# Copyright DataStax, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
These functions are used to convert Python objects into CQL strings.
When non-prepared statements are executed, these encoder functions are
called on each query parameter.
"""
import logging
log = logging.getLogger(__name__)
from binascii import hexlify
import calendar
import datetime
import math
import sys
import types
from uuid import UUID
import six
if six.PY3:
import ipaddress
from cassandra.util import (OrderedDict, OrderedMap, OrderedMapSerializedKey,
sortedset, Time, Date)
if six.PY3:
long = int
def cql_quote(term):
# The ordering of this method is important for the result of this method to
# be a native str type (for both Python 2 and 3)
if isinstance(term, str):
return "'%s'" % str(term).replace("'", "''")
# This branch of the if statement will only be used by Python 2 to catch
# unicode strings, text_type is used to prevent type errors with Python 3.
elif isinstance(term, six.text_type):
return "'%s'" % term.encode('utf8').replace("'", "''")
else:
return str(term)
[docs]class ValueSequence(list):
pass
[docs]class Encoder(object):
"""
A container for mapping python types to CQL string literals when working
with non-prepared statements. The type :attr:`~.Encoder.mapping` can be
directly customized by users.
"""
mapping = None
"""
A map of python types to encoder functions.
"""
def __init__(self):
self.mapping = {
float: self.cql_encode_float,
bytearray: self.cql_encode_bytes,
str: self.cql_encode_str,
int: self.cql_encode_object,
UUID: self.cql_encode_object,
datetime.datetime: self.cql_encode_datetime,
datetime.date: self.cql_encode_date,
datetime.time: self.cql_encode_time,
Date: self.cql_encode_date_ext,
Time: self.cql_encode_time,
dict: self.cql_encode_map_collection,
OrderedDict: self.cql_encode_map_collection,
OrderedMap: self.cql_encode_map_collection,
OrderedMapSerializedKey: self.cql_encode_map_collection,
list: self.cql_encode_list_collection,
tuple: self.cql_encode_list_collection, # TODO: change to tuple in next major
set: self.cql_encode_set_collection,
sortedset: self.cql_encode_set_collection,
frozenset: self.cql_encode_set_collection,
types.GeneratorType: self.cql_encode_list_collection,
ValueSequence: self.cql_encode_sequence
}
if six.PY2:
self.mapping.update({
unicode: self.cql_encode_unicode,
buffer: self.cql_encode_bytes,
long: self.cql_encode_object,
types.NoneType: self.cql_encode_none,
})
else:
self.mapping.update({
memoryview: self.cql_encode_bytes,
bytes: self.cql_encode_bytes,
type(None): self.cql_encode_none,
ipaddress.IPv4Address: self.cql_encode_ipaddress,
ipaddress.IPv6Address: self.cql_encode_ipaddress
})
[docs] def cql_encode_none(self, val):
"""
Converts :const:`None` to the string 'NULL'.
"""
return 'NULL'
[docs] def cql_encode_unicode(self, val):
"""
Converts :class:`unicode` objects to UTF-8 encoded strings with quote escaping.
"""
return cql_quote(val.encode('utf-8'))
[docs] def cql_encode_str(self, val):
"""
Escapes quotes in :class:`str` objects.
"""
return cql_quote(val)
if six.PY3:
def cql_encode_bytes(self, val):
return (b'0x' + hexlify(val)).decode('utf-8')
elif sys.version_info >= (2, 7):
def cql_encode_bytes(self, val): # noqa
return b'0x' + hexlify(val)
else:
# python 2.6 requires string or read-only buffer for hexlify
[docs] def cql_encode_bytes(self, val): # noqa
return b'0x' + hexlify(buffer(val))
[docs] def cql_encode_object(self, val):
"""
Default encoder for all objects that do not have a specific encoder function
registered. This function simply calls :meth:`str()` on the object.
"""
return str(val)
def cql_encode_float(self, val):
"""
Encode floats using repr to preserve precision
"""
if math.isinf(val):
return 'Infinity' if val > 0 else '-Infinity'
elif math.isnan(val):
return 'NaN'
else:
return repr(val)
[docs] def cql_encode_datetime(self, val):
"""
Converts a :class:`datetime.datetime` object to a (string) integer timestamp
with millisecond precision.
"""
timestamp = calendar.timegm(val.utctimetuple())
return str(long(timestamp * 1e3 + getattr(val, 'microsecond', 0) / 1e3))
[docs] def cql_encode_date(self, val):
"""
Converts a :class:`datetime.date` object to a string with format
``YYYY-MM-DD``.
"""
return "'%s'" % val.strftime('%Y-%m-%d')
def cql_encode_time(self, val):
"""
Converts a :class:`cassandra.util.Time` object to a string with format
``HH:MM:SS.mmmuuunnn``.
"""
return "'%s'" % val
def cql_encode_date_ext(self, val):
"""
Encodes a :class:`cassandra.util.Date` object as an integer
"""
# using the int form in case the Date exceeds datetime.[MIN|MAX]YEAR
return str(val.days_from_epoch + 2 ** 31)
[docs] def cql_encode_sequence(self, val):
"""
Converts a sequence to a string of the form ``(item1, item2, ...)``. This
is suitable for ``IN`` value lists.
"""
return '(%s)' % ', '.join(self.mapping.get(type(v), self.cql_encode_object)(v)
for v in val)
cql_encode_tuple = cql_encode_sequence
"""
Converts a sequence to a string of the form ``(item1, item2, ...)``. This
is suitable for ``tuple`` type columns.
"""
[docs] def cql_encode_map_collection(self, val):
"""
Converts a dict into a string of the form ``{key1: val1, key2: val2, ...}``.
This is suitable for ``map`` type columns.
"""
return '{%s}' % ', '.join('%s: %s' % (
self.mapping.get(type(k), self.cql_encode_object)(k),
self.mapping.get(type(v), self.cql_encode_object)(v)
) for k, v in six.iteritems(val))
[docs] def cql_encode_list_collection(self, val):
"""
Converts a sequence to a string of the form ``[item1, item2, ...]``. This
is suitable for ``list`` type columns.
"""
return '[%s]' % ', '.join(self.mapping.get(type(v), self.cql_encode_object)(v) for v in val)
[docs] def cql_encode_set_collection(self, val):
"""
Converts a sequence to a string of the form ``{item1, item2, ...}``. This
is suitable for ``set`` type columns.
"""
return '{%s}' % ', '.join(self.mapping.get(type(v), self.cql_encode_object)(v) for v in val)
[docs] def cql_encode_all_types(self, val):
"""
Converts any type into a CQL string, defaulting to ``cql_encode_object``
if :attr:`~Encoder.mapping` does not contain an entry for the type.
"""
return self.mapping.get(type(val), self.cql_encode_object)(val)
if six.PY3:
def cql_encode_ipaddress(self, val):
"""
Converts an ipaddress (IPV4Address, IPV6Address) to a CQL string. This
is suitable for ``inet`` type columns.
"""
return "'%s'" % val.compressed