"""
This helps the XFR in process with accumulating parts of diff and applying
-it to the datasource.
+it to the datasource. It also has a 'single update mode' which is useful
+for DDNS.
The name of the module is not yet fully decided. We might want to move it
-under isc.datasrc or somewhere else, because we might want to reuse it with
-future DDNS process. But until then, it lives here.
+under isc.datasrc or somewhere else, because we are reusing it with DDNS.
+But for now, it lives here.
"""
import isc.dns
the changes to underlying data source right away, but keeps them for
a while.
"""
- def __init__(self, ds_client, zone, replace=False, journaling=False):
+ def __init__(self, ds_client, zone, replace=False, journaling=False,
+ single_update_mode=False):
"""
Initializes the diff to a ready state. It checks the zone exists
in the datasource and if not, NoSuchZone is raised. This also creates
incoming updates but does not support journaling, the Diff object
will still continue applying the diffs with disabling journaling.
+ If single_update_mode is true, the update is expected to only contain
+ 1 set of changes (i.e. one set of additions, and one set of deletions).
+ If so, the additions and deletions are kept separately, and applied
+ in one go upon commit() or apply(). In this mode, additions and
+ deletions can be done in any order. The first addition and the
+ first addition still have to be the new and old SOA records,
+ respectively. Once apply() or commit() has been called, this
+ requirement is renewed (since the diff object is essentialy reset).
+
You can also expect isc.datasrc.Error or isc.datasrc.NotImplemented
exceptions.
"""
raise NoSuchZone("Zone " + str(zone) +
" does not exist in the data source " +
str(ds_client))
- self.__buffer = []
+ self.__single_update_mode = single_update_mode
+ if single_update_mode:
+ self.__additions = []
+ self.__deletions = []
+ else:
+ self.__buffer = []
def __check_commited(self):
"""
It does all the real work of add_data and delete_data, including
all checks.
+
+ Raises a ValueError in several cases:
+ - if the rrset contains multiple rrs
+ - if the class of the rrset does not match that of the update
+ - in single_update_mode if the first rr is not of type SOA (both
+ for addition and deletion)
+ - in single_update_mode if any later rr is of type SOA (both for
+ addition and deletion)
"""
self.__check_commited()
if rr.get_rdata_count() != 1:
raise ValueError("The rrset's class " + str(rr.get_class()) +
" does not match updater's " +
str(self.__updater.get_class()))
- self.__buffer.append((operation, rr))
- if len(self.__buffer) >= DIFF_APPLY_TRESHOLD:
- # Time to auto-apply, so the data don't accumulate too much
- self.apply()
+ if self.__single_update_mode:
+ if operation == 'add':
+ # First addition must be SOA
+ if len(self.__additions) == 0 and\
+ rr.get_type() != isc.dns.RRType.SOA():
+ raise ValueError("First addition in single update mode " +
+ "must be of type SOA")
+ # And later additions may not
+ elif len(self.__additions) != 0 and\
+ rr.get_type() == isc.dns.RRType.SOA():
+ raise ValueError("Multiple SOA records in single " +
+ "update mode addition")
+ self.__additions.append((operation, rr))
+ elif operation == 'delete':
+ if len(self.__deletions) == 0 and\
+ rr.get_type() != isc.dns.RRType.SOA():
+ raise ValueError("First deletion in single update mode " +
+ "must be of type SOA")
+ # And later deletions may not
+ elif len(self.__deletions) != 0 and\
+ rr.get_type() == isc.dns.RRType.SOA():
+ raise ValueError("Multiple SOA records in single " +
+ "update mode deletion")
+ self.__deletions.append((operation, rr))
+ else:
+ self.__buffer.append((operation, rr))
+ if len(self.__buffer) >= DIFF_APPLY_TRESHOLD:
+ # Time to auto-apply, so the data don't accumulate too much
+ # This is not done for DDNS type data
+ self.apply()
def add_data(self, rr):
"""
"""
self.__data_common(rr, 'delete')
+
def compact(self):
"""
Tries to compact the operations in buffer a little by putting some of
sigdata2 = rrset2.get_rdata()[0].to_text().split()[0]
return sigdata1 == sigdata2
- buf = []
- for (op, rrset) in self.__buffer:
- old = buf[-1][1] if len(buf) > 0 else None
- if old is None or op != buf[-1][0] or \
- rrset.get_name() != old.get_name() or \
- (not same_type(rrset, old)):
- buf.append((op, isc.dns.RRset(rrset.get_name(),
- rrset.get_class(),
- rrset.get_type(),
- rrset.get_ttl())))
- if rrset.get_ttl() != buf[-1][1].get_ttl():
- logger.warn(LIBXFRIN_DIFFERENT_TTL, rrset.get_ttl(),
- buf[-1][1].get_ttl(), rrset.get_name(),
- rrset.get_class(), rrset.get_type())
- for rdatum in rrset.get_rdata():
- buf[-1][1].add_rdata(rdatum)
- self.__buffer = buf
+ def compact_buffer(buffer_to_compact):
+ '''Internal helper function for compacting buffers, compacts the
+ given buffer.
+ Returns the compacted buffer.
+ '''
+ buf = []
+ for (op, rrset) in buffer_to_compact:
+ old = buf[-1][1] if len(buf) > 0 else None
+ if old is None or op != buf[-1][0] or \
+ rrset.get_name() != old.get_name() or \
+ (not same_type(rrset, old)):
+ buf.append((op, isc.dns.RRset(rrset.get_name(),
+ rrset.get_class(),
+ rrset.get_type(),
+ rrset.get_ttl())))
+ if rrset.get_ttl() != buf[-1][1].get_ttl():
+ logger.warn(LIBXFRIN_DIFFERENT_TTL, rrset.get_ttl(),
+ buf[-1][1].get_ttl(), rrset.get_name(),
+ rrset.get_class(), rrset.get_type())
+ for rdatum in rrset.get_rdata():
+ buf[-1][1].add_rdata(rdatum)
+ return buf
+
+ if self.__single_update_mode:
+ self.__additions = compact_buffer(self.__additions)
+ self.__deletions = compact_buffer(self.__deletions)
+ else:
+ self.__buffer = compact_buffer(self.__buffer)
def apply(self):
"""
It also can raise isc.datasrc.Error. If that happens, you should stop
using this object and abort the modification.
"""
- self.__check_commited()
- # First, compact the data
- self.compact()
- try:
- # Then pass the data inside the data source
- for (operation, rrset) in self.__buffer:
+ def apply_buffer(buf):
+ '''
+ Helper method to apply all operations in the given buffer
+ '''
+ for (operation, rrset) in buf:
if operation == 'add':
self.__updater.add_rrset(rrset)
elif operation == 'delete':
self.__updater.delete_rrset(rrset)
else:
raise ValueError('Unknown operation ' + operation)
+
+ self.__check_commited()
+ # First, compact the data
+ self.compact()
+ try:
+ # Then pass the data inside the data source
+ if self.__single_update_mode:
+ apply_buffer(self.__deletions)
+ apply_buffer(self.__additions)
+ else:
+ apply_buffer(self.__buffer)
+
# As everything is already in, drop the buffer
except:
# If there's a problem, we can't continue.
self.__updater = None
raise
- self.__buffer = []
+ # all went well, reset state of buffers
+ if self.__single_update_mode:
+ self.__additions = []
+ self.__deletions = []
+ else:
+ self.__buffer = []
def commit(self):
"""
Probably useful only for testing and introspection purposes. Don't
modify the list.
+
+ Raises a ValueError if the buffer is in single_update_mode.
+ """
+ if self.__single_update_mode:
+ # This operation is only valid if the multi-update mode
+ raise ValueError("Compound buffer requested in single-update mode")
+ else:
+ return self.__buffer
+
+ def get_single_update_buffers(self):
+ """
+ Returns the current buffers of changes not yet passed into the data
+ source. It is a tuple of the current deletions and additions, which
+ each are in a form like [('add', rrset), ('delete', rrset),
+ ('delete', rrset), ...].
+
+ Probably useful only for testing and introspection purposes. Don't
+ modify the list.
+
+ Raises a ValueError if the buffer is not in single_update_mode.
"""
- return self.__buffer
+ if not self.__single_update_mode:
+ # This operation is only valid if the multi-update mode
+ raise ValueError("Compound buffer requested in single-update mode")
+ else:
+ return (self.__deletions, self.__additions)
diff.compact()
self.assertEqual(2, len(diff.get_buffer()))
- def test_relpace(self):
- """
+ def test_replace(self):
+ '''
Test that when we want to replace the whole zone, it is propagated.
- """
+ '''
self.__should_replace = True
diff = Diff(self, "example.org.", True)
self.assertTrue(self.__updater_requested)
+ 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_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.
+ '''
+
+ # First create some RRsets to play with
+ soa = RRset(Name('example.org.'), self.__rrclass, RRType.SOA(),
+ RRTTL(3600))
+ soa.add_rdata(Rdata(soa.get_type(), soa.get_class(),
+ "ns.example.org. foo.example.org. 1234 28800 "+
+ "7200 604800 3600"))
+
+ a = RRset(Name('www.example.org.'), self.__rrclass, RRType.A(),
+ RRTTL(3600))
+ a.add_rdata(Rdata(a.get_type(), a.get_class(),
+ "192.0.2.1"))
+
+ a2 = RRset(Name('www.example.org.'), self.__rrclass, RRType.A(),
+ RRTTL(3600))
+ a2.add_rdata(Rdata(a2.get_type(), a2.get_class(),
+ "192.0.2.2"))
+
+ # full rrset for A (to check compact())
+ a_1_2 = RRset(Name('www.example.org.'), self.__rrclass, RRType.A(),
+ RRTTL(3600))
+ a_1_2.add_rdata(Rdata(a_1_2.get_type(), a_1_2.get_class(),
+ "192.0.2.1"))
+ a_1_2.add_rdata(Rdata(a_1_2.get_type(), a_1_2.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(soa)
+ # And then A should as well
+ diff.add_data(a)
+ diff.add_data(a2)
+ # But another SOA should fail again
+ self.assertRaises(ValueError, diff.add_data, soa)
+
+ # Same for delete
+ self.assertRaises(ValueError, diff.delete_data, a)
+ diff.delete_data(soa)
+ diff.delete_data(a)
+ diff.delete_data(a2)
+ self.assertRaises(ValueError, diff.delete_data, soa)
+
+ # Not compacted yet, so the buffers should be as we
+ # filled them
+ (delbuf, addbuf) = diff.get_single_update_buffers()
+ self.assertEqual([('delete', soa), ('delete', a), ('delete', a2)], delbuf)
+ self.assertEqual([('add', soa), ('add', a), ('add', a2)], 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(soa.to_text(), delbuf[0][1].to_text())
+ self.assertEqual(2, len(delbuf[1]))
+ self.assertEqual('delete', delbuf[1][0])
+ self.assertEqual(a_1_2.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(soa.to_text(), addbuf[0][1].to_text())
+ self.assertEqual(2, len(addbuf[1]))
+ self.assertEqual('add', addbuf[1][0])
+ self.assertEqual(a_1_2.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)
+
+
if __name__ == "__main__":
isc.log.init("bind10")
isc.log.resetUnitTestRootLogger()
projects / thirdparty / kea.git / commitdiff
