server/sockets.js

   1 const url = require('url');
   2
   3 // Node version in Ubuntu 16.04 does not know about URL class
   4 // NOTE: url is already transformed, without ?xxx=yyy... parts
   5 function getJsonFromUrl(url)
   6 {
   7   const query = url.substr(2); //starts with "/?"
   8   let result = {};
   9   query.split("&").forEach((part) => {
  10     const item = part.split("=");
  11     result[item[0]] = decodeURIComponent(item[1]);
  12   });
  13   return result;
  14 }
  15
  16 module.exports = function(wss) {
  17   // Associative array page --> sid --> tmpId --> socket
  18   // "page" is either "/" for hall or "/game/some_gid" for Game,
  19   // tmpId is required if a same user (browser) has different tabs
  20   let clients = {};
  21   wss.on("connection", (socket, req) => {
  22     const query = getJsonFromUrl(req.url);
  23     const sid = query["sid"];
  24     const tmpId = query["tmpId"];
  25     const page = query["page"];
  26     const notifyRoom = (page,code,obj={}) => {
  27       if (!clients[page])
  28         return;
  29       Object.keys(clients[page]).forEach(k => {
  30         Object.keys(clients[page][k]).forEach(x => {
  31           if (k == sid && x == tmpId)
  32             return;
  33           clients[page][k][x].send(JSON.stringify(Object.assign(
  34             {code:code, from:sid}, obj)));
  35         });
  36       });
  37     };
  38     const deleteConnexion = () => {
  39       if (!clients[page] || !clients[page][sid] || !clients[page][sid][tmpId])
  40         return; //job already done
  41       delete clients[page][sid][tmpId];
  42       if (Object.keys(clients[page][sid]).length == 0)
  43       {
  44         delete clients[page][sid];
  45         if (Object.keys(clients[page]) == 0)
  46           delete clients[page];
  47       }
  48     };
  49     const messageListener = (objtxt) => {
  50       let obj = JSON.parse(objtxt);
  51       if (!!obj.target)
  52       {
  53         // Check if receiver is connected, because there may be some lag
  54         // between a client disconnects and another notice.
  55         if (Array.isArray(obj.target))
  56         {
  57           if (!clients[page][obj.target[0]] ||
  58             !clients[page][obj.target[0]][obj.target[1]])
  59           {
  60             return;
  61           }
  62         }
  63         else if (!clients[page][obj.target])
  64           return;
  65       }
  66       switch (obj.code)
  67       {
  68         // Wait for "connect" message to notify connection to the room,
  69         // because if game loading is slow the message listener might
  70         // not be ready too early.
  71         case "connect":
  72         {
  73           notifyRoom(page, "connect");
  74           if (page.indexOf("/game/") >= 0)
  75             notifyRoom("/", "gconnect", {page:page});
  76           break;
  77         }
  78         case "disconnect":
  79           // When page changes:
  80           deleteConnexion();
  81           if (!clients[page] || !clients[page][sid])
  82           {
  83             // I effectively disconnected from this page:
  84             notifyRoom(page, "disconnect");
  85             if (page.indexOf("/game/") >= 0)
  86               notifyRoom("/", "gdisconnect", {page:page});
  87           }
  88           break;
  89         case "killme":
  90         {
  91           // Self multi-connect: manual removal + disconnect
  92           const doKill = (pg) => {
  93             Object.keys(clients[pg][obj.sid]).forEach(x => {
  94               clients[pg][obj.sid][x].send(JSON.stringify({code: "killed"}));
  95             });
  96             delete clients[pg][obj.sid];
  97           };
  98           const disconnectFromOtherConnexion = (pg,code,o={}) => {
  99             Object.keys(clients[pg]).forEach(k => {
 100               if (k != obj.sid)
 101               {
 102                 Object.keys(clients[pg][k]).forEach(x => {
 103                   clients[pg][k][x].send(JSON.stringify(Object.assign(
 104                     {code:code, from:obj.sid}, o)));
 105                 });
 106               }
 107             });
 108           };
 109           Object.keys(clients).forEach(pg => {
 110             if (!!clients[pg][obj.sid])
 111             {
 112               doKill(pg);
 113               disconnectFromOtherConnexion(pg, "disconnect");
 114               if (pg.indexOf("/game/") >= 0)
 115                 disconnectFromOtherConnexion("/", "gdisconnect", {page:pg});
 116             }
 117           });
 118           break;
 119         }
 120         case "pollclients": //from Hall or Game
 121         {
 122           let sockIds = [];
 123           Object.keys(clients[page]).forEach(k => {
 124             // Avoid polling myself: no new information to get
 125             if (k != sid)
 126               sockIds.push(k);
 127           });
 128           socket.send(JSON.stringify({code:"pollclients", sockIds:sockIds}));
 129           break;
 130         }
 131         case "pollclientsandgamers": //from Hall
 132         {
 133           let sockIds = [];
 134           Object.keys(clients["/"]).forEach(k => {
 135             // Avoid polling myself: no new information to get
 136             if (k != sid)
 137               sockIds.push({sid:k});
 138           });
 139           // NOTE: a "gamer" could also just be an observer
 140           Object.keys(clients).forEach(p => {
 141             if (p != "/")
 142             {
 143               Object.keys(clients[p]).forEach(k => {
 144                 if (k != sid)
 145                   sockIds.push({sid:k, page:p}); //page needed for gamers
 146               });
 147             }
 148           });
 149           socket.send(JSON.stringify({code:"pollclientsandgamers", sockIds:sockIds}));
 150           break;
 151         }
 152
 153         // Asking something: from is fully identified,
 154         // but the requested resource can be from any tmpId (except current!)
 155         case "askidentity":
 156         case "asklastate":
 157         case "askchallenge":
 158         case "askgame":
 159         case "askfullgame":
 160         {
 161           const tmpIds = Object.keys(clients[page][obj.target]);
 162           if (obj.target == sid) //targetting myself
 163           {
 164             const idx_myTmpid = tmpIds.findIndex(x => x == tmpId);
 165             if (idx_myTmpid >= 0)
 166               tmpIds.splice(idx_myTmpid, 1);
 167           }
 168           const tmpId_idx = Math.floor(Math.random() * tmpIds.length);
 169           clients[page][obj.target][tmpIds[tmpId_idx]].send(
 170             JSON.stringify({code:obj.code, from:[sid,tmpId]}));
 171           break;
 172         }
 173
 174         // Some Hall events: target all tmpId's (except mine),
 175         case "refusechallenge":
 176         case "startgame":
 177           Object.keys(clients[page][obj.target]).forEach(x => {
 178             if (obj.target != sid || x != tmpId)
 179             {
 180               clients[page][obj.target][x].send(JSON.stringify(
 181                 {code:obj.code, data:obj.data}));
 182             }
 183           });
 184           break;
 185
 186         // Notify all room: mostly game events
 187         case "newchat":
 188         case "newchallenge":
 189         case "newgame":
 190         case "deletechallenge":
 191         case "newmove":
 192         case "resign":
 193         case "abort":
 194         case "drawoffer":
 195         case "draw":
 196           notifyRoom(page, obj.code, {data:obj.data});
 197           break;
 198
 199         // Passing, relaying something: from isn't needed,
 200         // but target is fully identified (sid + tmpId)
 201         case "challenge":
 202         case "fullgame":
 203         case "game":
 204         case "identity":
 205         case "lastate":
 206           clients[page][obj.target[0]][obj.target[1]].send(JSON.stringify(
 207             {code:obj.code, data:obj.data}));
 208           break;
 209       }
 210     };
 211     const closeListener = () => {
 212       // For tab or browser closing:
 213       deleteConnexion();
 214     };
 215     // Update clients object: add new connexion
 216     if (!clients[page])
 217       clients[page] = {[sid]: {[tmpId]: socket}};
 218     else if (!clients[page][sid])
 219       clients[page][sid] = {[tmpId]: socket};
 220     else
 221       clients[page][sid][tmpId] = socket;
 222     socket.on("message", messageListener);
 223     socket.on("close", closeListener);
 224   });
 225 }