Commit 1289391c authored by Yoshinori Okuji's avatar Yoshinori Okuji

Backport beforeCommitHook from Zope 2.8.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@16724 20353a03-c40f-0410-a6d1-a30d3c3de9de
parent 7e8e812e
##############################################################################
############################################################################
#
# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
# Copyright (c) 2002,2005 Nexedi SARL and Contributors. All Rights Reserved.
# Copyright (c) 2004 Zope Corporation and Contributors.
# Copyright (c) 2002,2005,2007 Nexedi SA and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
############################################################################
import sys
# Adding commit_prepare to the zodb transaction
# Add beforeCommitHook into Transaction under Zope 2.7. This API is compatible
# with Zope 2.8.
try:
from ZODB import Transaction, POSException
from zLOG import LOG, ERROR
from ZODB.Transaction import Transaction
super__commit = Transaction.commit
super__init = Transaction.__init__
hosed = Transaction.hosed
hosed_msg = Transaction.hosed_msg
free_transaction = Transaction.free_transaction
jar_cmp = Transaction.jar_cmp
def __init__(self, *args, **kw):
super__init(self, *args, **kw)
self._before_commit = []
def commit(self, subtransaction=None):
"""Finalize the transaction."""
objects = self._objects
subjars = []
if subtransaction:
if self._sub is None:
# Must store state across multiple subtransactions
# so that the final commit can commit all subjars.
self._sub = {}
else:
if self._sub is not None:
# This commit is for a top-level transaction that
# has previously committed subtransactions. Do
# one last subtransaction commit to clear out the
# current objects, then commit all the subjars.
if objects:
self.commit(1)
objects = []
subjars = self._sub.values()
subjars.sort(jar_cmp)
self._sub = None
# If there were any non-subtransaction-aware jars
# involved in earlier subtransaction commits, we need
# to add them to the list of jars to commit.
if self._non_st_objects is not None:
objects.extend(self._non_st_objects)
self._non_st_objects = None
if (objects or subjars) and hosed:
# Something really bad happened and we don't
# trust the system state.
raise POSException.TransactionError, hosed_msg
# It's important that:
#
# - Every object in self._objects is either committed or
# aborted.
#
# - For each object that is committed we call tpc_begin on
# it's jar at least once
#
# - For every jar for which we've called tpc_begin on, we
# either call tpc_abort or tpc_finish. It is OK to call
# these multiple times, as the storage is required to ignore
# these calls if tpc_begin has not been called.
#
# - That we call tpc_begin() in a globally consistent order,
# so that concurrent transactions involving multiple storages
# do not deadlock.
try:
ncommitted = 0
jars = self._get_jars(objects, subtransaction)
try:
# Do prepare until number of jars is stable - this could
# create infinite loop
jars_len = -1
objects_len = len(self._objects)
while len(jars) != jars_len:
jars_len = len(jars)
self._commit_prepare(jars, subjars, subtransaction)
if len(self._objects) != objects_len:
objects.extend(self._objects[objects_len:])
objects_len = len(self._objects)
jars = self._get_jars(objects, subtransaction)
# If not subtransaction, then jars will be modified.
self._commit_begin(jars, subjars, subtransaction)
ncommitted += self._commit_objects(objects)
if not subtransaction:
# Unless this is a really old jar that doesn't
# implement tpc_vote(), it must raise an exception
# if it can't commit the transaction.
for jar in jars:
try:
vote = jar.tpc_vote
except AttributeError:
pass
else:
vote(self)
# Handle multiple jars separately. If there are
# multiple jars and one fails during the finish, we
# mark this transaction manager as hosed.
if len(jars) == 1:
self._finish_one(jars[0])
else:
self._finish_many(jars)
except:
# Ugh, we got an got an error during commit, so we
# have to clean up. First save the original exception
# in case the cleanup process causes another
# exception.
error = sys.exc_info()
try:
self._commit_error(objects, ncommitted, jars, subjars)
except:
LOG('ZODB', ERROR,
"A storage error occured during transaction "
"abort. This shouldn't happen.",
error=error)
raise error[0], error[1], error[2]
finally:
del objects[:] # clear registered
if not subtransaction and self._id is not None:
free_transaction()
def _commit_prepare(self, jars, subjars, subtransaction):
if subtransaction:
assert not subjars
for jar in jars:
tpc_prepare = getattr(jar, 'tpc_prepare', None)
if tpc_prepare is not None:
try:
tpc_prepare(self, subtransaction)
except TypeError:
# Assume that TypeError means that tpc_begin() only
# takes one argument, and that the jar doesn't
# support subtransactions.
tpc_prepare(self)
else:
# Perform tpc_prepare for both jars and subjars.
# Note that it must not be executed for the same jar
# more than once. Also, this should not merge the jars
# in place, as _commit_begin will do that.
for jar in subjars:
tpc_prepare = getattr(jar, 'tpc_prepare', None)
if tpc_prepare is not None:
tpc_prepare(self)
for jar in jars:
if jar not in subjars:
tpc_prepare = getattr(jar, 'tpc_prepare', None)
if tpc_prepare is not None:
tpc_prepare(self)
Transaction.Transaction.commit = commit
Transaction.Transaction._commit_prepare = _commit_prepare
self._callBeforeCommitHooks()
return super__commit(self, subtransaction=subtransaction)
def beforeCommitHook(self, hook, *args, **kws):
self._before_commit.append((hook, args, kws))
def _callBeforeCommitHooks(self):
# Call all hooks registered, allowing further registrations
# during processing.
while self._before_commit:
hook, args, kws = self._before_commit.pop(0)
hook(*args, **kws)
from new import instancemethod
Transaction.__init__ = instancemethod(__init__, None, Transaction)
Transaction.commit = instancemethod(commit, None, Transaction)
Transaction.beforeCommitHook = instancemethod(beforeCommitHook, None,
Transaction)
Transaction._callBeforeCommitHooks = instancemethod(_callBeforeCommitHooks,
None, Transaction)
except ImportError:
# On Zope 2.8, do not patch Transaction. Instead, we use a before commit hook.
# On Zope 2.8, do not patch Transaction.
pass
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