[Android] Convert to DeviceUtils versions of IsOnline, HasRoot, and EnableRoot.

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """
 Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=W0613
 
 import multiprocessing
 import os
 import sys
 
 import pylib.android_commands
 from pylib.device import adb_wrapper
 from pylib.device import decorators
+from pylib.device import device_errors
 
 CHROME_SRC_DIR = os.path.abspath(
     os.path.join(os.path.dirname(__file__), '..', '..', '..', '..'))
 sys.path.append(os.path.join(
     CHROME_SRC_DIR, 'third_party', 'android_testrunner'))
 import errors
 
 _DEFAULT_TIMEOUT = 30
 _DEFAULT_RETRIES = 3
 
@@ skipping 42 matching lines @@
   """ Restarts the adb server.
 
   Raises:
     CommandFailedError if we fail to kill or restart the server.
   """
   pylib.android_commands.AndroidCommands().RestartAdbServer()
 
 
 class DeviceUtils(object):
 
-  def __init__(self, device):
+  def __init__(self, device, default_timeout=_DEFAULT_TIMEOUT,
+               default_retries=_DEFAULT_RETRIES):
+    """ DeviceUtils constructor.
+
+    Args:
+      device: Either a device serial, an existing AdbWrapper instance, an
+              an existing AndroidCommands instance, or nothing.
+      default_timeout: An integer containing the default number of seconds to
+                       wait for an operation to complete if no explicit value
+                       is provided.
+      default_retries: An integer containing the default number or times an
+                       operation should be retried on failure if no explicit
+                       value is provided.
+    """
     self.old_interface = None
     if isinstance(device, basestring):
       self.old_interface = pylib.android_commands.AndroidCommands(device)
     elif isinstance(device, adb_wrapper.AdbWrapper):
       self.old_interface = pylib.android_commands.AndroidCommands(str(device))
     elif isinstance(device, pylib.android_commands.AndroidCommands):
       self.old_interface = device
     elif not device:
       self.old_interface = pylib.android_commands.AndroidCommands()
+    else:
+      raise device_errors.DeviceUnreachableError('Unexpected device type?')

[craigdh, 2014/05/14 20:33:08]

This error message is confusing (is my physical device the wrong type?). Maybe
"Unsupported type passed for argument 'device'". This should really be a
standard ValueError as this is programmer error.

[jbudorick, 2014/05/14 21:02:01]

Done.

+    self._default_timeout = default_timeout
+    self._default_retries = default_retries
 
+  @decorators.WithTimeoutAndRetriesFromInstance(
+      '_default_timeout', '_default_retries')

[craigdh, 2014/05/14 20:33:08]

I think it would be fine to default to these values, I don't know that being
explicit is particularly useful here and it adds a bit of noise. Just my two
cents.

[jbudorick, 2014/05/14 21:02:01]

Holding for now, but I'm interested to hear what the others have to say about
this. I don't really have an opinion either way. Doing it explicitly seems a bit
more clear, but it also is a bit noisier.

+  def IsOnline(self, timeout=None, retries=None):
+    """ Checks whether the device is online.
+
+    Args:
+      timeout: An integer containing the number of seconds to wait for the
+               operation to complete.
+      retries: An integer containing the number of times the operation should
+               be retried if it fails.
+    Returns:
+      True if the device is online, False otherwise.
+    """
+    return self.old_interface.IsOnline()
+
+  @decorators.WithTimeoutAndRetriesFromInstance(
+      '_default_timeout', '_default_retries')
+  def HasRoot(self, timeout=None, retries=None):
+    """ Checks whether or not adbd has root priveleges.
+
+    Args:
+      timeout: An integer containing the number of seconds to wait for the
+               operation to complete.
+      retries: An integer containing the number of times the operation should
+               be retried if it fails.
+    Returns:
+      True if adbd has root priveleges, False otherwise.
+    """
+    return self.old_interface.IsRootEnabled()
+
+  @decorators.WithTimeoutAndRetriesFromInstance(
+      '_default_timeout', '_default_retries')
+  def EnableRoot(self, timeout=None, retries=None):
+    """ Restarts adbd with root priveleges.
+
+    Args:
+      timeout: An integer containing the number of seconds to wait for the
+               operation to complete.
+      retries: An integer containing the number of times the operation should
+               be retried if it fails.
+    Raises:
+      CommandFailedError if root could not be enabled.
+    """
+    if not self.old_interface.EnableAdbRoot():
+      raise device_errors.CommandFailedError(
+          'adb root', 'Could not enable root.')
+