[PATCH 09/11] ds: share long_step between NNTP and IMAP

[Eric Wong <e@80x24.org>]

It's not actually used by our POP3 code at the moment,
but it may be soon to reduce memory usage when loading
50K smsg objects into memory.
---
 lib/PublicInbox/DS.pm   | 44 +++++++++++++++++++++++++--
 lib/PublicInbox/IMAP.pm | 47 ++---------------------------
 lib/PublicInbox/NNTP.pm | 67 +++++++++--------------------------------
 lib/PublicInbox/POP3.pm | 39 ------------------------
 4 files changed, 58 insertions(+), 139 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index f0181b54..fee31e3d 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -650,18 +650,56 @@ sub shutdn ($) {
 
 sub zflush {} # overridden by NNTPdeflate and IMAPdeflate
 
+sub long_response_done {} # overridden by Net::NNTP
+
+sub long_step {
+	my ($self) = @_;
+	# wbuf is unset or empty, here; {long} may add to it
+	my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
+	my $more = eval { $cb->($self, @args) };
+	if ($@ || !$self->{sock}) { # something bad happened...
+		delete $self->{long_cb};
+		my $elapsed = now() - $t0;
+		$@ and $self->err("%s during long response[$fd] - %0.6f",
+				    $@, $elapsed);
+		$self->out(" deferred[$fd] aborted - %0.6f", $elapsed);
+		$self->close;
+	} elsif ($more) { # $self->{wbuf}:
+		# control passed to ibx_async_cat if $more == \undef
+		requeue_once($self) if !ref($more);
+	} else { # all done!
+		delete $self->{long_cb};
+		$self->long_response_done;
+		my $elapsed = now() - $t0;
+		my $fd = fileno($self->{sock});
+		$self->out(" deferred[$fd] done - %0.6f", $elapsed);
+		my $wbuf = $self->{wbuf}; # do NOT autovivify
+		requeue($self) unless $wbuf && @$wbuf;
+	}
+}
+
 sub requeue_once {
 	my ($self) = @_;
 	# COMPRESS users all share the same DEFLATE context.
-	# Flush it here to ensure clients don't see
-	# each other's data
+	# Flush it here to ensure clients don't see each other's data
 	$self->zflush;
 
 	# no recursion, schedule another call ASAP,
 	# but only after all pending writes are done.
 	# autovivify wbuf.  wbuf may be populated by $cb,
 	# no need to rearm if so: (push returns new size of array)
-	requeue($self) if push(@{$self->{wbuf}}, $self->can('long_step')) == 1;
+	requeue($self) if push(@{$self->{wbuf}}, \&long_step) == 1;
+}
+
+sub long_response ($$;@) {
+	my ($self, $cb, @args) = @_; # cb returns true if more, false if done
+	my $sock = $self->{sock} or return;
+	# make sure we disable reading during a long response,
+	# clients should not be sending us stuff and making us do more
+	# work while we are stream a response to them
+	$self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
+	long_step($self); # kick off!
+	undef;
 }
 
 sub dwaitpid ($;$$) {
diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 18a12564..ce0dce0f 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -1035,7 +1035,7 @@ sub cmd_uid_fetch ($$$$;@) {
 	my $range_info = range_step($self, \$range_csv);
 	return "$tag $range_info\r\n" if !ref($range_info);
 	uo2m_hibernate($self) if $cb == \&fetch_blob; # slow, save RAM
-	long_response($self, $cb, $tag, [], $range_info, $ops, $partial);
+	$self->long_response($cb, $tag, [], $range_info, $ops, $partial);
 }
 
 sub cmd_fetch ($$$$;@) {
@@ -1050,7 +1050,7 @@ sub cmd_fetch ($$$$;@) {
 	my $range_info = range_step($self, \$range_csv);
 	return "$tag $range_info\r\n" if !ref($range_info);
 	uo2m_hibernate($self) if $cb == \&fetch_blob; # slow, save RAM
-	long_response($self, $cb, $tag, [], $range_info, $ops, $partial);
+	$self->long_response($cb, $tag, [], $range_info, $ops, $partial);
 }
 
 sub msn_convert ($$) {
@@ -1094,7 +1094,7 @@ sub search_common {
 	my ($sql, $range_info) = delete @$q{qw(sql range_info)};
 	if (!scalar(keys %$q)) { # overview.sqlite3
 		$self->msg_more('* SEARCH');
-		long_response($self, \&search_uid_range,
+		$self->long_response(\&search_uid_range,
 				$tag, $sql, $range_info, $want_msn);
 	} elsif ($q = $q->{xap}) {
 		my $srch = $self->{ibx}->isrch or
@@ -1165,35 +1165,6 @@ sub process_line ($$) {
 	$self->write($res);
 }
 
-sub long_step {
-	my ($self) = @_;
-	# wbuf is unset or empty, here; {long} may add to it
-	my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
-	my $more = eval { $cb->($self, @args) };
-	if ($@ || !$self->{sock}) { # something bad happened...
-		delete $self->{long_cb};
-		my $elapsed = now() - $t0;
-		if ($@) {
-			err($self,
-			    "%s during long response[$fd] - %0.6f",
-			    $@, $elapsed);
-		}
-		out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
-		$self->close;
-	} elsif ($more) { # $self->{wbuf}:
-		# control passed to ibx_async_cat if $more == \undef
-		$self->requeue_once($self) if !ref($more);
-	} else { # all done!
-		delete $self->{long_cb};
-		my $elapsed = now() - $t0;
-		my $fd = fileno($self->{sock});
-		out($self, " deferred[$fd] done - %0.6f", $elapsed);
-		my $wbuf = $self->{wbuf}; # do NOT autovivify
-
-		$self->requeue unless $wbuf && @$wbuf;
-	}
-}
-
 sub err ($$;@) {
 	my ($self, $fmt, @args) = @_;
 	printf { $self->{imapd}->{err} } $fmt."\n", @args;
@@ -1204,18 +1175,6 @@ sub out ($$;@) {
 	printf { $self->{imapd}->{out} } $fmt."\n", @args;
 }
 
-sub long_response ($$;@) {
-	my ($self, $cb, @args) = @_; # cb returns true if more, false if done
-
-	my $sock = $self->{sock} or return;
-	# make sure we disable reading during a long response,
-	# clients should not be sending us stuff and making us do more
-	# work while we are stream a response to them
-	$self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
-	long_step($self); # kick off!
-	undef;
-}
-
 # callback used by PublicInbox::DS for any (e)poll (in/out/hup/err)
 sub event_step {
 	my ($self) = @_;
diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 5eb6112c..2a59cbd7 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -122,7 +122,7 @@ sub list_active_i { # "LIST ACTIVE" and also just "LIST" (no args)
 sub list_active ($;$) { # called by cmd_list
 	my ($self, $wildmat) = @_;
 	wildmat2re($wildmat);
-	long_response($self, \&list_active_i, [
+	$self->long_response(\&list_active_i, [
 		grep(/$wildmat/, @{$self->{nntpd}->{groupnames}}) ]);
 }
 
@@ -141,7 +141,7 @@ sub list_active_times_i {
 sub list_active_times ($;$) { # called by cmd_list
 	my ($self, $wildmat) = @_;
 	wildmat2re($wildmat);
-	long_response($self, \&list_active_times_i, [
+	$self->long_response(\&list_active_times_i, [
 		grep(/$wildmat/, @{$self->{nntpd}->{groupnames}}) ]);
 }
 
@@ -160,7 +160,7 @@ sub list_newsgroups_i {
 sub list_newsgroups ($;$) { # called by cmd_list
 	my ($self, $wildmat) = @_;
 	wildmat2re($wildmat);
-	long_response($self, \&list_newsgroups_i, [
+	$self->long_response(\&list_newsgroups_i, [
 		grep(/$wildmat/, @{$self->{nntpd}->{groupnames}}) ]);
 }
 
@@ -178,7 +178,7 @@ sub cmd_list ($;$$) {
 		$arg->($self, @args);
 	} else {
 		$self->msg_more("215 list of newsgroups follows\r\n");
-		long_response($self, \&list_active_i, [ # copy array
+		$self->long_response(\&list_active_i, [ # copy array
 			@{$self->{nntpd}->{groupnames}} ]);
 	}
 }
@@ -210,9 +210,9 @@ sub cmd_listgroup ($;$$) {
 	if (defined $range) {
 		my $r = get_range($self, $range);
 		return $r unless ref $r;
-		long_response($self, \&listgroup_range_i, @$r);
+		$self->long_response(\&listgroup_range_i, @$r);
 	} else { # grab every article number
-		long_response($self, \&listgroup_all_i, \(my $num = 0));
+		$self->long_response(\&listgroup_all_i, \(my $num = 0));
 	}
 }
 
@@ -268,7 +268,7 @@ sub cmd_newgroups ($$$;$$) {
 
 	# TODO dists
 	$self->msg_more("231 list of new newsgroups follows\r\n");
-	long_response($self, \&newgroups_i, $ts, \(my $i = 0),
+	$self->long_response(\&newgroups_i, $ts, \(my $i = 0),
 				$self->{nntpd}->{groupnames});
 }
 
@@ -339,7 +339,7 @@ sub cmd_newnews ($$$$;$$) {
 				@{$self->{nntpd}->{groupnames}}));
 	return ".\r\n" unless scalar(@names);
 	my $prev = 0;
-	long_response($self, \&newnews_i, \@names, $ts, \$prev);
+	$self->long_response(\&newnews_i, \@names, $ts, \$prev);
 }
 
 sub cmd_group ($$) {
@@ -613,46 +613,7 @@ sub get_range ($$) {
 	$beg > $end ? "420 No article(s) selected\r\n" : [ \$beg, $end ];
 }
 
-sub long_step {
-	my ($self) = @_;
-	# wbuf is unset or empty, here; {long} may add to it
-	my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
-	my $more = eval { $cb->($self, @args) };
-	if ($@ || !$self->{sock}) { # something bad happened...
-		delete $self->{long_cb};
-		my $elapsed = now() - $t0;
-		if ($@) {
-			err($self,
-			    "%s during long response[$fd] - %0.6f",
-			    $@, $elapsed);
-		}
-		out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
-		$self->close;
-	} elsif ($more) { # $self->{wbuf}:
-		# control passed to ibx_async_cat if $more == \undef
-		$self->requeue_once if !ref($more);
-	} else { # all done!
-		delete $self->{long_cb};
-		$self->write(\".\r\n"); # TODO get rid of this
-		my $elapsed = now() - $t0;
-		my $fd = fileno($self->{sock});
-		out($self, " deferred[$fd] done - %0.6f", $elapsed);
-		my $wbuf = $self->{wbuf}; # do NOT autovivify
-		$self->requeue unless $wbuf && @$wbuf;
-	}
-}
-
-sub long_response ($$;@) {
-	my ($self, $cb, @args) = @_; # cb returns true if more, false if done
-
-	my $sock = $self->{sock} or return;
-	# make sure we disable reading during a long response,
-	# clients should not be sending us stuff and making us do more
-	# work while we are stream a response to them
-	$self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
-	long_step($self); # kick off!
-	undef;
-}
+sub long_response_done { $_[0]->write(\".\r\n") } # overrides superclass
 
 sub hdr_msgid_range_i {
 	my ($self, $beg, $end) = @_;
@@ -674,7 +635,7 @@ sub hdr_message_id ($$$) { # optimize XHDR Message-ID [range] for slrnpull.
 		my $r = get_range($self, $range);
 		return $r unless ref $r;
 		$self->msg_more($xhdr ? r221 : r225);
-		long_response($self, \&hdr_msgid_range_i, @$r);
+		$self->long_response(\&hdr_msgid_range_i, @$r);
 	}
 }
 
@@ -746,7 +707,7 @@ sub hdr_xref ($$$) { # optimize XHDR Xref [range] for rtin
 		my $r = get_range($self, $range);
 		return $r unless ref $r;
 		$self->msg_more($xhdr ? r221 : r225);
-		long_response($self, \&xref_range_i, @$r);
+		$self->long_response(\&xref_range_i, @$r);
 	}
 }
 
@@ -790,7 +751,7 @@ sub hdr_smsg ($$$$) {
 		my $r = get_range($self, $range);
 		return $r unless ref $r;
 		$self->msg_more($xhdr ? r221 : r225);
-		long_response($self, \&smsg_range_i, @$r, $field);
+		$self->long_response(\&smsg_range_i, @$r, $field);
 	}
 }
 
@@ -860,7 +821,7 @@ sub cmd_xrover ($;$) {
 	my $r = get_range($self, $range);
 	return $r unless ref $r;
 	$self->msg_more("224 Overview information follows\r\n");
-	long_response($self, \&xrover_i, @$r);
+	$self->long_response(\&xrover_i, @$r);
 }
 
 sub over_line ($$$) {
@@ -924,7 +885,7 @@ sub cmd_xover ($;$) {
 	my ($beg, $end) = @$r;
 	$self->msg_more(
 		"224 Overview information follows for $$beg to $end\r\n");
-	long_response($self, \&xover_i, @$r);
+	$self->long_response(\&xover_i, @$r);
 }
 
 sub compressed { undef }
diff --git a/lib/PublicInbox/POP3.pm b/lib/PublicInbox/POP3.pm
index 741b5e58..60eedea7 100644
--- a/lib/PublicInbox/POP3.pm
+++ b/lib/PublicInbox/POP3.pm
@@ -55,45 +55,6 @@ sub out ($$;@) {
 	printf { $self->{pop3d}->{out} } $fmt."\n", @args;
 }
 
-sub long_step {
-	my ($self) = @_;
-	# wbuf is unset or empty, here; {long} may add to it
-	my ($fd, $cb, $t0, @args) = @{$self->{long_cb}};
-	my $more = eval { $cb->($self, @args) };
-	if ($@ || !$self->{sock}) { # something bad happened...
-		delete $self->{long_cb};
-		my $elapsed = now() - $t0;
-		if ($@) {
-			err($self,
-			    "%s during long response[$fd] - %0.6f",
-			    $@, $elapsed);
-		}
-		out($self, " deferred[$fd] aborted - %0.6f", $elapsed);
-		$self->close;
-	} elsif ($more) { # $self->{wbuf}:
-		# control passed to ibx_async_cat if $more == \undef
-		requeue_once($self) if !ref($more);
-	} else { # all done!
-		delete $self->{long_cb};
-		my $elapsed = now() - $t0;
-		my $fd = fileno($self->{sock});
-		out($self, " deferred[$fd] done - %0.6f", $elapsed);
-		my $wbuf = $self->{wbuf}; # do NOT autovivify
-		$self->requeue unless $wbuf && @$wbuf;
-	}
-}
-
-sub long_response ($$;@) {
-	my ($self, $cb, @args) = @_; # cb returns true if more, false if done
-	my $sock = $self->{sock} or return;
-	# make sure we disable reading during a long response,
-	# clients should not be sending us stuff and making us do more
-	# work while we are stream a response to them
-	$self->{long_cb} = [ fileno($sock), $cb, now(), @args ];
-	long_step($self); # kick off!
-	undef;
-}
-
 sub do_greet {
 	my ($self) = @_;
 	my $s = $self->{salt} = sprintf('%x.%x', int(rand(0x7fffffff)), time);