deb-python-cassandra-driver/cassandra/cython_utils.pyx
2017-04-24 17:20:57 -04:00

63 lines
2.0 KiB
Cython

# 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.
"""
Duplicate module of util.py, with some accelerated functions
used for deserialization.
"""
from libc.math cimport modf, round, fabs
from cpython.datetime cimport (
timedelta_new,
# cdef inline object timedelta_new(int days, int seconds, int useconds)
# Create timedelta object using DateTime CAPI factory function.
# Note, there are no range checks for any of the arguments.
import_datetime,
# Datetime C API initialization function.
# You have to call it before any usage of DateTime CAPI functions.
)
import datetime
import sys
cdef bint is_little_endian
from cassandra.util import is_little_endian
import_datetime()
DEF DAY_IN_SECONDS = 86400
DATETIME_EPOC = datetime.datetime(1970, 1, 1)
cdef datetime_from_timestamp(double timestamp):
cdef int days = <int> (timestamp / DAY_IN_SECONDS)
cdef int64_t days_in_seconds = (<int64_t> days) * DAY_IN_SECONDS
cdef int seconds = <int> (timestamp - days_in_seconds)
cdef double tmp
cdef double micros_left = modf(timestamp, &tmp) * 1000000.
micros_left = modf(micros_left, &tmp)
cdef int microseconds = <int> tmp
# rounding to emulate fp math in delta_new
cdef int x_odd
tmp = round(micros_left)
if fabs(tmp - micros_left) == 0.5:
x_odd = microseconds & 1
tmp = 2.0 * round((micros_left + x_odd) * 0.5) - x_odd
microseconds += <int>tmp
return DATETIME_EPOC + timedelta_new(days, seconds, microseconds)