Merge remote-tracking branch 'origin/nntp-compress'

* origin/nntp-compress:
  nntp: improve error reporting for COMPRESS
  nntp: reduce memory overhead of zlib
  nntp: support COMPRESS DEFLATE per RFC 8054
  nntp: move LINE_MAX constant to the top
  nntp: use msg_more as a method

diff --combined lib/PublicInbox/DS.pm
index 51515bf6b5730c3ddadb374a4e6aaa02b3f6a31d,b16b189629ff16d459bc7c79bb0155e43d9642ea..1e51dc41c1dbc46cc5d1011ef7d1b2b6ff95ba86
--- 1/lib/PublicInbox/DS.pm
--- 2/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@@ -16,7 -16,7 +16,7 @@@
  package PublicInbox::DS;
  use strict;
  use bytes;
 -use POSIX ();
 +use POSIX qw(WNOHANG);
  use IO::Handle qw();
  use Fcntl qw(SEEK_SET :DEFAULT);
  use Time::HiRes qw(clock_gettime CLOCK_MONOTONIC);
@@@ -38,8 -38,6 +38,8 @@@ use Carp   qw(croak confess carp)
  require File::Spec;
  
  my $nextq = []; # queue for next_tick
 +my $WaitPids = [];               # list of [ pid, callback, callback_arg ]
 +my $reap_timer;
  our (
       %DescriptorMap,             # fd (num) -> PublicInbox::DS object
       $Epoll,                     # Global epoll fd (or DSKQXS ref)
@@@ -66,8 -64,6 +66,8 @@@ Reset all stat
  =cut
  sub Reset {
      %DescriptorMap = ();
 +    $WaitPids = [];
 +    $reap_timer = undef;
      @ToClose = ();
      $LoopTimeout = -1;  # no timeout by default
      @Timers = ();
@@@ -219,33 -215,7 +219,33 @@@ sub RunTimers 
      return $timeout;
  }
  
 +# We can't use waitpid(-1) safely here since it can hit ``, system(),
 +# and other things.  So we scan the $WaitPids list, which is hopefully
 +# not too big.
 +sub reap_pids {
 +    my $tmp = $WaitPids;
 +    $WaitPids = [];
 +    $reap_timer = undef;
 +    foreach my $ary (@$tmp) {
 +        my ($pid, $cb, $arg) = @$ary;
 +        my $ret = waitpid($pid, WNOHANG);
 +        if ($ret == 0) {
 +            push @$WaitPids, $ary;
 +        } elsif ($cb) {
 +            eval { $cb->($arg, $pid) };
 +        }
 +    }
 +    if (@$WaitPids) {
 +        # we may not be donea, and we may miss our
 +        $reap_timer = AddTimer(undef, 1, \&reap_pids);
 +    }
 +}
 +
 +# reentrant SIGCHLD handler (since reap_pids is not reentrant)
 +sub enqueue_reap ($) { push @$nextq, \&reap_pids };
 +
  sub EpollEventLoop {
 +    local $SIG{CHLD} = \&enqueue_reap;
      while (1) {
          my @events;
          my $i;
@@@ -583,7 -553,9 +583,9 @@@ sub msg_more ($$) 
              return 0;
          }
      }
-     $self->write(\($_[1]));
+ 
+     # don't redispatch into NNTPdeflate::write
+     PublicInbox::DS::write($self, \($_[1]));
  }
  
  sub epwait ($$) {
@@@ -625,21 -597,6 +627,21 @@@ sub shutdn ($) 
        $self->close;
      }
  }
 +
 +# must be called with eval, PublicInbox::DS may not be loaded (see t/qspawn.t)
 +sub dwaitpid ($$$) {
 +    my ($pid, $cb, $arg) = @_;
 +    my $chld = $SIG{CHLD};
 +    if (defined($chld) && $chld eq \&enqueue_reap) {
 +        push @$WaitPids, [ $pid, $cb, $arg ];
 +
 +        # We could've just missed our SIGCHLD, cover it, here:
 +        requeue(\&reap_pids);
 +    } else {
 +        die "Not in EventLoop\n";
 +    }
 +}
 +
  package PublicInbox::DS::Timer;
  # [$abs_float_firetime, $coderef];
  sub cancel {