[Android] Move some pylib modules into devil/

build/android/pylib/cmd_helper.py

-# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# 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.
 
-"""A wrapper for subprocess to make calling shell commands easier."""
+# pylint: disable=unused-wildcard-import
+# pylint: disable=wildcard-import
 
-import logging
-import os
-import pipes
-import select
-import signal
-import string
-import StringIO
-import subprocess
-import time
-
-# fcntl is not available on Windows.
-try:
-  import fcntl
-except ImportError:
-  fcntl = None
-
-_SafeShellChars = frozenset(string.ascii_letters + string.digits + '@%_-+=:,./')
-
-def SingleQuote(s):
-  """Return an shell-escaped version of the string using single quotes.
-
-  Reliably quote a string which may contain unsafe characters (e.g. space,
-  quote, or other special characters such as '$').
-
-  The returned value can be used in a shell command line as one token that gets
-  to be interpreted literally.
-
-  Args:
-    s: The string to quote.
-
-  Return:
-    The string quoted using single quotes.
-  """
-  return pipes.quote(s)
-
-def DoubleQuote(s):
-  """Return an shell-escaped version of the string using double quotes.
-
-  Reliably quote a string which may contain unsafe characters (e.g. space
-  or quote characters), while retaining some shell features such as variable
-  interpolation.
-
-  The returned value can be used in a shell command line as one token that gets
-  to be further interpreted by the shell.
-
-  The set of characters that retain their special meaning may depend on the
-  shell implementation. This set usually includes: '$', '`', '\', '!', '*',
-  and '@'.
-
-  Args:
-    s: The string to quote.
-
-  Return:
-    The string quoted using double quotes.
-  """
-  if not s:
-    return '""'
-  elif all(c in _SafeShellChars for c in s):
-    return s
-  else:
-    return '"' + s.replace('"', '\\"') + '"'
-
-
-def Popen(args, stdout=None, stderr=None, shell=None, cwd=None, env=None):
-  return subprocess.Popen(
-      args=args, cwd=cwd, stdout=stdout, stderr=stderr,
-      shell=shell, close_fds=True, env=env,
-      preexec_fn=lambda: signal.signal(signal.SIGPIPE, signal.SIG_DFL))
-
-
-def Call(args, stdout=None, stderr=None, shell=None, cwd=None, env=None):
-  pipe = Popen(args, stdout=stdout, stderr=stderr, shell=shell, cwd=cwd,
-               env=env)
-  pipe.communicate()
-  return pipe.wait()
-
-
-def RunCmd(args, cwd=None):
-  """Opens a subprocess to execute a program and returns its return value.
-
-  Args:
-    args: A string or a sequence of program arguments. The program to execute is
-      the string or the first item in the args sequence.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-
-  Returns:
-    Return code from the command execution.
-  """
-  logging.info(str(args) + ' ' + (cwd or ''))
-  return Call(args, cwd=cwd)
-
-
-def GetCmdOutput(args, cwd=None, shell=False):
-  """Open a subprocess to execute a program and returns its output.
-
-  Args:
-    args: A string or a sequence of program arguments. The program to execute is
-      the string or the first item in the args sequence.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-    shell: Whether to execute args as a shell command.
-
-  Returns:
-    Captures and returns the command's stdout.
-    Prints the command's stderr to logger (which defaults to stdout).
-  """
-  (_, output) = GetCmdStatusAndOutput(args, cwd, shell)
-  return output
-
-
-def _ValidateAndLogCommand(args, cwd, shell):
-  if isinstance(args, basestring):
-    if not shell:
-      raise Exception('string args must be run with shell=True')
-  else:
-    if shell:
-      raise Exception('array args must be run with shell=False')
-    args = ' '.join(SingleQuote(c) for c in args)
-  if cwd is None:
-    cwd = ''
-  else:
-    cwd = ':' + cwd
-  logging.info('[host]%s> %s', cwd, args)
-  return args
-
-
-def GetCmdStatusAndOutput(args, cwd=None, shell=False):
-  """Executes a subprocess and returns its exit code and output.
-
-  Args:
-    args: A string or a sequence of program arguments. The program to execute is
-      the string or the first item in the args sequence.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-    shell: Whether to execute args as a shell command. Must be True if args
-      is a string and False if args is a sequence.
-
-  Returns:
-    The 2-tuple (exit code, output).
-  """
-  status, stdout, stderr = GetCmdStatusOutputAndError(
-      args, cwd=cwd, shell=shell)
-
-  if stderr:
-    logging.critical(stderr)
-  if len(stdout) > 4096:
-    logging.debug('Truncated output:')
-  logging.debug(stdout[:4096])
-  return (status, stdout)
-
-def GetCmdStatusOutputAndError(args, cwd=None, shell=False):
-  """Executes a subprocess and returns its exit code, output, and errors.
-
-  Args:
-    args: A string or a sequence of program arguments. The program to execute is
-      the string or the first item in the args sequence.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-    shell: Whether to execute args as a shell command. Must be True if args
-      is a string and False if args is a sequence.
-
-  Returns:
-    The 2-tuple (exit code, output).
-  """
-  _ValidateAndLogCommand(args, cwd, shell)
-  pipe = Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-               shell=shell, cwd=cwd)
-  stdout, stderr = pipe.communicate()
-  return (pipe.returncode, stdout, stderr)
-
-
-class TimeoutError(Exception):
-  """Module-specific timeout exception."""
-
-  def __init__(self, output=None):
-    super(TimeoutError, self).__init__()
-    self._output = output
-
-  @property
-  def output(self):
-    return self._output
-
-
-def _IterProcessStdout(process, timeout=None, buffer_size=4096,
-                       poll_interval=1):
-  assert fcntl, 'fcntl module is required'
-  try:
-    # Enable non-blocking reads from the child's stdout.
-    child_fd = process.stdout.fileno()
-    fl = fcntl.fcntl(child_fd, fcntl.F_GETFL)
-    fcntl.fcntl(child_fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
-
-    end_time = (time.time() + timeout) if timeout else None
-    while True:
-      if end_time and time.time() > end_time:
-        raise TimeoutError()
-      read_fds, _, _ = select.select([child_fd], [], [], poll_interval)
-      if child_fd in read_fds:
-        data = os.read(child_fd, buffer_size)
-        if not data:
-          break
-        yield data
-      if process.poll() is not None:
-        break
-  finally:
-    try:
-      # Make sure the process doesn't stick around if we fail with an
-      # exception.
-      process.kill()
-    except OSError:
-      pass
-    process.wait()
-
-
-def GetCmdStatusAndOutputWithTimeout(args, timeout, cwd=None, shell=False,
-                                     logfile=None):
-  """Executes a subprocess with a timeout.
-
-  Args:
-    args: List of arguments to the program, the program to execute is the first
-      element.
-    timeout: the timeout in seconds or None to wait forever.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-    shell: Whether to execute args as a shell command. Must be True if args
-      is a string and False if args is a sequence.
-    logfile: Optional file-like object that will receive output from the
-      command as it is running.
-
-  Returns:
-    The 2-tuple (exit code, output).
-  """
-  _ValidateAndLogCommand(args, cwd, shell)
-  output = StringIO.StringIO()
-  process = Popen(args, cwd=cwd, shell=shell, stdout=subprocess.PIPE,
-                  stderr=subprocess.STDOUT)
-  try:
-    for data in _IterProcessStdout(process, timeout=timeout):
-      if logfile:
-        logfile.write(data)
-      output.write(data)
-  except TimeoutError:
-    raise TimeoutError(output.getvalue())
-
-  return process.returncode, output.getvalue()
-
-
-def IterCmdOutputLines(args, timeout=None, cwd=None, shell=False,
-                       check_status=True):
-  """Executes a subprocess and continuously yields lines from its output.
-
-  Args:
-    args: List of arguments to the program, the program to execute is the first
-      element.
-    cwd: If not None, the subprocess's current directory will be changed to
-      |cwd| before it's executed.
-    shell: Whether to execute args as a shell command. Must be True if args
-      is a string and False if args is a sequence.
-    check_status: A boolean indicating whether to check the exit status of the
-      process after all output has been read.
-
-  Yields:
-    The output of the subprocess, line by line.
-
-  Raises:
-    CalledProcessError if check_status is True and the process exited with a
-      non-zero exit status.
-  """
-  cmd = _ValidateAndLogCommand(args, cwd, shell)
-  process = Popen(args, cwd=cwd, shell=shell, stdout=subprocess.PIPE,
-                  stderr=subprocess.STDOUT)
-  buffer_output = ''
-  for data in _IterProcessStdout(process, timeout=timeout):
-    buffer_output += data
-    has_incomplete_line = buffer_output[-1] not in '\r\n'
-    lines = buffer_output.splitlines()
-    buffer_output = lines.pop() if has_incomplete_line else ''
-    for line in lines:
-      yield line
-  if buffer_output:
-    yield buffer_output
-  if check_status and process.returncode:
-    raise subprocess.CalledProcessError(process.returncode, cmd)
+from devil.utils.cmd_helper import *