AnyEvent-MP/MP/DataConn.pm

=head1 NAME

AnyEvent::MP::DataConn - create socket connections between nodes

=head1 SYNOPSIS

   use AnyEvent::MP::DataConn;

=head1 DESCRIPTION

This module can be used to create socket connections between the local and
a remote node in the aemp network. The socket can be used freely for any
purpose, and in most cases, this mechanism is a good way to transport big
chunks of binary data.

The connections created by this module use the same security mechanisms
as normal AEMP connections (secure authentication, optional use of TLS),
and in fact, use the same listening port as AEMP connections, so when two
nodes can reach each other, they can, with high probability, creare a data
connection between them.

The protocol is, however, not the AEMP transport protocol, so this will
only work between nodes implementing the "aemp-dataconn" protocol.

=head1 FUNCTIONS

=over 4

=cut

package AnyEvent::MP::DataConn;

use common::sense;
use Carp ();
use POSIX ();

use AnyEvent ();
use AnyEvent::Util ();

use AnyEvent::MP;
use AnyEvent::MP::Kernel ();
use AnyEvent::MP::Global ();

our $ID = "a";
our %STATE;

# another node tells us to await a connection
sub _expect {
   my ($id, $timeout, $initspec) = @_;

   $STATE{$id} = {
      id   => $id,
      to   => (AE::timer $timeout, 0, sub {
         $STATE{$id}{done}->(undef);
      }),
      done => sub {
         my ($hdl, $error) = @_;

         %{delete $STATE{$id}} = ();

         if (defined $hdl) {
            my ($func, @args) = @$initspec;
            (AnyEvent::MP::Kernel::load_func $func)->(@args, $hdl);
         }
      },
   };
}

# AEMP::Transport call for dataconn-connections
sub _inject {
   my ($conn, $error) = @_;

   my $hdl = defined $error ? undef : delete $conn->{hdl};
   my $id = $conn->{local_greeting}{dataconn_id} || $conn->{remote_greeting}{dataconn_id}
      or return;

   $conn->destroy;

   ($STATE{$id} or return)->{done}->($hdl, $error);
}

# actively connect to some other node
sub _connect {
   my ($id, $node) = @_;

   my $state = $STATE{$id}
      or return;

   my $addr = $AnyEvent::MP::Global::addr{$node};

   @$addr
      or return $state->{fail}("$node: no listeners found");

   # I love hardcoded constants  !
   $state->{next} = AE::timer 0, 2, sub {
      my $endpoint = shift @$addr
         or return delete $state->{next};

      my ($host, $port) = AnyEvent::Socket::parse_hostport $endpoint
         or return;

      my $transport; $transport = AnyEvent::MP::Transport::mp_connect
         $host, $port,
         protocol => "aemp-dataconn",
         local_greeting => { dataconn_id => $id },
         sub { $transport->destroy }, #TODO: destroys handshaked conenctions too early
      ;
   };
}

=item AnyEvent::MP::DataConn::connect_to $node, $timeout, [$initfunc, @initdata], $cb->($handle)

Creates a socket connection between the local node and the node C<$node>
(which can also be specified as a port).

When the connection could be successfully created, the C<$initfunc>
will be called with the given C<@initdata> on the remote node (similar
to C<snd_to_func> or C<spawn>), and the C<AnyEvent::Handle> object
representing the remote connection end as additional argument.

Also, the callback given as last argument will be called with the
AnyEvent::Handle object for the local side.

The AnyEvent::Handle objects will be in a "quiescent" state - you could rip
out the file handle and forget about it, but it is recommended to use it,
as the security settings might have called for a TLS connection. If you
opt to use it, you at least have to set an C<on_error> callback.

In case of any error (timeout etc.), nothing will be called on
the remote side, and the local port will be C<kil>'ed with an C<<
AnyEvent::MP::DataConn => "error message" >> kill reason.

=cut

sub connect_to($$$;@) {
   my ($node, $timeout, $initspec, @localmsg) = @_;
   my $port = $SELF;
   $node = node_of $node;

   my $id = (++$ID) . "\@$NODE";

   # damn, why do my simple state hashes resemble objects so quickly
   my $state = $STATE{$id} = {
      id   => (++$ID) . "\@$NODE",
      to   => (AE::timer $timeout, 0, sub {
         $STATE{$id}{done}->(undef, "$node: unable to establish connection within $timeout seconds");
      }),
      done => sub {
         my ($hdl, $error) = @_;

         warn "done<@_>\n";#d#

         delete $AnyEvent::MP::Global::ON_SETUP{$id};
         %{delete $STATE{$id}} = ();

         if (defined $hdl) {
            snd @localmsg, $hdl;
         } else {
            kil $port, AnyEvent::MP::DataConn:: => $error;
         }
      },
   };

   if (AnyEvent::MP::Kernel::port_is_local $node) {
      return kil $port, AnyEvent::MP::DataConn:: =>
         "connect_to does not yet support local/local connections, please bug me about it";

   } else {
      AnyEvent::MP::Kernel::snd_to_func $node, AnyEvent::MP::DataConn::_expect:: => $id, $timeout, $initspec;

      $state->{wait} = sub {
         if (my $addr = $AnyEvent::MP::Global::addr{$node}) {
            delete $AnyEvent::MP::Global::ON_SETUP{$id};

            # continue connect
            if (@$addr) {
               # node has listeners, so connect
               _connect $id, $node;
            } else {
               # no listeners, ask it to connect to us
               AnyEvent::MP::Kernel::snd_to_func $node, AnyEvent::MP::DataConn::_connect:: => $id, $node;
            }
         } else {
            # wait for the next global setup handshake
            $AnyEvent::MP::Global::ON_SETUP{$id} = $state->{wait};
         };
      };

      $state->{wait}->();
   }
}

=back

=head1 SEE ALSO

L<AnyEvent::MP>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.3
Committed:	Sun Nov 8 01:15:25 2009 UTC (14 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.2:	+49 -46 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			AnyEvent::MP::DataConn - create socket connections between nodes
4
5			=head1 SYNOPSIS
6
7			use AnyEvent::MP::DataConn;
8
9			=head1 DESCRIPTION
10
11			This module can be used to create socket connections between the local and
12			a remote node in the aemp network. The socket can be used freely for any
13			purpose, and in most cases, this mechanism is a good way to transport big
14			chunks of binary data.
15
16			The connections created by this module use the same security mechanisms
17			as normal AEMP connections (secure authentication, optional use of TLS),
18			and in fact, use the same listening port as AEMP connections, so when two
19			nodes can reach each other, they can, with high probability, creare a data
20			connection between them.
21
22			The protocol is, however, not the AEMP transport protocol, so this will
23			only work between nodes implementing the "aemp-dataconn" protocol.
24
25			=head1 FUNCTIONS
26
27			=over 4
28
29			=cut
30
31			package AnyEvent::MP::DataConn;
32
33			use common::sense;
34			use Carp ();
35			use POSIX ();
36
37			use AnyEvent ();
38			use AnyEvent::Util ();
39
40			use AnyEvent::MP;
41	root	1.2	use AnyEvent::MP::Kernel ();
42			use AnyEvent::MP::Global ();
43
44			our $ID = "a";
45			our %STATE;
46
47	root	1.3	# another node tells us to await a connection
48			sub _expect {
49	root	1.2	my ($id, $timeout, $initspec) = @_;
50
51	root	1.3	$STATE{$id} = {
52			id => $id,
53			to => (AE::timer $timeout, 0, sub {
54			$STATE{$id}{done}->(undef);
55			}),
56			done => sub {
57			my ($hdl, $error) = @_;
58
59			%{delete $STATE{$id}} = ();
60	root	1.2
61	root	1.3	if (defined $hdl) {
62			my ($func, @args) = @$initspec;
63			(AnyEvent::MP::Kernel::load_func $func)->(@args, $hdl);
64			}
65	root	1.2	},
66			};
67			}
68	root	1.1
69	root	1.3	# AEMP::Transport call for dataconn-connections
70	root	1.1	sub _inject {
71			my ($conn, $error) = @_;
72	root	1.2
73	root	1.3	my $hdl = defined $error ? undef : delete $conn->{hdl};
74			my $id = $conn->{local_greeting}{dataconn_id} \|\| $conn->{remote_greeting}{dataconn_id}
75			or return;
76
77			$conn->destroy;
78
79			($STATE{$id} or return)->{done}->($hdl, $error);
80	root	1.1	}
81
82	root	1.3	# actively connect to some other node
83	root	1.2	sub _connect {
84	root	1.3	my ($id, $node) = @_;
85	root	1.2
86			my $state = $STATE{$id}
87			or return;
88
89	root	1.3	my $addr = $AnyEvent::MP::Global::addr{$node};
90	root	1.2
91			@$addr
92	root	1.3	or return $state->{fail}("$node: no listeners found");
93	root	1.2
94	root	1.3	# I love hardcoded constants !
95	root	1.2	$state->{next} = AE::timer 0, 2, sub {
96			my $endpoint = shift @$addr
97			or return delete $state->{next};
98
99			my ($host, $port) = AnyEvent::Socket::parse_hostport $endpoint
100			or return;
101
102			my $transport; $transport = AnyEvent::MP::Transport::mp_connect
103			$host, $port,
104			protocol => "aemp-dataconn",
105	root	1.3	local_greeting => { dataconn_id => $id },
106			sub { $transport->destroy }, #TODO: destroys handshaked conenctions too early
107	root	1.2	;
108			};
109			}
110
111			=item AnyEvent::MP::DataConn::connect_to $node, $timeout, [$initfunc, @initdata], $cb->($handle)
112	root	1.1
113			Creates a socket connection between the local node and the node C<$node>
114			(which can also be specified as a port).
115
116			When the connection could be successfully created, the C<$initfunc>
117			will be called with the given C<@initdata> on the remote node (similar
118			to C<snd_to_func> or C<spawn>), and the C<AnyEvent::Handle> object
119	root	1.2	representing the remote connection end as additional argument.
120	root	1.1
121	root	1.2	Also, the callback given as last argument will be called with the
122			AnyEvent::Handle object for the local side.
123	root	1.1
124	root	1.2	The AnyEvent::Handle objects will be in a "quiescent" state - you could rip
125	root	1.1	out the file handle and forget about it, but it is recommended to use it,
126	root	1.2	as the security settings might have called for a TLS connection. If you
127	root	1.1	opt to use it, you at least have to set an C<on_error> callback.
128
129	root	1.2	In case of any error (timeout etc.), nothing will be called on
130			the remote side, and the local port will be C<kil>'ed with an C<<
131	root	1.1	AnyEvent::MP::DataConn => "error message" >> kill reason.
132
133			=cut
134
135			sub connect_to($$$;@) {
136			my ($node, $timeout, $initspec, @localmsg) = @_;
137			my $port = $SELF;
138			$node = node_of $node;
139
140	root	1.2	my $id = (++$ID) . "\@$NODE";
141	root	1.1
142	root	1.2	# damn, why do my simple state hashes resemble objects so quickly
143			my $state = $STATE{$id} = {
144	root	1.3	id => (++$ID) . "\@$NODE",
145			to => (AE::timer $timeout, 0, sub {
146			$STATE{$id}{done}->(undef, "$node: unable to establish connection within $timeout seconds");
147	root	1.2	}),
148	root	1.3	done => sub {
149			my ($hdl, $error) = @_;
150
151			warn "done<@_>\n";#d#
152
153			delete $AnyEvent::MP::Global::ON_SETUP{$id};
154			%{delete $STATE{$id}} = ();
155
156			if (defined $hdl) {
157			snd @localmsg, $hdl;
158			} else {
159			kil $port, AnyEvent::MP::DataConn:: => $error;
160			}
161	root	1.2	},
162	root	1.1	};
163
164	root	1.2	if (AnyEvent::MP::Kernel::port_is_local $node) {
165	root	1.1	return kil $port, AnyEvent::MP::DataConn:: =>
166			"connect_to does not yet support local/local connections, please bug me about it";
167	root	1.2
168	root	1.1	} else {
169	root	1.3	AnyEvent::MP::Kernel::snd_to_func $node, AnyEvent::MP::DataConn::_expect:: => $id, $timeout, $initspec;
170	root	1.2
171			$state->{wait} = sub {
172			if (my $addr = $AnyEvent::MP::Global::addr{$node}) {
173			delete $AnyEvent::MP::Global::ON_SETUP{$id};
174
175			# continue connect
176			if (@$addr) {
177			# node has listeners, so connect
178	root	1.3	_connect $id, $node;
179	root	1.2	} else {
180			# no listeners, ask it to connect to us
181	root	1.3	AnyEvent::MP::Kernel::snd_to_func $node, AnyEvent::MP::DataConn::_connect:: => $id, $node;
182	root	1.2	}
183			} else {
184			# wait for the next global setup handshake
185			$AnyEvent::MP::Global::ON_SETUP{$id} = $state->{wait};
186			};
187	root	1.1	};
188	root	1.2
189			$state->{wait}->();
190	root	1.1	}
191			}
192
193			=back
194
195			=head1 SEE ALSO
196
197			L<AnyEvent::MP>.
198
199			=head1 AUTHOR
200
201			Marc Lehmann <schmorp@schmorp.de>
202			http://home.schmorp.de/
203
204			=cut
205
206			1
207