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# Copyright (c) 2021 Jeff Irion and contributors
#
# This file is part of the adb-shell package. It incorporates work
# covered by the following license notice:
#
#
# Copyright 2014 Google Inc. All rights reserved.
#
# 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.
"""A class for creating a socket connection with the device and sending and receiving data.
* :class:`TcpTransport`
* :meth:`TcpTransport.bulk_read`
* :meth:`TcpTransport.bulk_write`
* :meth:`TcpTransport.close`
* :meth:`TcpTransport.connect`
"""
import select
import socket
from .base_transport import BaseTransport
from ..exceptions import TcpTimeoutException
class TcpTransport(BaseTransport):
"""TCP connection object.
Parameters
----------
host : str
The address of the device; may be an IP address or a host name
port : int
The device port to which we are connecting (default is 5555)
Attributes
----------
_connection : socket.socket, None
A socket connection to the device
_host : str
The address of the device; may be an IP address or a host name
_port : int
The device port to which we are connecting (default is 5555)
"""
def __init__(self, host, port=5555):
self._host = host
self._port = port
self._connection = None
def close(self):
"""Close the socket connection.
"""
if self._connection:
try:
self._connection.shutdown(socket.SHUT_RDWR)
except OSError:
pass
self._connection.close()
self._connection = None
def connect(self, transport_timeout_s):
"""Create a socket connection to the device.
Parameters
----------
transport_timeout_s : float, None
Set the timeout on the socket instance
"""
self._connection = socket.create_connection((self._host, self._port), timeout=transport_timeout_s)
if transport_timeout_s:
# Put the socket in non-blocking mode
# https://docs.python.org/3/library/socket.html#socket.socket.settimeout
self._connection.setblocking(False)
def bulk_read(self, numbytes, transport_timeout_s):
"""Receive data from the socket.
Parameters
----------
numbytes : int
The maximum amount of data to be received
transport_timeout_s : float, None
When the timeout argument is omitted, ``select.select`` blocks until at least one file descriptor is ready. A time-out value of zero specifies a poll and never blocks.
Returns
-------
bytes
The received data
Raises
------
TcpTimeoutException
Reading timed out.
"""
readable, _, _ = select.select([self._connection], [], [], transport_timeout_s)
if readable:
return self._connection.recv(numbytes)
msg = 'Reading from {}:{} timed out ({} seconds)'.format(self._host, self._port, transport_timeout_s)
raise TcpTimeoutException(msg)
def bulk_write(self, data, transport_timeout_s):
"""Send data to the socket.
Parameters
----------
data : bytes
The data to be sent
transport_timeout_s : float, None
When the timeout argument is omitted, ``select.select`` blocks until at least one file descriptor is ready. A time-out value of zero specifies a poll and never blocks.
Returns
-------
int
The number of bytes sent
Raises
------
TcpTimeoutException
Sending data timed out. No data was sent.
"""
_, writeable, _ = select.select([], [self._connection], [], transport_timeout_s)
if writeable:
return self._connection.send(data)
msg = 'Sending data to {}:{} timed out after {} seconds. No data was sent.'.format(self._host, self._port, transport_timeout_s)
raise TcpTimeoutException(msg)
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