-# Copyright (C) 2016 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2020 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
# This is exposed via the 'pi-httpd.async' key in the PSGI env hash.
# The name of this key is not even stable!
-# Currently is is intended for use with read-only pipes.
+# Currently intended for use with read-only pipes with expensive
+# processes such as git-http-backend(1), cgit(1)
package PublicInbox::HTTPD::Async;
use strict;
use warnings;
-use base qw(Danga::Socket);
-use fields qw(cb cleanup);
-use Scalar::Util qw(weaken);
-require PublicInbox::EvCleanup;
+use base qw(PublicInbox::DS);
+use fields qw(http fh cb arg end_obj);
+use Errno qw(EAGAIN);
+use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
+# 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, $cleanup) = @_;
+ my ($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_obj unsupported w/o $io' if $end_obj;
+ return;
+ }
+
my $self = fields::new($class);
IO::Handle::blocking($io, 0);
- $self->SUPER::new($io);
- $self->{cb} = $cb;
- $self->{cleanup} = $cleanup;
- $self->watch_read(1);
+ $self->SUPER::new($io, EPOLLIN | EPOLLET);
+ $self->{cb} = $cb; # initial read callback
+ $self->{arg} = $arg; # arg for $cb
+ $self->{end_obj} = $end_obj; # like END{}, can ->event_step
$self;
}
-sub restart_read_cb ($) {
+sub event_step {
my ($self) = @_;
- sub { $self->watch_read(1) }
-}
-
-sub async_pass {
- my ($self, $io, $fh, $bref) = @_;
- # In case the client HTTP connection ($io) dies, it
- # will automatically close this ($self) object.
- $io->{forward} = $self;
- $fh->write($$bref);
- my $restart_read = restart_read_cb($self);
- weaken($self);
- $self->{cb} = sub {
- my $r = sysread($self->{sock}, $$bref, 8192);
+ if (my $cb = delete $self->{cb}) {
+ # this may call async_pass when headers are done
+ $cb->(delete $self->{arg});
+ } elsif (my $sock = $self->{sock}) {
+ my $http = $self->{http};
+ # $self->{sock} is a read pipe for git-http-backend or cgit
+ # and 65536 is the default Linux pipe size
+ my $r = sysread($sock, my $buf, 65536);
if ($r) {
- $fh->write($$bref);
- if ($io->{write_buf_size}) {
- $self->watch_read(0);
- $io->write($restart_read); # D::S::write
+ $self->{fh}->write($buf); # may call $http->close
+ if ($http->{sock}) { # !closed
+ $self->requeue;
+ # let other clients get some work done, too
+ return;
}
- # stay in watch_read, but let other clients
- # get some work done, too.
- return;
- } elsif (!defined $r) {
- return if $!{EAGAIN} || $!{EINTR};
+
+ # else: fall through to close below...
+ } elsif (!defined $r && $! == EAGAIN) {
+ return; # EPOLLET means we'll be notified
}
- # Done! Error handling will happen in $fh->close
- # called by the {cleanup} handler
- $io->{forward} = undef;
- $self->close;
- }
+ # Done! Error handling will happen in $self->{fh}->close
+ # called by end_obj->event_step handler
+ delete $http->{forward};
+ $self->close; # queues end_obj->event_step to be called
+ } # else { # we may've been requeued but closed by $http
}
-sub event_read { $_[0]->{cb}->() }
-sub event_hup { $_[0]->{cb}->() }
-sub event_err { $_[0]->{cb}->() }
-sub sysread { shift->{sock}->sysread(@_) }
+# once this is called, all data we read is passed to the
+# to the PublicInbox::HTTP instance ($http) via $fh->write
+sub async_pass {
+ my ($self, $http, $fh, $bref) = @_;
+ # In case the client HTTP connection ($http) dies, it
+ # will automatically close this ($self) object.
+ $http->{forward} = $self;
+
+ # write anything we overread when we were reading headers
+ $fh->write($$bref); # PublicInbox:HTTP::{chunked,identity}_wcb
+
+ # we're done with this, free this memory up ASAP since the
+ # calls after this may use much memory:
+ $$bref = undef;
+ $self->{http} = $http;
+ $self->{fh} = $fh;
+
+ # either hit EAGAIN or ->requeue to keep EPOLLET happy
+ event_step($self);
+}
+
+# may be called as $forward->close in PublicInbox::HTTP or EOF (event_step)
sub close {
- my $self = shift;
- my $cleanup = $self->{cleanup};
- $self->{cleanup} = $self->{cb} = undef;
- $self->SUPER::close(@_);
+ my $self = $_[0];
+ $self->SUPER::close; # DS::close
# we defer this to the next timer loop since close is deferred
- PublicInbox::EvCleanup::asap($cleanup) if $cleanup;
+ 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);
+ }
}
1;