Hi Tim, I have two suggestions, I hope one of them helps. 1) Attached is a TM.py file that I wrote based on the one you mention below. I've tried to make it more obvious and better documented. 2) Don't use this kind of functionality, but rather use sub-transaction commits. The first suggestion has more overhead than what I assume you would need, but the second one won't work for all situations. A Fishbowl proposal of mine, HashingSupport, was going to use the same kind of hook you are asking about. In this case though, using sub-transaction commits made a lot more sense. In general though, I think that _v_* attributes pose a non-trivial problem that probably requires a hook on abort() if not commit() as well. John Tim McLaughlin wrote: > Is there a hook for before the transaction is committed for objects which > subclass Persistent? I found __inform_commit__ for a "registered" object, > but I can't seem to get that to work as I thought it did. I also tried > subclassing TM like a DA, but to no avail. > > TIA, > Tim > > ___________________________________________________________ > Tim McLaughlin BCSwebservices.net > Director, Technical Group 1950 Old Gallows Road > tel: (703) 790.8081 x111 Suite 201 > [EMAIL PROTECTED] Vienna, VA 22182 > www .bcswebservices. net > > > _______________________________________________ > Zope-Dev maillist - [EMAIL PROTECTED] > http://lists.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope ) -- . . . . . . . . . . . . . . . . . . . . . . . . John D. Heintz | Senior Engineer 1016 La Posada Dr. | Suite 240 | Austin TX 78752 T 512.633.1198 | [EMAIL PROTECTED] w w w . d a t a c h a n n e l . c o m
############################################################################## # # Zope Public License (ZPL) Version 1.0 # ------------------------------------- # # Copyright (c) Digital Creations. All rights reserved. # # This license has been certified as Open Source(tm). # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are # met: # # 1. Redistributions in source code must retain the above copyright # notice, this list of conditions, and the following disclaimer. # # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions, and the following disclaimer in # the documentation and/or other materials provided with the # distribution. # # 3. Digital Creations requests that attribution be given to Zope # in any manner possible. Zope includes a "Powered by Zope" # button that is installed by default. 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Modified redistributions of any form whatsoever must retain # the following acknowledgment: # # "This product includes software developed by Digital Creations # for use in the Z Object Publishing Environment # (http://www.zope.org/)." # # Intact (re-)distributions of any official Zope release do not # require an external acknowledgement. # # 7. Modifications are encouraged but must be packaged separately as # patches to official Zope releases. Distributions that do not # clearly separate the patches from the original work must be clearly # labeled as unofficial distributions. Modifications which do not # carry the name Zope may be packaged in any form, as long as they # conform to all of the clauses above. # # # Disclaimer # # THIS SOFTWARE IS PROVIDED BY DIGITAL CREATIONS ``AS IS'' AND ANY # EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DIGITAL CREATIONS OR ITS # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF # USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # # # This software consists of contributions made by Digital Creations and # many individuals on behalf of Digital Creations. Specific # attributions are listed in the accompanying credits file. # ############################################################################## """Provide support for linking an external transaction manager with Zope's """ class TM: """Mix-in class that provides transaction management support A sub class should call self._register() whenever it performs any transaction-dependent operations (e.g. sql statements). The sub class will need to override: _begin if necessary _vote to raise an except if necessary _finish to finallize work, _abort to roll-back work """ def _begin(self): """Hook method to begin external transaction. This may be called multiple times,""" pass def _vote(self): """Hook method to vote on success of transaction commit. This will only be called once,""" pass def _finish(self): """Hook method to complete transaction work. This may be called multiple times.""" pass def _abort(self): """Hook method to undo transaction work. This may be called multiple times.""" pass _registered=None class Surrogate: "A ZODB persistent look-alike." def __init__(self, connection): self._p_jar=connection def _register(self): """This method will register a surrogate persistent object with the transaction. This surrogate will include me in the tpc_* two-phase commit process.""" if not self._registered: try: get_transaction().register(TM.Surrogate(self)) self._registered=1 except: import traceback traceback.print_exc() pass def commit(self, *ignored): "We don't need to actually do an storing." pass def tpc_begin(self, *ignored): "Connection method to begin a commit." self._begin() def tpc_vote(self, *ignored): "Connection method to vote on commit success." self._vote() def tpc_finish(self, *ignored): """Connection method to signal commit success. This should *never* fail""" try: self._finish() finally: self._registered=0 def abort(self, *ignored): """Connnection method to signal commit failure. This should *never* fail""" try: self._abort() finally: self._registered=0
