X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FHTTPD%2FAsync.pm;h=9e592f47412bf4f7aa1c32555196ee92b13a06de;hb=9ea503ef65426070303fe1929f456b3591d74d93;hp=d182c11886c5f4b1557d9e0828469fcdb7ae7b28;hpb=bfa40d0c4a970e5af0eae0441920a491c4f6fa1d;p=public-inbox.git

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index d182c118..9e592f47 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2016-2019 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 #
 # XXX This is a totally unstable API for public-inbox internal use only
@@ -6,63 +6,68 @@
 # The name of this key is not even stable!
 # Currently intended for use with read-only pipes with expensive
 # processes such as git-http-backend(1), cgit(1)
+#
+# fields:
+# http: PublicInbox::HTTP ref
+# fh: PublicInbox::HTTP::{Identity,Chunked} ref (can ->write + ->close)
+# cb: initial read callback
+# arg: arg for {cb}
+# end_obj: CODE or object which responds to ->event_step when ->close is called
 package PublicInbox::HTTPD::Async;
 use strict;
-use warnings;
-use base qw(PublicInbox::DS);
-use fields qw(cb arg end end_arg);
+use parent qw(PublicInbox::DS);
 use Errno qw(EAGAIN);
-use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
+use PublicInbox::Syscall qw(EPOLLIN);
 
 # This is called via: $env->{'pi-httpd.async'}->()
 # $io is a read-only pipe ($rpipe) for now, but may be a
 # bidirectional socket in the future.
 sub new {
-	my ($class, $io, $cb, $arg, $end, $end_arg) = @_;
+	my ($class, $io, $cb, $arg, $end_obj) = @_;
 
 	# no $io? call $cb at the top of the next event loop to
 	# avoid recursion:
 	unless (defined($io)) {
 		PublicInbox::DS::requeue($cb ? $cb : $arg);
-		die '$end unsupported w/o $io' if $end;
+		die '$end_obj unsupported w/o $io' if $end_obj;
 		return;
 	}
-
-	my $self = fields::new($class);
-	IO::Handle::blocking($io, 0);
-	$self->SUPER::new($io, EPOLLIN | EPOLLET);
-	$self->{cb} = $cb; # initial read callback, later replaced by main_cb
-	$self->{arg} = $arg; # arg for $cb
-	$self->{end} = $end; # like END {}, but only for this object
-	$self->{end_arg} = $end_arg; # arg for $end
-	$self;
+	my $self = bless {
+		cb => $cb, # initial read callback
+		arg => $arg, # arg for $cb
+		end_obj => $end_obj, # like END{}, can ->event_step
+	}, $class;
+	my $pp = tied *$io;
+	$pp->{fh}->blocking(0) // die "$io->blocking(0): $!";
+	$self->SUPER::new($io, EPOLLIN);
 }
 
-sub main_cb ($$) {
-	my ($http, $fh) = @_;
-	sub {
-		my ($self) = @_;
+sub event_step {
+	my ($self) = @_;
+	if (my $cb = delete $self->{cb}) {
+		# this may call async_pass when headers are done
+		$cb->(my $refcnt_guard = delete $self->{arg});
+	} elsif (my $sock = $self->{sock}) {
+		# $http may be undef if discarding body output from cgit on 404
+		my $http = $self->{http} or return $self->close;
 		# $self->{sock} is a read pipe for git-http-backend or cgit
 		# and 65536 is the default Linux pipe size
-		my $r = sysread($self->{sock}, my $buf, 65536);
+		my $r = sysread($sock, my $buf, 65536);
 		if ($r) {
-			$fh->write($buf); # may call $http->close
-			if ($http->{sock}) { # !closed
-				$self->requeue;
-				# let other clients get some work done, too
-				return;
-			}
+			$self->{fh}->write($buf); # may call $http->close
+			# let other clients get some work done, too
+			return if $http->{sock}; # !closed
 
 			# else: fall through to close below...
 		} elsif (!defined $r && $! == EAGAIN) {
-			return; # EPOLLET means we'll be notified
+			return; # EPOLLIN means we'll be notified
 		}
 
-		# Done! Error handling will happen in $fh->close
-		# called by the {end} handler
+		# Done! Error handling will happen in $self->{fh}->close
+		# called by end_obj->event_step handler
 		delete $http->{forward};
-		$self->close; # queues ->{end} to be called
-	}
+		$self->close; # queues end_obj->event_step to be called
+	} # else { # we may've been requeued but closed by $http
 }
 
 # once this is called, all data we read is passed to the
@@ -73,33 +78,31 @@ sub async_pass {
 	# will automatically close this ($self) object.
 	$http->{forward} = $self;
 
-	# write anything we overread when we were reading headers
-	$fh->write($$bref); # PublicInbox:HTTP::{chunked,identity}_wcb
+	# write anything we overread when we were reading headers.
+	# This is typically PublicInbox:HTTP::{chunked,identity}_wcb,
+	# but may be PublicInbox::GzipFilter::write.  PSGI requires
+	# *_wcb methods respond to ->write (and ->close), not ->print
+	$fh->write($$bref);
 
 	# we're done with this, free this memory up ASAP since the
 	# calls after this may use much memory:
 	$$bref = undef;
 
-	# replace the header read callback with the main one
-	my $cb = $self->{cb} = main_cb($http, $fh);
-	$cb->($self); # either hit EAGAIN or ->requeue to keep EPOLLET happy
-}
-
-sub event_step {
-	# {cb} may be undef after ->requeue due to $http->close happening
-	my $cb = $_[0]->{cb} or return;
-	$cb->(@_);
+	$self->{http} = $http;
+	$self->{fh} = $fh;
 }
 
-# may be called as $forward->close in PublicInbox::HTTP or EOF (main_cb)
+# may be called as $forward->close in PublicInbox::HTTP or EOF (event_step)
 sub close {
 	my $self = $_[0];
-	delete $self->{cb};
 	$self->SUPER::close; # DS::close
 
 	# we defer this to the next timer loop since close is deferred
-	if (my $end = delete $self->{end}) {
-		PublicInbox::DS::requeue($end);
+	if (my $end_obj = delete $self->{end_obj}) {
+		# this calls $end_obj->event_step
+		# (likely PublicInbox::Qspawn::event_step,
+		#  NOT PublicInbox::HTTPD::Async::event_step)
+		PublicInbox::DS::requeue($end_obj);
 	}
 }