Added support of operational transformation

lib/ot/editor-socketio-server.js

@@ -0,0 +1,146 @@
+'use strict';
+
+var EventEmitter = require('events').EventEmitter;
+var TextOperation = require('./text-operation');
+var WrappedOperation = require('./wrapped-operation');
+var Server = require('./server');
+var Selection = require('./selection');
+var util = require('util');
+
+var LZString = require('lz-string');
+
+function EditorSocketIOServer(document, operations, docId, mayWrite) {
+    EventEmitter.call(this);
+    Server.call(this, document, operations);
+    this.users = {};
+    this.docId = docId;
+    this.mayWrite = mayWrite || function (_, cb) {
+        cb(true);
+    };
+}
+
+util.inherits(EditorSocketIOServer, Server);
+extend(EditorSocketIOServer.prototype, EventEmitter.prototype);
+
+function extend(target, source) {
+    for (var key in source) {
+        if (source.hasOwnProperty(key)) {
+            target[key] = source[key];
+        }
+    }
+}
+
+EditorSocketIOServer.prototype.addClient = function (socket) {
+    var self = this;
+    socket.join(this.docId);
+    var docOut = {
+        str: this.document,
+        revision: this.operations.length,
+        clients: this.users
+    };
+    socket.emit('doc', LZString.compressToUTF16(JSON.stringify(docOut)));
+    socket.on('operation', function (revision, operation, selection) {
+        operation = LZString.decompressFromUTF16(operation);
+        operation = JSON.parse(operation);
+        self.mayWrite(socket, function (mayWrite) {
+            if (!mayWrite) {
+                console.log("User doesn't have the right to edit.");
+                return;
+            }
+            self.onOperation(socket, revision, operation, selection);
+        });
+    });
+    socket.on('get_operations', function (base, head) {
+        self.onGetOperations(socket, base, head);
+    });
+    socket.on('selection', function (obj) {
+        self.mayWrite(socket, function (mayWrite) {
+            if (!mayWrite) {
+                console.log("User doesn't have the right to edit.");
+                return;
+            }
+            self.updateSelection(socket, obj && Selection.fromJSON(obj));
+        });
+    });
+    socket.on('disconnect', function () {
+        //console.log("Disconnect");
+        socket.leave(self.docId);
+        self.onDisconnect(socket);
+        /*
+        if (socket.manager && socket.manager.sockets.clients(self.docId).length === 0) {
+          self.emit('empty-room');
+        }
+        */
+    });
+};
+
+EditorSocketIOServer.prototype.onOperation = function (socket, revision, operation, selection) {
+    var wrapped;
+    try {
+        wrapped = new WrappedOperation(
+            TextOperation.fromJSON(operation),
+            selection && Selection.fromJSON(selection)
+        );
+    } catch (exc) {
+        console.error("Invalid operation received: " + exc);
+        return;
+    }
+
+    try {
+        var clientId = socket.id;
+        var wrappedPrime = this.receiveOperation(revision, wrapped);
+        //console.log("new operation: " + JSON.stringify(wrapped));
+        this.getClient(clientId).selection = wrappedPrime.meta;
+        revision = this.operations.length;
+        socket.emit('ack', revision);
+        socket.broadcast.in(this.docId).emit(
+            'operation', clientId, revision,
+            wrappedPrime.wrapped.toJSON(), wrappedPrime.meta
+        );
+        this.isDirty = true;
+    } catch (exc) {
+        console.error(exc);
+    }
+};
+
+EditorSocketIOServer.prototype.onGetOperations = function (socket, base, head) {
+    var operations = this.operations.slice(base, head).map(function (op) {
+        return op.wrapped.toJSON();
+    });
+    operations = LZString.compressToUTF16(JSON.stringify(operations));
+    socket.emit('operations', head, operations);
+};
+
+EditorSocketIOServer.prototype.updateSelection = function (socket, selection) {
+    var clientId = socket.id;
+    if (selection) {
+        this.getClient(clientId).selection = selection;
+    } else {
+        delete this.getClient(clientId).selection;
+    }
+    socket.broadcast.to(this.docId).emit('selection', clientId, selection);
+};
+
+EditorSocketIOServer.prototype.setName = function (socket, name) {
+    var clientId = socket.id;
+    this.getClient(clientId).name = name;
+    socket.broadcast.to(this.docId).emit('set_name', clientId, name);
+};
+
+EditorSocketIOServer.prototype.setColor = function (socket, color) {
+    var clientId = socket.id;
+    this.getClient(clientId).color = color;
+    socket.broadcast.to(this.docId).emit('set_color', clientId, color);
+};
+
+EditorSocketIOServer.prototype.getClient = function (clientId) {
+    return this.users[clientId] || (this.users[clientId] = {});
+};
+
+EditorSocketIOServer.prototype.onDisconnect = function (socket) {
+    var clientId = socket.id;
+    delete this.users[clientId];
+    socket.broadcast.to(this.docId).emit('client_left', clientId);
+};
+
+module.exports = EditorSocketIOServer;