view roundup/cgi/TAL/XMLParser.py @ 6433:c1d3fbcdbfbd

issue2551142 - Import of retired node ... unique constraint failure. Title: Import of retired node with username after active node fails with unique constraint failure. More fixes needed for mysql and postgresql. mysql: add unique constraint for (keyvalue, __retired__) when creating class in the database. On schema change if class is changed, remove the unique constraint too. upgrade version of rdbms database from 5 to 6 to add constraint to all version 5 databases that were created as version 5 and didn't get the unique constraint. Make no changes on version 5 databases upgraded from version 4, the upgrade process to 5 added the constraint. Make no changes to other databases (sqlite, postgres) during upgrade from version 5 to 6. postgres: Handle the exception raised on unique constraint violation. The exception invalidates the database connection so it can't be used to recover from the exception. Added two new database methods: checkpoint_data - performs a db.commit under postgres does nothing on other backends restore_connection_on_error - does a db.rollback on postgres, does nothing on other backends with the rollback() done on the connection I can use the database connection to fixup the import that failed on the unique constraint. This makes postgres slower but without the commit after every imported object, the rollback will delete all the entries done up to this point. Trying to figure out how to make the caller do_import batch and recover from this failure is beyond me. Also dismissed having to process the export csv file before importing. Pushing that onto a user just seems wrong. Also since import/export isn't frequently done the lack of surprise on having a failing import and reduced load/frustration for the user seems worth it. Also the import can be run in verbose mode where it prints out a row as it is processed, so it may take a while, ut the user can get feedback. db_test-base.py: add test for upgrade from 5 to 6.
author John Rouillard <rouilj@ieee.org>
date Thu, 10 Jun 2021 12:52:05 -0400
parents 14a61eabcea8
children
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##############################################################################
#
# Copyright (c) 2001, 2002 Zope Corporation 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.
# 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
#
##############################################################################
# Modifications for Roundup:
# 1. commented out zLOG references
# 2. use roundup.anypy.urllib_
"""
Generic expat-based XML parser base class.
"""

#import zLOG

class XMLParser:

    ordered_attributes = 0

    handler_names = [
        "StartElementHandler",
        "EndElementHandler",
        "ProcessingInstructionHandler",
        "CharacterDataHandler",
        "UnparsedEntityDeclHandler",
        "NotationDeclHandler",
        "StartNamespaceDeclHandler",
        "EndNamespaceDeclHandler",
        "CommentHandler",
        "StartCdataSectionHandler",
        "EndCdataSectionHandler",
        "DefaultHandler",
        "DefaultHandlerExpand",
        "NotStandaloneHandler",
        "ExternalEntityRefHandler",
        "XmlDeclHandler",
        "StartDoctypeDeclHandler",
        "EndDoctypeDeclHandler",
        "ElementDeclHandler",
        "AttlistDeclHandler"
        ]

    def __init__(self, encoding=None):
        self.parser = p = self.createParser()
        # Make sure we don't get fed unicode strings in Python 2 as we
        # can't handle those
        if hasattr(self.parser, 'returns_unicode'):
            self.parser.returns_unicode = False
        if self.ordered_attributes:
            try:
                self.parser.ordered_attributes = self.ordered_attributes
            except AttributeError:
                #zLOG.LOG("TAL.XMLParser", zLOG.INFO, 
                #         "Can't set ordered_attributes")
                self.ordered_attributes = 0
        for name in self.handler_names:
            method = getattr(self, name, None)
            if method is not None:
                try:
                    setattr(p, name, method)
                except AttributeError:
                    #zLOG.LOG("TAL.XMLParser", zLOG.PROBLEM,
                    #         "Can't set expat handler %s" % name)
                    pass

    def createParser(self, encoding=None):
        global XMLParseError
        try:
            from Products.ParsedXML.Expat import pyexpat
            XMLParseError = pyexpat.ExpatError
            return pyexpat.ParserCreate(encoding, ' ')
        except ImportError:
            from xml.parsers import expat
            XMLParseError = expat.ExpatError
            return expat.ParserCreate(encoding, ' ')

    def parseFile(self, filename):
        self.parseStream(open(filename))

    def parseString(self, s):
        self.parser.Parse(s, 1)

    def parseURL(self, url):
        import roundup.anypy.urllib_
        self.parseStream(roundup.anypy.urllib_.urlopen(url))

    def parseStream(self, stream):
        self.parser.ParseFile(stream)

    def parseFragment(self, s, end=0):
        self.parser.Parse(s, end)

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