def flatten_instance(self, value, caps, freezing):
self.check_capabilities(Capabilities.instance_values, value, caps, freezing)
referenceable = getattr(value, "referenceable", True)
if referenceable:
deref = self._prepare(value)
if deref is not None:
return deref
snapshot = value.snapshot()
if self._source_ver is not None:
# TODO: If external adapter is needed change this to a cast
if IVersionAdapter.providedBy(value):
adapter = IVersionAdapter(value)
snapshot = adapter.adapt_version(snapshot, self._source_ver, self._target_ver)
dump = self.flatten_value(snapshot, caps, freezing)
if freezing:
packer, data = self.pack_frozen_instance, [dump]
else:
packer, data = (self.pack_instance, [[self.pack_type_name, value.type_name], dump])
if referenceable:
return self._preserve(value, packer, data)
else:
return packer, data
def flatten_instance(self, value, caps, freezing):
self.check_capabilities(Capabilities.instance_values, value,
caps, freezing)
referenceable = getattr(value, "referenceable", True)
if referenceable:
deref = self._prepare(value)
if deref is not None:
return deref
snapshot = value.snapshot()
if IVersionAdapter.providedBy(value):
source = self.get_source_ver(value, snapshot)
target = self.get_target_ver(value, snapshot)
if target is not None:
if target != source:
snapshot = value.adapt_version(snapshot, source, target)
value.store_version(snapshot, target)
dump = self.flatten_value(snapshot, caps, freezing)
if freezing:
packer, data = self.pack_frozen_instance, [dump]
else:
packer, data = (self.pack_instance,
[[self.pack_type_name, value.type_name], dump])
if referenceable:
return self._preserve(value, packer, data)
else:
return packer, data
def _adapt_snapshot(self, restorator, snapshot):
if self._source_ver is not None:
# TODO: If external adapter is needed change this to a cast
if IVersionAdapter.providedBy(restorator):
adapter = IVersionAdapter(restorator)
snapshot = adapter.adapt_version(snapshot, self._source_ver, self._target_ver)
return snapshot
def restore_instance(self, type_name, data, refid=None,
restorator=None, instance=None):
if restorator is None:
restorator = self._lookup_restorator(type_name)
if instance is None:
# Prepare the instance for recovery
instance = restorator.prepare()
if instance is None:
# Immutable type, we can't delay restoration
snapshot = self.unpack_data(data)
old_snapshot = copy.copy(snapshot)
snapshot = self._adapt_snapshot(restorator, snapshot)
instance = restorator.restore(snapshot)
self._instances.append((None, instance, None, refid))
if old_snapshot != snapshot:
self._migrated = True
if IVersionAdapter.providedBy(instance):
instance.set_migrated()
return instance
# Delay the instance restoration for later to handle circular refs
return self.delayed_unpacking(instance,
self._continue_restoring_instance,
restorator, instance, data, refid)
def finish_unpacking(self):
while self._pending:
fun, args, kwargs = self._pending.pop(0)
fun(*args, **kwargs)
# Initialize delayed mutable instances in creation order
for restorator, instance, snapshot, _refid in self._instances:
if restorator is not None:
# delayed mutable instances
old_snapshot = copy.copy(snapshot)
snapshot = self._adapt_snapshot(restorator, snapshot)
instance.recover(snapshot)
if old_snapshot != snapshot:
self._migrated = True
if IVersionAdapter.providedBy(instance):
instance.set_migrated()
# Calls the instances post restoration callback in reversed order
# in an intent to reduce the possibilities of instances relying
# on there references being fully restored when called.
# This should not be relied on anyway.
for _, instance, _, _ in reversed(self._instances):
restored_fun = getattr(instance, "restored", None)
if restored_fun is not None:
restored_fun()
def convert(self, data):
try:
# Pre-convert the data if a convertor was specified
converted = self.pre_convertion(data)
# Unpack the first level of values
unpacked = self.unpack_data(converted)
# Continue unpacking level by level
self.finish_unpacking()
# Inform object that it has migrated if this is a case
if (IVersionAdapter.providedBy(unpacked) and
self._migrated):
unpacked.set_migrated()
# Should be finished by now
return unpacked
finally:
# Reset the state to cleanup all references
self.reset()
def migration_script(connection):
log.info("script", "Running the migration script.")
index = yield connection.query_view(view.DocumentByType,
group_level=2, parse_result=False)
try:
for (type_name, version), count in index:
restorator = serialization.lookup(type_name)
if not restorator:
log.error(
'script', "Failed to lookup the restorator for the "
"type name: %s. There is %d objects like this in the"
" database. They will not be migrated.", type_name,
count)
if (IVersionAdapter.providedBy(restorator) and
((version is None and restorator.version > 1) or
(version is not None and version < restorator.version))):
log.info('script', "I will migrate %d documents of the "
"type: %s from version %s to %d", count,
type_name, version, restorator.version)
migrated = 0
while migrated < count:
fetched = yield connection.query_view(
view.DocumentByType,
key=(type_name, version),
limit=15,
reduce=False,
include_docs=True)
migrated += len(fetched)
if not fetched:
break
log.info("script", "Migrated %d documents of the type %s "
"from %s version to %s", migrated, type_name,
version, restorator.version)
except Exception:
error.handle_exception("script", None,
"Failed running migration script")
raise
def testAdaptation(self):
self.assertTrue(IVersionAdapter.providedBy(A))
