X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FSearchThread.pm;h=450a06f43bc86f6266d32811e6efd507ffe94c7a;hb=ec2df4c3b80104a0bf15b0d917d82264bbf9b50e;hp=41fe859e76af60aa30cc7aa2481ba00d14d4a12a;hpb=172416d1cd465da4242cc744a3f309d307f1311d;p=public-inbox.git

diff --git a/lib/PublicInbox/SearchThread.pm b/lib/PublicInbox/SearchThread.pm
index 41fe859e..450a06f4 100644
--- a/lib/PublicInbox/SearchThread.pm
+++ b/lib/PublicInbox/SearchThread.pm
@@ -4,10 +4,10 @@
 # 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
 #
@@ -20,304 +20,137 @@
 package PublicInbox::SearchThread;
 use strict;
 use warnings;
-use Email::Abstract;
-
-sub new {
-	return bless {
-		messages => $_[1],
-		id_table => {},
-		rootset  => []
-	}, $_[0];
-}
-
-sub _get_hdr {
-	my ($class, $msg, $hdr) = @_;
-	Email::Abstract->get_header($msg, $hdr) || '';
-}
-
-sub _uniq {
-	my %seen;
-	return grep { !$seen{$_}++ } @_;
-}
-
-sub _references {
-	my $class = shift;
-	my $msg = shift;
-	my @references = ($class->_get_hdr($msg, "References") =~ /<([^>]+)>/g);
-	my $foo = $class->_get_hdr($msg, "In-Reply-To");
-	chomp $foo;
-	$foo =~ s/.*?<([^>]+)>.*/$1/;
-	push @references, $foo
-	  if $foo =~ /^\S+\@\S+$/ && (!@references || $references[-1] ne $foo);
-	return _uniq(@references);
-}
-
-sub _msgid {
-	my ($class, $msg) = @_;
-	my $id = $class->_get_hdr($msg, "Message-ID");
-	die "attempt to thread message with no id" unless $id;
-	chomp $id;
-	$id =~ s/^<([^>]+)>.*/$1/; # We expect this not to have <>s
-	return $id;
-}
-
-sub rootset { @{$_[0]{rootset}} }
 
 sub thread {
-	my $self = shift;
-	$self->_setup();
-	$self->{rootset} = [ grep { !$_->parent } values %{$self->{id_table}} ];
-	$self->_finish();
-}
-
-sub _finish {
-	my $self = shift;
-	delete $self->{id_table};
-	delete $self->{seen};
-}
-
-sub _get_cont_for_id {
-	my $self = shift;
-	my $id = shift;
-	$self->{id_table}{$id} ||= $self->_container_class->new($id);
+	my ($messages, $ordersub, $ibx) = @_;
+	my $id_table = {};
+	_add_message($id_table, $_) foreach @$messages;
+	my $rootset = [ grep {
+			!delete($_->{parent}) && $_->visible($ibx)
+		} values %$id_table ];
+	$id_table = undef;
+	$rootset = $ordersub->($rootset);
+	$_->order_children($ordersub, $ibx) for @$rootset;
+	$rootset;
 }
 
-sub _container_class { 'PublicInbox::SearchThread::Container' }
-
-sub _setup {
-	my ($self) = @_;
-
-	_add_message($self, $_) foreach @{$self->{messages}};
+sub _get_cont_for_id ($$) {
+	my ($id_table, $mid) = @_;
+	$id_table->{$mid} ||= PublicInbox::SearchThread::Msg->new($mid);
 }
 
 sub _add_message ($$) {
-	my ($self, $message) = @_;
+	my ($id_table, $smsg) = @_;
 
 	# A. if id_table...
-	my $this_container = $self->_get_cont_for_id($self->_msgid($message));
-	$this_container->message($message);
+	my $this = _get_cont_for_id($id_table, $smsg->{mid});
+	$this->{smsg} = $smsg;
 
 	# B. For each element in the message's References field:
-	my @refs = $self->_references($message);
+	defined(my $refs = $smsg->{references}) or return;
 
+	# 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 (@refs) {
+	foreach my $ref ($refs =~ m/<([^>]+)>/g) {
 		# Find a Container object for the given Message-ID
-		my $container = $self->_get_cont_for_id($ref);
-
-		# Link the References field's Containers together in the
-		# order implied by the References header
-		# * If they are already linked don't change the existing links
-		# * Do not add a link if adding that link would introduce
-		#   a loop...
-
+		my $cont = _get_cont_for_id($id_table, $ref);
+
+		# Link the References field's Containers together in
+		# the order implied by the References header
+		#
+		# * If they are already linked don't change the
+		#   existing links
+		# * Do not add a link if adding that link would
+		#   introduce a loop...
 		if ($prev &&
-			!$container->parent &&  # already linked
-			!$container->has_descendent($prev) # would loop
+			!$cont->{parent} &&  # already linked
+			!$cont->has_descendent($prev) # would loop
 		   ) {
-			$prev->add_child($container);
+			$prev->add_child($cont);
 		}
-		$prev = $container;
+		$prev = $cont;
 	}
 
 	# C. Set the parent of this message to be the last element in
-	# References...
-	if ($prev &&
-		!$this_container->has_descendent($prev) # would loop
-	   ) {
-		$prev->add_child($this_container)
+	# References.
+	if (defined $prev && !$this->has_descendent($prev)) { # would loop
+		$prev->add_child($this);
 	}
 }
 
-sub order {
-	my $self = shift;
-	my $ordersub = shift;
-
-	# make a fake root
-	my $root = $self->_container_class->new( 'fakeroot' );
-	$root->add_child( $_ ) for @{ $self->{rootset} };
-
-	# sort it
-	$root->order_children( $ordersub );
-
-	# and untangle it
-	my @kids = $root->children;
-	$self->{rootset} = \@kids;
-	$root->remove_child($_) for @kids;
-}
-
-package PublicInbox::SearchThread::Container;
+package PublicInbox::SearchThread::Msg;
+use strict;
+use warnings;
 use Carp qw(croak);
-use Scalar::Util qw(weaken);
 
-sub new { my $self = shift; bless { id => shift }, $self; }
+sub new {
+	bless {
+		id => $_[1],
+		children => {}, # becomes an array when sorted by ->order(...)
+	}, $_[0];
+}
 
-sub message { $_[0]->{message} = $_[1] if @_ == 2; $_[0]->{message} }
-sub parent { @_ == 2 ? weaken($_[0]->{parent} = $_[1]) : $_[0]->{parent} }
-sub child { $_[0]->{child} = $_[1] if @_ == 2; $_[0]->{child} }
-sub next { $_[0]->{next} = $_[1] if @_ == 2; $_[0]->{next} }
-sub messageid { $_[0]->{id} }
+sub topmost {
+	my ($self) = @_;
+	my @q = ($self);
+	while (my $cont = shift @q) {
+		return $cont if $cont->{smsg};
+		push @q, values %{$cont->{children}};
+	}
+	undef;
+}
 
 sub add_child {
 	my ($self, $child) = @_;
 	croak "Cowardly refusing to become my own parent: $self"
 	  if $self == $child;
 
-	if (grep { $_ == $child } $self->children) {
-		# All is potentially correct with the world
-		$child->parent($self);
-		return;
-	}
-
-	$child->parent->remove_child($child) if $child->parent;
+	my $cid = $child->{id};
 
-	$child->next($self->child);
-	$self->child($child);
-	$child->parent($self);
-}
-
-sub remove_child {
-	my ($self, $child) = @_;
-	return unless $self->child;
-	if ($self->child == $child) {  # First one's easy.
-		$self->child($child->next);
-		$child->next(undef);
-		$child->parent(undef);
-		return;
+	# reparenting:
+	if (defined(my $parent = $child->{parent})) {
+		delete $parent->{children}->{$cid};
 	}
 
-	my $x = $self->child;
-	my $prev = $x;
-	while ($x = $x->next) {
-		if ($x == $child) {
-			$prev->next($x->next); # Unlink x
-			$x->next(undef);
-			$x->parent(undef);	 # Deparent it
-			return;
-		}
-		$prev = $x;
-	}
-	# oddly, we can get here
-	$child->next(undef);
-	$child->parent(undef);
+	$self->{children}->{$cid} = $child;
+	$child->{parent} = $self;
 }
 
 sub has_descendent {
-	my $self = shift;
-	my $child = shift;
-	die "Assertion failed: $child" unless eval {$child};
-	my $there = 0;
-	$self->recurse_down(sub { $there = 1 if $_[0] == $child });
-
-	return $there;
-}
-
-sub children {
-	my $self = shift;
-	my @children;
-	my $visitor = $self->child;
-	while ($visitor) {
-		push @children, $visitor;
-		$visitor = $visitor->next
+	my ($self, $child) = @_;
+	my %seen; # loop prevention
+	while ($child) {
+		return 1 if $self == $child || $seen{$child}++;
+		$child = $child->{parent};
 	}
-	return @children;
+	0;
 }
 
-sub set_children {
-	my $self = shift;
-	my $walk = $self->child( shift );
-	while (@_) { $walk = $walk->next( shift ) }
-	$walk->next(undef) if $walk;
+# 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, $ibx) = @_;
+	($self->{smsg} ||= eval { $ibx->smsg_by_mid($self->{id}) }) ||
+	 (scalar values %{$self->{children}});
 }
 
 sub order_children {
-	my $self = shift;
-	my $ordersub = shift;
-
-	return unless $ordersub;
-
-	my $sub = sub {
-		my $cont = shift;
-		my @children = $cont->children;
-		return if @children < 2;
-		$cont->set_children( $ordersub->( @children ) );
-	};
-	$self->iterate_down( undef, $sub );
-	undef $sub;
-}
+	my ($cur, $ordersub, $ibx) = @_;
 
-# non-recursive version of recurse_down to avoid stack depth warnings
-sub recurse_down {
-	my ($self, $callback) = @_;
-	my %seen;
-	my @q = ($self);
-	while (my $cont = shift @q) {
-		$seen{$cont}++;
-		$callback->($cont);
-
-		if (my $next = $cont->next) {
-			if ($seen{$next}) {
-				$cont->next(undef);
-			} else {
-				push @q, $next;
-			}
-		}
-		if (my $child = $cont->child) {
-			if ($seen{$child}) {
-				$cont->child(undef);
-			} else {
-				push @q, $child;
-			}
-		}
-	}
-}
-
-sub iterate_down {
-	my $self = shift;
-	my ($before, $after) = @_;
-
-	my %seen;
-	my $walk = $self;
-	my $depth = 0;
-	my @visited;
-	while ($walk) {
-		push @visited, [ $walk, $depth ];
-		$before->($walk, $depth) if $before;
+	my %seen = ($cur => 1); # self-referential loop prevention
+	my @q = ($cur);
+	while (defined($cur = shift @q)) {
+		my $c = $cur->{children}; # The hashref here...
 
-		# spot/break loops
-		$seen{$walk}++;
-
-		my $child = $walk->child;
-		if ($child && $seen{$child}) {
-			$walk->child(undef);
-			$child = undef;
-		}
-
-		my $next = $walk->next;
-		if ($next && $seen{$next}) {
-			$walk->next(undef);
-			$next = undef;
-		}
-
-		# go down, or across
-		if ($child) {
-			$next = $child;
-			++$depth;
-		}
-
-		# no next?  look up
-		if (!$next) {
-			my $up = $walk;
-			while ($up && !$next) {
-				$up = $up->parent;
-				--$depth;
-				$next = $up->next if $up;
-			}
-		}
-		$walk = $next;
+		$c = [ grep { !$seen{$_}++ && visible($_, $ibx) } values %$c ];
+		$c = $ordersub->($c) if scalar @$c > 1;
+		$cur->{children} = $c; # ...becomes an arrayref
+		push @q, @$c;
 	}
-	return unless $after;
-	while (@visited) { $after->(@{ pop @visited }) }
 }
 
 1;