3
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I'm trying to generate a fresh XML file using Perl XML::Mini::Document. It's working fine, but I don't know whether it's the right way to do it. Performance is the problem for me; it takes more time when the when record count increases.

Is there any other module better doing than this one in performance and easier way?

#!/usr/bin/perl -w

use warnings;
use XML::Mini::Document;

my $outfile = "D:/Test.xml";

my $nSequence = 1000;
my $sRandom_Name = "";
my $sRandom_Desc = "";
my $newDoc = XML::Mini::Document->new();
my $newDocRoot = $newDoc->getRoot();
my $xmlHeader = $newDocRoot->header('xml');
$xmlHeader->attribute('version', '1.0');
$xmlHeader->attribute('encoding', 'UTF-8');

my $records= $newDocRoot->createChild('records');

for(0..9) {

   for(1..6) { 
      $sRandom_Name = $sRandom_Name.(chr(int(rand(25) + 65)));
   }
   for(1..15) { 
      $sRandom_Desc = $sRandom_Desc.(chr(int(rand(25) + 97)));
   }

   my $record = $records->createChild('record');

   $record->createChild('ID')->text($nSequence=$nSequence+1);
   $record->createChild('Name')->text($sRandom_Name);
   $record->createChild('Desc')->text($sRandom_Desc);

   print $newDoc->toFile($outfile);
}

My output should look like this one:

<?xml version="1.0" encoding="UTF-8" ?>
   <records>
    <record>
         <ID>1001</ID>
         <Name>ASDSDF</Name>
         <Desc>ASDFsdsdfcwefSC</Desc>
      </record>
      <record>
         <ID>1002</ID>
         <Name>KDFNND</Name>
         <Desc>WEFsdssccwefSC</Desc>
      </record>
      <record>
         <ID>1003</ID>
         <Name>PORJDX</Name>
         <Desc>XceFsdsdfcASmsd</Desc>
      </record>
      .
      .
      .
   </records>
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migrated from stackoverflow.com May 12 '15 at 13:45

This question came from our site for professional and enthusiast programmers.

  • \$\begingroup\$ @lazy: Note that your call to toFile is inside the for loop. That means the file is going to be overwritten ten times each time the program is run \$\endgroup\$ – Borodin May 12 '15 at 12:05
  • \$\begingroup\$ Related - making XML with XML::Twig: stackoverflow.com/questions/29009370/assembling-xml-in-perl \$\endgroup\$ – Sobrique May 12 '15 at 12:09
  • \$\begingroup\$ @Borodin when i used that toFile outside of the loop it says Out of memory! for 1 million records \$\endgroup\$ – lazy May 12 '15 at 12:15
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Yes, that's pretty good. It's essential to include use strict at the top of every Perl program you write, and use warnings is preferable to -w on the command line. You should also avoid capital letters in identifiers for lexical variables, as they are reserved for use in global identifiers such as package names

I would write something more Perlish like this

#!/usr/bin/perl

use strict;
use warnings;

use XML::Mini::Document;

use constant OUTFILE => 'D:/Test.xml';

sub rand_letter { chr(ord('A') + rand(26)) }

my $new_doc = XML::Mini::Document->new;
my $root    = $new_doc->getRoot;
my $header  = $root->header('xml');
$header->attribute(version  => '1.0');
$header->attribute(encoding => 'UTF-8');

my $records= $root->createChild('records');

my $sequence = 1000;

for ( 0..9 ) {

    my $record = $records->createChild('record');

    my ($random_name, $random_desc);
    $random_name .= rand_letter for 1 .. 6;
    $random_desc .= rand_letter for 1 .. 15;

    $record->createChild(ID   => ++$sequence);
    $record->createChild(Name => $random_name);
    $record->createChild(Desc => $random_desc);
}

open my $fh, '>', OUTFILE or die $!;
select $fh;
print $new_doc->toString;
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2
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If what you're looking for is speed and low memory usage then you should look at XML::Writer which will output the data directly to a file instead of building an in-memory structure

This program demonstrates. It will output a million records in a minute or two.

#!/usr/bin/perl

use strict;
use warnings;

use XML::Writer;

sub rand_letter { chr(ord('A') + rand(26)) }

use constant OUTFILE => 'D:/Test.xml';

open my $fh, '>', OUTFILE or die $!;

my $writer = XML::Writer->new(
    OUTPUT      => $fh,
    ENCODING    => 'utf-8',
    DATA_MODE   => 1,
    DATA_INDENT => ' ' x 4,
);
$writer->xmlDecl;
$writer->startTag('records');

my $sequence = 1000;

for ( 0..9 ) {

    my ($random_name, $random_desc);
    $random_name .= rand_letter for 1 .. 6;
    $random_desc .= rand_letter for 1 .. 15;

    $writer->startTag('record');
    $writer->dataElement(ID   => ++$sequence);
    $writer->dataElement(Name => $random_name);
    $writer->dataElement(Desc => $random_desc);
    $writer->endTag('record');
}

$writer->endTag('records');
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