Refactor: Extract item cache methods

This commit is contained in:
Unrud 2017-07-27 19:08:04 +02:00
parent 46c636e642
commit 0a1de26ae5

View File

@ -1179,6 +1179,55 @@ class Collection(BaseCollection):
item, metadata = self._get_with_metadata(href, verify_href=verify_href)
return item
def _item_cache_hash(self, raw_text):
_hash = md5()
_hash.update(self._item_cache_tag)
_hash.update(raw_text)
return _hash.hexdigest()
def _store_item_cache(self, href, vobject_item, cache_hash=None):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
text = vobject_item.serialize()
if cache_hash is None:
cache_hash = self._item_cache_hash(text.encode(self._encoding))
etag = get_etag(text)
uid = get_uid_from_object(vobject_item)
tag, start, end = xmlutils.find_tag_and_time_range(vobject_item)
self._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((cache_hash, uid, etag, text,
tag, start, end), f)
except PermissionError:
pass
return cache_hash, uid, etag, text, tag, start, end
def _load_item_cache(self, href):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
cache_hash = uid = etag = text = tag = start = end = None
try:
with open(os.path.join(cache_folder, href), "rb") as f:
cache_hash, uid, etag, text, tag, start, end = pickle.load(f)
except FileNotFoundError as e:
pass
except (pickle.UnpicklingError, ValueError) as e:
self.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, tag, start, end
def _clean_item_cache(self):
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
self._clean_cache(cache_folder, (
href for href in scandir(cache_folder) if not
os.path.isfile(os.path.join(self._filesystem_path, href))))
def _get_with_metadata(self, href, verify_href=True):
"""Like ``get`` but additonally returns the following metadata:
tag, start, end: see ``xmlutils.find_tag_and_time_range``. If
@ -1197,74 +1246,41 @@ class Collection(BaseCollection):
path = os.path.join(self._filesystem_path, href)
try:
with open(path, "rb") as f:
btext = f.read()
raw_text = f.read()
except (FileNotFoundError, IsADirectoryError):
return None, None
# The hash of the component in the file system. This is used to check,
# if the entry in the cache is still valid.
input_hash = md5()
input_hash.update(self._item_cache_tag)
input_hash.update(btext)
input_hash = input_hash.hexdigest()
cache_folder = os.path.join(self._filesystem_path, ".Radicale.cache",
"item")
cinput_hash = cuid = cetag = ctext = ctag = cstart = cend = None
try:
with open(os.path.join(cache_folder, href), "rb") as f:
cinput_hash, cuid, cetag, ctext, ctag, cstart, cend = \
pickle.load(f)
except FileNotFoundError as e:
pass
except (pickle.UnpicklingError, ValueError) as e:
self.logger.warning(
"Failed to load item cache entry %r in %r: %s",
href, self.path, e, exc_info=True)
input_hash = self._item_cache_hash(raw_text)
cache_hash, uid, etag, text, tag, start, end = self._load_item_cache(
href)
vobject_item = None
if input_hash != cinput_hash:
if input_hash != cache_hash:
try:
vobject_item = Item(self, href=href,
text=btext.decode(self._encoding)).item
check_and_sanitize_item(vobject_item, uid=cuid,
vobject_items = tuple(vobject.readComponents(
raw_text.decode(self._encoding)))
if len(vobject_items) != 1:
raise RuntimeError(
"Content contains %d components" % len(vobject_items))
vobject_item = vobject_items[0]
check_and_sanitize_item(vobject_item, uid=uid,
tag=self.get_meta("tag"))
# Serialize the object again, to normalize the text
# representation. The storage may have been edited externally.
ctext = vobject_item.serialize()
cache_hash, uid, etag, text, tag, start, end = \
self._store_item_cache(href, vobject_item, input_hash)
except Exception as e:
raise RuntimeError("Failed to load item %r in %r: %s" %
(href, self.path, e)) from e
cetag = get_etag(ctext)
cuid = get_uid_from_object(vobject_item)
try:
ctag, cstart, cend = xmlutils.find_tag_and_time_range(
vobject_item)
except Exception as e:
raise RuntimeError("Failed to find tag and time range of item "
"%r from %r: %s" % (href, self.path,
e)) from e
self._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((input_hash, cuid, cetag, ctext,
ctag, cstart, cend), f)
except PermissionError:
pass
# Clean cache entries (max once per request)
# This happens once after new uploads, or if the data in the
# file system was edited externally.
# Clean cache entriesn once after the data in the file system was
# edited externally.
if not self._item_cache_cleaned:
self._item_cache_cleaned = True
self._clean_cache(cache_folder, (
href for href in scandir(cache_folder) if not
os.path.isfile(os.path.join(self._filesystem_path, href))))
self._clean_item_cache()
last_modified = time.strftime(
"%a, %d %b %Y %H:%M:%S GMT",
time.gmtime(os.path.getmtime(path)))
return Item(
self, href=href, last_modified=last_modified, etag=cetag,
text=ctext, item=vobject_item, uid=cuid), (ctag, cstart, cend)
self, href=href, last_modified=last_modified, etag=etag,
text=text, item=vobject_item, uid=uid), (tag, start, end)
def get_multi2(self, hrefs):
# It's faster to check for file name collissions here, because