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1 | # Copyright © 2008-2010 Raphaël Hertzog <hertzog@debian.org> |
2 | # | |
3 | # This program is free software; you can redistribute it and/or modify | |
4 | # it under the terms of the GNU General Public License as published by | |
5 | # the Free Software Foundation; either version 2 of the License, or | |
6 | # (at your option) any later version. | |
7 | # | |
8 | # This program is distributed in the hope that it will be useful, | |
9 | # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | # GNU General Public License for more details. | |
12 | # | |
13 | # You should have received a copy of the GNU General Public License | |
14 | # along with this program. If not, see <https://www.gnu.org/licenses/>. | |
15 | ||
16 | package Dpkg::Compression::Process; | |
17 | ||
18 | use strict; | |
19 | use warnings; | |
20 | ||
21 | our $VERSION = '1.00'; | |
22 | ||
23 | use Carp; | |
24 | ||
25 | use Dpkg::Compression; | |
26 | use Dpkg::ErrorHandling; | |
27 | use Dpkg::Gettext; | |
28 | use Dpkg::IPC; | |
29 | ||
30 | =encoding utf8 | |
31 | ||
32 | =head1 NAME | |
33 | ||
34 | Dpkg::Compression::Process - run compression/decompression processes | |
35 | ||
36 | =head1 DESCRIPTION | |
37 | ||
38 | This module provides an object oriented interface to run and manage | |
39 | compression/decompression processes. | |
40 | ||
41 | =head1 METHODS | |
42 | ||
43 | =over 4 | |
44 | ||
45 | =item $proc = Dpkg::Compression::Process->new(%opts) | |
46 | ||
47 | Create a new instance of the object. Supported options are "compression" | |
48 | and "compression_level" (see corresponding set_* functions). | |
49 | ||
50 | =cut | |
51 | ||
52 | sub new { | |
53 | my ($this, %args) = @_; | |
54 | my $class = ref($this) || $this; | |
55 | my $self = {}; | |
56 | bless $self, $class; | |
57 | $self->set_compression($args{compression} || compression_get_default()); | |
58 | $self->set_compression_level($args{compression_level} || | |
59 | compression_get_default_level()); | |
60 | return $self; | |
61 | } | |
62 | ||
63 | =item $proc->set_compression($comp) | |
64 | ||
65 | Select the compression method to use. It errors out if the method is not | |
66 | supported according to C<compression_is_supported> (of | |
67 | B<Dpkg::Compression>). | |
68 | ||
69 | =cut | |
70 | ||
71 | sub set_compression { | |
72 | my ($self, $method) = @_; | |
73 | error(g_('%s is not a supported compression method'), $method) | |
74 | unless compression_is_supported($method); | |
75 | $self->{compression} = $method; | |
76 | } | |
77 | ||
78 | =item $proc->set_compression_level($level) | |
79 | ||
80 | Select the compression level to use. It errors out if the level is not | |
81 | valid according to C<compression_is_valid_level> (of | |
82 | B<Dpkg::Compression>). | |
83 | ||
84 | =cut | |
85 | ||
86 | sub set_compression_level { | |
87 | my ($self, $level) = @_; | |
88 | error(g_('%s is not a compression level'), $level) | |
89 | unless compression_is_valid_level($level); | |
90 | $self->{compression_level} = $level; | |
91 | } | |
92 | ||
93 | =item @exec = $proc->get_compress_cmdline() | |
94 | ||
95 | =item @exec = $proc->get_uncompress_cmdline() | |
96 | ||
97 | Returns a list ready to be passed to C<exec>, its first element is the | |
98 | program name (either for compression or decompression) and the following | |
99 | elements are parameters for the program. | |
100 | ||
101 | When executed the program acts as a filter between its standard input | |
102 | and its standard output. | |
103 | ||
104 | =cut | |
105 | ||
106 | sub get_compress_cmdline { | |
107 | my $self = shift; | |
108 | my @prog = (@{compression_get_property($self->{compression}, 'comp_prog')}); | |
109 | my $level = '-' . $self->{compression_level}; | |
110 | $level = '--' . $self->{compression_level} | |
111 | if $self->{compression_level} !~ m/^[1-9]$/; | |
112 | push @prog, $level; | |
113 | return @prog; | |
114 | } | |
115 | ||
116 | sub get_uncompress_cmdline { | |
117 | my $self = shift; | |
118 | return (@{compression_get_property($self->{compression}, 'decomp_prog')}); | |
119 | } | |
120 | ||
121 | sub _sanity_check { | |
122 | my ($self, %opts) = @_; | |
123 | # Check for proper cleaning before new start | |
124 | error(g_('Dpkg::Compression::Process can only start one subprocess at a time')) | |
125 | if $self->{pid}; | |
126 | # Check options | |
127 | my $to = my $from = 0; | |
128 | foreach my $thing (qw(file handle string pipe)) { | |
129 | $to++ if $opts{"to_$thing"}; | |
130 | $from++ if $opts{"from_$thing"}; | |
131 | } | |
132 | croak 'exactly one to_* parameter is needed' if $to != 1; | |
133 | croak 'exactly one from_* parameter is needed' if $from != 1; | |
134 | return %opts; | |
135 | } | |
136 | ||
137 | =item $proc->compress(%opts) | |
138 | ||
139 | Starts a compressor program. You must indicate where it will read its | |
140 | uncompressed data from and where it will write its compressed data to. | |
141 | This is accomplished by passing one parameter C<to_*> and one parameter | |
142 | C<from_*> as accepted by B<Dpkg::IPC::spawn>. | |
143 | ||
144 | You must call C<wait_end_process> after having called this method to | |
145 | properly close the sub-process (and verify that it exited without error). | |
146 | ||
147 | =cut | |
148 | ||
149 | sub compress { | |
150 | my ($self, %opts) = @_; | |
151 | ||
152 | $self->_sanity_check(%opts); | |
153 | my @prog = $self->get_compress_cmdline(); | |
154 | $opts{exec} = \@prog; | |
155 | $self->{cmdline} = "@prog"; | |
156 | $self->{pid} = spawn(%opts); | |
157 | delete $self->{pid} if $opts{to_string}; # wait_child already done | |
158 | } | |
159 | ||
160 | =item $proc->uncompress(%opts) | |
161 | ||
162 | Starts a decompressor program. You must indicate where it will read its | |
163 | compressed data from and where it will write its uncompressed data to. | |
164 | This is accomplished by passing one parameter C<to_*> and one parameter | |
165 | C<from_*> as accepted by B<Dpkg::IPC::spawn>. | |
166 | ||
167 | You must call C<wait_end_process> after having called this method to | |
168 | properly close the sub-process (and verify that it exited without error). | |
169 | ||
170 | =cut | |
171 | ||
172 | sub uncompress { | |
173 | my ($self, %opts) = @_; | |
174 | ||
175 | $self->_sanity_check(%opts); | |
176 | my @prog = $self->get_uncompress_cmdline(); | |
177 | $opts{exec} = \@prog; | |
178 | $self->{cmdline} = "@prog"; | |
179 | $self->{pid} = spawn(%opts); | |
180 | delete $self->{pid} if $opts{to_string}; # wait_child already done | |
181 | } | |
182 | ||
183 | =item $proc->wait_end_process(%opts) | |
184 | ||
185 | Call B<Dpkg::IPC::wait_child> to wait until the sub-process has exited | |
186 | and verify its return code. Any given option will be forwarded to | |
187 | the C<wait_child> function. Most notably you can use the "nocheck" option | |
188 | to verify the return code yourself instead of letting C<wait_child> do | |
189 | it for you. | |
190 | ||
191 | =cut | |
192 | ||
193 | sub wait_end_process { | |
194 | my ($self, %opts) = @_; | |
195 | $opts{cmdline} //= $self->{cmdline}; | |
196 | wait_child($self->{pid}, %opts) if $self->{pid}; | |
197 | delete $self->{pid}; | |
198 | delete $self->{cmdline}; | |
199 | } | |
200 | ||
201 | =back | |
202 | ||
203 | =head1 CHANGES | |
204 | ||
205 | =head2 Version 1.00 (dpkg 1.15.6) | |
206 | ||
207 | Mark the module as public. | |
208 | ||
209 | =cut | |
210 | ||
211 | 1; |