147 lines
4.1 KiB
Python
147 lines
4.1 KiB
Python
|
import hashlib
|
||
|
|
import os
|
||
|
|
from textwrap import dedent
|
||
|
|
|
||
|
|
from ..cache import BaseCache
|
||
|
|
from ..controller import CacheController
|
||
|
|
|
||
|
|
try:
|
||
|
|
FileNotFoundError
|
||
|
|
except NameError:
|
||
|
|
# py2.X
|
||
|
|
FileNotFoundError = (IOError, OSError)
|
||
|
|
|
||
|
|
|
||
|
|
def _secure_open_write(filename, fmode):
|
||
|
|
# We only want to write to this file, so open it in write only mode
|
||
|
|
flags = os.O_WRONLY
|
||
|
|
|
||
|
|
# os.O_CREAT | os.O_EXCL will fail if the file already exists, so we only
|
||
|
|
# will open *new* files.
|
||
|
|
# We specify this because we want to ensure that the mode we pass is the
|
||
|
|
# mode of the file.
|
||
|
|
flags |= os.O_CREAT | os.O_EXCL
|
||
|
|
|
||
|
|
# Do not follow symlinks to prevent someone from making a symlink that
|
||
|
|
# we follow and insecurely open a cache file.
|
||
|
|
if hasattr(os, "O_NOFOLLOW"):
|
||
|
|
flags |= os.O_NOFOLLOW
|
||
|
|
|
||
|
|
# On Windows we'll mark this file as binary
|
||
|
|
if hasattr(os, "O_BINARY"):
|
||
|
|
flags |= os.O_BINARY
|
||
|
|
|
||
|
|
# Before we open our file, we want to delete any existing file that is
|
||
|
|
# there
|
||
|
|
try:
|
||
|
|
os.remove(filename)
|
||
|
|
except (IOError, OSError):
|
||
|
|
# The file must not exist already, so we can just skip ahead to opening
|
||
|
|
pass
|
||
|
|
|
||
|
|
# Open our file, the use of os.O_CREAT | os.O_EXCL will ensure that if a
|
||
|
|
# race condition happens between the os.remove and this line, that an
|
||
|
|
# error will be raised. Because we utilize a lockfile this should only
|
||
|
|
# happen if someone is attempting to attack us.
|
||
|
|
fd = os.open(filename, flags, fmode)
|
||
|
|
try:
|
||
|
|
return os.fdopen(fd, "wb")
|
||
|
|
|
||
|
|
except:
|
||
|
|
# An error occurred wrapping our FD in a file object
|
||
|
|
os.close(fd)
|
||
|
|
raise
|
||
|
|
|
||
|
|
|
||
|
|
class FileCache(BaseCache):
|
||
|
|
|
||
|
|
def __init__(
|
||
|
|
self,
|
||
|
|
directory,
|
||
|
|
forever=False,
|
||
|
|
filemode=0o0600,
|
||
|
|
dirmode=0o0700,
|
||
|
|
use_dir_lock=None,
|
||
|
|
lock_class=None,
|
||
|
|
):
|
||
|
|
|
||
|
|
if use_dir_lock is not None and lock_class is not None:
|
||
|
|
raise ValueError("Cannot use use_dir_lock and lock_class together")
|
||
|
|
|
||
|
|
try:
|
||
|
|
from lockfile import LockFile
|
||
|
|
from lockfile.mkdirlockfile import MkdirLockFile
|
||
|
|
except ImportError:
|
||
|
|
notice = dedent(
|
||
|
|
"""
|
||
|
|
NOTE: In order to use the FileCache you must have
|
||
|
|
lockfile installed. You can install it via pip:
|
||
|
|
pip install lockfile
|
||
|
|
"""
|
||
|
|
)
|
||
|
|
raise ImportError(notice)
|
||
|
|
|
||
|
|
else:
|
||
|
|
if use_dir_lock:
|
||
|
|
lock_class = MkdirLockFile
|
||
|
|
|
||
|
|
elif lock_class is None:
|
||
|
|
lock_class = LockFile
|
||
|
|
|
||
|
|
self.directory = directory
|
||
|
|
self.forever = forever
|
||
|
|
self.filemode = filemode
|
||
|
|
self.dirmode = dirmode
|
||
|
|
self.lock_class = lock_class
|
||
|
|
|
||
|
|
@staticmethod
|
||
|
|
def encode(x):
|
||
|
|
return hashlib.sha224(x.encode()).hexdigest()
|
||
|
|
|
||
|
|
def _fn(self, name):
|
||
|
|
# NOTE: This method should not change as some may depend on it.
|
||
|
|
# See: https://github.com/ionrock/cachecontrol/issues/63
|
||
|
|
hashed = self.encode(name)
|
||
|
|
parts = list(hashed[:5]) + [hashed]
|
||
|
|
return os.path.join(self.directory, *parts)
|
||
|
|
|
||
|
|
def get(self, key):
|
||
|
|
name = self._fn(key)
|
||
|
|
try:
|
||
|
|
with open(name, "rb") as fh:
|
||
|
|
return fh.read()
|
||
|
|
|
||
|
|
except FileNotFoundError:
|
||
|
|
return None
|
||
|
|
|
||
|
|
def set(self, key, value):
|
||
|
|
name = self._fn(key)
|
||
|
|
|
||
|
|
# Make sure the directory exists
|
||
|
|
try:
|
||
|
|
os.makedirs(os.path.dirname(name), self.dirmode)
|
||
|
|
except (IOError, OSError):
|
||
|
|
pass
|
||
|
|
|
||
|
|
with self.lock_class(name) as lock:
|
||
|
|
# Write our actual file
|
||
|
|
with _secure_open_write(lock.path, self.filemode) as fh:
|
||
|
|
fh.write(value)
|
||
|
|
|
||
|
|
def delete(self, key):
|
||
|
|
name = self._fn(key)
|
||
|
|
if not self.forever:
|
||
|
|
try:
|
||
|
|
os.remove(name)
|
||
|
|
except FileNotFoundError:
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
def url_to_file_path(url, filecache):
|
||
|
|
"""Return the file cache path based on the URL.
|
||
|
|
|
||
|
|
This does not ensure the file exists!
|
||
|
|
"""
|
||
|
|
key = CacheController.cache_url(url)
|
||
|
|
return filecache._fn(key)
|