view: remove recursion from thread skeleton dump

This should help prevent OOM errors from arbitrarily
deep threads and will make our streaming interface
easier-to-implement.

1 files changed, 7 insertions, 6 deletions

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index a1b45e90..e09fbd51 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -386,8 +386,12 @@ sub thread_skel {
                 upfx => "$tpfx../",
                 dst => $dst,
         };
-        for (thread_results(load_results($sres))->rootset) {
-                skel_dump($state, $_, 0);
+        my @q = map { (0, $_) } thread_results(load_results($sres))->rootset;
+        while (@q) {
+                my $level = shift @q;
+                my $node = shift @q or next;
+                skel_dump($state, $level, $node);
+                unshift @q, $level+1, $node->child, $level, $node->next;
         }
         $ctx->{next_msg} = $state->{next_msg};
         $ctx->{parent_msg} = $parent;
@@ -714,8 +718,7 @@ sub _skel_header {
 }
 
 sub skel_dump {
-        my ($state, $node, $level) = @_;
-        return unless $node;
+        my ($state, $level, $node) = @_;
         if (my $mime = $node->message) {
                 my $hdr = $mime->header_obj;
                 my $mid = mid_clean($hdr->header_raw('Message-ID'));
@@ -734,8 +737,6 @@ sub skel_dump {
                         $$dst .= qq{&lt;<a\nhref="$href">$html</a>&gt;\n};
                 }
         }
-        skel_dump($state, $node->child, $level+1);
-        skel_dump($state, $node->next, $level);
 }
 
 sub sort_ts {