imapd+nntpd: drop timer-based expiration

It's needlessly complex and O(n), so it doesn't scale well to a
high number of clients nor is it easy-to-scale with the data
structures available to us in pure Perl.

In any case, I see no evidence of either -imapd nor -nntpd
experiencing high connection loads on public-facing sites.
-httpd has never had its own timer-based expiration, either.

Fwiw, public-inbox.org itself has been running a public-facing
HTTP/HTTPS server with no userspace idle client expiration for
the past 8 years or with no ill effect.  Clients can come and go
as they wish, and SO_KEEPALIVE takes care of truly broken
connections if they're gone for ~2 hours.

Internet connections drop all time, so it should be harmless to
drop connections w/o warning since both NNTP and IMAP protocols
have well-defined semantics for determining if a message was
truncated (as does HTTP/1.1+).

1 files changed, 1 insertions, 36 deletions

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 9cca02d7..bf8c4466 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -37,9 +37,7 @@ our @EXPORT_OK = qw(now msg_more dwaitpid add_timer add_uniq_timer);
 my %Stack;
 my $nextq; # queue for next_tick
 my $wait_pids; # list of [ pid, callback, callback_arg ]
-my $EXPMAP; # fd -> idle_time
-our $EXPTIME = 180; # 3 minutes
-my ($reap_armed);
+my $reap_armed;
 my $ToClose; # sockets to close when event loop is done
 our (
      %DescriptorMap,             # fd (num) -> PublicInbox::DS object
@@ -76,7 +74,6 @@ sub Reset {
                 # we may be iterating inside one of these on our stack
                 my @q = delete @Stack{keys %Stack};
                 for my $q (@q) { @$q = () }
-                $EXPMAP = undef;
                 $wait_pids = $nextq = $ToClose = undef;
                 $ep_io = undef; # closes real $Epoll FD
                 $Epoll = undef; # may call DSKQXS::DESTROY
@@ -251,9 +248,6 @@ sub PostEventLoop () {
                 $ToClose = undef; # will be autovivified on push
                 @$close_now = map { fileno($_) } @$close_now;
 
-                # order matters, destroy expiry times, first:
-                delete @$EXPMAP{@$close_now};
-
                 # ->DESTROY methods may populate ToClose
                 delete @DescriptorMap{@$close_now};
         }
@@ -655,35 +649,6 @@ sub dwaitpid ($;$$) {
         }
 }
 
-sub expire_old () {
-        my $cur = $EXPMAP or return;
-        $EXPMAP = undef;
-        my $old = now() - $EXPTIME;
-        while (my ($fd, $idle_at) = each %$cur) {
-                if ($idle_at < $old) {
-                        my $ds_obj = $DescriptorMap{$fd};
-                        $EXPMAP->{$fd} = $idle_at if !$ds_obj->shutdn;
-                } else {
-                        $EXPMAP->{$fd} = $idle_at;
-                }
-        }
-        add_uniq_timer('expire', 60, \&expire_old) if $EXPMAP;
-}
-
-sub update_idle_time {
-        my ($self) = @_;
-        my $sock = $self->{sock} or return;
-        $EXPMAP->{fileno($sock)} = now();
-        add_uniq_timer('expire', 60, \&expire_old);
-}
-
-sub not_idle_long {
-        my ($self, $now) = @_;
-        my $sock = $self->{sock} or return;
-        my $idle_at = $EXPMAP->{fileno($sock)} or return;
-        ($idle_at + $EXPTIME) > $now;
-}
-
 1;
 
 =head1 AUTHORS (Danga::Socket)