def _ValidateQuery(self, query, query_info):
"""Ensure that the given query matches the query_info.
Args:
query: datastore_pb.Query instance we are chacking
query_info: datastore_pb.Query instance we want to match
Raises BadRequestError on failure.
"""
error_msg = 'Cursor does not match query: %s'
if query_info.filter_list() != query.filter_list():
raise BadRequestError(error_msg % 'filters do not match')
if query_info.order_list() != query.order_list():
raise BadRequestError(error_msg % 'orders do not match')
for attr in ('ancestor', 'kind', 'name_space', 'search_query'):
query_info_has_attr = getattr(query_info, 'has_%s' % attr)
query_info_attr = getattr(query_info, attr)
query_has_attr = getattr(query, 'has_%s' % attr)
query_attr = getattr(query, attr)
if query_info_has_attr():
if not query_has_attr() or query_info_attr() != query_attr():
raise BadRequestError(error_msg %
('%s does not match' % attr))
elif query_has_attr():
raise BadRequestError(error_msg % ('%s does not match' % attr))
def ParsePropertyQuery(query, filters, orders):
"""Parse __property__ queries.
Raises exceptions for illegal queries.
Args:
query: A Query PB.
filters: the normalized filters from query.
orders: the normalized orders from query.
Returns:
The kind range (a ValueRange over (kind, property) pairs) requested
in the query.
"""
if query.has_transaction():
raise BadRequestError(
'transactional queries on __property__ not allowed')
key_range = ParseKeyFilteredQuery(filters, orders)
key_range.Remap(lambda x: _PropertyKeyToString(x, ''))
if query.has_ancestor():
ancestor = datastore_types.Key._FromPb(query.ancestor())
ancestor_kind, ancestor_property = _PropertyKeyToString(ancestor, None)
if ancestor_property is not None:
key_range.Update(datastore_pb.Query_Filter.EQUAL,
(ancestor_kind, ancestor_property))
else:
key_range.Update(datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL,
(ancestor_kind, ''))
key_range.Update(datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL,
(ancestor_kind + '\0', ''))
query.clear_ancestor()
return key_range
def ParseKeyFilteredQuery(filters, orders):
"""Parse queries which only allow filters and ascending-orders on __key__.
Raises exceptions for illegal queries.
Args:
filters: the normalized filters of a query.
orders: the normalized orders of a query.
Returns:
The key range (a ValueRange over datastore_types.Key) requested in the
query.
"""
remaining_filters = []
key_range = ValueRange()
key_prop = datastore_types._KEY_SPECIAL_PROPERTY
for f in filters:
op = f.op()
if not (f.property_size() == 1 and f.property(0).name() == key_prop
and not (op == datastore_pb.Query_Filter.IN
or op == datastore_pb.Query_Filter.EXISTS)):
remaining_filters.append(f)
continue
val = f.property(0).value()
if not val.has_referencevalue():
raise BadRequestError('__key__ kind must be compared to a key')
limit = datastore_types.FromReferenceProperty(val)
key_range.Update(op, limit)
remaining_orders = []
for o in orders:
if not (o.direction() == datastore_pb.Query_Order.ASCENDING
and o.property() == datastore_types._KEY_SPECIAL_PROPERTY):
remaining_orders.append(o)
else:
break
if remaining_filters:
raise BadRequestError('Only comparison filters on ' + key_prop +
' supported')
if remaining_orders:
raise BadRequestError('Only ascending order on ' + key_prop +
' supported')
return key_range
def _KindKeyToString(key):
"""Extract kind name from __kind__ key.
Raises an ApplicationError if the key is not of the form '__kind__'/name.
Args:
key: a key for a __kind__ instance.
Returns:
kind specified by key.
"""
key_path = key.to_path()
if (len(key_path) == 2 and key_path[0] == '__kind__'
and isinstance(key_path[1], basestring)):
return key_path[1]
raise BadRequestError('invalid Key for __kind__ table')
def _NamespaceKeyToString(key):
"""Extract namespace name from __namespace__ key.
Raises an ApplicationError if the key is not of the form '__namespace__'/name
or '__namespace__'/_EMPTY_NAMESPACE_ID.
Args:
key: a key for a __namespace__ instance.
Returns:
namespace specified by key.
"""
key_path = key.to_path()
if len(key_path) == 2 and key_path[0] == '__namespace__':
if key_path[1] == datastore_types._EMPTY_NAMESPACE_ID:
return ''
if isinstance(key_path[1], basestring):
return key_path[1]
raise BadRequestError('invalid Key for __namespace__ table')
def ParseNamespaceQuery(query, filters, orders):
"""Parse __namespace__ queries.
Raises exceptions for illegal queries.
Args:
query: A Query PB.
filters: the normalized filters from query.
orders: the normalized orders from query.
Returns:
The kind range (a ValueRange over string) requested in the query.
"""
if query.has_ancestor():
raise BadRequestError('ancestor queries on __namespace__ not allowed')
key_range = ParseKeyFilteredQuery(filters, orders)
key_range.Remap(_NamespaceKeyToString)
return key_range
def _PropertyKeyToString(key, default_property):
"""Extract property name from __property__ key.
Raises an ApplicationError if the key is not of the form
'__kind__'/kind, '__property__'/property or '__kind__'/kind
Args:
key: a key for a __property__ instance.
default_property: property value to return when key only has a kind.
Returns:
kind, property if key = '__kind__'/kind, '__property__'/property
kind, default_property if key = '__kind__'/kind
"""
key_path = key.to_path()
if (len(key_path) == 2 and key_path[0] == '__kind__'
and isinstance(key_path[1], basestring)):
return (key_path[1], default_property)
if (len(key_path) == 4 and key_path[0] == '__kind__'
and isinstance(key_path[1], basestring)
and key_path[2] == '__property__'
and isinstance(key_path[3], basestring)):
return (key_path[1], key_path[3])
raise BadRequestError('invalid Key for __property__ table')
