+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# op dispatch socket, reads a message, runs a sub
+# There may be multiple producers, but (for now) only one consumer
+# Used for lei_xsearch and maybe other things
+# "literal" => [ sub, @operands ]
+# /regexp/ => [ sub, @operands ]
+package PublicInbox::PktOp;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::DS);
+use Errno qw(EAGAIN EINTR);
+use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
+use Socket qw(AF_UNIX MSG_EOR SOCK_SEQPACKET);
+
+sub new {
+ my ($cls, $r, $ops, $in_loop) = @_;
+ my $self = bless { sock => $r, ops => $ops, re => [] }, $cls;
+ if (ref($ops) eq 'ARRAY') {
+ my %ops;
+ for my $op (@$ops) {
+ if (ref($op->[0])) {
+ push @{$self->{re}}, $op;
+ } else {
+ $ops{$op->[0]} = $op->[1];
+ }
+ }
+ $self->{ops} = \%ops;
+ }
+ if ($in_loop) { # iff using DS->EventLoop
+ $r->blocking(0);
+ $self->SUPER::new($r, EPOLLIN|EPOLLET);
+ }
+ $self;
+}
+
+# returns a blessed object as the consumer, and a GLOB/IO for the producer
+sub pair {
+ my ($cls, $ops, $in_loop) = @_;
+ my ($c, $p);
+ socketpair($c, $p, AF_UNIX, SOCK_SEQPACKET, 0) or die "socketpair: $!";
+ (new($cls, $c, $ops, $in_loop), $p);
+}
+
+sub close {
+ my ($self) = @_;
+ my $c = $self->{sock} or return;
+ $c->blocking ? delete($self->{sock}) : $self->SUPER::close;
+}
+
+sub event_step {
+ my ($self) = @_;
+ my $c = $self->{sock};
+ my $msg;
+ do {
+ my $n = recv($c, $msg, 128, 0);
+ unless (defined $n) {
+ return if $! == EAGAIN;
+ next if $! == EINTR;
+ $self->close;
+ die "recv: $!";
+ }
+ my $op = $self->{ops}->{$msg};
+ unless ($op) {
+ for my $re_op (@{$self->{re}}) {
+ $msg =~ $re_op->[0] or next;
+ $op = $re_op->[1];
+ last;
+ }
+ }
+ die "BUG: unknown message: `$msg'" unless $op;
+ my ($sub, @args) = @$op;
+ $sub->(@args);
+ return $self->close if $msg eq ''; # close on EOF
+ } while (1);
+}
+
+1;