syndicate-js/packages/driver-udp-node/src/index.js

116 lines
3.5 KiB
JavaScript

//---------------------------------------------------------------------------
// @syndicate-lang/driver-udp-node, UDP support for Syndicate/js
// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//---------------------------------------------------------------------------
import { currentFacet, Observe, Dataspace, Bytes } from "@syndicate-lang/core";
import { createSocket } from "dgram";
const { sleep } = activate require("@syndicate-lang/driver-timer");
assertion type UdpPeer(host, port); // A remote peer
assertion type UdpHandle(id); // A local "anonymous" UDP socket
assertion type UdpListener(port); // A local bound UDP socket
assertion type UdpMulticastGroupMember(localAddress, groupAddress, interfaceName);
assertion type UdpMulticastLoopback(localAddress, enabled);
message type UdpPacket(source, destination, payload);
export {
UdpPeer, UdpHandle, UdpListener,
UdpMulticastGroupMember,
UdpMulticastLoopback,
UdpPacket,
};
spawn named 'UdpDriver' {
during Observe($addr(UdpListener($port))) spawn named ['UdpListener', port] {
_socket.call(this, addr, port);
}
during Observe($addr(UdpHandle($id))) spawn named ['UdpHandle', id] {
_socket.call(this, addr, 0);
}
}
function _socket(addr, port) {
const facet = currentFacet();
let finish = Dataspace.backgroundTask();
on stop finish();
let socket = null;
field this.connected = false;
const connect = () => {
disconnect();
socket = createSocket({ type: "udp4", reuseAddr: true });
if (port) {
socket.bind(port);
}
socket.on('error', Dataspace.wrapExternal((e) => {
console.error('UdpSocket', addr, e.message);
disconnect();
sleep(1000, connect);
}));
socket.on('listening', Dataspace.wrapExternal(() => { this.connected = true; }));
socket.on('message', Dataspace.wrapExternal((message, rinfo) => {
send UdpPacket(UdpPeer(rinfo.address, rinfo.port), addr, Bytes.fromIO(message));
}));
};
const disconnect = () => {
if (socket) {
try { socket.close(); } catch (_e) { console.error('Closing', addr, _e); }
socket = null;
}
this.connected = false;
};
on start connect();
on stop disconnect();
assert addr when (this.connected);
on message UdpPacket(addr, UdpPeer($host, $port), $payload) {
payload = Bytes.toIO(payload);
socket.send(payload, 0, payload.length, port, host, Dataspace.wrapExternal((err) => {
if (err) {
console.error(err);
}
}));
}
during UdpMulticastGroupMember(addr, $group, $ifName) {
on (this.connected) {
socket.addMembership(group, ifName || (void 0));
}
on stop {
if (socket) {
socket.dropMembership(group, ifName || (void 0));
}
}
}
during UdpMulticastLoopback(addr, $enabled) {
on (this.connected) {
socket.setMulticastLoopback(enabled);
}
}
}