diff rlgterm.js @ 159:a613380ffdc2

RLGWebD: excise polling. WebSockets are supported nearly everywhere now. Listing current games and watching them are still broken.
author John "Elwin" Edwards
date Sat, 03 Jan 2015 15:23:04 -0500
parents e54018b26ed8
children a2a25b7631f1
line wrap: on
line diff
--- a/rlgterm.js	Thu Jan 01 15:56:22 2015 -0500
+++ b/rlgterm.js	Sat Jan 03 15:23:04 2015 -0500
@@ -1,60 +1,5 @@
 /* rlgterm.js: Roguelike Gallery's driver for termemu.js */
 
-// A state machine that keeps track of polling the server.
-var ajaxstate = {
-  state: 0,
-  timerID: null,
-  clear: function () {
-    if (this.timerID != null) {
-      window.clearTimeout(this.timerID);
-      this.timerID = null;
-    }
-  },
-  set: function (ms) {
-    this.clear();
-    this.timerID = window.setTimeout(getData, ms);
-  },
-  gotdata: function () {
-    this.set(1000);
-    this.state = 1;
-  },
-  gotnothing: function () {
-    if (this.state == 0) {
-      this.set(1000);
-      this.state = 1;
-    }
-    else if (this.state < 4) {
-      this.set(4000);
-      this.state++;
-    }
-    else if (session.playing) {
-      if (this.state < 8) {
-        this.set(15000);
-        this.state++;
-      }
-      else {
-        /* It's been over a minute.  Stop polling. */
-        this.clear();
-      }
-    }
-    else {
-      /* If watching, it can't stop polling entirely, because there
-       * are no POST events to start it up again. */
-      this.set(10000);
-    }
-  },
-  posted: function (wasdata) {
-    if (wasdata) {
-      this.set(1000);
-      this.state = 1;
-    }
-    else {
-      this.set(200);
-      this.state = 0;
-    }
-  }
-};
-
 /* Data on the available games. */
 var games = {
   "rogue3": {
@@ -81,7 +26,7 @@
 
 var session = {
   /* The session id assigned by the server. */
-  id: null,
+  connect: false,
   /* Login name and key are now in sessionStorage. */
   /* Whether the game is being played or just watched. */
   playing: false,
@@ -165,119 +110,15 @@
   return;
 }
 
-/* State for sending and receiving messages. */
-var nsend = 0; // The number of the next packet to send.
-var nrecv = 0; // The next packet expected.
-var msgQ = []; // Queue for out-of-order messages.
-
-/* Processes a message from the server, returning true or false if it was a 
- * data message with or without data, null if not data.
- * All non-special responseTexts should be handed directly to this function.
- */
-function processMsg(msg) {
-  var msgDicts;
-  var havedata = null; // eventual return value
-  try {
-    msgDicts = JSON.parse(msg);
-  } catch (e) {
-    if (e instanceof SyntaxError)
-      return null;
-  }
-  if (msgDicts.length === 0)
-    return false;
-  for (var j = 0; j < msgDicts.length; j++) {
-    if (!msgDicts[j].t)
-      continue;
-    else if (msgDicts[j].t == "E") {
-      if (msgDicts[j].c == 1 || msgDicts[j].c == 6 || msgDicts[j].c == 7) {
-        gameover();
-        if (msgDicts[j].c == 1) {
-          logout();
-        }
-      }
-      debug(1, "Server error: " + msgDicts[j].s);
-    }
-    // A data message
-    else if (msgDicts[j].t == "d") {
-      if (msgDicts[j].n === nrecv) {
-        writeData(msgDicts[j].d);
-        nrecv++;
-        /* Process anything in the queue that's now ready. */
-        var next;
-        while ((next = msgQ.shift()) !== undefined) {
-          writeData(next.d);
-          nrecv++;
-        }
-      }
-      else if (msgDicts[j].n > nrecv) {
-        /* The current message comes after one still missing.  Queue this one
-         * for later use. */
-        debug(1, "Got packet " + msgDicts[j].n + ", expected " + nrecv);
-        msgQ[msgDicts[j].n - nrecv - 1] = msgDicts[j];
-      }
-      else {
-        /* This message's number was encountered previously. */
-        debug(1, "Discarding packet " + msgDicts[j].n + ", expected " + nrecv);
-      }
-      havedata = true;
-    }
-    else if (msgDicts[j].t == "T") {
-      setTitle(msgDicts[j].d);
-    }
-    else if (msgDicts[j].t == "q") {
-      gameover();
-    }
-    else {
-      debug(1, "Unrecognized server message " + msg);
-    }
-  }
-  return havedata;
-}
-
-function getData() {
-  if (session.id == null)
-    return;
-  var datareq = new XMLHttpRequest();
-  var msg = JSON.stringify({"id": session.id, "t": "n"});
-  datareq.onerror = errHandler;
-  datareq.onreadystatechange = function () {
-    if (datareq.readyState == 4 && datareq.status == 200) {
-      var wasdata = processMsg(datareq.responseText);
-      if (wasdata != null) {
-        if (wasdata)
-          ajaxstate.gotdata();
-        else
-          ajaxstate.gotnothing();
-      }
-      return;
-    }
-  };
-  datareq.open('POST', '/feed', true);
-  datareq.send(msg);
-  return;
-}
-
-function postResponseHandler() {
-  if (this.readyState == 4 && this.status == 200) {
-    // We might want to do something with wasdata someday.
-    var wasdata = processMsg(this.responseText);
-    ajaxstate.posted();
-    return;
-  }
-}
-
 function errHandler() {
   message("Unable to connect to the server.", "warn");
 }
 
 function sendback(str) {
   /* For responding to terminal queries. */
-  var msgDict = {"id": session.id, "t": "d", "n": nsend++, "d": str};
-  var datareq = new XMLHttpRequest();
-  datareq.onerror = errHandler;
-  datareq.onreadystatechange = postResponseHandler;
-  datareq.open('POST', '/feed', true);
-  datareq.send(JSON.stringify(msgDict));
+  if (session.sock) {
+    session.sock.send(JSON.stringify({"t": "d", "d": str}));
+  }
   return;
 }
 
@@ -323,14 +164,7 @@
   if (session.sock) {
     session.sock.send(JSON.stringify({"t": "d", "d": code}));
   }
-  else {
-    var datareq = new XMLHttpRequest();
-    var msgDict = {"id": session.id, "t": "d", "n": nsend++, "d": code};
-    datareq.onerror = errHandler;
-    datareq.onreadystatechange = postResponseHandler;
-    datareq.open('POST', '/feed', true);
-    datareq.send(JSON.stringify(msgDict));
-  }
+  /* Otherwise it is disconnected */
   return;
 }
 
@@ -386,14 +220,6 @@
   if (session.sock) {
     session.sock.send(JSON.stringify({"t": "d", "d": keystr}));
   }
-  else {
-    var datareq = new XMLHttpRequest();
-    var msgDict = {"id": session.id, "t": "d", "n": nsend++, "d": keystr};
-    datareq.onerror = errHandler;
-    datareq.onreadystatechange = postResponseHandler;
-    datareq.open('POST', '/feed', true);
-    datareq.send(JSON.stringify(msgDict));
-  }
   return;
 }
 
@@ -426,8 +252,8 @@
       break;
   }
   if (!window.WebSocket) {
-    message("Your browser does not support WebSockets. You can still play, " +
-            "but it will be slower, and may not work in the future.", "warn");
+    message("Your browser does not support WebSockets. " +
+            "This Web app will not work.", "warn");
   }
   return;
 }
@@ -454,8 +280,7 @@
 
 function formlogin(ev) {
   ev.preventDefault();
-  if (session.id != null)
-    return;
+  /* What to do if logged in already? */
   var loginmsg = {};
   loginmsg["name"] = document.getElementById("input_name").value;
   loginmsg["pw"] = document.getElementById("input_pw").value;
@@ -490,6 +315,7 @@
   return;
 }
 
+/* FIXME game list API has changed */
 function tableCurrent(gamelist) {
   var gamediv = document.getElementById("gametable");
   while (gamediv.children.length > 2)
@@ -533,7 +359,7 @@
 function wsCurrent() {
   if (!window.WebSocket)
     return;
-  if (session.id) {
+  if (session.connect) {
     /* Don't bother with status if already playing/watching. */
     if (statsock) {
       statsock.close();
@@ -569,11 +395,12 @@
   }
 }
 
+/* FIXME gamelist API has changed */
 function getcurrent(clear) {
   if (window.WebSocket) {
     return;
   }
-  if (session.id || clear) {
+  if (session.connect || clear) {
     if (statInterval) {
       window.clearInterval(statInterval);
       statInterval = null;
@@ -608,7 +435,7 @@
 }
 
 function getchoices() {
-  if (session.id != null || !("lcred" in sessionStorage))
+  if (session.connect || !("lcred" in sessionStorage))
     return;
   var req = new XMLHttpRequest();
   req.onerror = errHandler;
@@ -680,62 +507,6 @@
   return starter;
 }
 
-function startgame(game) {
-  if (session.id != null || !("lcred" in sessionStorage))
-    return;
-  if (window.WebSocket) {
-    wsStart(game);
-    return;
-  }
-  var smsg = {};
-  smsg["key"] = sessionStorage.getItem("lcred");
-  smsg["game"] = game.uname;
-  smsg["h"] = 24;
-  smsg["w"] = 80;
-  var req = new XMLHttpRequest();
-  req.onerror = errHandler;
-  req.onreadystatechange = function () {
-    if (req.readyState != 4 || req.status != 200) 
-      return;
-    var reply = JSON.parse(req.responseText);
-    if (reply.t == 's') {
-      /* Success */
-      session.id = reply.id;
-      session.playing = true;
-      termemu.resize(reply.h, reply.w);
-      message("You are now playing " + game.name + ".");
-      setmode("play");
-      getData();
-    }
-    else if (reply.t == 'E') {
-      if (reply.c == 1) {
-        logout();
-        message("The server forgot about you, please log in again.", "warn");
-      }
-      else if (reply.c == 4) {
-        if (reply.s == "dgamelaunch") {
-          message("You are already playing " + game.name + " over SSH.", 
-                  "warn");
-        }
-        else {
-          message("You are already playing " + game.name + 
-                  " in another browser window.", "warn");
-        }
-      }
-      else if (reply.c == 7) {
-        message("The game is being saved, try again in a few seconds.");
-      }
-      else {
-        message("The server says it can't start your game because \"" + 
-                reply.s + "\". This is probably a bug.", "warn");
-      }
-    }
-  };
-  req.open('POST', '/play', true);
-  req.send(JSON.stringify(smsg));
-  return;
-}
-
 function makeStopper(gname) {
   if (!(gname in games))
     return null;
@@ -774,12 +545,17 @@
   return;
 }
 
-function wsStart(game) {
+function startgame(game) {
+  if (!("lcred" in sessionStorage) || session.connect)
+    return;
+  if (!window.WebSocket) {
+    return;
+  }
   var sockurl = "ws://" + window.location.host + "/play/" + game.uname;
   sockurl += "?key=" + sessionStorage.getItem("lcred") + "&w=80&h=24";
   ws = new WebSocket(sockurl);
   ws.onopen = function (event) {
-    session.id = true;
+    session.connect = true;
     session.playing = true;
     session.sock = ws;
     setmode("play");
@@ -800,55 +576,20 @@
   };
 }
 
-function startwatching(gamenumber) {
-  if (session.id != null)
-    return;
-  if (window.WebSocket) {
-    wsWatch(gamenumber);
-    return;
-  }
-  var wmsg = {"n": Number(gamenumber)};
-  var req = new XMLHttpRequest();
-  req.onerror = errHandler;
-  req.onreadystatechange = function () {
-    if (req.readyState != 4 || req.status != 200) 
-      return;
-    var reply = JSON.parse(req.responseText);
-    if (reply.t == 'w') {
-      /* Success */
-      session.id = reply.id;
-      session.playing = false;
-      termemu.resize(reply.h, reply.w);
-      termemu.reset();
-      termemu.toAltBuf();
-      var pname = reply.p;
-      var gname = games[reply.g].name;
-      message("You are now watching " + pname + " play " + gname + ".");
-      setmode("watch");
-      getData();
-    }
-    else if (reply.t == 'E') {
-      message("The game could not be watched: " + reply.s, "warn");
-      getcurrent();
-    }
-  };
-  req.open('POST', '/watch', true);
-  req.send(JSON.stringify(wmsg));
-  return;
-}
-
-function makeWatcher(n) {
+function makeWatcher(t) {
   function watcher(ev) {
-    startwatching(n);
+    startwatching(t);
   }
   return watcher;
 }
 
-function wsWatch(gamenumber) {
-  var sockurl = "ws://" + window.location.host + "/watch/" + String(gamenumber);
+function startwatching(tag) {
+  if (session.connect)
+    return;
+  var sockurl = "ws://" + window.location.host + "/watch/" + tag;
   var ws = new WebSocket(sockurl);
   ws.onopen = function (event) {
-    session.id = true;
+    session.connect = true;
     session.sock = ws;
     setmode("watch");
   };
@@ -874,7 +615,8 @@
 
 function formreg(ev) {
   ev.preventDefault();
-  if (session.id != null)
+  /* This ought to check for being logged in instead. */
+  if (session.connect)
     return;
   var regmsg = {};
   regmsg["name"] = document.getElementById("regin_name").value;
@@ -925,20 +667,16 @@
 }
 
 function gameover() {
-  if (session.id == null)
+  if (!session.connect)
     return;
   /* TODO IFACE2 If the end was unexpected, tell player the game was saved. */
   if (session.playing)
     message("Finished playing.");
   else
     message("Finished watching.");
-  session.id = null;
+  session.connect = false;
   session.playing = false;
-  ajaxstate.clear();
   termemu.toNormBuf();
-  nsend = 0;
-  nrecv = 0;
-  msgQ = [];
   if ("lcred" in sessionStorage)
     setmode("choose");
   else
@@ -952,24 +690,14 @@
   setmode("login");
 }
 
+/* TODO determine whether this is needed */
 function stop() {
-  if (!session.id)
+  if (!session.connect)
     return;
   if (session.sock) {
     session.sock.close();
     return;
   }
-  var req = new XMLHttpRequest();
-  req.onerror = errHandler;
-  req.onreadystatechange = function () {
-    if (req.readyState == 4 && req.status == 200) {
-      processMsg(req.responseText);
-      return;
-    }
-  };
-  req.open('POST', '/feed', true);
-  req.send(JSON.stringify({"id": session.id, "t": "q"}));
-  return;
 }
 
 function setmode(mode, ev) {