def loadBefore(self, oid, tid):
"""
Return the most recent revision of oid before tid committed.
"""
if tid is maxtid or tid == maxtid:
# This is probably from ZODB.utils.load_current(), which
# is really trying to just get the current state of the
# object. This is almost entirely just from test cases; ZODB 5's mvccadapter
# doesn't even expose it, so ZODB.Connection doesn't use it.
#
# Shortcut the logic below by using load() (current),
# formatted in the way this method returns it:
#
# ``(state, tid # of state, tid_after_state)``
#
# where tid_after_state will naturally be None
return self.load(oid) + (None,)
oid_int = bytes8_to_int64(oid)
# TODO: This makes three separate queries, and also bypasses the cache.
# We should be able to fix at least the multiple queries.
if self.store_connection:
# Allow loading data from later transactions
# for conflict resolution.
# XXX: This doesn't seem to be used in conflict
# resolution. ZODB.ConflictResolution.tryToResolveConflict
# calls loadSerial(); About the only call in ZODB to
# loadBefore() is from BlobStorage.undo() (which
# RelStorage does not extend). Mixing and matching calls
# between connections using different isolation levels
# isn't great. Can we stop doing this?
cursor = self.store_connection.cursor
else:
cursor = self.load_connection.cursor
if not self.adapter.mover.exists(cursor, oid_int):
raise POSKeyError(oid)
state, start_tid = self.adapter.mover.load_before(
cursor, oid_int, bytes8_to_int64(tid))
if start_tid is None:
return None
if state is None:
# This can happen if something attempts to load
# an object whose creation has been undone, see load()
# This change fixes the test in
# TransactionalUndoStorage.checkUndoCreationBranch1
# self._log_keyerror doesn't work here, only in certain states.
raise POSKeyError(oid)
end_int = self.adapter.mover.get_object_tid_after(
cursor, oid_int, start_tid)
if end_int is not None:
end = int64_to_8bytes(end_int)
else:
end = None
return state, int64_to_8bytes(start_tid), end
def loadBlob(self, oid, serial):
"""Return the filename where the blob file can be found.
"""
filename = self.fshelper.getBlobFilename(oid, serial)
if not os.path.exists(filename):
raise POSKeyError("No blob file", oid, serial)
return filename
def patched_field_index_html(self,
instance,
REQUEST=None,
RESPONSE=None,
disposition='inline'):
""" Patch for index_html for field
"""
try:
blob = self._old_index_html(instance,
REQUEST=REQUEST,
RESPONSE=RESPONSE,
disposition=disposition)
if blob:
return blob
raise POSKeyError()
except POSKeyError:
logger.warning(
"BLOBWARNING: When doing index_html "
"for field %r for %r with request %r return an empty file", self,
instance, REQUEST)
if not RESPONSE:
RESPONSE = instance.REQUEST.RESPONSE
putils = getToolByName(instance, 'plone_utils')
putils.addPortalMessage('Discovered an empty BLOB file for %r' %
instance.absolute_url_path(),
type='warning')
RESPONSE.redirect(instance.absolute_url() + '/view')
def _loadBlobInternal(self, cursor, oid, serial, blob_lock=None):
blob_filename = self._cachedLoadBlobInternal(oid, serial)
if not blob_filename:
# All the blobs are in a shared directory. If the file
# isn't here, it's not anywhere.
raise POSKeyError("No blob file", oid, serial)
return blob_filename
def history(self, oid, version=None, size=1, filter=None):
# pylint:disable=unused-argument,too-many-locals
cursor = self.load_connection.cursor
oid_int = bytes8_to_int64(oid)
try:
rows = self.adapter.dbiter.iter_object_history(cursor, oid_int)
except KeyError:
raise POSKeyError(oid)
res = []
for tid_int, username, description, extension, length in rows:
tid = int64_to_8bytes(tid_int)
if extension:
d = loads(extension)
else:
d = {}
d.update({
"time": TimeStamp(tid).timeTime(),
"user_name": username or b'',
"description": description or b'',
"tid": tid,
"version": '',
"size": length,
"rs_tid_int": tid_int,
"rs_oid_int": oid_int,
})
if filter is None or filter(d):
res.append(d)
if size is not None and len(res) >= size:
break
return res
def load(self, oid, version=''):
# pylint:disable=unused-argument
oid_int = bytes8_to_int64(oid)
state, tid_int = self.__load_using_method(self.cache.load, oid_int)
if tid_int is None:
_log_keyerror(self.load_connection.cursor,
self.adapter,
oid_int,
"no tid found")
raise POSKeyError(oid)
if not state:
# This can happen if something attempts to load
# an object whose creation has been undone or which was deleted
# by IExternalGC.deleteObject().
_log_keyerror(self.load_connection.cursor,
self.adapter,
oid_int,
"creation has been undone")
raise POSKeyError(oid)
return state, int64_to_8bytes(tid_int)
def _loadBack_impl(self, oid, back, fail=True):
# shared implementation used by various _loadBack methods
#
# If the backpointer ultimately resolves to 0:
# If fail is True, raise KeyError for zero backpointer.
# If fail is False, return the empty data from the record
# with no backpointer.
while 1:
if not back:
# If backpointer is 0, object does not currently exist.
raise POSKeyError(oid)
h = self._read_data_header(back)
if h.plen:
return self._file.read(h.plen), h.tid, back, h.tloc
if h.back == 0 and not fail:
return None, h.tid, back, h.tloc
back = h.back
def _loadBlobLocked(self, cursor, oid, serial, blob_filename):
"""
Returns a filename that exists on disk, or raises a POSKeyError.
"""
# OK, it's not here and we (or someone) needs to get it. We
# want to avoid getting it multiple times. We want to avoid
# getting it multiple times even accross separate client
# processes on the same machine. We'll use file locking.
# (accomplished by our caller.)
# We got the lock, so it's our job to download it. First,
# we'll double check that someone didn't download it while
# we were getting the lock:
if os.path.exists(blob_filename):
return self._accessed(blob_filename)
self.download_blob(cursor, oid, serial, blob_filename)
if os.path.exists(blob_filename):
return self._accessed(blob_filename)
raise POSKeyError("No blob file", oid, serial)
def loadSerial(self, oid, serial):
"""Load a specific revision of an object"""
oid_int = bytes8_to_int64(oid)
tid_int = bytes8_to_int64(serial)
# If we've got this state cached exactly,
# use it. No need to poll or anything like that first;
# polling is unlikely to get us the state we want.
# If the data happens to have been removed from the database,
# due to a pack, this won't detect it if it was already cached
# and the pack happened somewhere else. This method is
# only used for conflict resolution, though, and we
# shouldn't be able to get to that point if the root revision
# went missing, right? Packing periodically takes the same locks we
# want to take for committing.
state = self.cache.loadSerial(oid_int, tid_int)
if state:
return state
for conn in self.store_connection, self.load_connection:
if not conn:
continue
# Allow loading data from later transactions for conflict
# resolution. In fact try that first because it's more
# likely that our old load connection can't see this new
# state (because this method is used only for conflict resolution).
state = self.adapter.mover.load_revision(
conn.cursor, oid_int, tid_int)
if state is not None:
break
if state is None or not state:
raise POSKeyError(oid)
return state
def __getattr__(self, name):
raise POSKeyError(name)
