catapult/systrace/systrace/util.py

# 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 optparse
import os
import random
import string
import subprocess
import sys


class OptionParserIgnoreErrors(optparse.OptionParser):
  """Wrapper for OptionParser that ignores errors and produces no output."""

  def error(self, msg):
    pass

  def exit(self, status=0, msg=None):
    pass

  def print_usage(self, out_file=None):
    pass

  def print_help(self, out_file=None):
    pass

  def print_version(self, out_file=None):
    pass


def add_adb_serial(adb_command, device_serial):
  """Add serial number to ADB shell command.

  ADB shell command is given as list, e.g.
  ['adb','shell','some_command','some_args'].
  This replaces it with:
  ['adb','shell',-s',device_serial,'some_command','some_args']

  Args:
     adb_command: ADB command list.
     device_serial: Device serial number.

  Returns:
     ADB command list with serial number added.
  """
  if device_serial is not None:
    adb_command.insert(1, device_serial)
    adb_command.insert(1, '-s')


def construct_adb_shell_command(shell_args, device_serial):
  """Construct an ADB shell command with given device serial and arguments.

  Args:
     shell_args: array of arguments to pass to adb shell.
     device_serial: if not empty, will add the appropriate command-line
        parameters so that adb targets the given device.
  """
  adb_command = ['adb', 'shell', ' '.join(shell_args)]
  add_adb_serial(adb_command, device_serial)
  return adb_command


def run_adb_command(adb_command):
  adb_output = []
  adb_return_code = 0
  try:
    adb_output = subprocess.check_output(adb_command, stderr=subprocess.STDOUT,
                                         shell=False, universal_newlines=True)
  except OSError as error:
    # This usually means that the adb executable was not found in the path.
    print >> sys.stderr, ('\nThe command "%s" failed with the following error:'
                          % ' '.join(adb_command))
    print >> sys.stderr, '    %s' % str(error)
    print >> sys.stderr, 'Is adb in your path?'
    adb_return_code = error.errno
    adb_output = error
  except subprocess.CalledProcessError as error:
    # The process exited with an error.
    adb_return_code = error.returncode
    adb_output = error.output

  return (adb_output, adb_return_code)


def run_adb_shell(shell_args, device_serial):
  """Runs "adb shell" with the given arguments.

  Args:
    shell_args: array of arguments to pass to adb shell.
    device_serial: if not empty, will add the appropriate command-line
        parameters so that adb targets the given device.
  Returns:
    A tuple containing the adb output (stdout & stderr) and the return code
    from adb.  Will exit if adb fails to start.
  """
  adb_command = construct_adb_shell_command(shell_args, device_serial)
  return run_adb_command(adb_command)


def get_device_sdk_version():
  """Uses adb to attempt to determine the SDK version of a running device."""

  getprop_args = ['getprop', 'ro.build.version.sdk']

  # get_device_sdk_version() is called before we even parse our command-line
  # args.  Therefore, parse just the device serial number part of the
  # command-line so we can send the adb command to the correct device.
  parser = OptionParserIgnoreErrors()
  parser.add_option('-e', '--serial', dest='device_serial', type='string')
  options, unused_args = parser.parse_args()  # pylint: disable=unused-variable

  success = False

  adb_output, adb_return_code = run_adb_shell(getprop_args,
                                              options.device_serial)

  if adb_return_code == 0:
    # ADB may print output other than the version number (e.g. it chould
    # print a message about starting the ADB server).
    # Break the ADB output into white-space delimited segments.
    parsed_output = str.split(adb_output)
    if parsed_output:
      # Assume that the version number is the last thing printed by ADB.
      version_string = parsed_output[-1]
      if version_string:
        try:
          # Try to convert the text into an integer.
          version = int(version_string)
        except ValueError:
          version = -1
        else:
          success = True

  if not success:
    sys.exit(1)

  return version


def generate_random_filename_for_test():
  """Used for temporary files used in tests.

  Files created from 'NamedTemporaryFile' have inconsistent reuse support across
  platforms, so it's not guaranteed that they can be reopened. Since many tests
  communicate files via path, we typically use this method, as well as
  manual file removal."""
  name = ''.join(random.choice(string.ascii_uppercase +
              string.digits) for _ in range(10))
  return os.path.abspath(name)