Implement degraded mode when too many editors are in a pad

www/common/cryptpad-common.js

@@ -1026,13 +1026,6 @@ define([
     };
     onlyoffice.onEvent = Util.mkEvent();
 
-    // Cursor
-    var cursor = common.cursor = {};
-    cursor.execCommand = function (data, cb) {
-        postMessage("CURSOR_COMMAND", data, cb);
-    };
-    cursor.onEvent = Util.mkEvent();
-
     // Mailbox
     var mailbox = common.mailbox = {};
     mailbox.execCommand = function (data, cb) {
@@ -2138,8 +2131,6 @@ define([
         },
         // OnlyOffice
         OO_EVENT: common.onlyoffice.onEvent.fire,
-        // Cursor
-        CURSOR_EVENT: common.cursor.onEvent.fire,
         // Mailbox
         MAILBOX_EVENT: common.mailbox.onEvent.fire,
         // Universal

www/common/metadata-manager.js

@@ -15,6 +15,7 @@ define(['json.sortify'], function (Sortify) {
         var priv = {};
         var dirty = true;
         var history = false;
+        var degraded = true;
         var changeHandlers = [];
         var lazyChangeHandlers = [];
         var titleChangeHandlers = [];
@@ -64,7 +65,7 @@ define(['json.sortify'], function (Sortify) {
                 if (members.indexOf(x) === -1 && !history) { return; }
                 mdo[x] = metadataObj.users[x];
             });
-            if (!priv.readOnly) {
+            if (!priv.readOnly && !degraded) {
                 mdo[meta.user.netfluxId] = meta.user;
             }
             metadataObj.users = mdo;
@@ -176,6 +177,10 @@ define(['json.sortify'], function (Sortify) {
             getMetadataLazy: function () {
                 return metadataLazyObj;
             },
+            setDegraded: function (bool) {
+                degraded = bool;
+            },
+            isDegraded: function () { return degraded; },
             onTitleChange: function (f) { titleChangeHandlers.push(f); },
             onChange: function (f) { changeHandlers.push(f); },
             onChangeLazy: function (f) { lazyChangeHandlers.push(f); },

www/common/outer/async-store.js

@@ -1482,17 +1482,6 @@ define([
             }
         };
 
-        // Cursor
-        Store.cursor = {
-            execCommand: function (clientId, data, cb) {
-                // The cursor module can only be used when the store is ready
-                onReadyEvt.reg(function () {
-                    if (!store.cursor) { return void cb ({error: 'Cursor channel is disabled'}); }
-                    store.cursor.execCommand(clientId, data, cb);
-                });
-            }
-        };
-
         // Mailbox
         Store.mailbox = {
             execCommand: function (clientId, data, cb) {
@@ -2335,7 +2324,7 @@ define([
                 store.messenger.leavePad(chanId);
             } catch (e) { console.error(e); }
             try {
-                store.cursor.leavePad(chanId);
+                store.modules['cursor'].leavePad(chanId);
             } catch (e) { console.error(e); }
             try {
                 store.onlyoffice.leavePad(chanId);
@@ -2357,9 +2346,6 @@ define([
             if (driveIdx !== -1) {
                 driveEventClients.splice(driveIdx, 1);
             }
-            try {
-                store.cursor.removeClient(clientId);
-            } catch (e) { console.error(e); }
             try {
                 store.onlyoffice.removeClient(clientId);
             } catch (e) { console.error(e); }
@@ -2499,17 +2485,6 @@ define([
             });
         };
 */
-        var loadCursor = function () {
-            store.cursor = Cursor.init(store, function (ev, data, clients) {
-                clients.forEach(function (cId) {
-                    postMessage(cId, 'CURSOR_EVENT', {
-                        ev: ev,
-                        data: data
-                    });
-                });
-            });
-        };
-
         var loadOnlyOffice = function () {
             store.onlyoffice = OnlyOffice.init(store, function (ev, data, clients) {
                 clients.forEach(function (cId) {
@@ -2656,7 +2631,7 @@ define([
                     };
                     postMessage(clientId, 'LOADING_DRIVE', data);
                 });
-                loadCursor();
+                loadUniversal(Cursor, 'cursor', waitFor);
                 loadOnlyOffice();
                 loadUniversal(Messenger, 'messenger', waitFor);
                 store.messenger = store.modules['messenger'];

www/common/outer/cursor.js

@@ -6,6 +6,8 @@ define([
 ], function (Util, Constants, Messages, Crypto) {
     var Cursor = {};
 
+    var DEGRADED = 3; // XXX Number of users before switching to degraded mode
+
     var convertToUint8 = function (obj) {
         var l = Object.keys(obj).length;
         var u = new Uint8Array(l);
@@ -21,6 +23,7 @@ define([
         if (!client || !client.cursor) { return; }
         var chan = ctx.channels[client.channel];
         if (!chan) { return; }
+        if (chan.degraded) { return; }
         if (!chan.sendMsg) { return; } // Store not synced yet, we're running with the cache
         var data = {
             id: client.id,
@@ -34,6 +37,7 @@ define([
 
     // Send all our cursors data when someone remote joins the channel
     var sendOurCursors = function (ctx, chan) {
+        if (chan.degraded) { return; }
         chan.clients.forEach(function (c) {
             var client = ctx.clients[c];
             if (!client) { return; }
@@ -77,6 +81,7 @@ define([
             // ==> Send the cursor position of the other tabs
             chan.clients.forEach(function (cl) {
                 var clientObj = ctx.clients[cl];
+                if (chan.degraded) { return; }
                 if (!clientObj) { return; }
                 ctx.emit('MESSAGE', {
                     id: clientObj.id,
@@ -90,6 +95,11 @@ define([
             return void cb();
         }
 
+        var updateDegraded = function (ctx, wc, chan) {
+            var m = wc.members;
+            chan.degraded = (m.length-1) >= DEGRADED;
+            ctx.emit('DEGRADED', { degraded: chan.degraded }, chan.clients);
+        };
         var onOpen = function (wc) {
 
             ctx.channels[channel] = ctx.channels[channel] || {};
@@ -113,11 +123,14 @@ define([
 
             wc.on('join', function () {
                 sendOurCursors(ctx, chan);
+                updateDegraded(ctx, wc, chan);
             });
             wc.on('leave', function (peer) {
                 ctx.emit('MESSAGE', {leave: true, id: peer}, chan.clients);
+                updateDegraded(ctx, wc, chan);
             });
             wc.on('message', function (cryptMsg) {
+                if (chan.degraded) { return; }
                 var msg = chan.encryptor.decrypt(cryptMsg, secret.keys && secret.keys.validateKey);
                 var parsed;
                 try {
@@ -129,6 +142,7 @@ define([
                 } catch (e) { console.error(e); }
             });
 
+
             chan.wc = wc;
             chan.sendMsg = function (msg, cb) {
                 cb = cb || function () {};
@@ -144,6 +158,8 @@ define([
             chan.clients = [client];
             first = false;
             cb();
+
+            updateDegraded(ctx, wc, chan);
         };
 
         network.join(channel).then(onOpen, function (err) {
@@ -223,10 +239,10 @@ define([
         delete ctx.clients[clientId];
     };
 
-    Cursor.init = function (store, emit) {
+    Cursor.init = function (cfg, waitFor, emit) {
         var cursor = {};
         var ctx = {
-            store: store,
+            store: cfg.store,
             emit: emit,
             channels: {},
             clients: {}

www/common/outer/store-rpc.js

@@ -67,8 +67,6 @@ define([
             ANON_GET_PREVIEW_CONTENT: Store.anonGetPreviewContent,
             // OnlyOffice
             OO_COMMAND: Store.onlyoffice.execCommand,
-            // Cursor
-            CURSOR_COMMAND: Store.cursor.execCommand,
             // Mailbox
             MAILBOX_COMMAND: Store.mailbox.execCommand,
             // Universal

www/common/sframe-app-framework.js

@@ -579,7 +579,7 @@ define([
                 common.openPadChat(onLocal);
                 if (!readOnly && cursorGetter) {
                     common.openCursorChannel(onLocal);
-                    cursor = common.createCursor();
+                    cursor = common.createCursor(onLocal);
                     cursor.onCursorUpdate(function (data) {
                         var newContentStr = cpNfInner.chainpad.getUserDoc();
                         var hjson = normalize(JSON.parse(newContentStr));

www/common/sframe-common-codemirror.js

@@ -530,6 +530,9 @@ define([
             }
         };
         exp.setRemoteCursor = function (data) {
+            if (data.reset) {
+                return void exp.removeCursors();
+            }
             if (data.leave) {
                 $('.cp-codemirror-cursor[id^='+data.id+']').each(function (i, el) {
                     var id = $(el).attr('id');

www/common/sframe-common-cursor.js

@@ -3,28 +3,13 @@ define([
 ], function (Util) {
     var module = {};
 
-    module.create = function (Common) {
+    module.create = function (Common, onLocal) {
         var exp = {};
-        var sframeChan = Common.getSframeChannel();
         var metadataMgr = Common.getMetadataMgr();
         var privateData = metadataMgr.getPrivateData();
         var share = Util.find(privateData, ['settings', 'general', 'cursor', 'share']);
         var show = Util.find(privateData, ['settings', 'general', 'cursor', 'show']);
 
-        var execCommand = function (cmd, data, cb) {
-            sframeChan.query('Q_CURSOR_COMMAND', {cmd: cmd, data: data}, function (err, obj) {
-                if (err || (obj && obj.error)) { return void cb(err || (obj && obj.error)); }
-                cb(void 0, obj);
-            });
-        };
-
-        exp.updateCursor = function (obj) {
-            if (share === false) { return; }
-            execCommand('UPDATE', obj, function (err) {
-                if (err) { console.error(err); }
-            });
-        };
-
         var messageHandlers = [];
         exp.onCursorUpdate = function (handler) {
             messageHandlers.push(handler);
@@ -40,15 +25,47 @@ define([
             });
         };
 
+        var onDegraded = function (data) {
+            if (data.degraded) {
+                // Enter degraded mode
+                onMessage({
+                    reset: true
+                });
+                metadataMgr.setDegraded(true);
+                return void metadataMgr.refresh();
+            }
+
+            setTimeout(function () {
+                metadataMgr.setDegraded(false);
+                metadataMgr.refresh();
+                setTimeout(onLocal);
+            });
+        };
 
-        sframeChan.on('EV_CURSOR_EVENT', function (obj) {
+        var onEvent = function (obj) {
             var cmd = obj.ev;
             var data = obj.data;
+            if (cmd === 'DEGRADED') {
+                onDegraded(data);
+                return;
+            }
             if (cmd === 'MESSAGE') {
                 onMessage(data);
                 return;
             }
+        };
+
+        var module = Common.makeUniversal('cursor', {
+            onEvent: onEvent
         });
+        var execCommand = module.execCommand;
+
+        exp.updateCursor = function (obj) {
+            if (share === false) { return; }
+            execCommand('UPDATE', obj, function (err) {
+                if (err) { console.error(err); }
+            });
+        };
 
         return exp;
     };

www/common/sframe-common-outer.js

@@ -1613,20 +1613,17 @@ define([
             }
 
             sframeChan.on('Q_CURSOR_OPENCHANNEL', function (data, cb) {
-                Cryptpad.cursor.execCommand({
+                Cryptpad.universal.execCommand({
+                    type: 'cursor',
+                    data: {
                         cmd: 'INIT_CURSOR',
                         data: {
                             channel: data,
                             secret: secret
                         }
+                    }
                 }, cb);
             });
-            Cryptpad.cursor.onEvent.reg(function (data) {
-                sframeChan.event('EV_CURSOR_EVENT', data);
-            });
-            sframeChan.on('Q_CURSOR_COMMAND', function (data, cb) {
-                Cryptpad.cursor.execCommand(data, cb);
-            });
 
             Cryptpad.onTimeoutEvent.reg(function () {
                 sframeChan.event('EV_WORKER_TIMEOUT');

www/common/toolbar.js

@@ -167,6 +167,7 @@ MessengerUI, Messages) {
         var $userlistContent = toolbar.userlistContent;
 
         var metadataMgr = config.metadataMgr;
+
         var online = !forceOffline && metadataMgr.isConnected();
         var userData = metadataMgr.getMetadata().users;
         var viewers = metadataMgr.getViewers();
@@ -217,13 +218,25 @@ MessengerUI, Messages) {
             numberOfViewUsers = '?';
         }
 
+        if (metadataMgr.isDegraded()) {
+            numberOfEditUsers = Math.max(metadataMgr.getChannelMembers().length - 1, 0);
+            numberOfViewUsers = '';
+        }
+
         // Update the buttons
         var fa_editusers = '<span class="fa fa-users"></span>';
-        var fa_viewusers = '<span class="fa fa-eye"></span>';
+        var fa_viewusers = numberOfViewUsers === '' ? '' : '<span class="fa fa-eye"></span>';
         var $spansmall = $('<span>').html(fa_editusers + ' ' + numberOfEditUsers + '&nbsp;&nbsp; ' + fa_viewusers + ' ' + numberOfViewUsers);
         $userButtons.find('.cp-dropdown-button-title').html('').append($spansmall);
 
         if (!online) { return; }
+
+        if (metadataMgr.isDegraded()) {
+            Messages.toolbar_degraded = "Too many editors are present in the pad. The userlist has been disabled to improve performances"; // XXX
+            $('<em>').text(Messages.toolbar_degraded).appendTo($editUsersList);
+            return;
+        }
+
         // Display the userlist
 
         // Editors

www/kanban/inner.js

@@ -1247,6 +1247,16 @@ define([
         });
         framework.onCursorUpdate(function (data) {
             if (!data) { return; }
+            if (data.reset) {
+                Object.keys(remoteCursors).forEach(function (id) {
+                    if (remoteCursors[id].clear) {
+                        remoteCursors[id].clear();
+                    }
+                    delete remoteCursors[id];
+                });
+                return;
+            }
+
             var id = data.id;
 
             // Clear existing cursor

www/pad/cursor.js

@@ -122,6 +122,9 @@ define([
         };
 
         exp.onCursorUpdate = function (data, hjson) {
+            if (data.reset) {
+                return void exp.removeCursors(inner);
+            }
             if (data.leave) {
                 if (data.id.length === 32) {
                     Object.keys(cursors).forEach(function (id) {