www: do not bump {over} refcnt on long responses

SQLite files may be replaced or removed by admins while
generating a large threads or mailbox responses.  Ensure we
don't hold onto DBI handles and associated file descriptors
past their cleanup.

3 files changed, 22 insertions, 19 deletions

diff --git a/lib/PublicInbox/GzipFilter.pm b/lib/PublicInbox/GzipFilter.pm
index c50c26c5..624c2ed3 100644
--- a/lib/PublicInbox/GzipFilter.pm
+++ b/lib/PublicInbox/GzipFilter.pm
@@ -84,6 +84,12 @@ sub gzip_or_die () {
         $gz;
 }
 
+sub gone { # what: search/over/mm
+        my ($ctx, $what) = @_;
+        warn "W: `$ctx->{ibx}->{name}' $what went away unexpectedly\n";
+        undef;
+}
+
 # for GetlineBody (via Qspawn) when NOT using $env->{'pi-httpd.async'}
 # Also used for ->getline callbacks
 sub translate ($$) {
diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index cec76182..dede4825 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -124,8 +124,9 @@ sub thread_cb {
                         return $smsg;
                 }
                 # refill result set
-                $ctx->{msgs} = $msgs = $ctx->{over}->get_thread($ctx->{mid},
-                                                                $ctx->{prev});
+                my $over = $ctx->{ibx}->over or return $ctx->gone('over');
+                $ctx->{msgs} = $msgs = $over->get_thread($ctx->{mid},
+                                                        $ctx->{prev});
                 return unless @$msgs;
                 $ctx->{prev} = $msgs->[-1];
         }
@@ -136,7 +137,6 @@ sub thread_mbox {
         my $msgs = $ctx->{msgs} = $over->get_thread($ctx->{mid}, {});
         return [404, [qw(Content-Type text/plain)], []] if !@$msgs;
         $ctx->{prev} = $msgs->[-1];
-        $ctx->{over} = $over; # bump refcnt
         require PublicInbox::MboxGz;
         PublicInbox::MboxGz::mbox_gz($ctx, \&thread_cb, $msgs->[0]->{subject});
 }
@@ -155,22 +155,23 @@ sub emit_range {
 
 sub all_ids_cb {
         my ($ctx) = @_;
+        my $over = $ctx->{ibx}->over or return $ctx->gone('over');
         my $ids = $ctx->{ids};
         do {
                 while ((my $num = shift @$ids)) {
-                        my $smsg = $ctx->{over}->get_art($num) or next;
+                        my $smsg = $over->get_art($num) or next;
                         return $smsg;
                 }
-                $ctx->{ids} = $ids = $ctx->{over}->ids_after(\($ctx->{prev}));
+                $ctx->{ids} = $ids = $over->ids_after(\($ctx->{prev}));
         } while (@$ids);
 }
 
 sub mbox_all_ids {
         my ($ctx) = @_;
         my $prev = 0;
-        $ctx->{over} = $ctx->{ibx}->over or
+        my $over = $ctx->{ibx}->over or
                 return PublicInbox::WWW::need($ctx, 'Overview');
-        my $ids = $ctx->{over}->ids_after(\$prev) or return
+        my $ids = $over->ids_after(\$prev) or return
                 [404, [qw(Content-Type text/plain)], ["No results found\n"]];
         $ctx->{ids} = $ids;
         $ctx->{prev} = $prev;
@@ -179,22 +180,16 @@ sub mbox_all_ids {
         PublicInbox::MboxGz::mbox_gz($ctx, \&all_ids_cb, 'all');
 }
 
-sub gone ($$) {
-        my ($ctx, $what) = @_;
-        warn "W: `$ctx->{ibx}->{inboxdir}' $what went away unexpectedly\n";
-        undef;
-}
-
 sub results_cb {
         my ($ctx) = @_;
-        my $over = $ctx->{ibx}->over or return gone($ctx, 'over');
+        my $over = $ctx->{ibx}->over or return $ctx->gone('over');
         while (1) {
                 while (defined(my $num = shift(@{$ctx->{ids}}))) {
                         my $smsg = $over->get_art($num) or next;
                         return $smsg;
                 }
                 # refill result set, deprioritize since there's many results
-                my $srch = $ctx->{ibx}->isrch or return gone($ctx, 'search');
+                my $srch = $ctx->{ibx}->isrch or return $ctx->gone('search');
                 my $mset = $srch->mset($ctx->{query}, $ctx->{qopts});
                 my $size = $mset->size or return;
                 $ctx->{qopts}->{offset} += $size;
@@ -206,7 +201,7 @@ sub results_cb {
 sub results_thread_cb {
         my ($ctx) = @_;
 
-        my $over = $ctx->{ibx}->over or return gone($ctx, 'over');
+        my $over = $ctx->{ibx}->over or return $ctx->gone('over');
         while (1) {
                 while (defined(my $num = shift(@{$ctx->{xids}}))) {
                         my $smsg = $over->get_art($num) or next;
@@ -217,7 +212,7 @@ sub results_thread_cb {
                 next if $over->expand_thread($ctx);
 
                 # refill result set, deprioritize since there's many results
-                my $srch = $ctx->{ibx}->isrch or return gone($ctx, 'search');
+                my $srch = $ctx->{ibx}->isrch or return $ctx->gone('search');
                 my $mset = $srch->mset($ctx->{query}, $ctx->{qopts});
                 my $size = $mset->size or return;
                 $ctx->{qopts}->{offset} += $size;
diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 805e785b..069b9680 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -31,7 +31,9 @@ sub msg_page_i {
         my ($ctx, $eml) = @_;
         if ($eml) { # called by WwwStream::async_eml or getline
                 my $smsg = $ctx->{smsg};
-                $ctx->{smsg} = $ctx->{over}->next_by_mid(@{$ctx->{next_arg}});
+                my $over = $ctx->{ibx}->over;
+                $ctx->{smsg} = $over ? $over->next_by_mid(@{$ctx->{next_arg}})
+                                : $ctx->gone('over');
                 $ctx->{mhref} = ($ctx->{nr} || $ctx->{smsg}) ?
                                 "../${\mid_href($smsg->{mid})}/" : '';
                 my $obuf = $ctx->{obuf} = _msg_page_prepare_obuf($eml, $ctx);
@@ -70,7 +72,7 @@ sub msg_page {
         my ($ctx) = @_;
         my $ibx = $ctx->{ibx};
         $ctx->{-obfs_ibx} = $ibx->{obfuscate} ? $ibx : undef;
-        my $over = $ctx->{over} = $ibx->over or return no_over_html($ctx);
+        my $over = $ibx->over or return no_over_html($ctx);
         my ($id, $prev);
         my $next_arg = $ctx->{next_arg} = [ $ctx->{mid}, \$id, \$prev ];