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Direktori : /usr/share/perl5/Dpkg/Deps/ |
Current File : //usr/share/perl5/Dpkg/Deps/AND.pm |
# 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::AND - list of AND dependencies =head1 DESCRIPTION This class represents a list of dependencies that must be met at the same time. It inherits from L<Dpkg::Deps::Multiple>. =cut package Dpkg::Deps::AND 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) = @_; # If any individual member can imply $o or NOT $o, we're fine foreach my $dep ($self->get_deps()) { my $implication = $dep->implies($o); return 1 if defined $implication and $implication == 1; return 0 if defined $implication and $implication == 0; } # If o is an AND, we might have an implication, if we find an # implication within us for each predicate in o if ($o->isa('Dpkg::Deps::AND')) { my $subset = 1; foreach my $odep ($o->get_deps()) { my $found = 0; foreach my $dep ($self->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) = @_; # Return 1 only if all members evaluates to true # Return 0 if at least one member evaluates to false # Return undef otherwise my $result = 1; foreach my $dep ($self->get_deps()) { my $eval = $dep->get_evaluation($facts); if (not defined $eval) { $result = undef; } elsif ($eval == 0) { $result = 0; last; } elsif ($eval == 1) { # Still possible } } 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, $facts, @knowndeps) = @_; my @new; WHILELOOP: while (@{$self->{list}}) { my $dep = shift @{$self->{list}}; my $eval = $dep->get_evaluation($facts); next if defined $eval and $eval == 1; foreach my $odep (@knowndeps, @new) { next WHILELOOP if $odep->implies($dep); } # When a dependency is implied by another dependency that # follows, then invert them # "a | b, c, a" becomes "a, c" and not "c, a" my $i = 0; foreach my $odep (@{$self->{list}}) { if (defined $odep and $odep->implies($dep)) { splice @{$self->{list}}, $i, 1; unshift @{$self->{list}}, $odep; next WHILELOOP; } $i++; } push @new, $dep; } $self->{list} = [ @new ]; } =back =head1 CHANGES =head2 Version 1.00 (dpkg 1.15.6) Mark the module as public. =cut 1;