1 files changed, 208 insertions, 0 deletions
diff --git a/scripts/Dpkg/Compression/Process.pm b/scripts/Dpkg/Compression/Process.pm
new file mode 100644
index 0000000..cf4c504
--- /dev/null
+++ b/scripts/Dpkg/Compression/Process.pm
@@ -0,0 +1,208 @@
+# Copyright © 2008-2010 Raphaël Hertzog <hertzog@debian.org>
+# Copyright © 2008-2022 Guillem Jover <guillem@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::Compression::Process - run compression/decompression processes
+
+=head1 DESCRIPTION
+
+This module provides an object oriented interface to run and manage
+compression/decompression processes.
+
+=cut
+
+package Dpkg::Compression::Process 1.00;
+
+use strict;
+use warnings;
+
+use Carp;
+
+use Dpkg::Compression;
+use Dpkg::ErrorHandling;
+use Dpkg::Gettext;
+use Dpkg::IPC;
+
+=head1 METHODS
+
+=over 4
+
+=item $proc = Dpkg::Compression::Process->new(%opts)
+
+Create a new instance of the object. Supported options are "compression"
+and "compression_level" (see corresponding set_* functions).
+
+=cut
+
+sub new {
+    my ($this, %args) = @_;
+    my $class = ref($this) || $this;
+    my $self = {};
+    bless $self, $class;
+    $self->set_compression($args{compression} || compression_get_default());
+    $self->set_compression_level($args{compression_level} ||
+        compression_get_default_level());
+    return $self;
+}
+
+=item $proc->set_compression($comp)
+
+Select the compression method to use. It errors out if the method is not
+supported according to compression_is_supported() (of
+L<Dpkg::Compression>).
+
+=cut
+
+sub set_compression {
+    my ($self, $method) = @_;
+    error(g_('%s is not a supported compression method'), $method)
+        unless compression_is_supported($method);
+    $self->{compression} = $method;
+}
+
+=item $proc->set_compression_level($level)
+
+Select the compression level to use. It errors out if the level is not
+valid according to compression_is_valid_level() (of
+L<Dpkg::Compression>).
+
+=cut
+
+sub set_compression_level {
+    my ($self, $level) = @_;
+
+    compression_set_level($self->{compression}, $level);
+}
+
+=item @exec = $proc->get_compress_cmdline()
+
+=item @exec = $proc->get_uncompress_cmdline()
+
+Returns a list ready to be passed to exec(), its first element is the
+program name (either for compression or decompression) and the following
+elements are parameters for the program.
+
+When executed the program acts as a filter between its standard input
+and its standard output.
+
+=cut
+
+sub get_compress_cmdline {
+    my $self = shift;
+
+    return compression_get_cmdline_compress($self->{compression});
+}
+
+sub get_uncompress_cmdline {
+    my $self = shift;
+
+    return compression_get_cmdline_decompress($self->{compression});
+}
+
+sub _check_opts {
+    my ($self, %opts) = @_;
+    # Check for proper cleaning before new start
+    error(g_('Dpkg::Compression::Process can only start one subprocess at a time'))
+        if $self->{pid};
+    # Check options
+    my $to = my $from = 0;
+    foreach my $thing (qw(file handle string pipe)) {
+        $to++ if $opts{"to_$thing"};
+        $from++ if $opts{"from_$thing"};
+    }
+    croak 'exactly one to_* parameter is needed' if $to != 1;
+    croak 'exactly one from_* parameter is needed' if $from != 1;
+    return %opts;
+}
+
+=item $proc->compress(%opts)
+
+Starts a compressor program. You must indicate where it will read its
+uncompressed data from and where it will write its compressed data to.
+This is accomplished by passing one parameter C<to_*> and one parameter
+C<from_*> as accepted by Dpkg::IPC::spawn().
+
+You must call wait_end_process() after having called this method to
+properly close the sub-process (and verify that it exited without error).
+
+=cut
+
+sub compress {
+    my ($self, %opts) = @_;
+
+    $self->_check_opts(%opts);
+    my @prog = $self->get_compress_cmdline();
+    $opts{exec} = \@prog;
+    $self->{cmdline} = "@prog";
+    $self->{pid} = spawn(%opts);
+    delete $self->{pid} if $opts{to_string}; # wait_child already done
+}
+
+=item $proc->uncompress(%opts)
+
+Starts a decompressor program. You must indicate where it will read its
+compressed data from and where it will write its uncompressed data to.
+This is accomplished by passing one parameter C<to_*> and one parameter
+C<from_*> as accepted by Dpkg::IPC::spawn().
+
+You must call wait_end_process() after having called this method to
+properly close the sub-process (and verify that it exited without error).
+
+=cut
+
+sub uncompress {
+    my ($self, %opts) = @_;
+
+    $self->_check_opts(%opts);
+    my @prog = $self->get_uncompress_cmdline();
+    $opts{exec} = \@prog;
+    $self->{cmdline} = "@prog";
+    $self->{pid} = spawn(%opts);
+    delete $self->{pid} if $opts{to_string}; # wait_child already done
+}
+
+=item $proc->wait_end_process(%opts)
+
+Call Dpkg::IPC::wait_child() to wait until the sub-process has exited
+and verify its return code. Any given option will be forwarded to
+the wait_child() function. Most notably you can use the "nocheck" option
+to verify the return code yourself instead of letting wait_child() do
+it for you.
+
+=cut
+
+sub wait_end_process {
+    my ($self, %opts) = @_;
+    $opts{cmdline} //= $self->{cmdline};
+    wait_child($self->{pid}, %opts) if $self->{pid};
+    delete $self->{pid};
+    delete $self->{cmdline};
+}
+
+=back
+
+=head1 CHANGES
+
+=head2 Version 1.00 (dpkg 1.15.6)
+
+Mark the module as public.
+
+=cut
+
+1;