 |
 |
|
|
 |
| |
 |
Downloads > Add-On |
|
|
|
| |
|
|
|
|
| |
Memory optimisation
InformationsAuthor: Philip Clarke
License: Freeware
DescriptionNormally FPDF compresses the entire PDF in the _putpages() method at the very end of PDF
generation, this can lead to a large uncompressed PDF being stored in memory.
This modification compresses each finished page in _endpage() reducing the overall memory
usage when generating large PDFs.
To test with minimal external influences, use a file such as the provided test.php. In one
terminal window as root run top like so:
~> top -q | grep php
then run the script from the command line, using:
~> php -q test.php > with_opt.pdf
The "top" terminal window will scroll detailing memory usage of php (press q to exit).
Then altering test.php to use the base class and running:
~> php -q test.php > no_opt.pdf
will show the original behaviour giving identical sized PDF files (no_opt.pdf and
with_opt.pdf). On a 600 MHz dual processor typical results were that the optimised php
code uses a maximum of 7.3 Megabytes wheareas the original uses 15 M. Both tests
typically take 2 minutes 15 secs. Over very large reports (2000 pages +) the optimised
version is very slightly slower by a few seconds.
Source
<?php
require('fpdf.php');
class PDF_Opt extends FPDF
{
function _putpages()
{
$nb=$this->page;
if(!empty($this->AliasNbPages))
{
//Replace number of pages
for($n=1;$n<=$nb;$n++)
$this->pages[$n]=($this->compress) ? gzcompress(str_replace($this->AliasNbPages, $nb, gzuncompress($this->pages[$n]))) : str_replace($this->AliasNbPages, $nb, $this->pages[$n]) ;
}
if($this->DefOrientation=='P')
{
$wPt=$this->fwPt;
$hPt=$this->fhPt;
}
else
{
$wPt=$this->fhPt;
$hPt=$this->fwPt;
}
$filter=($this->compress) ? '/Filter /FlateDecode ' : '';
for($n=1;$n<=$nb;$n++)
{
//Page
$this->_newobj();
$this->_out('<</Type /Page');
$this->_out('/Parent 1 0 R');
if(isset($this->OrientationChanges[$n]))
$this->_out(sprintf('/MediaBox [0 0 %.2f %.2f]', $hPt, $wPt));
$this->_out('/Resources 2 0 R');
if(isset($this->PageLinks[$n]))
{
//Links
$annots='/Annots [';
foreach($this->PageLinks[$n] as $pl)
{
$rect=sprintf('%.2f %.2f %.2f %.2f', $pl[0], $pl[1], $pl[0]+$pl[2], $pl[1]-$pl[3]);
$annots.='<</Type /Annot /Subtype /Link /Rect ['.$rect.'] /Border [0 0 0] ';
if(is_string($pl[4]))
$annots.='/A <</S /URI /URI '.$this->_textstring($pl[4]).'>>>>';
else
{
$l=$this->links[$pl[4]];
$h=isset($this->OrientationChanges[$l[0]]) ? $wPt : $hPt;
$annots.=sprintf('/Dest [%d 0 R /XYZ 0 %.2f null]>>', 1+2*$l[0], $h-$l[1]*$this->k);
}
}
$this->_out($annots.']');
}
$this->_out('/Contents '.($this->n+1).' 0 R>>');
$this->_out('endobj');
//Page content
$this->_newobj();
$this->_out('<<'.$filter.'/Length '.strlen($this->pages[$n]).'>>');
$this->_putstream($this->pages[$n]);
$this->_out('endobj');
}
//Pages root
$this->offsets[1]=strlen($this->buffer);
$this->_out('1 0 obj');
$this->_out('<</Type /Pages');
$kids='/Kids [';
for($i=0;$i<$nb;$i++)
$kids.=(3+2*$i).' 0 R ';
$this->_out($kids.']');
$this->_out('/Count '.$nb);
$this->_out(sprintf('/MediaBox [0 0 %.2f %.2f]', $wPt, $hPt));
$this->_out('>>');
$this->_out('endobj');
}
function _endpage()
{
//End of page contents
$this->pages[$this->page] = ($this->compress) ? gzcompress($this->pages[$this->page]) : $this->pages[$this->page];
$this->state=1;
}
}
?>
|
ExampleHere is an example of test script.
<?php
ini_set('memory_limit', '100M');
ini_set('max_execution_time', 0);
define('FPDF_FONTPATH', 'font/');
require('memory_opt.php');
// for testing purposes only stops a bug where command line php
// believes that headers have already been sent
class TESTING_PDF extends PDF_Opt
{
function Output()
{
echo $this->buffer;
}
}
$pdf = new TESTING_PDF();
$pdf->Open();
$pdf->AddPage();
$pdf->SetFont('Arial', '', 9);
// generate a constant amount of text for testing
for($i=1; $i<200; $i++)
$txt .= 'ashfsd kjsahkasjh akjhdsfjkh djshf sjkh ' ;
for($i=1; $i<1000; $i++)
$pdf->Write(9, $txt);
$pdf->Close();
$pdf->Output();
?>
|
DownloadZIP | TGZ
| | |