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 available 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 $self->{rootset} = [ grep { !$_->{parent} } values %$id_table ];
39 sub _get_cont_for_id ($$) {
40 my ($self, $mid) = @_;
41 $self->{id_table}{$mid} ||= PublicInbox::SearchThread::Msg->new($mid);
44 sub _add_message ($$) {
45 my ($self, $smsg) = @_;
48 my $this = _get_cont_for_id($self, $smsg->{mid});
49 $this->{smsg} = $smsg;
51 # B. For each element in the message's References field:
53 if (defined(my $refs = $smsg->{references})) {
54 foreach my $ref ($refs =~ m/<([^>]+)>/g) {
55 # Find a Container object for the given Message-ID
56 my $cont = _get_cont_for_id($self, $ref);
58 # Link the References field's Containers together in
59 # the order implied by the References header
61 # * If they are already linked don't change the
63 # * Do not add a link if adding that link would
66 !$cont->{parent} && # already linked
67 !$cont->has_descendent($prev) # would loop
69 $prev->add_child($cont);
75 # C. Set the parent of this message to be the last element in
77 if ($prev && !$this->has_descendent($prev)) { # would loop
78 $prev->add_child($this)
83 my ($self, $ordersub) = @_;
84 my $rootset = $ordersub->($self->{rootset});
85 $self->{rootset} = $rootset;
86 $_->order_children($ordersub) for @$rootset;
89 package PublicInbox::SearchThread::Msg;
93 use Scalar::Util qw(weaken);
98 children => {}, # becomes an array when sorted by ->order(...)
103 my ($self, $child) = @_;
104 croak "Cowardly refusing to become my own parent: $self"
107 my $cid = $child->{id};
108 $self->{children}->{$cid} = $child;
111 if (defined(my $parent = $child->{parent})) {
112 delete $parent->{children}->{$cid};
115 weaken($child->{parent} = $self);
119 my ($cur, $child) = @_;
121 my @q = ($cur->{parent} || $cur);
123 while (defined($cur = shift @q)) {
124 return 1 if $cur == $child;
126 if (!$seen{$cur}++) {
127 push @q, values %{$cur->{children}};
134 my ($cur, $ordersub) = @_;
136 my %seen = ($cur => 1);
138 while (defined($cur = shift @q)) {
139 my $c = $cur->{children}; # The hashref here...
141 $c = [ grep { !$seen{$_}++ } values %$c ]; # spot/break loops
142 $c = $ordersub->($c) if scalar @$c > 1;
143 $cur->{children} = $c; # ...becomes an arrayref