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Diffstat (limited to '')
| -rw-r--r-- | scripts/Dpkg/Compression/Process.pm | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/scripts/Dpkg/Compression/Process.pm b/scripts/Dpkg/Compression/Process.pm new file mode 100644 index 0000000..9b733cc --- /dev/null +++ b/scripts/Dpkg/Compression/Process.pm @@ -0,0 +1,211 @@ +# Copyright © 2008-2010 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/>. + +package Dpkg::Compression::Process; + +use strict; +use warnings; + +our $VERSION = '1.00'; + +use Carp; + +use Dpkg::Compression; +use Dpkg::ErrorHandling; +use Dpkg::Gettext; +use Dpkg::IPC; + +=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. + +=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 C<compression_is_supported> (of +B<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 C<compression_is_valid_level> (of +B<Dpkg::Compression>). + +=cut + +sub set_compression_level { + my ($self, $level) = @_; + error(g_('%s is not a compression level'), $level) + unless compression_is_valid_level($level); + $self->{compression_level} = $level; +} + +=item @exec = $proc->get_compress_cmdline() + +=item @exec = $proc->get_uncompress_cmdline() + +Returns a list ready to be passed to C<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 $self = shift; + my @prog = (@{compression_get_property($self->{compression}, 'comp_prog')}); + my $level = '-' . $self->{compression_level}; + $level = '--' . $self->{compression_level} + if $self->{compression_level} !~ m/^[1-9]$/; + push @prog, $level; + return @prog; +} + +sub get_uncompress_cmdline { + my $self = shift; + return (@{compression_get_property($self->{compression}, 'decomp_prog')}); +} + +sub _sanity_check { + 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 $proc->compress(%opts) + +Starts a compressor program. You must indicate where it will read its +uncompressed data from and where it will write its compressed data to. +This is accomplished by passing one parameter C<to_*> and one parameter +C<from_*> as accepted by B<Dpkg::IPC::spawn>. + +You must call C<wait_end_process> after having called this method to +properly close the sub-process (and verify that it exited without error). + +=cut + +sub compress { + my ($self, %opts) = @_; + + $self->_sanity_check(%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 $proc->uncompress(%opts) + +Starts a decompressor program. You must indicate where it will read its +compressed data from and where it will write its uncompressed data to. +This is accomplished by passing one parameter C<to_*> and one parameter +C<from_*> as accepted by B<Dpkg::IPC::spawn>. + +You must call C<wait_end_process> after having called this method to +properly close the sub-process (and verify that it exited without error). + +=cut + +sub uncompress { + my ($self, %opts) = @_; + + $self->_sanity_check(%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 $proc->wait_end_process(%opts) + +Call B<Dpkg::IPC::wait_child> to wait until the sub-process has exited +and verify its return code. Any given option will be forwarded to +the C<wait_child> function. Most notably you can use the "nocheck" option +to verify the return code yourself instead of letting C<wait_child> do +it for you. + +=cut + +sub wait_end_process { + my ($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; |