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# Copyright © 1998 Richard Braakman
# Copyright © 1999 Darren Benham
# Copyright © 2000 Sean 'Shaleh' Perry
# Copyright © 2004 Frank Lichtenheld
# Copyright © 2006 Russ Allbery
# Copyright © 2007-2009 Raphaël Hertzog <hertzog@debian.org>
# Copyright © 2008-2009, 2012-2014 Guillem Jover <guillem@debian.org>
#
# This program is free software; you may 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 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::Deps::OR - list of OR dependencies
=head1 DESCRIPTION
This class represents a list of dependencies of which only one must be met
for the dependency to be true. It inherits from L<Dpkg::Deps::Multiple>.
=cut
package Dpkg::Deps::OR 1.00;
use strict;
use warnings;
use parent qw(Dpkg::Deps::Multiple);
=head1 METHODS
=over 4
=item $dep->output([$fh])
The output() method uses " | " to join the list of sub-dependencies.
=cut
sub output {
my ($self, $fh) = @_;
my $res = join(' | ', map {
$_->output()
} grep {
not $_->is_empty()
} $self->get_deps());
if (defined $fh) {
print { $fh } $res;
}
return $res;
}
=item $dep->implies($other_dep)
Returns 1 when $dep implies $other_dep. Returns 0 when $dep implies
NOT($other_dep). Returns undef when there's no implication. $dep and
$other_dep do not need to be of the same type.
=cut
sub implies {
my ($self, $o) = @_;
# Special case for AND with a single member, replace it by its member
if ($o->isa('Dpkg::Deps::AND')) {
my @subdeps = $o->get_deps();
if (scalar(@subdeps) == 1) {
$o = $subdeps[0];
}
}
# In general, an OR dependency can't imply anything except if each
# of its member implies a member in the other OR dependency
if ($o->isa('Dpkg::Deps::OR')) {
my $subset = 1;
foreach my $dep ($self->get_deps()) {
my $found = 0;
foreach my $odep ($o->get_deps()) {
$found = 1 if $dep->implies($odep);
}
$subset = 0 if not $found;
}
return 1 if $subset;
}
return;
}
=item $dep->get_evaluation($facts)
Evaluates the dependency given a list of installed packages and a list of
virtual packages provided. These lists are part of the
L<Dpkg::Deps::KnownFacts> object given as parameters.
Returns 1 when it's true, 0 when it's false, undef when some information
is lacking to conclude.
=cut
sub get_evaluation {
my ($self, $facts) = @_;
# Returns false if all members evaluates to 0
# Returns true if at least one member evaluates to true
# Returns undef otherwise
my $result = 0;
foreach my $dep ($self->get_deps()) {
my $eval = $dep->get_evaluation($facts);
if (not defined $eval) {
$result = undef;
} elsif ($eval == 1) {
$result = 1;
last;
} elsif ($eval == 0) {
# Still possible to have a false evaluation
}
}
return $result;
}
=item $dep->simplify_deps($facts, @assumed_deps)
Simplifies the dependency as much as possible given the list of facts (see
object L<Dpkg::Deps::KnownFacts>) and a list of other dependencies that are
known to be true.
=cut
sub simplify_deps {
my ($self, $facts) = @_;
my @new;
WHILELOOP:
while (@{$self->{list}}) {
my $dep = shift @{$self->{list}};
my $eval = $dep->get_evaluation($facts);
if (defined $eval and $eval == 1) {
$self->{list} = [];
return;
}
foreach my $odep (@new, @{$self->{list}}) {
next WHILELOOP if $odep->implies($dep);
}
push @new, $dep;
}
$self->{list} = [ @new ];
}
=back
=head1 CHANGES
=head2 Version 1.00 (dpkg 1.15.6)
Mark the module as public.
=cut
1;
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