device_list.py revision 47f0f1e200da8a481462f364f822c98fe1b1cd5b 
1# Copyright 2014 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 module to keep track of devices across builds."""
6
7import json
8import logging
9import os
10
11
12def GetPersistentDeviceList(file_name):
13  """Returns a list of devices.
14
15  Args:
16    file_name: the file name containing a list of devices.
17
18  Returns: List of device serial numbers that were on the bot.
19  """
20  if not os.path.isfile(file_name):
21    logging.warning('Device file %s doesn\'t exist.', file_name)
22    return []
23
24  try:
25    with open(file_name) as f:
26      devices = json.load(f)
27    if not isinstance(devices, list) or not all(isinstance(d, basestring)
28                                                for d in devices):
29      logging.warning('Unrecognized device file format: %s', devices)
30      return []
31    return [d for d in devices if d != '(error)']
32  except ValueError:
33    logging.exception(
34        'Error reading device file %s. Falling back to old format.', file_name)
35
36  # TODO(bpastene) Remove support for old unstructured file format.
37  with open(file_name) as f:
38    return [d for d in f.read().splitlines() if d != '(error)']
39
40
41def WritePersistentDeviceList(file_name, device_list):
42  path = os.path.dirname(file_name)
43  assert isinstance(device_list, list)
44  # If there is a problem with ADB "(error)" can be added to the device list.
45  # These should be removed before saving.
46  device_list = [d for d in device_list if d != '(error)']
47  if not os.path.exists(path):
48    os.makedirs(path)
49  with open(file_name, 'w') as f:
50    json.dump(device_list, f)
51