python/mxnet/_ffi/base.py - master - githubmirror/incubator-mxnet

python/mxnet/_ffi/base.py
71 строка2 KB
Sheng Zha
[DEV] switch nose with pytest (#18025)
23 апр 2020, 09:53
23 апр 2020, 09:53faccd91
# 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.
# coding: utf-8
# pylint: disable=invalid-name
"""Base library for MXNet FFI.
Acknowledgement: This file originates from incubator-tvm
"""
import sys
import ctypes
import numpy as np

string_types = (str,)
integer_types = (int, np.int32)
numeric_types = integer_types + (float, np.float32)
# this function is needed for python3
# to convert ctypes.char_p .value back to python str
if sys.platform == "win32":
    encoding = 'cp' + str(ctypes.cdll.kernel32.GetACP())
    py_str = lambda x: x.decode(encoding)
else:
    py_str = lambda x: x.decode('utf-8')

#----------------------------
# helper function in ctypes.
#----------------------------
def c_str(string):
    """Create ctypes char * from a python string
    Parameters
    ----------
    string : string type
        python string

    Returns
    -------
    str : c_char_p
        A char pointer that can be passed to C API
    """
    return ctypes.c_char_p(string.encode('utf-8'))


def c_array(ctype, values):
    """Create ctypes array from a python array

    Parameters
    ----------
    ctype : ctypes data type
        data type of the array we want to convert to

    values : tuple or list
        data content

    Returns
    -------
    out : ctypes array
        Created ctypes array
    """
    return (ctype * len(values))(*values)