# This license differs from the rest of public-inbox
#
# Our own jwz-style threading class based on Mail::Thread from CPAN.
-# Mail::Thread is unmaintained and available on some distros.
+# Mail::Thread is unmaintained and unavailable on some distros.
# We also do not want pruning or subject grouping, since we want
# to encourage strict threading and hopefully encourage people
-# to use proper In-Reply-To.
+# to use proper In-Reply-To/References.
#
# This includes fixes from several open bugs for Mail::Thread
#
package PublicInbox::SearchThread;
use strict;
use warnings;
-
-sub new {
- return bless {
- messages => $_[1],
- id_table => {},
- rootset => []
- }, $_[0];
-}
+use PublicInbox::MID qw($MID_EXTRACT);
sub thread {
- my $self = shift;
- _add_message($self, $_) foreach @{$self->{messages}};
- my $id_table = delete $self->{id_table};
- $self->{rootset} = [ grep { !$_->{parent} } values %$id_table ];
-}
-
-sub _get_cont_for_id ($$) {
- my ($self, $mid) = @_;
- $self->{id_table}{$mid} ||= PublicInbox::SearchThread::Msg->new($mid);
-}
-
-sub _add_message ($$) {
- my ($self, $smsg) = @_;
-
- # A. if id_table...
- my $this = _get_cont_for_id($self, $smsg->{mid});
- $this->{smsg} = $smsg;
-
- # B. For each element in the message's References field:
- my $prev;
- if (defined(my $refs = $smsg->{references})) {
- foreach my $ref ($refs =~ m/<([^>]+)>/g) {
+ my ($msgs, $ordersub, $ctx) = @_;
+ my (%id_table, @imposters);
+ keys(%id_table) = scalar @$msgs; # pre-size
+
+ # A. put all current non-imposter $msgs (non-ghosts) into %id_table
+ # (imposters are messages with reused Message-IDs)
+ # Sadly, we sort here anyways since the fill-in-the-blanks References:
+ # can be shakier if somebody used In-Reply-To with multiple, disparate
+ # messages. So, take the client Date: into account since we can't
+ # always determine ordering when somebody uses multiple In-Reply-To.
+ my @kids = sort { $a->{ds} <=> $b->{ds} } grep {
+ # this delete saves around 4K across 1K messages
+ # TODO: move this to a more appropriate place, breaks tests
+ # if we do it during psgi_cull
+ delete $_->{num};
+ bless $_, 'PublicInbox::SearchThread::Msg';
+ if (exists $id_table{$_->{mid}}) {
+ $_->{children} = [];
+ push @imposters, $_; # we'll deal with them later
+ undef;
+ } else {
+ $_->{children} = {}; # will become arrayref later
+ $id_table{$_->{mid}} = $_;
+ defined($_->{references});
+ }
+ } @$msgs;
+ for my $smsg (@kids) {
+ # This loop exists to help fill in gaps left from missing
+ # messages. It is not needed in a perfect world where
+ # everything is perfectly referenced, only the last ref
+ # matters.
+ my $prev;
+ for my $ref ($smsg->{references} =~ m/$MID_EXTRACT/go) {
# Find a Container object for the given Message-ID
- my $cont = _get_cont_for_id($self, $ref);
+ my $cont = $id_table{$ref} //=
+ PublicInbox::SearchThread::Msg::ghost($ref);
# Link the References field's Containers together in
# the order implied by the References header
}
$prev = $cont;
}
- }
- # C. Set the parent of this message to be the last element in
- # References...
- if ($prev && !$this->has_descendent($prev)) { # would loop
- $prev->add_child($this)
+ # C. Set the parent of this message to be the last element in
+ # References.
+ if (defined $prev && !$smsg->has_descendent($prev)) {
+ $prev->add_child($smsg);
+ }
}
-}
-
-sub order {
- my ($self, $ordersub) = @_;
- my $rootset = $ordersub->($self->{rootset});
- $self->{rootset} = $rootset;
- $_->order_children($ordersub) for @$rootset;
+ my $ibx = $ctx->{ibx};
+ my @rootset = grep { # n.b.: delete prevents cyclic refs
+ !delete($_->{parent}) && $_->visible($ibx)
+ } values %id_table;
+ $ordersub->(\@rootset);
+ $_->order_children($ordersub, $ctx) for @rootset;
+
+ # parent imposter messages with reused Message-IDs
+ unshift(@{$id_table{$_->{mid}}->{children}}, $_) for @imposters;
+ \@rootset;
}
package PublicInbox::SearchThread::Msg;
+use base qw(PublicInbox::Smsg);
use strict;
use warnings;
use Carp qw(croak);
-use Scalar::Util qw(weaken);
-sub new {
+# declare a ghost smsg (determined by absence of {blob})
+sub ghost {
bless {
- id => $_[1],
+ mid => $_[0],
children => {}, # becomes an array when sorted by ->order(...)
- }, $_[0];
+ }, __PACKAGE__;
+}
+
+sub topmost {
+ my ($self) = @_;
+ my @q = ($self);
+ while (my $cont = shift @q) {
+ return $cont if $cont->{blob};
+ push @q, values %{$cont->{children}};
+ }
+ undef;
}
sub add_child {
croak "Cowardly refusing to become my own parent: $self"
if $self == $child;
- my $cid = $child->{id};
- $self->{children}->{$cid} = $child;
+ my $cid = $child->{mid};
# reparenting:
if (defined(my $parent = $child->{parent})) {
delete $parent->{children}->{$cid};
}
- weaken($child->{parent} = $self);
+ $self->{children}->{$cid} = $child;
+ $child->{parent} = $self;
}
sub has_descendent {
- my ($cur, $child) = @_;
- my %seen;
- my @q = ($cur->{parent} || $cur);
-
- while (defined($cur = shift @q)) {
- return 1 if $cur == $child;
-
- if (!$seen{$cur}++) {
- push @q, values %{$cur->{children}};
- }
+ my ($self, $child) = @_;
+ my %seen; # loop prevention
+ while ($child) {
+ return 1 if $self == $child || $seen{$child}++;
+ $child = $child->{parent};
}
0;
}
+# Do not show/keep ghosts iff they have no children. Sometimes
+# a ghost Message-ID is the result of a long header line
+# being folded/mangled by a MUA, and not a missing message.
+sub visible ($$) {
+ my ($self, $ibx) = @_;
+ return 1 if $self->{blob};
+ if (my $by_mid = $ibx->smsg_by_mid($self->{mid})) {
+ %$self = (%$self, %$by_mid);
+ 1;
+ } else {
+ (scalar values %{$self->{children}});
+ }
+}
+
sub order_children {
- my ($cur, $ordersub) = @_;
+ my ($cur, $ordersub, $ctx) = @_;
- my %seen = ($cur => 1);
+ my %seen = ($cur => 1); # self-referential loop prevention
my @q = ($cur);
+ my $ibx = $ctx->{ibx};
while (defined($cur = shift @q)) {
- my $c = $cur->{children}; # The hashref here...
-
- $c = [ grep { !$seen{$_}++ } values %$c ]; # spot/break loops
- $c = $ordersub->($c) if scalar @$c > 1;
- $cur->{children} = $c; # ...becomes an arrayref
- push @q, @$c;
+ # the {children} hashref here...
+ my @c = grep { !$seen{$_}++ && visible($_, $ibx) }
+ values %{delete $cur->{children}};
+ $ordersub->(\@c) if scalar(@c) > 1;
+ $cur->{children} = \@c; # ...becomes an arrayref
+ push @q, @c;
}
}