blob: 19c3bca468da75b5e39e321fa39eb4b21c0f1e47 [file] [log] [blame]
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Common file and os related utilities, including tempdir manipulation."""
import contextlib
import errno
import os
import shutil
import tempfile
from chromite.lib import cros_build_lib
# Env vars that tempdir can be gotten from; minimally, this
# needs to match python's tempfile module and match normal
# unix standards.
def ExpandPath(path):
"""Returns path after passing through realpath and expanduser."""
return os.path.realpath(os.path.expanduser(path))
def WriteFile(path, content, mode='w', atomic=False):
"""Write the given content to disk.
path: Pathway to write the content to.
content: Content to write. May be either an iterable, or a string.
mode: Optional; if binary mode is necessary, pass 'wb'. If appending is
desired, 'w+', etc.
atomic: If the updating of the file should be done atomically. Note this
option is incompatible w/ append mode.
write_path = path
if atomic:
write_path = path + '.tmp'
if isinstance(content, basestring):
content = [content]
with open(write_path, mode) as f:
if not atomic:
os.rename(write_path, path)
except EnvironmentError:
def ReadFile(path, mode='r'):
"""Read a given file on disk. Primarily useful for one off small files."""
with open(path, mode) as f:
def SafeUnlink(path):
"""Unlink a file from disk, ignoring if it doesn't exist.
Returns True if the file existed and was removed, False if it didn't exist.
return True
except EnvironmentError, e:
if e.errno != errno.ENOENT:
return False
def SafeMakedirs(path, mode=0775, sudo=False):
"""Make parent directories if needed. Ignore if existing.
path: The path to create. Intermediate directories will be created as
mode: The access permissions in the style of chmod.
sudo: If True, create it via sudo, thus root owned.
EnvironmentError: if the makedir failed and it was non sudo.
RunCommandError: If sudo mode, and the command failed for any reason.
True if the directory had to be created, False if otherwise.
if sudo:
if os.path.isdir(path):
return False
['mkdir', '-p', '--mode', oct(mode), path], print_cmd=False,
redirect_stderr=True, redirect_stdout=True)
return True
os.makedirs(path, mode)
return True
except EnvironmentError, e:
if e.errno != errno.EEXIST or not os.path.isdir(path):
return False
# pylint: disable=W0212,R0904,W0702
def _TempDirSetup(self, prefix='tmp', update_env=True):
"""Generate a tempdir, modifying the object, and env to use it.
Specifically, if update_env is True, then from this invocation forward,
python and all subprocesses will use this location for their tempdir.
The matching _TempDirTearDown restores the env to what it was.
# Stash the old tempdir that was used so we can
# switch it back on the way out.
self.tempdir = tempfile.mkdtemp(prefix=prefix)
os.chmod(self.tempdir, 0700)
if update_env:
with tempfile._once_lock:
self._tempdir_value = tempfile._get_default_tempdir()
self._tempdir_env = tuple((x, os.environ.get(x))
# Now update TMPDIR/TEMP/TMP, and poke the python
# internal to ensure all subprocess/raw tempfile
# access goes into this location.
os.environ.update((x, self.tempdir) for x in _TEMPDIR_ENV_VARS)
# Finally, adjust python's cached value (we know it's cached by here
# since we invoked _get_default_tempdir from above). Note this
# is necessary since we want *all* output from that point
# forward to go to this location.
tempfile.tempdir = self.tempdir
# pylint: disable=W0212,R0904,W0702
def _TempDirTearDown(self):
# Note that _TempDirSetup may have failed, resulting in these attributes
# not being set; this is why we use getattr here (and must).
tempdir = getattr(self, 'tempdir', None)
if tempdir is not None:
except EnvironmentError, e:
# Suppress ENOENT since we may be invoked
# in a context where parallel wipes of the tempdir
# may be occuring; primarily during hard shutdowns.
if e.errno != errno.ENOENT:
# Restore environment modification if necessary.
tempdir_value = getattr(self, '_tempdir_value', None)
if tempdir_value is not None:
with tempfile._once_lock:
tempfile.tempdir = self._tempdir_value
for key, value in self._tempdir_env:
if value is None:
os.environ.pop(key, None)
os.environ[key] = value
def TempDirContextManager(prefix='tmp', storage=None):
"""ContextManager constraining all tempfile/TMPDIR activity to a tempdir"""
if storage is None:
# Fake up a mutable object.
# TOOD(build): rebase this to EasyAttr from cros_test_lib once it moves
# to an importable location.
class foon(object):
storage = foon()
_TempDirSetup(storage, prefix=prefix)
# pylint: disable=W0212,R0904,W0702
def TempDirDecorator(func):
"""Populates self.tempdir with path to a temporary writeable directory."""
def f(self, *args, **kwargs):
with TempDirContextManager(storage=self):
return func(self, *args, **kwargs)
f.__name__ = func.__name__
f.__doc__ = func.__doc__
f.__module__ = func.__module__
return f
def TempFileDecorator(func):
"""Populates self.tempfile with path to a temporary writeable file"""
def f(self, *args, **kwargs):
with tempfile.NamedTemporaryFile(dir=self.tempdir, delete=False) as f:
self.tempfile =
return func(self, *args, **kwargs)
f.__name__ = func.__name__
f.__doc__ = func.__doc__
f.__module__ = func.__module__
return TempDirDecorator(f)