Re: [xsl] XSLT3 - Streaming + Recursive File Output

["Mailing Lists Mail daktapaal@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

idiv as in integer division

On Aug 12, 2016 6:22 AM, "Mailing Lists Mail" <daktapaal@xxxxxxxxx> wrote:

> Dr. Kay.
> Thank you for your explanation. This is my first ever streaming stylesheet
> and your explanations are very educational to me. I have some questions.
> In your point A, you said we can switch off the multi Threading in the
> result document. How do we do that?
> In point B, foreach , you typed idiv .. should it be div ? is it a typo or
> is there a new operator called idiv
>
> Point c. Changing initial unnamed template to streamable produced no
> results. No files generated. Also in the examples given in the spec i did
> not see any mode on the initial template
>
> Thank you Michael for your insights .. i have learned a lot by asking the
> question.
>
> Dak
>
> On Aug 11, 2016 7:13 PM, "Michael Kay mike@xxxxxxxxxxxx" <
> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> (A) don't equate xsl:fork with multi-threading. In fact, the current
>> implementation of xsl:fork in Saxon is not multi-threaded
>> (xsl:result-document might be, but you can switch it off). (Saxon's
>> streamed processing uses a push model, which complicates many things, but
>> pushing parser events to multiple consumers doesn't require multitple
>> threads).
>>
>> (B) I think your recursive named template can be replaced with a
>> streamable call on xsl:for-each-group, something like
>>
>> <xsl:for-each-group select="*:species" group-adjacent="(position()-1)
>> idiv 1000">
>>   <xsl:result-document href="species{position()}.xml">
>>     <species><xsl:copy-of select="current-group()"/></species>
>>   </xsl:result-document>
>> </xsl:for-each-group>
>>
>> Compared with your approach, this solution has the advantage of not
>> imposing an arbitrary limit on the number of elements to be processed.
>>
>> (C) I would expect the initial unnamed mode should be streamable.
>>
>> (D) In the latest XSLT 3.0 we've provided "streamable stylesheet
>> functions" - not yet implemented in Saxon - but we stopped short at
>> streamable named templates. But you couldn't do this kind of batching using
>> streamable stylesheet functions either. A human reader can see in your code
>> that the Nth recursive call of the template is always processing nodes that
>> are later in document order than the (N-1)th recursive call, but it would
>> require a phenomenal amount of analysis for a theorem-prover to establish
>> that during static analysis, and even if you could prove it streamable,
>> generating a streamable execution plan would be far from trivial.
>>
>> Michael Kay
>> Saxonica
>>
>>
>> > On 11 Aug 2016, at 23:07, Mailing Lists Mail daktapaal@xxxxxxxxx <
>> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> >
>> > Dear All,
>> > I have the following problem to solve using XSLT3 Streaming , which I
>> > have been trying for some time now and i find a road block no matter
>> > which way I choose. Seems to be an interesting issue to solve, which
>> > when resolved, will be a very good learning for me.
>> >
>> > I have a HUGE XML ( obviously a starting point for XSlt3 Streaming)
>> >
>> > I am using : SaxonEE9-7-0-7J
>> >
>> > Problem Definition
>> >
>> > 1. Remove a set of nodes(Species) from the source
>> > tree(UniverseKingdom.xml), which can be  around 1000,000
>> > 2. Create a File called UniverseKingdom-without-species.xml which has
>> > every element in UniverseKingdom, except the Species nodes
>> > 3. Create batches of 1000 species and throw them out into
>> > AnimalKingdomSpeciesBatch1.xml and so on and so forth till all the
>> > Species are covered.
>> >
>> > So when the Program runs, I get
>> > 1. UniverseKingdom-without-species.xml  and 1000 files , each with
>> > 1000 Species, with appropriate file names
>> > AnimalKingdomSpeciesBatch1.xml ... to
>> > AnimalKingdomSpeciesBatch1000.xml
>> >
>> > What I did so far ( after many attempts and which I thought should
>> > work  but did not work )
>> > <xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1
>> 999/XSL/Transform"
>> >    xmlns:xs="http://www.w3.org/2001/XMLSchema";>
>> >    <xsl:mode name="stream" streamable="yes" on-no-match="shallow-copy"/>
>> >    <xsl:strip-space elements="*"/>
>> >    <xsl:output method="xml" indent="yes"/>
>> >    <xsl:template match="/">
>> >        <xsl:result-document href="output\UniverseKingdom-w
>> ithout-species.xml">
>> >            <xsl:stream href="UniverseKingdom.xml">
>> >                <xsl:fork>
>> >                    <xsl:sequence>
>> >                        <xsl:apply-templates mode="stream"/>
>> >                    </xsl:sequence>
>> >                    <xsl:sequence>
>> >                        <xsl:for-each
>> > select="*:UniverseKingdom/*:AnimalKingdom">
>> >                              <!-- Call Recursive Templates here -->
>> >                            <xsl:call-templates
>> name="batch-animal-species"/>
>> >                        </xsl:for-each>
>> >                    </xsl:sequence>
>> >                </xsl:fork>
>> >            </xsl:stream>
>> >        </xsl:result-document>
>> >    </xsl:template>
>> >    <xsl:template name="batch-animal-species">
>> >        <xsl:param name="limit" select="1000000"/>
>> >        <xsl:param name="batch" select="1"/>
>> >        <xsl:param name="start" select="1"/>
>> >        <xsl:param name="end" select="1000"/>
>> >        <xsl:if test="$start &lt;= $limit ">
>> >            <xsl:result-document
>> > href="output\AnimalKingdomSpeciesBatch{$batch}-.xml">
>> >                <species>
>> >                    <xsl:for-each select="*:species[position() =
>> > ($start to $end) ]">
>> >                        <species>
>> >                            <xsl:copy-of select="."/>
>> >                        </species>
>> >                    </xsl:for-each>
>> >                </species>
>> >            </xsl:result-document>
>> >            <xsl:call-template name="batch-animal-species">
>> >                <xsl:with-param name="batch" select="$batch+1"/>
>> >                <xsl:with-param name="start" select="$end+1"/>
>> >                <xsl:with-param name="end" select="$end+1000"/>
>> >            </xsl:call-template>
>> >        </xsl:if>
>> >    </xsl:template>
>> >    <xsl:template match="*:species" mode="stream"/>
>> > </xsl:stylesheet>
>> >
>> >
>> > Here, the issue was with the template batch-animal-species . Saxon
>> > Throws Error :
>> >
>> > e:\perf\xslt3>java  -jar saxon9ee.jar   str.xml splitter.x
>> > sl  -o:StreamAni.xml
>> > Static error at xsl:template on line 22 column 91 of splitter.xsl:
>> >  XTSE3430: Template rule is declared streamable but it does not
>> > satisfy the streamability rules.
>> >  * Operand . of CallTemplate#batch-animal-species selects streamed
>> nodes in a
>> > context
>> >  that allows arbitrary navigation (line 43)
>> > Errors were reported during stylesheet compilation
>> >
>> >
>> > I know that the logic for chunking various batched files could be made
>> > better or even questionable.. But I was not expecting that the
>> > Call-Template will fail.
>> >
>> > I am hoping some ninja warriors of XSLT3 can help me with this issue//
>> > Seriously can not take No for an answer :) a lot is dependent on this
>> > ...
>> >
>> > Also, if someone can think of an intelligent way for me to get this
>> > done with a smarter code, and possibly without using fork( there is a
>> > admin sitting somewhere in the System who has asked us to create code
>> > without the multiple threads. He wants to be responsible for the
>> > number of threads and discourages people from spawning multiple
>> > threads. If not possible, then I will enforce that forking has to be
>> > done.)
>> > Please help ...
>> > Dak.Tap