/usr/lib/python3/dist-packages/pyvisa-py/protocols/usbraw.py is in python3-pyvisa-py 0.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 | # -*- coding: utf-8 -*-
"""
pyvisa-py.protocols.usbraw
~~~~~~~~~~~~~~~~~~~~~~~~~~
Implements Session to control USB Raw devices
Loosely based on PyUSBTMC:python module to handle USB-TMC(Test and Measurement class)　devices.
by Noboru Yamamot, Accl. Lab, KEK, JAPAN
This file is an offspring of the Lantz Project.
:copyright: 2014 by PyVISA-py Authors, see AUTHORS for more details.
:license: MIT, see LICENSE for more details.
"""
from __future__ import division, unicode_literals, print_function, absolute_import
from .usbtmc import USBRaw as USBRaw
import usb
from .usbutil import find_devices, find_interfaces, find_endpoint, usb_find_desc
def find_raw_devices(vendor=None, product=None, serial_number=None, custom_match=None, **kwargs):
"""Find connected USB RAW devices. See usbutil.find_devices for more info.
"""
def is_usbraw(dev):
if custom_match and not custom_match(dev):
return False
return bool(find_interfaces(dev, bInterfaceClass=0xFF, bInterfaceSubClass=0xFF))
return find_devices(vendor, product, serial_number, is_usbraw, **kwargs)
class USBRawDevice(USBRaw):
RECV_CHUNK = 1024 ** 2
find_devices = staticmethod(find_raw_devices)
def __init__(self, vendor=None, product=None, serial_number=None, **kwargs):
super(USBRawDevice, self).__init__(vendor, product, serial_number, **kwargs)
if not (self.usb_recv_ep and self.usb_send_ep):
raise ValueError("USBRAW device must have both Bulk-In and Bulk-out endpoints.")
def write(self, data):
"""Send raw bytes to the instrument.
:param data: bytes to be sent to the instrument
:type data: bytes
"""
begin, end, size = 0, 0, len(data)
bytes_sent = 0
raw_write = super(USBRawDevice, self).write
while not end > size:
begin = end
end = begin + self.RECV_CHUNK
bytes_sent += raw_write(data[begin:end])
return bytes_sent
def read(self, size):
"""Read raw bytes from the instrument.
:param size: amount of bytes to be sent to the instrument
:type size: integer
:return: received bytes
:return type: bytes
"""
raw_read = super(USBRawDevice, self).read
raw_write = super(USBRawDevice, self).write
received = b''
while not len(received) >= size:
resp = raw_read(self.RECV_CHUNK)
received += resp
return received
|