# -*- Mode: cperl; coding: utf-8; cperl-indent-level: 4 -*- use strict; package CPAN::Queue::Item; # CPAN::Queue::Item::new ; sub new { my($class,@attr) = @_; my $self = bless { @attr }, $class; return $self; } sub as_string { my($self) = @_; $self->{qmod}; } # r => requires, b => build_requires, c => commandline sub reqtype { my($self) = @_; $self->{reqtype}; } sub optional { my($self) = @_; $self->{optional}; } package CPAN::Queue; # One use of the queue is to determine if we should or shouldn't # announce the availability of a new CPAN module # Now we try to use it for dependency tracking. For that to happen # we need to draw a dependency tree and do the leaves first. This can # easily be reached by running CPAN.pm recursively, but we don't want # to waste memory and run into deep recursion. So what we can do is # this: # CPAN::Queue is the package where the queue is maintained. Dependencies # often have high priority and must be brought to the head of the queue, # possibly by jumping the queue if they are already there. My first code # attempt tried to be extremely correct. Whenever a module needed # immediate treatment, I either unshifted it to the front of the queue, # or, if it was already in the queue, I spliced and let it bypass the # others. This became a too correct model that made it impossible to put # an item more than once into the queue. Why would you need that? Well, # you need temporary duplicates as the manager of the queue is a loop # that # # (1) looks at the first item in the queue without shifting it off # # (2) cares for the item # # (3) removes the item from the queue, *even if its agenda failed and # even if the item isn't the first in the queue anymore* (that way # protecting against never ending queues) # # So if an item has prerequisites, the installation fails now, but we # want to retry later. That's easy if we have it twice in the queue. # # I also expect insane dependency situations where an item gets more # than two lives in the queue. Simplest example is triggered by 'install # Foo Foo Foo'. People make this kind of mistakes and I don't want to # get in the way. I wanted the queue manager to be a dumb servant, not # one that knows everything. # # Who would I tell in this model that the user wants to be asked before # processing? I can't attach that information to the module object, # because not modules are installed but distributions. So I'd have to # tell the distribution object that it should ask the user before # processing. Where would the question be triggered then? Most probably # in CPAN::Distribution::rematein. use vars qw{ @All $VERSION }; $VERSION = "5.5002"; # CPAN::Queue::queue_item ; sub queue_item { my($class,@attr) = @_; my $item = "$class\::Item"->new(@attr); $class->qpush($item); return 1; } # CPAN::Queue::qpush ; sub qpush { my($class,$obj) = @_; push @All, $obj; CPAN->debug(sprintf("in new All[%s]", join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @All), )) if $CPAN::DEBUG; } # CPAN::Queue::first ; sub first { my $obj = $All[0]; $obj; } # CPAN::Queue::delete_first ; sub delete_first { my($class,$what) = @_; my $i; for my $i (0..$#All) { if ( $All[$i]->{qmod} eq $what ) { splice @All, $i, 1; last; } } CPAN->debug(sprintf("after delete_first mod[%s] All[%s]", $what, join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @All) )) if $CPAN::DEBUG; } # CPAN::Queue::jumpqueue ; sub jumpqueue { my $class = shift; my @what = @_; CPAN->debug(sprintf("before jumpqueue All[%s] what[%s]", join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @All), join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @what), )) if $CPAN::DEBUG; unless (defined $what[0]{reqtype}) { # apparently it was not the Shell that sent us this enquiry, # treat it as commandline $what[0]{reqtype} = "c"; } my $inherit_reqtype = $what[0]{reqtype} =~ /^(c|r)$/ ? "r" : "b"; WHAT: for my $what_tuple (@what) { my($qmod,$reqtype,$optional) = @$what_tuple{qw(qmod reqtype optional)}; if ($reqtype eq "r" && $inherit_reqtype eq "b" ) { $reqtype = "b"; } my $jumped = 0; for (my $i=0; $i<$#All;$i++) { #prevent deep recursion if ($All[$i]{qmod} eq $qmod) { $jumped++; } } # high jumped values are normal for popular modules when # dealing with large bundles: XML::Simple, # namespace::autoclean, UNIVERSAL::require CPAN->debug("qmod[$qmod]jumped[$jumped]") if $CPAN::DEBUG; my $obj = "$class\::Item"->new( qmod => $qmod, reqtype => $reqtype, optional => !! $optional, ); unshift @All, $obj; } CPAN->debug(sprintf("after jumpqueue All[%s]", join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @All) )) if $CPAN::DEBUG; } # CPAN::Queue::exists ; sub exists { my($self,$what) = @_; my @all = map { $_->{qmod} } @All; my $exists = grep { $_->{qmod} eq $what } @All; # warn "in exists what[$what] all[@all] exists[$exists]"; $exists; } # CPAN::Queue::delete ; sub delete { my($self,$mod) = @_; @All = grep { $_->{qmod} ne $mod } @All; CPAN->debug(sprintf("after delete mod[%s] All[%s]", $mod, join("",map {sprintf " %s\[%s][%s]\n",$_->{qmod},$_->{reqtype},$_->{optional}} @All) )) if $CPAN::DEBUG; } # CPAN::Queue::nullify_queue ; sub nullify_queue { @All = (); } # CPAN::Queue::size ; sub size { return scalar @All; } sub reqtype_of { my($self,$mod) = @_; my $best = ""; for my $item (grep { $_->{qmod} eq $mod } @All) { my $c = $item->{reqtype}; if ($c eq "c") { $best = $c; last; } elsif ($c eq "r") { $best = $c; } elsif ($c eq "b") { if ($best eq "") { $best = $c; } } else { die "Panic: in reqtype_of: reqtype[$c] seen, should never happen"; } } return $best; } 1; __END__ =head1 NAME CPAN::Queue - internal queue support for CPAN.pm =head1 LICENSE This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut