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Merge pull request #1008 from finwo/manhattan-nts

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Rewrote nts
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Mark Nadal 2020-09-17 22:29:25 -07:00 committed by GitHub
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1 changed files with 77 additions and 37 deletions
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nts.js
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@ -1,40 +1,80 @@
;(function(){
var Gun = (typeof window !== "undefined")? window.Gun : require('./gun');
var Gun = (typeof window !== "undefined")? window.Gun : require('./gun');
var dam = 'nts';
var smooth = 2;
Gun.on('create', function(root){ // switch to DAM, deprecated old
var opt = root.opt, mesh = opt.mesh;
if(!mesh){ return }
var asks = {};
mesh.hear['nts'] = function(msg, peer){
if(msg.nts){
(asks[msg['@']]||noop)(msg);
return;
}
mesh.say({dam: 'nts', nts: Gun.state(), '@': msg['#']}, peer);
}
var peers = 0;
root.on('hi', function(peer){ this.to.next(peer);
peers++;
setTimeout(function ping(){
var NTS = {}, ack = String.random(3), msg = {'#': ack, dam: 'nts'};
NTS.start = Gun.state();
asks[ack] = function(msg){
NTS.end = Gun.state();
delete asks[ack];
NTS.latency = (NTS.end - NTS.start)/2;
if(!msg.nts){ return }
NTS.calc = NTS.latency + msg.nts;
NTS.step = (NTS.end - NTS.calc)/2;
Gun.state.drift -= NTS.step * (1/(peers||1));
NTS.next = Math.min(2e4, Math.max(250, 150000 / Math.abs((NTS.end - NTS.calc)||1)));
console.log("I am now", Gun.state(), "they are", NTS.calc, "time sync in", NTS.next/1000, 'sec.');
setTimeout(ping, NTS.next); // Thanks @finwo ! https://discord.com/channels/612645357850984470/612645357850984473/755334349699809300
}
mesh.say(msg, peer);
}, 1);
});
root.on('bye', function(peer){ --peers; this.to.next(peer) });
});
Gun.on('create', function(root){ // switch to DAM, deprecated old
var opt = root.opt, mesh = opt.mesh;
if(!mesh) return;
// test by opening up examples/game/nts.html on devices that aren't NTP synced.
}());
// Track connections
var connections = [];
root.on('hi', function(peer) {
this.to.next(peer);
connections.push({peer, latency: 0, offset: 0, next: 0});
});
root.on('bye', function(peer) {
this.to.next(peer);
var found = connections.find(connection => connection.peer.id == peer.id);
if (!found) return;
connections.splice(connections.indexOf(found), 1);
});
function response(msg, connection) {
var now = Date.now(); // Lack of drift intentional, provides more accurate RTT
connection.latency = (now - msg.nts[0]) / 2;
connection.offset = (msg.nts[1] + connection.latency) - (now + Gun.state.drift);
console.log(connection.offset);
Gun.state.drift += connection.offset / (connections.length + smooth);
console.log(`Update time by local: ${connection.offset} / ${connections.length + smooth}`);
}
// Handle echo & setting based on known connection latency as well
mesh.hear[dam] = function(msg, peer) {
console.log('MSG', msg);
var now = Date.now() + Gun.state.drift;
var connection = connections.find(connection => connection.peer.id == peer.id);
if (!connection) return;
if (msg.nts.length >= 2) return response(msg, connection);
mesh.say({dam, '@': msg['#'], nts: msg.nts.concat(now)}, peer);
connection.offset = msg.nts[0] + connection.latency - now;
Gun.state.drift += connection.offset / (connections.length + smooth);
console.log(`Update time by remote: ${connection.offset} / ${connections.length + smooth}`);
};
// Handle ping transmission
setTimeout(function trigger() {
console.log('TRIGGER');
if (!connections.length) return setTimeout(trigger, 100);
var now = Date.now(); // Lack of drift intentional, provides more accurate RTT & NTP reference
// Send pings
connections.forEach(function(connection) {
if (connection.next > now) return;
mesh.say({
dam,
'#': String.random(3),
nts: [now],
});
});
// Plan next round of pings
connections.forEach(function(connection) {
if (connection.next > now) return;
// https://discord.com/channels/612645357850984470/612645357850984473/755334349699809300
var delay = Math.min(2e4, Math.max(250, 150000 / Math.abs((connection.offset)||1)));
connection.next = now + delay;
});
// Plan next trigger round
// May overshoot by runtime of this function
var nextRound = Infinity;
connections.forEach(function(connection) {
nextRound = Math.min(nextRound, connection.next);
});
setTimeout(trigger, nextRound - now);
console.log(`Next sync round in ${(nextRound - now) / 1000} seconds`);
}, 1);
});
}());