oslo.utils/oslo_utils/fileutils.py

108 lines
2.9 KiB
Python

# Copyright 2011 OpenStack Foundation.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
File utilities.
.. versionadded:: 1.8
"""
import contextlib
import errno
import logging
import os
import stat
import tempfile
from oslo_utils import excutils
LOG = logging.getLogger(__name__)
_DEFAULT_MODE = stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO
def ensure_tree(path, mode=_DEFAULT_MODE):
"""Create a directory (and any ancestor directories required)
:param path: Directory to create
:param mode: Directory creation permissions
"""
try:
os.makedirs(path, mode)
except OSError as exc:
if exc.errno == errno.EEXIST:
if not os.path.isdir(path):
raise
else:
raise
def delete_if_exists(path, remove=os.unlink):
"""Delete a file, but ignore file not found error.
:param path: File to delete
:param remove: Optional function to remove passed path
"""
try:
remove(path)
except OSError as e:
if e.errno != errno.ENOENT:
raise
@contextlib.contextmanager
def remove_path_on_error(path, remove=delete_if_exists):
"""Protect code that wants to operate on PATH atomically.
Any exception will cause PATH to be removed.
:param path: File to work with
:param remove: Optional function to remove passed path
"""
try:
yield
except Exception:
with excutils.save_and_reraise_exception():
remove(path)
def write_to_tempfile(content, path=None, suffix='', prefix='tmp'):
"""Create a temporary file containing data.
Create a temporary file containing specified content, with a specified
filename suffix and prefix. The tempfile will be created in a default
location, or in the directory `path`, if it is not None. `path` and its
parent directories will be created if they don't exist.
:param content: bytestring to write to the file
:param path: same as parameter 'dir' for mkstemp
:param suffix: same as parameter 'suffix' for mkstemp
:param prefix: same as parameter 'prefix' for mkstemp
For example: it can be used in database tests for creating
configuration files.
.. versionadded:: 1.9
"""
if path:
ensure_tree(path)
(fd, path) = tempfile.mkstemp(suffix=suffix, dir=path, prefix=prefix)
try:
os.write(fd, content)
finally:
os.close(fd)
return path