pogojig/support/lib/util.py
Michael Schwarz 3566dbc943 PEP8
2017-09-20 20:33:29 +02:00

130 lines
3.2 KiB
Python

import contextlib
import inspect
import os
import re
import shutil
import subprocess
import sys
import tempfile
class UserError(Exception):
def __init__(self, message, *args):
super(UserError, self).__init__(message.format(*args))
def main(fn):
"""
Decorator for "main" functions. Decorates a function that should be
called when the containing module is run as a script (e.g. via python -m
<module>).
"""
frame = inspect.currentframe().f_back
def wrapped_fn(*args, **kwargs):
try:
fn(*args, **kwargs)
except UserError as e:
print >> sys.stderr, 'Error:', e
sys.exit(1)
except KeyboardInterrupt:
sys.exit(2)
if frame.f_globals['__name__'] == '__main__':
wrapped_fn(*sys.argv[1:])
# Allow the main function also to be called explicitly
return wrapped_fn
def rename_atomic(source_path, target_path):
"""
Move the file at source_path to target_path.
If both paths reside on the same device, os.rename() is used, otherwise
the file is copied to a temporary name next to target_path and moved from
there using os.rename().
"""
source_dir_stat = os.stat(os.path.dirname(source_path))
target_dir_stat = os.stat(os.path.dirname(target_path))
if source_dir_stat.st_dev == target_dir_stat.st_dev:
os.rename(source_path, target_path)
else:
temp_path = target_path + '~'
shutil.copyfile(source_path, temp_path)
os.rename(temp_path, target_path)
@contextlib.contextmanager
def TemporaryDirectory():
dir = tempfile.mkdtemp()
try:
yield dir
finally:
shutil.rmtree(dir)
@contextlib.contextmanager
def command_context(args, remove_env=[], set_env={}, working_dir=None, use_stderr=False):
env = dict(os.environ)
for i in remove_env:
del env[i]
for k, v in set_env.items():
env[k] = v
if use_stderr:
stderr = subprocess.PIPE
else:
stderr = None
try:
process = subprocess.Popen(args, env=env, cwd=working_dir, stderr=stderr)
except OSError as e:
raise UserError('Error running {}: {}', args[0], e)
try:
yield process
except:
try:
process.kill()
except OSError:
# Ignore exceptions here so we don't mask the
# already-being-thrown exception.
pass
raise
finally:
# Use communicate so that we won't deadlock if the process generates
# some unread output.
process.communicate()
if process.returncode:
raise UserError('Command failed: {}', ' '.join(args))
def command(args, remove_env=[], set_env={}, working_dir=None):
with command_context(args, remove_env, set_env, working_dir):
pass
def bash_escape_string(string):
return "'{}'".format(re.sub("'", "'\"'\"'", string))
def write_file(path, data):
temp_path = path + '~'
with open(temp_path, 'wb') as file:
file.write(data)
os.rename(temp_path, path)
def read_file(path):
with open(path, 'rb') as file:
return file.read()