Subject: Re: [xsl] Performance improvement for a recursive function? From: Manfred Staudinger <manfred.staudinger@xxxxxxxxx> Date: Tue, 13 Dec 2011 10:44:29 +0100 |
Hi Wolfgang, What a great solution: execution time is down to 7 sec (from 14 minutes). Thanks a lot, Manfred On 13/12/2011, Wolfgang Laun <wolfgang.laun@xxxxxxxxx> wrote: > I forgot to mention that the result of this function must be processed with > string-join(my:compose-path-data($Data),'') > -W > > On 13 December 2011 08:46, Wolfgang Laun <wolfgang.laun@xxxxxxxxx> wrote: >> This function permits processing of all contained commands. >> >> I don't have the time to analyze what should be done for each; I saw >> that m0,0 was dropped. >> >> It's fast enough now :-) >> >> -W >> >> <xsl:function name="my:compose-path-data" as="xs:string*"> >> <xsl:param name="data" as="xs:string*"/> >> <xsl:analyze-string select = "$data" >> regex = "[ Mlm](\d+),(\d+)|[hv](\d+)|z"> >> <xsl:matching-substring> >> <xsl:variable name="cmd" select="substring(regex-group(0),1,1)"/> >> <xsl:choose> >> <xsl:when test="$cmd = (' ', 'M', 'l', 'm')"> >> <xsl:value-of >> select="concat($cmd,regex-group(1),',',regex-group(2))"/> >> </xsl:when> >> <xsl:when test="$cmd = ('h', 'v')"> >> <xsl:value-of select="concat($cmd,regex-group(3))"/> >> </xsl:when> >> <xsl:when test="$cmd = 'z'"> >> <xsl:value-of select="$cmd"/> >> </xsl:when> >> </xsl:choose> >> </xsl:matching-substring> >> </xsl:analyze-string> >> </xsl:function> >> >> >> On 13 December 2011 01:07, Manfred Staudinger >> <manfred.staudinger@xxxxxxxxx> wrote: >>> Hi, >>> >>> I need some help to improve the performance of a function, as I have >>> run out of ideas what to change! >>> >>> In the process to convert some data to SVG I transform (or even break >>> up) @Data attribute of the Path element and then use the function >>> my:compose-path-data [1] to put the parts together into a string >>> again. The attribute string is a succession of path commands, where >>> each path command (see the global variable below) consists of a one >>> byte character followed by zero, one, or two integers. Having about >>> 2200 Path elements, most of them have a @Data attribute with between 5 >>> an 50 path commands. >>> >>> A few attribute strings are bigger (up to 1MB) and contain up to >>> 100000 path commands. As the function is called for each path command >>> it is tail recursive, but the performance is still a big problem: to >>> process 41337 path commands it takes 861 sec! The first 5000 path >>> commands are processed in 14 sec (at 355.87 per sec) the last 5000 >>> take 671 sec (only at 7.5 per sec). >>> >>> What Saxon reports [2] is consistent with the above. In case you want >>> to try it, I have uploaded the specific test case here: >>> http:///test.rudolphina.org/test01-perform-data.xsl >>> http:///test.rudolphina.org/test01-perform-data-org.xml >>> >>> Using Saxon-HE 9.3.0.5J and Java version 1.6.0_14 on Windows. XP Home. >>> Hardware ASUS Eee PC 1000H with Intel. Atom N270 (1.60 GHz) >>> >>> Regards, >>> Manfred >>> >>> [1] >>> <xsl:function name="my:compose-path-data" as="xs:string*"> >>> <xsl:param name="c" as="xs:integer*"/> >>> <xsl:param name="i-c" as="xs:integer"/> >>> <xsl:param name="xy" as="xs:integer*"/> >>> <xsl:param name="i-xy" as="xs:integer"/> >>> <xsl:param name="i-end" as="xs:integer"/> >>> <xsl:param name="result" as="xs:string?"/> >>> <xsl:variable name="cmd" select="key('path', $c[$i-c], $path-cmd)" >>> as="element()?"/> >>> <xsl:sequence select="if ($i-c gt $i-end) >>> then $result >>> else my:compose-path-data($c, $i-c + 1, >>> $xy, $i-xy + xs:integer($cmd/n), >>> $i-end, >>> concat($result, $cmd/@char, if ($cmd/n=2) >>> then (: M, m, l, (blank) :) concat($xy[$i-xy], ',', >>> $xy[$i-xy+1]) >>> else if ($cmd/n=1) >>> then (: h, v :) string($xy[$i-xy]) >>> else (: z :) ()) >>> )"/> >>> </xsl:function> >>> >>> and on the stylesheet level >>> <xsl:variable name="path-cmd"> >>> <path> >>> <cmd char=" "><n>2</n><code>32</code></cmd> >>> <cmd char="M"><n>2</n><code>77</code></cmd> >>> <cmd char="l"><n>2</n><code>108</code></cmd> >>> <cmd char="m"><n>2</n><code>109</code></cmd> >>> <cmd char="h"><n>1</n><code>104</code></cmd> >>> <cmd char="v"><n>1</n><code>118</code></cmd> >>> <cmd char="z"><n>0</n><code>122</code></cmd> >>> </path> >>> </xsl:variable> >>> <xsl:key name="path" match="cmd" use="xs:integer(code)"/><!-- $path-cmd >>> --> >>> >>> [2] >>> Stylesheet compilation time: 4218 milliseconds >>> Using parser org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser >>> net.sf.saxon.tree.tiny.TinyBuilder >>> Tree built in 1375 milliseconds >>> Tree size: 4 nodes, 0 characters, 11 attributes >>> Execution time: 14m 31.579s (871579ms) >>> Memory used: 36559128 >>> NamePool contents: 33 entries in 33 chains. 8 prefixes, 8 URIs
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