import contextlib
import os
import shutil
import tempfile
_cache_root = os.environ.get(
'LINEFLOW_ROOT',
os.path.join(os.path.expanduser('~'), '.cache', 'lineflow'))
@contextlib.contextmanager
def tempdir(**kwargs):
ignore_errors = kwargs.pop('ignore_errors', False)
temp_dir = tempfile.mkdtemp(**kwargs)
try:
yield temp_dir
finally:
shutil.rmtree(temp_dir, ignore_errors=ignore_errors)
def get_cache_root() -> str:
return _cache_root
def set_cache_root(path: str) -> None:
global _cache_root
_cache_root = path
def get_cache_directory(cache_name: str,
create_directory: bool = True) -> str:
path = os.path.join(_cache_root, cache_name)
if create_directory:
try:
os.makedirs(path)
except OSError:
if not os.path.isdir(path):
raise
return path
def cache_or_load_file(path, creator, loader):
if os.path.exists(path):
return loader(path)
try:
os.makedirs(_cache_root)
except OSError:
if not os.path.isdir(_cache_root):
raise RuntimeError('cannot create cache directory')
with tempdir() as temp_dir:
filename = os.path.basename(path)
temp_path = os.path.join(temp_dir, filename)
content = creator(temp_path)
if not os.path.exists(path):
shutil.move(temp_path, path)
return content
