| # Copyright 2015 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import socket |
| import struct |
| |
| |
| class RemoteFileConnectionException(Exception): |
| def __init__(self, *args, **kwargs): |
| Exception.__init__(self, *args, **kwargs) |
| |
| |
| class RemoteFileConnection(object): |
| """Client for remote_file_reader server, allowing to read files on an |
| remote device. |
| """ |
| def __init__(self, host, port): |
| self._host = host |
| self._port = port |
| self._socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
| self._size_struct = struct.Struct("!i") |
| |
| def __del__(self): |
| self.disconnect() |
| |
| def connect(self): |
| self._socket.connect((self._host, self._port)) |
| |
| def disconnect(self): |
| self._socket.close() |
| |
| def open(self, filename): |
| self._send("O %s\n" % filename) |
| result = self._receive(1) |
| if result != 'O': |
| raise RemoteFileConnectionException("Unable to open file " + filename) |
| |
| def seek(self, pos, mode=0): |
| self._send("S %d %d\n" % (pos, mode)) |
| result = self._receive(1) |
| if result != 'O': |
| raise RemoteFileConnectionException("Unable to seek in file.") |
| |
| def read(self, size=0): |
| assert size > 0 |
| self._send("R %d\n" % size) |
| result = self._receive(1) |
| if result != 'O': |
| raise RemoteFileConnectionException("Unable to read file.") |
| read_size = self._size_struct.unpack(self._receive(4))[0] |
| return self._receive(read_size) |
| |
| def _send(self, data): |
| while len(data) > 0: |
| sent = self._socket.send(data) |
| if sent == 0: |
| raise RemoteFileConnectionException("Socket connection broken.") |
| data = data[sent:] |
| |
| def _receive(self, length): |
| result = [] |
| while length > 0: |
| chunk = self._socket.recv(length) |
| if chunk == '': |
| raise RemoteFileConnectionException("Socket connection broken.") |
| result.append(chunk) |
| length -= len(chunk) |
| return ''.join(result) |