File Coverage

blib/lib/PDF/Builder/Basic/PDF/Filter.pm
Criterion Covered Total %
statement 28 42 66.6
branch 0 8 0.0
condition 0 6 0.0
subroutine 9 10 90.0
pod 1 2 50.0
total 38 68 55.8


line stmt bran cond sub pod time code
1             #=======================================================================
2             #
3             # THIS IS A REUSED PERL MODULE, FOR PROPER LICENCING TERMS SEE BELOW:
4             #
5             # Copyright Martin Hosken
6             #
7             # No warranty or expression of effectiveness, least of all regarding
8             # anyone's safety, is implied in this software or documentation.
9             #
10             # This specific module is licensed under the Perl Artistic License.
11             # Effective 28 January 2021, the original author and copyright holder,
12             # Martin Hosken, has given permission to use and redistribute this module
13             # under the MIT license.
14             #
15             #=======================================================================
16             package PDF::Builder::Basic::PDF::Filter;
17              
18 40     40   346 use strict;
  40         85  
  40         1374  
19 40     40   218 use warnings;
  40         77  
  40         2215  
20              
21             our $VERSION = '3.023'; # VERSION
22             our $LAST_UPDATE = '3.022'; # manually update whenever code is changed
23              
24 40     40   19007 use PDF::Builder::Basic::PDF::Filter::ASCII85Decode;
  40         113  
  40         1284  
25 40     40   19348 use PDF::Builder::Basic::PDF::Filter::ASCIIHexDecode;
  40         108  
  40         1404  
26 40     40   19580 use PDF::Builder::Basic::PDF::Filter::FlateDecode;
  40         167  
  40         2107  
27 40     40   24535 use PDF::Builder::Basic::PDF::Filter::LZWDecode;
  40         153  
  40         1799  
28 40     40   21381 use PDF::Builder::Basic::PDF::Filter::RunLengthDecode;
  40         110  
  40         1650  
29 40     40   282 use Scalar::Util qw(blessed reftype);
  40         83  
  40         11764  
30              
31             =head1 NAME
32              
33             PDF::Builder::Basic::PDF::Filter - Abstract superclass for PDF stream filters
34              
35             =head1 SYNOPSIS
36              
37             $f = PDF::Builder::Basic::PDF::Filter->new();
38             $str = $f->outfilt($str, 1);
39             print OUTFILE $str;
40              
41             while (read(INFILE, $dat, 4096))
42             { $store .= $f->infilt($dat, 0); }
43             $store .= $f->infilt("", 1);
44              
45             =head1 DESCRIPTION
46              
47             A Filter object contains state information for the process of outputting
48             and inputting data through the filter. The precise state information stored
49             is up to the particular filter and may range from nothing to whole objects
50             created and destroyed.
51              
52             Each filter stores different state information for input and output and thus
53             may handle one input filtering process and one output filtering process at
54             the same time.
55              
56             =head1 METHODS
57              
58             =head2 PDF::Builder::Basic::PDF::Filter->new()
59              
60             Creates a new filter object with empty state information ready for processing
61             data both input and output.
62              
63             =head2 $dat = $f->infilt($str, $isend)
64              
65             Filters from output to input the data. Notice that C<$isend == 0> implies that
66             there is more data to come and so following it C<$f> may contain state
67             information (usually due to the break-off point of C<$str> not being tidy).
68             Subsequent calls will incorporate this stored state information.
69              
70             C<$isend == 1> implies that there is no more data to follow. The final state of
71             C<$f> will be that the state information is empty. Error messages are most
72             likely to occur here since if there is required state information to be stored
73             following this data, then that would imply an error in the data.
74              
75             =head2 $str = $f->outfilt($dat, $isend)
76              
77             Filter stored data ready for output. Parallels C.
78              
79             =cut
80              
81             sub new {
82 5     5 1 118 my $class = shift();
83 5         12 my $self = {};
84              
85 5         14 bless $self, $class;
86              
87 5         33 return $self;
88             }
89              
90             sub release {
91 0     0 0   my $self = shift();
92 0 0         return $self unless ref($self);
93              
94             # delete stuff that we know we can, here
95 0           my @tofree = map { delete $self->{$_} } keys %$self;
  0            
96              
97 0           while (my $item = shift @tofree) {
98 0           my $ref = ref($item);
99 0 0 0       if (blessed($item) and $item->can('release')) {
    0 0        
    0          
100 0           $item->release();
101             } elsif ($ref eq 'ARRAY') {
102 0           push @tofree, @$item ;
103             } elsif (defined(reftype($ref)) and reftype($ref) eq 'HASH') {
104 0           release($item);
105             }
106             }
107              
108             # check that everything has gone
109 0           foreach my $key (keys %$self) {
110             # warn ref($self) . " still has '$key' key left after release.\n";
111 0           $self->{$key} = undef;
112 0           delete $self->{$key};
113             }
114 0           return;
115             }
116              
117             1;