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 // Helper to safe-send some message through a (web-)socket:
  17 function send(socket, message)
  18 {
  19   if (!!socket && socket.readyState == 1)
  20     socket.send(JSON.stringify(message));
  21 }
  22
  23 module.exports = function(wss) {
  24   // Associative array page --> sid --> tmpId --> socket
  25   // "page" is either "/" for hall or "/game/some_gid" for Game,
  26   // tmpId is required if a same user (browser) has different tabs
  27   let clients = {};
  28   wss.on("connection", (socket, req) => {
  29     const query = getJsonFromUrl(req.url);
  30     const sid = query["sid"];
  31     const tmpId = query["tmpId"];
  32     const page = query["page"];
  33     const notifyRoom = (page,code,obj={}) => {
  34       if (!clients[page])
  35         return;
  36       Object.keys(clients[page]).forEach(k => {
  37         Object.keys(clients[page][k]).forEach(x => {
  38           if (k == sid && x == tmpId)
  39             return;
  40           send(clients[page][k][x], Object.assign({code:code, from:sid}, obj));
  41         });
  42       });
  43     };
  44     const deleteConnexion = () => {
  45       if (!clients[page] || !clients[page][sid] || !clients[page][sid][tmpId])
  46         return; //job already done
  47       delete clients[page][sid][tmpId];
  48       if (Object.keys(clients[page][sid]).length == 0)
  49       {
  50         delete clients[page][sid];
  51         if (Object.keys(clients[page]) == 0)
  52           delete clients[page];
  53       }
  54     };
  55     const doDisconnect = () => {
  56       deleteConnexion();
  57       if (!clients[page] || !clients[page][sid])
  58       {
  59         // I effectively disconnected from this page:
  60         notifyRoom(page, "disconnect");
  61         if (page.indexOf("/game/") >= 0)
  62           notifyRoom("/", "gdisconnect", {page:page});
  63       }
  64     };
  65     const messageListener = (objtxt) => {
  66       let obj = JSON.parse(objtxt);
  67       switch (obj.code)
  68       {
  69         // Wait for "connect" message to notify connection to the room,
  70         // because if game loading is slow the message listener might
  71         // not be ready too early.
  72         case "connect":
  73         {
  74           notifyRoom(page, "connect");
  75           if (page.indexOf("/game/") >= 0)
  76             notifyRoom("/", "gconnect", {page:page});
  77           break;
  78         }
  79         case "disconnect":
  80           // When page changes:
  81           doDisconnect();
  82           break;
  83         case "killme":
  84         {
  85           // Self multi-connect: manual removal + disconnect
  86           const doKill = (pg) => {
  87             Object.keys(clients[pg][obj.sid]).forEach(x => {
  88               send(clients[pg][obj.sid][x], {code: "killed"});
  89             });
  90             delete clients[pg][obj.sid];
  91           };
  92           const disconnectFromOtherConnexion = (pg,code,o={}) => {
  93             Object.keys(clients[pg]).forEach(k => {
  94               if (k != obj.sid)
  95               {
  96                 Object.keys(clients[pg][k]).forEach(x => {
  97                   send(clients[pg][k][x], Object.assign({code:code, from:obj.sid}, o));
  98                 });
  99               }
 100             });
 101           };
 102           Object.keys(clients).forEach(pg => {
 103             if (!!clients[pg][obj.sid])
 104             {
 105               doKill(pg);
 106               disconnectFromOtherConnexion(pg, "disconnect");
 107               if (pg.indexOf("/game/") >= 0 && !!clients["/"])
 108                 disconnectFromOtherConnexion("/", "gdisconnect", {page:pg});
 109             }
 110           });
 111           break;
 112         }
 113         case "pollclients": //from Hall or Game
 114         {
 115           let sockIds = [];
 116           Object.keys(clients[page]).forEach(k => {
 117             // Avoid polling myself: no new information to get
 118             if (k != sid)
 119               sockIds.push(k);
 120           });
 121           send(socket, {code:"pollclients", sockIds:sockIds});
 122           break;
 123         }
 124         case "pollclientsandgamers": //from Hall
 125         {
 126           let sockIds = [];
 127           Object.keys(clients["/"]).forEach(k => {
 128             // Avoid polling myself: no new information to get
 129             if (k != sid)
 130               sockIds.push({sid:k});
 131           });
 132           // NOTE: a "gamer" could also just be an observer
 133           Object.keys(clients).forEach(p => {
 134             if (p != "/")
 135             {
 136               Object.keys(clients[p]).forEach(k => {
 137                 if (k != sid)
 138                   sockIds.push({sid:k, page:p}); //page needed for gamers
 139               });
 140             }
 141           });
 142           send(socket, {code:"pollclientsandgamers", sockIds:sockIds});
 143           break;
 144         }
 145
 146         // Asking something: from is fully identified,
 147         // but the requested resource can be from any tmpId (except current!)
 148         case "askidentity":
 149         case "asklastate":
 150         case "askchallenge":
 151         case "askgame":
 152         case "askfullgame":
 153         {
 154           const pg = obj.page || page; //required for askidentity and askgame
 155           const tmpIds = Object.keys(clients[pg][obj.target]);
 156           if (obj.target == sid) //targetting myself
 157           {
 158             const idx_myTmpid = tmpIds.findIndex(x => x == tmpId);
 159             if (idx_myTmpid >= 0)
 160               tmpIds.splice(idx_myTmpid, 1);
 161           }
 162           const tmpId_idx = Math.floor(Math.random() * tmpIds.length);
 163           send(clients[pg][obj.target][tmpIds[tmpId_idx]], {code:obj.code, from:[sid,tmpId,page]});
 164           break;
 165         }
 166
 167         // Some Hall events: target all tmpId's (except mine),
 168         case "refusechallenge":
 169         case "startgame":
 170           Object.keys(clients[page][obj.target]).forEach(x => {
 171             if (obj.target != sid || x != tmpId)
 172               send(clients[page][obj.target][x], {code:obj.code, data:obj.data});
 173           });
 174           break;
 175
 176         // Notify all room: mostly game events
 177         case "newchat":
 178         case "newchallenge":
 179         case "newgame":
 180         case "deletechallenge":
 181         case "newmove":
 182         case "resign":
 183         case "abort":
 184         case "drawoffer":
 185         case "draw":
 186           notifyRoom(page, obj.code, {data:obj.data});
 187           break;
 188
 189         // Passing, relaying something: from isn't needed,
 190         // but target is fully identified (sid + tmpId)
 191         case "challenge":
 192         case "fullgame":
 193         case "game":
 194         case "identity":
 195         case "lastate":
 196         {
 197           const pg = obj.target[2] || page; //required for identity and game
 198           send(clients[pg][obj.target[0]][obj.target[1]], {code:obj.code, data:obj.data});
 199           break;
 200         }
 201       }
 202     };
 203     const closeListener = () => {
 204       // TODO: BUG: this is triggered twice when anonymous reloads page
 205       // (+ registered users, everyone in Hall).
 206       // For tab or browser closing:
 207       doDisconnect();
 208     };
 209     // Update clients object: add new connexion
 210     if (!clients[page])
 211       clients[page] = {[sid]: {[tmpId]: socket}};
 212     else if (!clients[page][sid])
 213       clients[page][sid] = {[tmpId]: socket};
 214     else
 215       clients[page][sid][tmpId] = socket;
 216     socket.on("message", messageListener);
 217     socket.on("close", closeListener);
 218   });
 219 }