8 WebPAC::Input - core module for input file format
16 our $VERSION = '0.01';
20 This module will load particular loader module and execute it's functions.
22 Perhaps a little code snippet.
26 my $db = WebPAC::Input->new(
29 lookup => $lookup_obj,
32 $db->open('/path/to/database');
33 print "database size: ",$db->size,"\n";
34 while (my $row = $db->fetch) {
43 Create new input database object.
45 my $db = new WebPAC::Input(
47 code_page => 'ISO-8859-2',
50 Optional parametar C<code_page> specify application code page (which will be
51 used internally). This should probably be your terminal encoding, and by
52 default, it C<ISO-8859-2>.
61 $self->{'code_page'} ||= 'ISO-8859-2';
63 $self ? return $self : return undef;
68 C<low_mem> options is double-edged sword. If enabled, WebPAC
69 will run on memory constraint machines (which doesn't have enough
70 physical RAM to create memory structure for whole source database).
72 If your machine has 512Mb or more of RAM and database is around 10000 records,
73 memory shouldn't be an issue. If you don't have enough physical RAM, you
74 might consider using virtual memory (if your operating system is handling it
75 well, like on FreeBSD or Linux) instead of dropping to L<DBM::Deep> to handle
76 parsed structure of ISIS database (this is what C<low_mem> option does).
78 Hitting swap at end of reading source database is probably o.k. However,
79 hitting swap before 90% will dramatically decrease performance and you will
80 be better off with C<low_mem> and using rest of availble memory for
81 operating system disk cache (Linux is particuallary good about this).
82 However, every access to database record will require disk access, so
83 generation phase will be slower 10-100 times.
85 Parsed structures are essential - you just have option to trade RAM memory
86 (which is fast) for disk space (which is slow). Be sure to have planty of
87 disk space if you are using C<low_mem> and thus L<DBM::Deep>.
89 However, when WebPAC is running on desktop machines (or laptops :-), it's
90 highly undesireable for system to start swapping. Using C<low_mem> option can
91 reduce WecPAC memory usage to around 64Mb for same database with lookup
92 fields and sorted indexes which stay in RAM. Performance will suffer, but
93 memory usage will really be minimal. It might be also more confortable to
94 run WebPAC reniced on those machines.
99 Dobrica Pavlinusic, C<< <dpavlin@rot13.org> >>
101 =head1 COPYRIGHT & LICENSE
103 Copyright 2005 Dobrica Pavlinusic, All Rights Reserved.
105 This program is free software; you can redistribute it and/or modify it
106 under the same terms as Perl itself.
110 1; # End of WebPAC::Input