The Perl and Raku Conference 2025: Greenville, South Carolina - June 27-29 Learn more

GUILLEM / Dpkg-1.22.18 / lib / Dpkg / Interface / Storable.pm 

            

              
1
2
3
4
5
6
7
8
9
10
11
12
13
14
—
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
—
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
—
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
—
133
134
135
136
137
138
139
140
141
142
143
144
145
146
—
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163

              
# Copyright © 2010 Raphaël Hertzog <hertzog@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
=encoding utf8
=head1 NAME
Dpkg::Interface::Storable - common methods related to object serialization
=head1 DESCRIPTION
Dpkg::Interface::Storable is only meant to be used as parent
class for other classes. It provides common methods that are
all implemented on top of two basic methods parse() and output().
=cut
package Dpkg::Interface::Storable 1.01;
use strict;
use warnings;
use Carp;
use Dpkg::Gettext;
use Dpkg::ErrorHandling;
use overload
    '""' => \&_stringify,
    'fallback' => 1;
=head1 BASE METHODS
Those methods must be provided by the class that wish to inherit
from Dpkg::Interface::Storable so that the methods provided can work.
=over 4
=item $obj->parse($fh[, $desc])
This methods initialize the object with the data stored in the
filehandle. $desc is optional and is a textual description of
the filehandle used in error messages.
=item $string = $obj->output([$fh])
This method returns a string representation of the object in $string
and it writes the same string to $fh (if it's defined).
=back
=head1 PROVIDED METHODS
=over 4
=item $obj->load($filename, %opts)
Initialize the object with the data stored in the file. The file can be
compressed, it will be decompressed on the fly by using a
L<Dpkg::Compression::FileHandle> object. If $opts{compression} is false the
decompression support will be disabled. If $filename is "-", then the
standard input is read (no compression is allowed in that case).
=cut
sub load {
    my ($self, $file, %opts) = @_;
    $opts{compression} //= 1;
    unless ($self->can('parse')) {
        croak ref($self) . ' cannot be loaded, it lacks the parse method';
    }
    my ($desc, $fh) = ($file, undef);
    if ($file eq '-') {
        $fh = \*STDIN;
        $desc = g_('<standard input>');
    } else {
        if ($opts{compression}) {
            require Dpkg::Compression::FileHandle;
            $fh = Dpkg::Compression::FileHandle->new();
        }
        open($fh, '<', $file) or syserr(g_('cannot read %s'), $file);
    }
    my $res = $self->parse($fh, $desc, %opts);
    if ($file ne '-') {
        close($fh) or syserr(g_('cannot close %s'), $file);
    }
    return $res;
}
=item $obj->save($filename, %opts)
Store the object in the file. If the filename ends with a known
compression extension, it will be compressed on the fly by using a
L<Dpkg::Compression::FileHandle> object. If $opts{compression} is false the
compression support will be disabled. If $filename is "-", then the
standard output is used (data are written uncompressed in that case).
=cut
sub save {
    my ($self, $file, %opts) = @_;
    $opts{compression} //= 1;
    unless ($self->can('output')) {
        croak ref($self) . ' cannot be saved, it lacks the output method';
    }
    my $fh;
    if ($file eq '-') {
        $fh = \*STDOUT;
    } else {
        if ($opts{compression}) {
            require Dpkg::Compression::FileHandle;
            $fh = Dpkg::Compression::FileHandle->new();
        }
        open($fh, '>', $file) or syserr(g_('cannot write %s'), $file);
    }
    $self->output($fh, %opts);
    if ($file ne '-') {
        close($fh) or syserr(g_('cannot close %s'), $file);
    }
}
=item "$obj"
Return a string representation of the object.
=cut
sub _stringify {
    my $self = shift;
    unless ($self->can('output')) {
        croak ref($self) . ' cannot be stringified, it lacks the output method';
    }
    return $self->output();
}
=back
=head1 CHANGES
=head2 Version 1.01 (dpkg 1.19.0)
New options: The $obj->load() and $obj->save() methods support a new
compression option.
=head2 Version 1.00 (dpkg 1.15.6)
Mark the module as public.
=cut
1;