def map(entity, model, *args, **kwargs):
""" The Clean mapper maps over all UniqueMarker instances. """
alias = kwargs.get("db", "default")
namespace = settings.DATABASES.get(alias, {}).get("NAMESPACE", "")
model = decode_model(model)
if not entity.key().id_or_name().startswith(model._meta.db_table + "|"):
# Only include markers which are for this model
return
assert namespace == entity.namespace()
with disable_cache():
# At this point, the entity is a unique marker that is linked to an instance of 'model', now we should see if that instance exists!
instance_id = entity["instance"].id_or_name()
try:
instance = model.objects.using(alias).get(pk=instance_id)
except model.DoesNotExist:
logger.info("Deleting unique marker %s because the associated instance no longer exists", entity.key().id_or_name())
datastore.Delete(entity)
return
# Get the possible unique markers for the entity, if this one doesn't exist in that list then delete it
instance_entity, _ = django_instance_to_entities(connections[alias], instance._meta.fields, raw=True, instance=instance, check_null=False)
identifiers = unique_identifiers_from_entity(model, instance_entity, ignore_pk=True)
identifier_keys = [datastore.Key.from_path(UniqueMarker.kind(), i, namespace=entity["instance"].namespace()) for i in identifiers]
if entity.key() not in identifier_keys:
logger.info("Deleting unique marker %s because the it no longer represents the associated instance state", entity.key().id_or_name())
datastore.Delete(entity)
def map(instance, *args, **kwargs):
""" Figure out what markers the instance should use and verify they're attached to
this instance. Log any weirdness and in repair mode - recreate missing markers. """
action_id = kwargs.get("action_pk")
repair = kwargs.get("repair")
alias = kwargs.get("db", "default")
namespace = settings.DATABASES.get(alias, {}).get("NAMESPACE")
assert alias == (instance._state.db or "default")
entity, _ = django_instance_to_entities(connections[alias], instance._meta.fields, raw=True, instance=instance, check_null=False)
identifiers = unique_identifiers_from_entity(type(instance), entity, ignore_pk=True)
identifier_keys = [datastore.Key.from_path(UniqueMarker.kind(), i, namespace=namespace) for i in identifiers]
markers = datastore.Get(identifier_keys)
instance_key = str(entity.key())
markers_to_save = []
for i, m in zip(identifier_keys, markers):
marker_key = str(i)
if m is None:
# Missig marker
if repair:
new_marker = datastore.Entity(UniqueMarker.kind(), name=i.name(), namespace=namespace)
new_marker['instance'] = entity.key()
new_marker['created'] = datetime.datetime.now()
markers_to_save.append(new_marker)
else:
log(action_id, "missing_marker", instance_key, marker_key)
elif 'instance' not in m or not m['instance']:
# Marker with missining instance attribute
if repair:
m['instance'] = entity.key()
markers_to_save.append(m)
else:
log(action_id, "missing_instance", instance_key, marker_key)
elif m['instance'] != entity.key():
if isinstance(m['instance'], basestring):
m['instance'] = datastore.Key(m['instance'])
if repair:
markers_to_save.append(m)
else:
log(action_id, "old_instance_key", instance_key, marker_key)
if m['instance'] != entity.key():
# Marker already assigned to a different instance
log(action_id, "already_assigned", instance_key, marker_key)
# Also log in repair mode as reparing would break the other instance.
if markers_to_save:
datastore.Put(markers_to_save)
def __init__(self, connection, model, objs, fields, raw):
self.has_pk = any(x.primary_key for x in fields)
self.model = model
self.objs = objs
self.connection = connection
self.namespace = connection.ops.connection.settings_dict.get(
"NAMESPACE")
self.raw = raw
self.fields = fields
self.entities = []
self.included_keys = []
for obj in self.objs:
if self.has_pk:
# We must convert the PK value here, even though this normally happens in django_instance_to_entities otherwise
# custom PK fields don't work properly
value = self.model._meta.pk.get_db_prep_save(
self.model._meta.pk.pre_save(obj, True), self.connection)
self.included_keys.append(
get_datastore_key(self.model, value, self.namespace
) if value else None)
if value == 0:
raise IntegrityError(
"The datastore doesn't support 0 as a key value")
if not self.model._meta.pk.blank and self.included_keys[
-1] is None:
raise IntegrityError(
"You must specify a primary key value for {} instances"
.format(self.model))
else:
# We zip() self.entities and self.included_keys in execute(), so they should be the same length
self.included_keys.append(None)
# We don't use the values returned, but this does make sure we're
# doing the same validation as Django. See issue #493 for an
# example of how not doing this can mess things up
for field in fields:
field.get_db_prep_save(
getattr(obj, field.attname) if raw else field.pre_save(
obj, True),
connection=connection,
)
primary, descendents = django_instance_to_entities(
self.connection, self.fields, self.raw, obj)
# Append the entity, and any descendents to the list to insert
self.entities.append((primary, descendents))
def __init__(self, connection, model, objs, fields, raw):
self.has_pk = any(x.primary_key for x in fields)
self.model = model
self.objs = objs
self.connection = connection
self.namespace = connection.ops.connection.settings_dict.get("NAMESPACE")
self.raw = raw
self.fields = fields
self.entities = []
self.included_keys = []
for obj in self.objs:
if self.has_pk:
# We must convert the PK value here, even though this normally happens in
# django_instance_to_entities otherwise
# custom PK fields don't work properly
value = self.model._meta.pk.get_db_prep_save(
self.model._meta.pk.pre_save(obj, True),
self.connection
)
self.included_keys.append(
get_datastore_key(self.model, value, self.namespace)
if value else None
)
if value == 0:
raise IntegrityError("The datastore doesn't support 0 as a key value")
if not self.model._meta.pk.blank and self.included_keys[-1] is None:
raise IntegrityError("You must specify a primary key value for {} instances".format(self.model))
else:
# We zip() self.entities and self.included_keys in execute(), so they should be the same length
self.included_keys.append(None)
# We don't use the values returned, but this does make sure we're
# doing the same validation as Django. See issue #493 for an
# example of how not doing this can mess things up
for field in fields:
field.get_db_prep_save(
getattr(obj, field.attname) if raw else field.pre_save(obj, True),
connection=connection,
)
primary, descendents = django_instance_to_entities(
self.connection, self.fields, self.raw, obj
)
# Append the entity, and any descendents to the list to insert
self.entities.append((primary, descendents))
def txn():
caching.remove_entities_from_cache_by_key([key], self.namespace)
try:
result = rpc.Get(key)
except datastore_errors.EntityNotFoundError:
# Return false to indicate update failure
return False
if (
isinstance(self.select.gae_query, (Query, meta_queries.UniqueQuery)) # ignore QueryByKeys and NoOpQuery
and not utils.entity_matches_query(result, self.select.gae_query)
):
# Due to eventual consistency they query may have returned an entity which no longer
# matches the query
return False
original = copy.deepcopy(result)
instance_kwargs = {field.attname: value for field, param, value in self.values}
# Note: If you replace MockInstance with self.model, you'll find that some delete
# tests fail in the test app. This is because any unspecified fields would then call
# get_default (even though we aren't going to use them) which may run a query which
# fails inside this transaction. Given as we are just using MockInstance so that we can
# call django_instance_to_entities it on it with the subset of fields we pass in,
# what we have is fine.
meta = self.model._meta
instance = MockInstance(
_original=MockInstance(_meta=meta, **result),
_meta=meta,
**instance_kwargs
)
# Convert the instance to an entity
primary, descendents = django_instance_to_entities(
self.connection,
[x[0] for x in self.values], # Pass in the fields that were updated
True, instance,
model=self.model
)
# Update the entity we read above with the new values
result.update(primary)
# Remove fields which have been marked to be unindexed
for col in getattr(primary, "_properties_to_remove", []):
if col in result:
del result[col]
# Make sure that any polymodel classes which were in the original entity are kept,
# as django_instance_to_entities may have wiped them as well as added them.
polymodel_classes = list(set(
original.get(POLYMODEL_CLASS_ATTRIBUTE, []) + result.get(POLYMODEL_CLASS_ATTRIBUTE, [])
))
if polymodel_classes:
result[POLYMODEL_CLASS_ATTRIBUTE] = polymodel_classes
def perform_insert():
"""
Inserts result, and any descendents with their ancestor
value set
"""
inserted_key = rpc.Put(result)
if descendents:
for i, descendent in enumerate(descendents):
descendents[i] = Entity(
descendent.kind(),
parent=inserted_key,
namespace=inserted_key.namespace(),
id=descendent.key().id() or None,
name=descendent.key().name() or None
)
descendents[i].update(descendent)
rpc.Put(descendents)
if not constraints.has_active_unique_constraints(self.model):
# The fast path, no constraint checking
perform_insert()
caching.add_entities_to_cache(
self.model,
[result],
caching.CachingSituation.DATASTORE_PUT,
self.namespace,
skip_memcache=True,
)
else:
markers_to_acquire[:], markers_to_release[:] = constraints.get_markers_for_update(
self.model, original, result
)
perform_insert()
constraints.update_identifiers(markers_to_acquire, markers_to_release, result.key())
# If the rpc.Put() fails then the exception will only be raised when the
# transaction applies, which means that we will still get to here and will still have
# applied the marker changes (because they're in a nested, independent transaction).
# Hence we set this flag to tell us that we got this far and that we should roll them back.
rollback_markers[0] = True
# If something dies between here and the `return` statement then we'll have stale unique markers
try:
# Update the cache before dealing with unique markers, as CachingSituation.DATASTORE_PUT
# will only update the context cache
caching.add_entities_to_cache(
self.model,
[result],
caching.CachingSituation.DATASTORE_PUT,
self.namespace,
skip_memcache=True,
)
except:
# We ignore the exception because raising will rollback the transaction causing
# an inconsistent state
logger.exception("Unable to update the context cache")
pass
# Return true to indicate update success
return True
