view: remove recursion from expanded thread view

This should let us generate HTML for arbitrarily deep
threads without blowing the stack.

How it renders on the client side is another matter...

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index e09fbd5150850934b45680969267df18f9558ed2..bc4a44323d2aa6a801a3988f4e93199debe3c8f3 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -177,8 +177,13 @@ sub emit_thread_html {
                pre_anchor_entry($seen, $_) for (@$msgs);
                __thread_entry($state, $_, 0) for (@$msgs);
        } else {
-               my $th = thread_results($msgs);
-               thread_entry($state, $_, 0) for $th->rootset;
+               my @q = map { (0, $_) } thread_results($msgs)->rootset;
+               while (@q) {
+                       my $level = shift @q;
+                       my $node = shift @q or next;
+                       thread_entry($state, $level, $node);
+                       unshift @q, $level+1, $node->child, $level, $node->next;
+               }
                if (my $max = $state->{cur_level}) {
                        $state->{fh}->write(
                                ('</ul></li>' x ($max - 1)) . '</ul>');
@@ -618,8 +623,7 @@ sub __ghost_prepare {
 }
 
 sub thread_entry {
-       my ($state, $node, $level) = @_;
-       return unless $node;
+       my ($state, $level, $node) = @_;
        if (my $mime = $node->message) {
                unless (__thread_entry($state, $mime, $level)) {
                        __ghost_prepare($state, $node, $level);
@@ -627,9 +631,6 @@ sub thread_entry {
        } else {
                __ghost_prepare($state, $node, $level);
        }
-
-       thread_entry($state, $node->child, $level + 1);
-       thread_entry($state, $node->next, $level);
 }
 
 sub load_results {