In case the input document is parsed successfully, wouldn't the use of
<xsl:sequence> (instead of <xsl:copy-of>) result in using less memory?
Cheers,
Dimitre
On Sun, Sep 2, 2012 at 7:31 AM, Michael Kay <mike(_at_)saxonica(_dot_)com>
wrote:
Memory is used for the source document and for intermediate variables. In
Saxon, and I suspect in most processors, no memory is used for the result
tree provided that the transformation is writing directly to a serializer.
Intrinsically, all xsl:copy has to do is to send two events - startElement
and endElement - to the serializer.
I would strongly suspect that the out of memory error occurs during building
of the source tree, and will happen whatever transformation you run. For a
370Mb input document, you should probably allocate at least 2Gb of memory,
preferably more.
Michael Kay
Saxonica
On 02/09/2012 13:47, Costello, Roger L. wrote:
Hi Folks,
Does <xsl:copy> use a lot of memory?
Is there an alternative that is more efficient?
Consider this problem. I have an XML document in which some elements have
an id attribute and others have an idref attribute. If an element A
references element B, then I want to embed B inside A.
Example: I want to convert this:
<Test>
<A idref="b" />
<B id="b" />
</Test>
to this:
<Test>
<A>
<B id="b" />
</A>
<B id="b" />
</Test>
Notice that A references B, and after processing B is nested inside A.
Here's a template that handles elements with a reference:
<xsl:key name="ids" match="*[@id]" use="@id"/>
<xsl:template match="*[@idref]">
<xsl:variable name="refed-element" select="key('ids',
@idref)"/>
<xsl:copy>
<xsl:copy-of select="@* except @idref" />
<xsl:sequence select="$refed-element" />
</xsl:copy>
</xsl:template>
The complete program is below.
It works fine if:
(a) The XML document is small.
(b) I don't have to repeat this embedding process too many times.
However, such is not the case. I am dealing with an XML document that is
370 MB in size and has tens of thousands of references. And I have to repeat
the embedding process multiple times.
Saxon gives me an "out of memory error."
I suspect the reason for this is due to the <xsl:copy> command. I believe
it is making new copies, thereby consuming lots of memory. True?
So, is there an alternative to <xsl:copy> that is more efficient?
Is there a way to express the above template rule that is more efficient?
/Roger
-----------------------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
exclude-result-prefixes="#all"
version="2.0">
<xsl:output method="xml" />
<xsl:key name="ids" match="*[@id]" use="@id"/>
<xsl:template match="*[@idref]">
<xsl:variable name="refed-element" select="key('ids',
@idref)"/>
<xsl:copy>
<xsl:copy-of select="@* except @idref" />
<xsl:sequence select="$refed-element" />
</xsl:copy>
</xsl:template>
<xsl:template match="node()">
<xsl:copy>
<xsl:copy-of select="@*"/>
<xsl:apply-templates />
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail:
<mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail:
<mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--
--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.
--~------------------------------------------------------------------
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
To unsubscribe, go to: http://lists.mulberrytech.com/xsl-list/
or e-mail: <mailto:xsl-list-unsubscribe(_at_)lists(_dot_)mulberrytech(_dot_)com>
--~--