cp210x-program/pyusb/tests/utils.py

# Copyright (C) 2009-2011 Wander Lairson Costa 
# 
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import sys
import os.path
import operator
from ctypes import c_ubyte, POINTER, cast

parent_dir = os.path.split(os.getcwd())[0]

# if we are at PyUSB source tree, add usb package to python path
if os.path.exists(os.path.join(parent_dir, 'usb')):
    sys.path.insert(0, parent_dir)

import usb.core
import logging
import devinfo
import time
import unittest
import usb._interop as _interop

logger = logging.getLogger('usb.test')

# data generation functions
def get_array_data1(length = 10):
    return _interop.as_array(range(length))
def get_array_data2(length = 10):
    data = list(range(length))
    data.reverse()
    return _interop.as_array(data)
def get_list_data1(length = 10):
    return list(range(length))
def get_list_data2(length = 10):
    data = list(range(length))
    data.reverse()
    return data
def get_str_data1(length = 10):
    return ''.join([chr(x) for x in range(length)])
def get_str_data2(length = 10):
    data = list(range(length))
    data.reverse()
    return ''.join([chr(x) for x in data])
def to_array(data):
    return _interop.as_array(data)

def delay_after_reset():
    time.sleep(3) # necessary to wait device reenumeration

# check if our test hardware is present
def find_my_device(backend = None):
    try:
        return usb.core.find(backend=backend,
                             idVendor=devinfo.ID_VENDOR,
                             idProduct=devinfo.ID_PRODUCT)
    except Exception:
        return None

def run_tests(suite):
    runner = unittest.TextTestRunner()
    runner.run(suite)

def data_len(data):
    a = _interop.as_array(data)
    return len(data) * a.itemsize

def array_equals(a1, a2):
    if a1.typecode != 'u' and a2.typecode != 'u':
        return a1 == a2
    else:
        # as python3 strings are unicode, loads of trouble,
        # because we read data from USB devices are byte arrays
        l1 = len(a1) * a1.itemsize
        l2 = len(a2) * a2.itemsize
        if l1 != l2:
            return False
        c_ubyte_p = POINTER(c_ubyte)
        p1 = cast(a1.buffer_info()[0], c_ubyte_p)
        p2 = cast(a2.buffer_info()[0], c_ubyte_p)
        # we do a item by item compare we unicode is involved
        return all(map(operator.eq, p1[:l1], p2[:l2]))