ateague has asked for the wisdom of the Perl Monks concerning the following question:
Good evening!
I am attempting to merge several thousand small (<20KiB) PDF file together into one PDF using PDF::API2.
The merging script works correctly at the beginning, but quickly bogs down after processing ~100 PDFs before grinding to a halt with the following warnings:
Deep recursion on subroutine "PDF::API2::Basic::PDF::Objind::release" +at C:/Perl64/site/lib/PDF/API2/Basic/PDF/Objind.pm line 123. Deep recursion on subroutine "PDF::API2::Basic::PDF::Objind::release" +at C:/Perl64/site/lib/PDF/API2/Basic/PDF/Objind.pm line 123. Deep recursion on subroutine "PDF::API2::Basic::PDF::Objind::release" +at C:/Perl64/site/lib/PDF/API2/Basic/PDF/Objind.pm line 123. ...
Here is a small sample merging script that exhibits the problem
(the script used to generate the sample PDF files can be found in the READMORE section):
#!/usr/bin/perl use 5.018; use PDF::API2; use strict; use warnings; my $path = "./pdfs/"; my $out_pdf_file = 'merged.pdf'; my $out_pdf; opendir (my $DIR, $path) or die "Could not open $path:\n$!\n$^E"; chdir $path; while ( my $in_pdf_file = readdir $DIR ) { next if $in_pdf_file =~ /^\./; my $in_pdf = PDF::API2->open($in_pdf_file) or die "Error opening PDF + file [$in_pdf_file]:\n$!\n$^E"; # Append to output if PDF already exists if ( -e $out_pdf_file ) { $out_pdf = PDF::API2->open($out_pdf_file); } # Create new PDF if output does not exist else { $out_pdf = PDF::API2->new(-file => $out_pdf_file); } foreach my $page ( 1 .. $in_pdf->pages() ) { $out_pdf->import_page($in_pdf, $page, 0); } $out_pdf->update(); } closedir $DIR;
I cannot help but feel I am going about this merging process in a horribly inefficient way (Schlemiel the painter anyone?). Does anyone have any pointers toward a correct/more efficient merging technique?
Thank you for your time.
perl -v This is perl 5, version 18, subversion 2 (v5.18.2) built for MSWin32-x +64-multi-thread (with 1 registered patch, see perl -V for more detail) Copyright 1987-2013, Larry Wall Binary build 1802 [298023] provided by ActiveState http://www.ActiveSt +ate.com Built Apr 15 2014 10:38:37
perl -MPDF::API2 -E "say $PDF::API2::VERSION;" 2.023
Script used to generate the sample PDF files:
|
---|