Bug 641735 – Performance issue with perl-XML-SAX-0.14-8

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Bug 641735 - Performance issue with perl-XML-SAX-0.14-8

Summary:	Performance issue with perl-XML-SAX-0.14-8

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 5
Classification:	Red Hat
Component:	perl-XML-SAX (Show other bugs)
Sub Component:
Version:	5.5
Hardware:	All Linux

Priority	low Severity medium
Target Milestone:	rc
Target Release:	---
Assigned To:	Petr Pisar
QA Contact:	Petr Šplíchal
Docs Contact:

URL:
Whiteboard:
Keywords:	Patch

Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2010-10-10 15:44 EDT by Remi Collet
Modified:	2016-05-31 21:40 EDT (History)
CC List:	6 users (show)

See Also:
Fixed In Version:	perl-XML-SAX-0.14-10
Doc Type:	Bug Fix
Doc Text:	Cause Parsing long XML document through XML::Simple API if XML::SAX parser implementation is available. Consequence The parser running time is unacceptably long. Fix XML::SAX parser copied XML string on each token match. More efficient handling of consequent reading has been back-ported. Result Long XML documents are parsed in reasonable time.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2011-11-13 22:06:59 EST
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Simple test case (697.27 KB, text/plain) 2010-10-10 15:44 EDT, Remi Collet	no flags	Details
Test case (697.27 KB, text/plain) 2011-08-26 07:37 EDT, Petr Pisar	no flags	Details
Fix back-ported from 0.96 (2.15 KB, patch) 2011-08-26 08:08 EDT, Petr Pisar	no flags	Details \| Diff
Show Obsolete (1) Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
CPAN	29316	None	None	None	Never
Red Hat Product Errata	RHBA-2011:1446	normal	SHIPPED_LIVE	perl-XML-SAX bug fix update	2011-11-14 03:02:40 EST

Groups: None (edit)

Description Remi Collet 2010-10-10 15:44:28 EDT

Created attachment 452609 [details]
Simple test case

With the simple test attached, we notice really big perfomance issue when parsing large input which seems related to 
https://rt.cpan.org/Public/Bug/Display.html?id=29316
This issue is not present with more recent version

***** Test on Fedora 14 (perl-XMl-SAX-0.96-10)

# yum install perl-XML-Simple

$ time perl testxml.pl 
Request length : 714002
Parsed length : 15
real	0m0.829s

# yum install perl-XML-SAX

$ time perl testxml.pl 
Request length : 714002
Parsed length : 15
real	0m16.643s

***** Test on Red Hat Enterprise Linux 5.5

# yum install perl-XML-Simple

$ time perl /tmp/testxml.pl 
Request length : 713976
Parsed length : 16
real	0m0.890s

# yum install perl-XML-SAX

$ time perl /tmp/testxml.pl 
Request length : 713976
Parsed length : 16
real	9m20.425s

Comment 1 Remi Collet 2010-10-10 16:08:24 EDT

Of course, in the attached test case, the line 
$XML::Simple::PREFERRED_PARSER = 'XML::Parser'
Should be removed... (this is a workround to this issue)

Comment 2 Marcela Mašláňová 2010-10-11 03:17:31 EDT

Thanks for your report. Patch looks applicable on RHEL-5 version.

Comment 4 Petr Pisar 2011-08-26 07:37:53 EDT

Created attachment 520073 [details]
Test case

This is stricter version of original test case to prevent unintended here-document expansion.

Comment 5 Petr Pisar 2011-08-26 08:08:00 EDT

Created attachment 520075 [details]
Fix back-ported from 0.96

Comment 7 Petr Pisar 2011-10-06 03:37:47 EDT

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Cause
    Parsing long XML document through XML::Simple API if
    XML::SAX parser implementation is available.
Consequence
    The parser running time is unacceptably long.
Fix
    XML::SAX parser copied XML string on each token match.
    More efficient handling of consequent reading has been
    back-ported.
Result
    Long XML documents are parsed in reasonable time.

Comment 12 errata-xmlrpc 2011-11-13 22:06:59 EST

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1446.html

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