Source code for cassandra.encoder

# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# 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("'", "''")
        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, 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:`` 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