deb-python-cassandra-driver/cassandra/cython_marshal.pyx

85 lines
2.4 KiB
Cython

# -- cython: profile=True
#
# Copyright 2013-2017 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.
import six
from libc.stdint cimport (int8_t, int16_t, int32_t, int64_t,
uint8_t, uint16_t, uint32_t, uint64_t)
from libc.string cimport memcpy
from cassandra.buffer cimport Buffer, buf_read, to_bytes
cdef bint is_little_endian
from cassandra.util import is_little_endian
cdef bint PY3 = six.PY3
ctypedef fused num_t:
int64_t
int32_t
int16_t
int8_t
uint64_t
uint32_t
uint16_t
uint8_t
double
float
cdef inline num_t unpack_num(Buffer *buf, num_t *dummy=NULL): # dummy pointer because cython wants the fused type as an arg
"""
Copy to aligned destination, conditionally swapping to native byte order
"""
cdef Py_ssize_t start, end, i
cdef char *src = buf_read(buf, sizeof(num_t))
cdef num_t ret = 0
cdef char *out = <char*> &ret
if is_little_endian:
for i in range(sizeof(num_t)):
out[sizeof(num_t) - i - 1] = src[i]
else:
memcpy(out, src, sizeof(num_t))
return ret
cdef varint_unpack(Buffer *term):
"""Unpack a variable-sized integer"""
if PY3:
return varint_unpack_py3(to_bytes(term))
else:
return varint_unpack_py2(to_bytes(term))
# TODO: Optimize these two functions
cdef varint_unpack_py3(bytes term):
val = int(''.join(["%02x" % i for i in term]), 16)
if (term[0] & 128) != 0:
shift = len(term) * 8 # * Note below
val -= 1 << shift
return val
cdef varint_unpack_py2(bytes term): # noqa
val = int(term.encode('hex'), 16)
if (ord(term[0]) & 128) != 0:
shift = len(term) * 8 # * Note below
val = val - (1 << shift)
return val
# * Note *
# '1 << (len(term) * 8)' Cython tries to do native
# integer shifts, which overflows. We need this to
# emulate Python shifting, which will expand the long
# to accommodate