-# 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
# 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 cleanup);
+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, $cleanup) = @_;
+ my ($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);
- die 'cleanup unsupported w/o $io' if $cleanup;
+ PublicInbox::DS::requeue($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, EPOLLIN | EPOLLET);
- $self->{cb} = $cb;
- $self->{cleanup} = $cleanup;
- $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 ($$) {
- my ($http, $fh) = @_;
- sub {
- my ($self) = @_;
- my $r = sysread($self->{sock}, my $buf, 65536);
+sub event_step {
+ my ($self) = @_;
+ if (my $cb = delete $self->{cb}) {
+ # this may call async_pass when headers are done
+ $cb->(my $refcnt_guard = delete $self->{arg});
+ } elsif (my $sock = $self->{sock}) {
+ # $http may be undef if discarding body output from cgit on 404
+ my $http = $self->{http} or return $self->close;
+ # $self->{sock} is a read pipe for git-http-backend or cgit
+ # and 65536 is the default Linux pipe size
+ my $r = sysread($sock, my $buf, 65536);
if ($r) {
- $fh->write($buf); # may call $http->close
- if ($http->{sock}) { # !closed
- $self->requeue;
- # let other clients get some work done, too
- return;
- }
+ $self->{fh}->write($buf); # may call $http->close
+ # let other clients get some work done, too
+ return if $http->{sock}; # !closed
# else: fall through to close below...
} elsif (!defined $r && $! == EAGAIN) {
- return; # EPOLLET means we'll be notified
+ return; # EPOLLIN means we'll be notified
}
- # Done! Error handling will happen in $fh->close
- # called by the {cleanup} handler
+ # Done! Error handling will happen in $self->{fh}->close
+ # called by end_obj->event_step handler
delete $http->{forward};
- $self->close;
- }
+ $self->close; # queues end_obj->event_step to be called
+ } # else { # we may've been requeued but closed by $http
}
+# once this is called, all data we read is passed to the
+# to the PublicInbox::HTTP instance ($http) via $fh->write
sub async_pass {
my ($self, $http, $fh, $bref) = @_;
# In case the client HTTP connection ($http) dies, it
# will automatically close this ($self) object.
$http->{forward} = $self;
- $fh->write($$bref); # PublicInbox:HTTP::{chunked,identity}_wcb
- $$bref = undef; # we're done with this
- my $cb = $self->{cb} = main_cb($http, $fh);
- $cb->($self); # either hit EAGAIN or ->requeue to keep EPOLLET happy
-}
-sub event_step {
- # {cb} may be undef after ->requeue due to $http->close happening
- my $cb = $_[0]->{cb} or return;
- $cb->(@_);
+ # write anything we overread when we were reading headers.
+ # This is typically PublicInbox:HTTP::{chunked,identity}_wcb,
+ # but may be PublicInbox::GzipFilter::write. PSGI requires
+ # *_wcb methods respond to ->write (and ->close), not ->print
+ $fh->write($$bref);
+
+ $self->{http} = $http;
+ $self->{fh} = $fh;
}
+# may be called as $forward->close in PublicInbox::HTTP or EOF (event_step)
sub close {
my $self = $_[0];
- delete $self->{cb};
- $self->SUPER::close;
+ $self->SUPER::close; # DS::close
# we defer this to the next timer loop since close is deferred
- if (my $cleanup = delete $self->{cleanup}) {
- PublicInbox::DS::requeue($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);
}
}