Reland of 'Migrate device utils WriteFile to AdbWrapper'

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 logging
 import multiprocessing
 import os
 import re
 import sys
 import tempfile
 import time
 import zipfile
 
 import pylib.android_commands
 from pylib import cmd_helper
 from pylib.device import adb_wrapper
 from pylib.device import decorators
 from pylib.device import device_errors
 from pylib.device.commands import install_commands
 from pylib.utils import apk_helper
+from pylib.utils import device_temp_file
 from pylib.utils import host_utils
 from pylib.utils import parallelizer
 from pylib.utils import timeout_retry
 
 _DEFAULT_TIMEOUT = 30
 _DEFAULT_RETRIES = 3
 
 
 @decorators.WithExplicitTimeoutAndRetries(
     _DEFAULT_TIMEOUT, _DEFAULT_RETRIES)
@@ skipping 385 matching lines @@
       DeviceUnreachableError on missing device.
     """
     def env_quote(key, value):
       if not DeviceUtils._VALID_SHELL_VARIABLE.match(key):
         raise KeyError('Invalid shell variable name %r' % key)
       # using double quotes here to allow interpolation of shell variables
       return '%s=%s' % (key, cmd_helper.DoubleQuote(value))
 
     if not isinstance(cmd, basestring):
       cmd = ' '.join(cmd_helper.SingleQuote(s) for s in cmd)
-    if as_root and self.NeedsSU():
-      cmd = 'su -c %s' % cmd
     if env:
       env = ' '.join(env_quote(k, v) for k, v in env.iteritems())
       cmd = '%s %s' % (env, cmd)
     if cwd:
       cmd = 'cd %s && %s' % (cmd_helper.SingleQuote(cwd), cmd)
+    if as_root and self.NeedsSU():
+      # "su -c sh -c" allows using shell features in |cmd|
+      cmd = 'su -c sh -c %s' % cmd_helper.SingleQuote(cmd)
     if timeout is None:
       timeout = self._default_timeout
 
     try:
       output = self.adb.Shell(cmd)
     except device_errors.AdbShellCommandFailedError as e:
       if check_return:
         raise
       else:
         output = e.output
@@ skipping 426 matching lines @@
     # the implementation switch, and if file not found should raise exception.
     if as_root:
       if not self.old_interface.CanAccessProtectedFileContents():
         raise device_errors.CommandFailedError(
           'Cannot read from %s with root privileges.' % device_path)
       return self.old_interface.GetProtectedFileContents(device_path)
     else:
       return self.old_interface.GetFileContents(device_path)
 
   @decorators.WithTimeoutAndRetriesFromInstance()
-  def WriteFile(self, device_path, contents, as_root=False, timeout=None,
-                retries=None):
+  def WriteFile(self, device_path, contents, as_root=False, force_push=False,
+                timeout=None, retries=None):
     """Writes |contents| to a file on the device.
 
     Args:
       device_path: A string containing the absolute path to the file to write
-                   on the device.
+          on the device.
       contents: A string containing the data to write to the device.
       as_root: A boolean indicating whether the write should be executed with
-               root privileges.
+          root privileges (if available).
+      force_push: A boolean indicating whether to force the operation to be
+          performed by pushing a file to the device. The default is, when the
+          contents are short, to pass the contents using a shell script instead.
       timeout: timeout in seconds
       retries: number of retries
 
     Raises:
       CommandFailedError if the file could not be written on the device.
       CommandTimeoutError on timeout.
       DeviceUnreachableError on missing device.
     """
-    if as_root:
-      if not self.old_interface.CanAccessProtectedFileContents():
-        raise device_errors.CommandFailedError(
-            'Cannot write to %s with root privileges.' % device_path)
-      self.old_interface.SetProtectedFileContents(device_path, contents)
+    if len(contents) < 512 and not force_push:
+      cmd = 'echo -n %s > %s' % (cmd_helper.SingleQuote(contents),
+                                 cmd_helper.SingleQuote(device_path))
+      self.RunShellCommand(cmd, as_root=as_root, check_return=True)
     else:
-      self.old_interface.SetFileContents(device_path, contents)
-
-  @decorators.WithTimeoutAndRetriesFromInstance()
-  def WriteTextFile(self, device_path, text, as_root=False, timeout=None,
-                    retries=None):
-    """Writes |text| to a file on the device.
-
-    Assuming that |text| is a small string, this is typically more efficient
-    than |WriteFile|, as no files are pushed into the device.
-
-    Args:
-      device_path: A string containing the absolute path to the file to write
-                   on the device.
-      text: A short string of text to write to the file on the device.
-      as_root: A boolean indicating whether the write should be executed with
-               root privileges.
-      timeout: timeout in seconds
-      retries: number of retries
-
-    Raises:
-      CommandFailedError if the file could not be written on the device.
-      CommandTimeoutError on timeout.
-      DeviceUnreachableError on missing device.
-    """
-    cmd = 'echo %s > %s' % (cmd_helper.SingleQuote(text),
-                            cmd_helper.SingleQuote(device_path))
-    self.RunShellCommand(cmd, as_root=as_root, check_return=True)
+      with tempfile.NamedTemporaryFile() as host_temp:
+        host_temp.write(contents)
+        host_temp.flush()
+        if as_root and self.NeedsSU():
+          with device_temp_file.DeviceTempFile(self) as device_temp:
+            self.adb.Push(host_temp.name, device_temp.name)
+            # Here we need 'cp' rather than 'mv' because the temp and
+            # destination files might be on different file systems (e.g.
+            # on internal storage and an external sd card)
+            self.RunShellCommand(['cp', device_temp.name, device_path],
+                                 as_root=True, check_return=True)
+        else:
+          self.adb.Push(host_temp.name, device_path)
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def Ls(self, device_path, timeout=None, retries=None):
     """Lists the contents of a directory on the device.
 
     Args:
       device_path: A string containing the path of the directory on the device
                    to list.
       timeout: timeout in seconds
       retries: number of retries
@@ skipping 220 matching lines @@
     Returns:
       A Parallelizer operating over |devices|.
     """
     if not devices or len(devices) == 0:
       devices = pylib.android_commands.GetAttachedDevices()
     parallelizer_type = (parallelizer.Parallelizer if async
                          else parallelizer.SyncParallelizer)
     return parallelizer_type([
         d if isinstance(d, DeviceUtils) else DeviceUtils(d)
         for d in devices])