#

# Licensed to the Apache Software Foundation (ASF) under one or more

# contributor license agreements. See the NOTICE file distributed with

# this work for additional information regarding copyright ownership.

# The ASF licenses this file to You 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.

#

cimport libc.stdint

cimport libc.stdlib

cimport libc.string

from cpython.bytes cimport PyBytes_FromStringAndSize

cdef class LCGenerator(object):

def __cinit__(self):

self._a = 0x5DEECE66Dull

self._c = 0xBull

self._bits = 48

self._mask = (1ull << self._bits) - 1

self.seed(0)

cpdef void seed(self, libc.stdint.uint64_t seed):

self._seed = (seed * self._a + self._c) & self._mask

cpdef void seed_jdk(self, libc.stdint.uint64_t seed):

self._seed = (seed ^ self._a) & self._mask

cpdef libc.stdint.int32_t next_int(self):

self.seed(self._seed)

return <libc.stdint.int32_t>(self._seed >> (self._bits - 32))

cpdef libc.stdint.uint32_t next_uint(self):

self.seed(self._seed)

return <libc.stdint.uint32_t>(self._seed >> (self._bits - 32))

cpdef bytes randbytes(self, int length):

cdef libc.stdint.int32_t ints = (length + 3) // 4

cdef char* data = <char*>libc.stdlib.malloc(ints * 4)

cdef libc.stdint.uint32_t value

cdef libc.stdint.int32_t i

for i in range(0, ints, 1):

value = self.next_uint()

libc.string.memcpy(<void*>(data + i * 4), <void*>(& value), 4)

retval = PyBytes_FromStringAndSize(data, length)

libc.stdlib.free(data)

return retval

cpdef double random_sample(self):

return <double>(self.next_uint() >> 8) / <double>(1 << 24)