442872f6a8
Convert the given timezone aware datetimes to UTC in a similar manner as the DateTime column type does instead of resulting in an error.
114 lines
3.4 KiB
Python
114 lines
3.4 KiB
Python
from datetime import datetime
|
|
from uuid import uuid1
|
|
|
|
from cqlengine.exceptions import ValidationError
|
|
|
|
class QueryValue(object):
|
|
"""
|
|
Base class for query filter values. Subclasses of these classes can
|
|
be passed into .filter() keyword args
|
|
"""
|
|
|
|
_cql_string = ':{}'
|
|
|
|
def __init__(self, value, identifier=None):
|
|
self.value = value
|
|
self.identifier = uuid1().hex if identifier is None else identifier
|
|
|
|
def get_cql(self):
|
|
return self._cql_string.format(self.identifier)
|
|
|
|
def get_value(self):
|
|
return self.value
|
|
|
|
def get_dict(self, column):
|
|
return {self.identifier: column.to_database(self.get_value())}
|
|
|
|
@property
|
|
def cql(self):
|
|
return self.get_cql()
|
|
|
|
class BaseQueryFunction(QueryValue):
|
|
"""
|
|
Base class for filtering functions. Subclasses of these classes can
|
|
be passed into .filter() and will be translated into CQL functions in
|
|
the resulting query
|
|
"""
|
|
|
|
class MinTimeUUID(BaseQueryFunction):
|
|
"""
|
|
return a fake timeuuid corresponding to the smallest possible timeuuid for the given timestamp
|
|
|
|
http://cassandra.apache.org/doc/cql3/CQL.html#timeuuidFun
|
|
"""
|
|
|
|
_cql_string = 'MinTimeUUID(:{})'
|
|
|
|
def __init__(self, value):
|
|
"""
|
|
:param value: the time to create a maximum time uuid from
|
|
:type value: datetime
|
|
"""
|
|
if not isinstance(value, datetime):
|
|
raise ValidationError('datetime instance is required')
|
|
super(MinTimeUUID, self).__init__(value)
|
|
|
|
def get_value(self):
|
|
epoch = datetime(1970, 1, 1, tzinfo=self.value.tzinfo)
|
|
offset = epoch.tzinfo.utcoffset(epoch).total_seconds() if epoch.tzinfo else 0
|
|
|
|
return long(((self.value - epoch).total_seconds() - offset) * 1000)
|
|
|
|
def get_dict(self, column):
|
|
return {self.identifier: self.get_value()}
|
|
|
|
class MaxTimeUUID(BaseQueryFunction):
|
|
"""
|
|
return a fake timeuuid corresponding to the largest possible timeuuid for the given timestamp
|
|
|
|
http://cassandra.apache.org/doc/cql3/CQL.html#timeuuidFun
|
|
"""
|
|
|
|
_cql_string = 'MaxTimeUUID(:{})'
|
|
|
|
def __init__(self, value):
|
|
"""
|
|
:param value: the time to create a minimum time uuid from
|
|
:type value: datetime
|
|
"""
|
|
if not isinstance(value, datetime):
|
|
raise ValidationError('datetime instance is required')
|
|
super(MaxTimeUUID, self).__init__(value)
|
|
|
|
def get_value(self):
|
|
epoch = datetime(1970, 1, 1, tzinfo=self.value.tzinfo)
|
|
offset = epoch.tzinfo.utcoffset(epoch).total_seconds() if epoch.tzinfo else 0
|
|
|
|
return long(((self.value - epoch).total_seconds() - offset) * 1000)
|
|
|
|
def get_dict(self, column):
|
|
return {self.identifier: self.get_value()}
|
|
|
|
class Token(BaseQueryFunction):
|
|
"""
|
|
compute the token for a given partition key
|
|
|
|
http://cassandra.apache.org/doc/cql3/CQL.html#tokenFun
|
|
"""
|
|
|
|
def __init__(self, *values):
|
|
if len(values) == 1 and isinstance(values[0], (list, tuple)):
|
|
values = values[0]
|
|
super(Token, self).__init__(values, [uuid1().hex for i in values])
|
|
|
|
def get_dict(self, column):
|
|
items = zip(self.identifier, self.value, column.partition_columns)
|
|
return dict(
|
|
(id, col.to_database(val)) for id, val, col in items
|
|
)
|
|
|
|
def get_cql(self):
|
|
token_args = ', '.join(':{}'.format(id) for id in self.identifier)
|
|
return "token({})".format(token_args)
|
|
|