271 lines
7.0 KiB
Perl
271 lines
7.0 KiB
Perl
# Copyright © 2010 Raphaël Hertzog <hertzog@debian.org>
|
|
# Copyright © 2010-2013 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/>.
|
|
|
|
package Dpkg::Compression;
|
|
|
|
use strict;
|
|
use warnings;
|
|
|
|
our $VERSION = '1.02';
|
|
our @EXPORT = qw(
|
|
$compression_re_file_ext
|
|
compression_is_supported
|
|
compression_get_list
|
|
compression_get_property
|
|
compression_guess_from_filename
|
|
compression_get_file_extension_regex
|
|
compression_get_default
|
|
compression_set_default
|
|
compression_get_default_level
|
|
compression_set_default_level
|
|
compression_is_valid_level
|
|
);
|
|
|
|
use Exporter qw(import);
|
|
use Config;
|
|
|
|
use Dpkg::ErrorHandling;
|
|
use Dpkg::Gettext;
|
|
|
|
=encoding utf8
|
|
|
|
=head1 NAME
|
|
|
|
Dpkg::Compression - simple database of available compression methods
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
This modules provides a few public functions and a public regex to
|
|
interact with the set of supported compression methods.
|
|
|
|
=cut
|
|
|
|
my $COMP = {
|
|
gzip => {
|
|
file_ext => 'gz',
|
|
comp_prog => [ 'gzip', '--no-name' ],
|
|
decomp_prog => [ 'gunzip' ],
|
|
default_level => 9,
|
|
},
|
|
bzip2 => {
|
|
file_ext => 'bz2',
|
|
comp_prog => [ 'bzip2' ],
|
|
decomp_prog => [ 'bunzip2' ],
|
|
default_level => 9,
|
|
},
|
|
lzma => {
|
|
file_ext => 'lzma',
|
|
comp_prog => [ 'xz', '--format=lzma' ],
|
|
decomp_prog => [ 'unxz', '--format=lzma' ],
|
|
default_level => 6,
|
|
},
|
|
xz => {
|
|
file_ext => 'xz',
|
|
comp_prog => [ 'xz' ],
|
|
decomp_prog => [ 'unxz' ],
|
|
default_level => 6,
|
|
},
|
|
};
|
|
|
|
#
|
|
# XXX: The gzip package in Debian at some point acquired a Debian-specific
|
|
# --rsyncable option via a vendor patch. Which is not present in most of the
|
|
# major distributions, dpkg downstream systems, nor gzip upstream, who have
|
|
# stated they will most probably not accept it because people should be using
|
|
# pigz instead.
|
|
#
|
|
# This option should have never been accepted in dpkg, ever. But removing it
|
|
# now would probably cause demands for tarring and feathering. In addition
|
|
# we cannot use the Dpkg::Vendor logic because that would cause circular
|
|
# module dependencies. The whole affair is pretty disgusting really.
|
|
#
|
|
# Check the perl Config to discern Debian and hopefully derivatives too.
|
|
#
|
|
if ($Config{cf_by} eq 'Debian Project') {
|
|
push @{$COMP->{gzip}->{comp_prog}}, '--rsyncable';
|
|
}
|
|
|
|
# XXX: Backwards compatibility, stop exporting on VERSION 2.00.
|
|
## no critic (Variables::ProhibitPackageVars)
|
|
our $default_compression = 'xz';
|
|
our $default_compression_level = undef;
|
|
|
|
my $regex = join '|', map { $_->{file_ext} } values %$COMP;
|
|
our $compression_re_file_ext = qr/(?:$regex)/;
|
|
## use critic
|
|
|
|
=head1 FUNCTIONS
|
|
|
|
=over 4
|
|
|
|
=item @list = compression_get_list()
|
|
|
|
Returns a list of supported compression methods (sorted alphabetically).
|
|
|
|
=cut
|
|
|
|
sub compression_get_list {
|
|
my @list = sort keys %$COMP;
|
|
return @list;
|
|
}
|
|
|
|
=item compression_is_supported($comp)
|
|
|
|
Returns a boolean indicating whether the give compression method is
|
|
known and supported.
|
|
|
|
=cut
|
|
|
|
sub compression_is_supported {
|
|
my $comp = shift;
|
|
|
|
return exists $COMP->{$comp};
|
|
}
|
|
|
|
=item compression_get_property($comp, $property)
|
|
|
|
Returns the requested property of the compression method. Returns undef if
|
|
either the property or the compression method doesn't exist. Valid
|
|
properties currently include "file_ext" for the file extension,
|
|
"default_level" for the default compression level,
|
|
"comp_prog" for the name of the compression program and "decomp_prog" for
|
|
the name of the decompression program.
|
|
|
|
=cut
|
|
|
|
sub compression_get_property {
|
|
my ($comp, $property) = @_;
|
|
return unless compression_is_supported($comp);
|
|
return $COMP->{$comp}{$property} if exists $COMP->{$comp}{$property};
|
|
return;
|
|
}
|
|
|
|
=item compression_guess_from_filename($filename)
|
|
|
|
Returns the compression method that is likely used on the indicated
|
|
filename based on its file extension.
|
|
|
|
=cut
|
|
|
|
sub compression_guess_from_filename {
|
|
my $filename = shift;
|
|
foreach my $comp (compression_get_list()) {
|
|
my $ext = compression_get_property($comp, 'file_ext');
|
|
if ($filename =~ /^(.*)\.\Q$ext\E$/) {
|
|
return $comp;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
=item $regex = compression_get_file_extension_regex()
|
|
|
|
Returns a regex that matches a file extension of a file compressed with
|
|
one of the supported compression methods.
|
|
|
|
=cut
|
|
|
|
sub compression_get_file_extension_regex {
|
|
return $compression_re_file_ext;
|
|
}
|
|
|
|
=item $comp = compression_get_default()
|
|
|
|
Return the default compression method. It is "xz" unless
|
|
C<compression_set_default> has been used to change it.
|
|
|
|
=item compression_set_default($comp)
|
|
|
|
Change the default compression method. Errors out if the
|
|
given compression method is not supported.
|
|
|
|
=cut
|
|
|
|
sub compression_get_default {
|
|
return $default_compression;
|
|
}
|
|
|
|
sub compression_set_default {
|
|
my $method = shift;
|
|
error(g_('%s is not a supported compression'), $method)
|
|
unless compression_is_supported($method);
|
|
$default_compression = $method;
|
|
}
|
|
|
|
=item $level = compression_get_default_level()
|
|
|
|
Return the default compression level used when compressing data. It's "9"
|
|
for "gzip" and "bzip2", "6" for "xz" and "lzma", unless
|
|
C<compression_set_default_level> has been used to change it.
|
|
|
|
=item compression_set_default_level($level)
|
|
|
|
Change the default compression level. Passing undef as the level will
|
|
reset it to the compressor specific default, otherwise errors out if the
|
|
level is not valid (see C<compression_is_valid_level>).
|
|
|
|
=cut
|
|
|
|
sub compression_get_default_level {
|
|
if (defined $default_compression_level) {
|
|
return $default_compression_level;
|
|
} else {
|
|
return compression_get_property($default_compression, 'default_level');
|
|
}
|
|
}
|
|
|
|
sub compression_set_default_level {
|
|
my $level = shift;
|
|
error(g_('%s is not a compression level'), $level)
|
|
if defined($level) and not compression_is_valid_level($level);
|
|
$default_compression_level = $level;
|
|
}
|
|
|
|
=item compression_is_valid_level($level)
|
|
|
|
Returns a boolean indicating whether $level is a valid compression level
|
|
(it must be either a number between 1 and 9 or "fast" or "best")
|
|
|
|
=cut
|
|
|
|
sub compression_is_valid_level {
|
|
my $level = shift;
|
|
return $level =~ /^([1-9]|fast|best)$/;
|
|
}
|
|
|
|
=back
|
|
|
|
=head1 CHANGES
|
|
|
|
=head2 Version 1.02 (dpkg 1.17.2)
|
|
|
|
New function: compression_get_file_extension_regex()
|
|
|
|
Deprecated variables: $default_compression, $default_compression_level
|
|
and $compression_re_file_ext
|
|
|
|
=head2 Version 1.01 (dpkg 1.16.1)
|
|
|
|
Default compression level is not global any more, it is per compressor type.
|
|
|
|
=head2 Version 1.00 (dpkg 1.15.6)
|
|
|
|
Mark the module as public.
|
|
|
|
=cut
|
|
|
|
1;
|