1# Copyright 2013 The Chromium Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5"""A temp file that automatically gets pushed and deleted from a device.""" 6 7# pylint: disable=W0622 8 9import posixpath 10import random 11import threading 12 13from devil.android import device_errors 14from devil.utils import cmd_helper 15 16 17class DeviceTempFile(object): 18 19 def __init__(self, adb, suffix='', prefix='temp_file', dir='/data/local/tmp'): 20 """Find an unused temporary file path on the device. 21 22 When this object is closed, the file will be deleted on the device. 23 24 Args: 25 adb: An instance of AdbWrapper 26 suffix: The suffix of the name of the temp file. 27 prefix: The prefix of the name of the temp file. 28 dir: The directory on the device where to place the temp file. 29 """ 30 self._adb = adb 31 # Python's random module use 52-bit numbers according to its docs. 32 random_hex = hex(random.randint(0, 2 ** 52))[2:] 33 self.name = posixpath.join(dir, '%s-%s%s' % (prefix, random_hex, suffix)) 34 self.name_quoted = cmd_helper.SingleQuote(self.name) 35 36 def close(self): 37 """Deletes the temporary file from the device.""" 38 # ignore exception if the file is already gone. 39 def delete_temporary_file(): 40 try: 41 self._adb.Shell('rm -f %s' % self.name_quoted, expect_status=None) 42 except device_errors.AdbCommandFailedError: 43 # file does not exist on Android version without 'rm -f' support (ICS) 44 pass 45 46 # It shouldn't matter when the temp file gets deleted, so do so 47 # asynchronously. 48 threading.Thread( 49 target=delete_temporary_file, 50 name='delete_temporary_file(%s)' % self._adb.GetDeviceSerial()).start() 51 52 def __enter__(self): 53 return self 54 55 def __exit__(self, type, value, traceback): 56 self.close() 57