__create_find(ZoneFinder.NXDOMAIN, None, 0)
# Sanity check
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.NXDOMAIN)
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.NXDOMAIN)
# Add data and see it is returned
diff.add_data(self.__rrset3)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.NXDOMAIN)
# Add unrelated data, result should be the same
diff.add_data(self.__rrset2)
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.SUCCESS, self.__rrset3.get_rdata())
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.NXDOMAIN)
# Remove, result should now be NXDOMAIN again
diff.delete_data(self.__rrset3)
result, rrset, _ = diff.find_updated(self.__rrset3.get_name(),
self.__rrset3.get_type())
self.__check_find_call(diff.find_updated, self.__rrset3,
ZoneFinder.NXDOMAIN)
self.__check_find_call(diff.find, self.__rrset3,
ZoneFinder.NXDOMAIN)
def test_compact(self):
"""
Test the compaction works as expected, eg. it compacts only consecutive
changes of the same operation and on the same domain/type.
The test case checks that it does merge them, but also puts some
different operations "in the middle", changes the type and name and
places the same kind of change further away of each other to see they
are not merged in that case.
"""
diff = Diff(self, Name('example.org.'))
# Check we can do a compact on empty data, it shouldn't break
diff.compact()
self.assertEqual([], diff.get_buffer())
# This data is the way it should look like after the compact
# ('operation', 'domain.prefix', 'type', ['rdata', 'rdata'])
# The notes say why the each of consecutive can't be merged
data = [
('add', 'a', 'A', ['192.0.2.1', '192.0.2.2']),
# Different type.
('add', 'a', 'AAAA', ['2001:db8::1', '2001:db8::2']),
# Different operation
('delete', 'a', 'AAAA', ['2001:db8::3']),
# Different domain
('delete', 'b', 'AAAA', ['2001:db8::4']),
# This does not get merged with the first, even if logically
# possible. We just don't do this.
('add', 'a', 'A', ['192.0.2.3'])
]
# Now, fill the data into the diff, in a "flat" way, one by one
for (op, nprefix, rrtype, rdata) in data:
name = Name(nprefix + '.example.org.')
rrtype_obj = RRType(rrtype)
for rdatum in rdata:
rrset = RRset(name, self.__rrclass, rrtype_obj, self.__ttl)
rrset.add_rdata(Rdata(rrtype_obj, self.__rrclass, rdatum))
if op == 'add':
diff.add_data(rrset)
else:
diff.delete_data(rrset)
# Compact it
diff.compact()
# Now check they got compacted. They should be in the same order as
# pushed inside. So it should be the same as data modulo being in
# the rrsets and isc.dns objects.
def check():
buf = diff.get_buffer()
self.assertEqual(len(data), len(buf))
for (expected, received) in zip(data, buf):
(eop, ename, etype, edata) = expected
(rop, rrrset) = received
self.assertEqual(eop, rop)
ename_obj = Name(ename + '.example.org.')
self.assertEqual(ename_obj, rrrset.get_name())
# We check on names to make sure they are printed nicely
self.assertEqual(etype, str(rrrset.get_type()))
rdata = rrrset.get_rdata()
self.assertEqual(len(edata), len(rdata))
# It should also preserve the order
for (edatum, rdatum) in zip(edata, rdata):
self.assertEqual(edatum, str(rdatum))
check()
# Try another compact does nothing, but survives
diff.compact()
check()
def test_ttl(self):
"""
Test the TTL handling. A warn function should have been called if they
differ, but that's all, it should not crash or raise.
"""
self.orig_logger = isc.xfrin.diff.logger
try:
isc.xfrin.diff.logger = self
diff = Diff(self, Name('example.org.'))
diff.add_data(self.__rrset1)
rrset2 = RRset(Name('a.example.org.'), self.__rrclass,
self.__type, RRTTL(120))
rrset2.add_rdata(Rdata(self.__type, self.__rrclass, '192.10.2.2'))
diff.add_data(rrset2)
rrset2 = RRset(Name('a.example.org.'), self.__rrclass,
self.__type, RRTTL(6000))
rrset2.add_rdata(Rdata(self.__type, self.__rrclass, '192.10.2.3'))
diff.add_data(rrset2)
# They should get compacted together and complain.
diff.compact()
self.assertEqual(1, len(diff.get_buffer()))
# The TTL stays on the first value, no matter if smaller or bigger
# ones come later.
self.assertEqual(self.__ttl, diff.get_buffer()[0][1].get_ttl())
self.assertTrue(self.__warn_called)
finally:
isc.xfrin.diff.logger = self.orig_logger
def test_find_all_nonexistent_data(self):
diff = Diff(self, Name('example.org'), single_update_mode=True)
diff.add_data(self.__rrset_soa)
diff.delete_data(self.__rrset_soa)
self.__create_find_all(ZoneFinder.NXDOMAIN, [], 0)
# Sanity check
self.__check_find_all_call(diff.find_all_updated, self.__rrset2,
ZoneFinder.NXDOMAIN)
self.__check_find_all_call(diff.find_all, self.__rrset2,
ZoneFinder.NXDOMAIN)
# Adding data should change the result
diff.add_data(self.__rrset2)
self.__check_find_all_call(diff.find_all_updated, self.__rrset2,
ZoneFinder.SUCCESS, [ self.__rrset2 ])
self.__check_find_all_call(diff.find_all, self.__rrset2,
ZoneFinder.NXDOMAIN)
# Adding data at other name should not
diff.add_data(self.__rrset3)
self.__check_find_all_call(diff.find_all_updated, self.__rrset2,
ZoneFinder.SUCCESS, [ self.__rrset2 ])
self.__check_find_all_call(diff.find_all, self.__rrset2,
ZoneFinder.NXDOMAIN)
# Deleting it should revert to original
diff.delete_data(self.__rrset2)
self.__check_find_all_call(diff.find_all_updated, self.__rrset2,
ZoneFinder.NXDOMAIN)
self.__check_find_all_call(diff.find_all, self.__rrset2,
ZoneFinder.NXDOMAIN)
def test_add_delete_same(self):
'''
Test that if a record is added, then deleted, it is not added to
both buffers, but remove from the addition, and vice versa
'''
diff = Diff(self, Name('example.org.'), single_update_mode=True)
# Need SOA records first
diff.delete_data(self.__rrset_soa)
diff.add_data(self.__rrset_soa)
deletions, additions = diff.get_single_update_buffers()
self.assertEqual(1, len(deletions))
self.assertEqual(1, len(additions))
diff.add_data(self.__rrset1)
deletions, additions = diff.get_single_update_buffers()
self.assertEqual(1, len(deletions))
self.assertEqual(2, len(additions))
diff.delete_data(self.__rrset1)
deletions, additions = diff.get_single_update_buffers()
self.assertEqual(1, len(deletions))
self.assertEqual(1, len(additions))
diff.delete_data(self.__rrset2)
deletions, additions = diff.get_single_update_buffers()
self.assertEqual(2, len(deletions))
self.assertEqual(1, len(additions))
diff.add_data(self.__rrset2)
deletions, additions = diff.get_single_update_buffers()
self.assertEqual(1, len(deletions))
self.assertEqual(1, len(additions))
def test_single_update_mode(self):
'''
Test single-update mode. In this mode, updates and deletes can
be done in any order, but there may only be one changeset.
For both updates and deletes, exactly one SOA rr must be given,
and it must be the first change.
'''
# full rrset for A (to check compact())
txt = RRset(Name('c.example.org.'), self.__rrclass, RRType.TXT(),
RRTTL(3600))
txt.add_rdata(Rdata(txt.get_type(), txt.get_class(), "one"))
txt.add_rdata(Rdata(txt.get_type(), txt.get_class(), "two"))
txt.add_rdata(Rdata(txt.get_type(), txt.get_class(), "three"))
a = RRset(Name('d.example.org.'), self.__rrclass, RRType.A(),
RRTTL(3600))
a.add_rdata(Rdata(a.get_type(), a.get_class(), "192.0.2.1"))
a.add_rdata(Rdata(a.get_type(), a.get_class(), "192.0.2.2"))
diff = Diff(self, Name('example.org.'), single_update_mode=True)
# adding a first should fail
self.assertRaises(ValueError, diff.add_data, a)
# But soa should work
diff.add_data(self.__rrset_soa)
# And then A should as well
diff.add_data(self.__rrset3)
diff.add_data(self.__rrset4)
diff.add_data(self.__rrset5)
# But another SOA should fail again
self.assertRaises(ValueError, diff.add_data, self.__rrset_soa)
# Same for delete
self.assertRaises(ValueError, diff.delete_data, self.__rrset6)
diff.delete_data(self.__rrset_soa)
diff.delete_data(self.__rrset6)
diff.delete_data(self.__rrset7)
self.assertRaises(ValueError, diff.delete_data, self.__rrset_soa)
# Not compacted yet, so the buffers should be as we
# filled them
(delbuf, addbuf) = diff.get_single_update_buffers()
self.assertEqual([('delete', self.__rrset_soa),
('delete', self.__rrset6),
('delete', self.__rrset7)], delbuf)
self.assertEqual([('add', self.__rrset_soa),
('add', self.__rrset3),
('add', self.__rrset4),
('add', self.__rrset5)], addbuf)
# Compact should compact the A records in both buffers
diff.compact()
(delbuf, addbuf) = diff.get_single_update_buffers()
# need rrset equality again :/
self.assertEqual(2, len(delbuf))
self.assertEqual(2, len(delbuf[0]))
self.assertEqual('delete', delbuf[0][0])
self.assertEqual(self.__rrset_soa.to_text(), delbuf[0][1].to_text())
self.assertEqual(2, len(delbuf[1]))
self.assertEqual('delete', delbuf[1][0])
self.assertEqual(a.to_text(), delbuf[1][1].to_text())
self.assertEqual(2, len(addbuf))
self.assertEqual(2, len(addbuf[0]))
self.assertEqual('add', addbuf[0][0])
self.assertEqual(self.__rrset_soa.to_text(), addbuf[0][1].to_text())
self.assertEqual(2, len(addbuf[1]))
self.assertEqual('add', addbuf[1][0])
self.assertEqual(txt.to_text(), addbuf[1][1].to_text())
# Apply should reset the buffers
diff.apply()
(delbuf, addbuf) = diff.get_single_update_buffers()
self.assertEqual([], delbuf)
self.assertEqual([], addbuf)
# Now the change has been applied, and the buffers are cleared,
# Adding non-SOA records should fail again.
self.assertRaises(ValueError, diff.add_data, a)
self.assertRaises(ValueError, diff.delete_data, a)
