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| -rw-r--r-- | scripts/Dpkg/Deps/OR.pm | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/scripts/Dpkg/Deps/OR.pm b/scripts/Dpkg/Deps/OR.pm new file mode 100644 index 0000000..b2f8d03 --- /dev/null +++ b/scripts/Dpkg/Deps/OR.pm @@ -0,0 +1,174 @@ +# 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/>. + +package Dpkg::Deps::OR; + +=encoding utf8 + +=head1 NAME + +Dpkg::Deps::OR - list of OR dependencies + +=head1 DESCRIPTION + +This object represents a list of dependencies of which only one must be met +for the dependency to be true. It inherits from Dpkg::Deps::Multiple. + +=cut + +use strict; +use warnings; + +our $VERSION = '1.00'; + +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 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 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; |