1 # This library is free software; you can redistribute it and/or modify
2 # it under the same terms as Perl itself.
4 # This license differs from the rest of public-inbox
6 # Our own jwz-style threading class based on Mail::Thread from CPAN.
7 # Mail::Thread is unmaintained and unavailable on some distros.
8 # We also do not want pruning or subject grouping, since we want
9 # to encourage strict threading and hopefully encourage people
10 # to use proper In-Reply-To.
12 # This includes fixes from several open bugs for Mail::Thread
14 # Avoid circular references
15 # - https://rt.cpan.org/Public/Bug/Display.html?id=22817
17 # And avoid recursion in recurse_down:
18 # - https://rt.cpan.org/Ticket/Display.html?id=116727
19 # - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=833479
20 package PublicInbox::SearchThread;
34 _add_message($self, $_) foreach @{$self->{messages}};
35 my $id_table = delete $self->{id_table};
36 $self->{rootset} = [ grep {
37 !delete($_->{parent}) && $_->visible } values %$id_table ];
40 sub _get_cont_for_id ($$) {
41 my ($self, $mid) = @_;
42 $self->{id_table}{$mid} ||= PublicInbox::SearchThread::Msg->new($mid);
45 sub _add_message ($$) {
46 my ($self, $smsg) = @_;
49 my $this = _get_cont_for_id($self, $smsg->{mid});
50 $this->{smsg} = $smsg;
52 # B. For each element in the message's References field:
53 defined(my $refs = $smsg->{references}) or return;
55 # This loop exists to help fill in gaps left from missing
56 # messages. It is not needed in a perfect world where
57 # everything is perfectly referenced, only the last ref
60 foreach my $ref ($refs =~ m/<([^>]+)>/g) {
61 # Find a Container object for the given Message-ID
62 my $cont = _get_cont_for_id($self, $ref);
64 # Link the References field's Containers together in
65 # the order implied by the References header
67 # * If they are already linked don't change the
69 # * Do not add a link if adding that link would
72 !$cont->{parent} && # already linked
73 !$cont->has_descendent($prev) # would loop
75 $prev->add_child($cont);
80 # C. Set the parent of this message to be the last element in
82 $prev->add_child($this) if defined $prev;
86 my ($self, $ordersub) = @_;
87 my $rootset = $ordersub->($self->{rootset});
88 $self->{rootset} = $rootset;
89 $_->order_children($ordersub) for @$rootset;
92 package PublicInbox::SearchThread::Msg;
100 children => {}, # becomes an array when sorted by ->order(...)
107 while (my $cont = shift @q) {
108 return $cont if $cont->{smsg};
109 push @q, values %{$cont->{children}};
115 my ($self, $child) = @_;
116 croak "Cowardly refusing to become my own parent: $self"
119 my $cid = $child->{id};
122 if (defined(my $parent = $child->{parent})) {
123 delete $parent->{children}->{$cid};
126 $self->{children}->{$cid} = $child;
127 $child->{parent} = $self;
131 my ($self, $child) = @_;
132 my %seen; # loop prevention XXX may not be necessary
134 return 1 if $self == $child || $seen{$child}++;
135 $child = $child->{parent};
140 # Do not show/keep ghosts iff they have no children. Sometimes
141 # a ghost Message-ID is the result of a long header line
142 # being folded/mangled by a MUA, and not a missing message.
145 $self->{smsg} || scalar values %{$self->{children}};
149 my ($cur, $ordersub) = @_;
151 my %seen = ($cur => 1); # self-referential loop prevention
153 while (defined($cur = shift @q)) {
154 my $c = $cur->{children}; # The hashref here...
156 $c = [ grep { !$seen{$_}++ && visible($_) } values %$c ];
157 $c = $ordersub->($c) if scalar @$c > 1;
158 $cur->{children} = $c; # ...becomes an arrayref