2020-01-21 19:40:02 +01:00

107 lines
4.3 KiB
Python

# This file is part of Radicale Server - Calendar Server
# Copyright © 2014 Jean-Marc Martins
# Copyright © 2012-2017 Guillaume Ayoub
# Copyright © 2017-2018 Unrud <unrud@outlook.com>
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Radicale. If not, see <http://www.gnu.org/licenses/>.
import os
import pickle
import time
from hashlib import sha256
from radicale import pathutils, storage
from radicale.log import logger
class CollectionCacheMixin:
def _clean_cache(self, folder, names, max_age=None):
"""Delete all ``names`` in ``folder`` that are older than ``max_age``.
"""
age_limit = time.time() - max_age if max_age is not None else None
modified = False
for name in names:
if not pathutils.is_safe_filesystem_path_component(name):
continue
if age_limit is not None:
try:
# Race: Another process might have deleted the file.
mtime = os.path.getmtime(os.path.join(folder, name))
except FileNotFoundError:
continue
if mtime > age_limit:
continue
logger.debug("Found expired item in cache: %r", name)
# Race: Another process might have deleted or locked the
# file.
try:
os.remove(os.path.join(folder, name))
except (FileNotFoundError, PermissionError):
continue
modified = True
if modified:
self._storage._sync_directory(folder)
@staticmethod
def _item_cache_hash(raw_text):
_hash = sha256()
_hash.update(storage.CACHE_VERSION)
_hash.update(raw_text)
return _hash.hexdigest()
def _item_cache_content(self, item, cache_hash=None):
text = item.serialize()
if cache_hash is None:
cache_hash = self._item_cache_hash(text.encode(self._encoding))
return (cache_hash, item.uid, item.etag, text, item.name,
item.component_name, *item.time_range)
def _store_item_cache(self, href, item, cache_hash=None):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
content = self._item_cache_content(item, cache_hash)
self._storage._makedirs_synced(cache_folder)
try:
# Race: Other processes might have created and locked the
# file.
with self._atomic_write(os.path.join(cache_folder, href),
"wb") as f:
pickle.dump(content, f)
except PermissionError:
pass
return content
def _load_item_cache(self, href, input_hash):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
cache_hash = uid = etag = text = name = tag = start = end = None
try:
with open(os.path.join(cache_folder, href), "rb") as f:
cache_hash, *content = pickle.load(f)
if cache_hash == input_hash:
uid, etag, text, name, tag, start, end = content
except FileNotFoundError:
pass
except (pickle.UnpicklingError, ValueError) as e:
logger.warning("Failed to load item cache entry %r in %r: %s",
href, self.path, e, exc_info=True)
return cache_hash, uid, etag, text, name, tag, start, end
def _clean_item_cache(self):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
self._clean_cache(cache_folder, (
e.name for e in os.scandir(cache_folder) if not
os.path.isfile(os.path.join(self._filesystem_path, e.name))))