Enhancing parsing performance 2003-01-13 - By Jean Georges PERRIN
Hi,
Thanks for the hope message!
I was timing the whole method, I focused on parser creation and parse time
now.
I changed my code to:
public void load () {
DOMParser parser;
Logger log = ThinStructureConfiguration.getInstance().getLogger();
try {
long start = System.currentTimeMillis();
parser = new DOMParser();
long stop = System.currentTimeMillis();
log.finest ("Creating parser took " + (stop - start) + " ms");
}
catch (Exception e) {
log.severe ("Error: Unable to instantiate parser");
return;
}
try {
long start = System.currentTimeMillis();
parser.parse(m_file.toURI().toString());
long stop = System.currentTimeMillis();
log.finest ("Parsing of " + m_file.getName() + " took " + (stop -
start) + " ms");
m_document = parser.getDocument();
}
catch (SAXParseException e) {
// ignore
}
catch (Exception e) {
String msg;
msg = ("Error: Parse error occurred, " + e.getMessage());
if (e instanceof SAXException) {
e = ((SAXException)e).getException();
}
msg += '\n' + e.toString();
log.severe (msg);
}
}
Results are:
Jan 13, 2003 11:52:20 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Creating parser took 251 ms
Jan 13, 2003 11:52:25 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Parsing of emailpassword.xhtml took 5227 ms
Jan 13, 2003 11:52:25 PM com.awoma.ts.ui.Store add
INFO: Window definition emailpassword.xhtml added.
Jan 13, 2003 11:52:25 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Creating parser took 10 ms
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Parsing of emailpassword2.xhtml took 3085 ms
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.Store add
INFO: Window definition emailpassword2.xhtml added.
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Creating parser took 0 ms
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Parsing of emailpassword3.xhtml took 10 ms
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.Store add
INFO: Window definition emailpassword3.xhtml added.
Jan 13, 2003 11:52:29 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Creating parser took 0 ms
Jan 13, 2003 11:52:31 PM com.awoma.ts.ui.impl.XHTML11Window load
FINEST: Parsing of emailpassword4.xhtml took 2774 ms
All files are identical, except #3 where I removed all references to the
external world.
I use Xerces J 2.2.1 (according to build.xml).
Conclusions & questions:
1/ Creation of DOMParser() is slow the first time, but ridiculous
afterwards, so there is no need for enhancing that much.
2/ My parser seems to want to check the validity through external
connection. How can I remove those without modifying all my files?
jgp
> -----Original Message-----
> From: Simon Kitching [mailto:simon@(protected)]
> Sent: Monday, January 13, 2003 23:24
> To: jgp@(protected)
> Cc: xerces-j-user@(protected)
> Subject: Re: Enhancing parsing performance
>
> Hi Jean Georges,
>
> Firstly, does the document you are parsing contain a DTD or schema
> reference? If it uses http://acme.com/xyz.dtd, then much of your parsing
> time may actually be in retrieval of the remote dtd. And if the
> dtd/schema is large then time will be spent processing it. If this is
> the case, there are optimisations available for both these problems.
>
> Secondly, you don't say exactly what you are timing. Is it the complete
> application time, or the time taken by the method you include below, or
> just the time for the parse method?
>
> Thirdly, you don't mention which version of Xerces you are using...
>
> Providing information on the above would allow people to provide better
> suggestions for you..
>
> I certainly see better performance than you do, so there is hope :-)
>
> Regards,
>
> Simon
>
> On Tue, 2003-01-14 at 10:56, Jean Georges PERRIN wrote:
> > Hi,
> >
> > Thanks for those who helped me with cloning...
> >
> > I am a little surprised with performance. Maybe there are some basic
> things
> > I am doing wrong.
> >
> > I am parsing a 3 Kb XHTML file and it takes me about 4s, cloning the
> tree
> > takes me roughly a ridiculous amount of time (10ms). This on an Athlon
> XP
> > 1800+ running XP (sure I could switch to Linux but it is not planned for
> now
> > :) ).
> >
> > My code for parsing:
> > protected void load () {
> > DOMParser parser;
> >
> > try {
> > parser = new DOMParser();
> > }
> > catch (Exception e) {
> > log.severe ("Error: Unable to instantiate parser");
> > return;
> > }
> >
> > try {
> > parser.parse(m_file.toURI().toString());
> > m_document = parser.getDocument();
> > }
> > catch (SAXParseException e) {
> > // ignore
> > }
> > catch (Exception e) {
> > String msg;
> > msg = ("Error: Parse error occurred, " + e.getMessage());
> > if (e instanceof SAXException) {
> > e = ((SAXException)e).getException();
> > }
> > msg += '\n' + e.toString();
> > log.severe (msg);
> > }
> > }
> >
> > Questions:
> > 1/ is static'ing my parser will enhance the process?
> > 2/ can I "pre" create some objects I can reuse?
> > 3/ are there some eventual verification I can turn off?
> >
> > My code for cloning:
> > public Object clone() {
> > XHTML11Window win = new XHTML11Window(m_file);
> > win.m_document = new DocumentImpl();
> > win.m_document.importNode(m_document.getDocumentElement(), true);
> >
> > return win;
> > }
> >
> > I haven't checked that they really were cloned, but it looks as if they
> > were...
> >
> > Any tips are more than welcome!
> >
> > Jean Georges PERRIN
> >
> >
> >
> > ---------------------------------------------------------------------
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> > For additional commands, e-mail: xerces-j-user-help@(protected)
> >
> >
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