AttributeError: 'ImageScalingQueueDataManager' object has no attribute 'savepoint'

[zopyx]

@datakurre

The queue scaling branch throws this exception in a few random cases:

020-05-14 16:41:03,679 ERROR   [Zope.SiteErrorLog:251][waitress] 1589467263.6787560.29447680220729955 http://localhost:20081/plone_portal/russiaplatform/en/news-events/events/POST_application_json_
Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 156, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 338, in publish_module
  Module ZPublisher.WSGIPublisher, line 256, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 62, in call_object
  Module plone.rest.service, line 22, in __call__
  Module plone.restapi.services, line 21, in render
  Module plone.restapi.services.content.add, line 89, in reply
  Module plone.restapi.services.content.utils, line 95, in add
  Module Products.BTreeFolder2.BTreeFolder2, line 464, in _setObject
  Module zope.event, line 32, in notify
  Module zope.component.event, line 27, in dispatch
  Module zope.component._api, line 124, in subscribers
  Module zope.interface.registry, line 442, in subscribers
  Module zope.interface.adapter, line 607, in subscribers
  Module zope.component.event, line 36, in objectEventNotify
  Module zope.component._api, line 124, in subscribers
  Module zope.interface.registry, line 442, in subscribers
  Module zope.interface.adapter, line 607, in subscribers
  Module plone.app.versioningbehavior.subscribers, line 109, in create_initial_version_after_adding
  Module Products.CMFEditions.CopyModifyMergeRepositoryTool, line 336, in save
  Module ugent.patches.products_cmfeditions, line 9, in _recursiveSave
  Module Products.CMFEditions.ArchivistTool, line 267, in prepare
  Module Products.CMFEditions.ModifierRegistryTool, line 135, in getReferencedAttributes
  Module plone.app.versioningbehavior.modifiers, line 116, in getReferencedAttributes
  Module Products.CMFEditions.CopyModifyMergeRepositoryTool, line 410, in retrieve
  Module Products.CMFEditions.CopyModifyMergeRepositoryTool, line 557, in _retrieve
  Module transaction._manager, line 267, in savepoint
  Module transaction._manager, line 147, in savepoint
  Module transaction._transaction, line 229, in savepoint
  Module transaction._transaction, line 345, in _saveAndRaiseCommitishError
  Module transaction._compat, line 50, in reraise
  Module transaction._transaction, line 226, in savepoint
  Module transaction._transaction, line 714, in __init__
TypeError: ('Savepoints unsupported', <plone.namedfile.queue.ImageScalingQueueDataManager object at 0x7f2494d526a0>)
2020-05-14 16:41:04,032 ERROR   [txn.139806391416576:465][waitress] Error in tpc_abort() on manager <Connection at 7f2744a35470>
Traceback (most recent call last):
  File "/home/ajung/sandboxes/ugent-portaal-plone-4x/eggs/transaction-2.4.0-py3.7.egg/transaction/_transaction.py", line 711, in __init__
    savepoint = datamanager.savepoint
AttributeError: 'ImageScalingQueueDataManager' object has no attribute 'savepoint'

[datakurre]

@zopyx Awesome! Thanks for testing and reporting. (Not the first transaction manager where I forget the existence of savepoints...)

[zopyx]

@datakurre is there a simple workaround for this issue or a way to ignore the missing savepoint() implementation safely?

[datakurre]

@zopyx In the case of CMDEditions I don't know any, and I'm sorry that I have not been able to work on this yet.

That said a very minimal savepoint implementation should be enough.

A quess for the required implementation: ImageScalingQueueDataManager should implement ISavepointDatamanager with method savepoint returning a dummy IDatamanagerSavepoint object. Dummy should be enough, because ImageScalingQueueDataManager does nothing in its commit (it only queues at the end of the second phase of the commit, tpc_finish).

@implementer(IDataManagerSavepoint)
class NoOpSavepoint(object):
    def rollback(self):
        return

@implementer(ISavepointDataManager)
class ImageScalingQueueDataManager(object):
    ...
    def savepoint(self):
        return NoOpSavepoint()

plone.namedfile/plone/namedfile/queue.py

Line 294 in e755a8a

class ImageScalingQueueDataManager(object):

According to https://github.com/zopefoundation/transaction/blob/master/transaction/interfaces.py

[mauritsvanrees]

@datakurre Any plans of turning your branch into a PR? Or is more work needed?

The transaction savepoint code from your last comment seems good. It works fine when I try the same fix for zope.sendmail.delivery, which suffers from the same problem in combination with CMFEditions. BTW, that is for the same customer as Andreas reported this namedfile problem for.

[datakurre]

Plans yes, scheduled time no :( For real pull this needs rebasing and tests. But I have been running this for a few production sites since the development, and I definitely want to have this also in the future. Thanks for confirming the savepoint. It is also encouraging to know that there’s some interest for this.

…

On 17. Dec 2020, 18.27 +0200, Maurits van Rees ***@***.***>, wrote: @datakurre Any plans of turning your branch into a PR? Or is more work needed? The transaction savepoint code from your last comment seems good. It works fine when I try the same fix for zope.sendmail.delivery, which suffers from the same problem in combination with CMFEditions. BTW, that is for the same customer as Andreas reported this namedfile problem for. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.