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.

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index a1b45e9002b4397c7bb26b28786866223c362b35..e09fbd5150850934b45680969267df18f9558ed2 100644 (file)
--- 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 {