[DevTools] Refactor connection-related classes.

third_party/WebKit/Source/devtools/front_end/sdk/Channels.js

+// Copyright (c) 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @constructor
+ * @extends {WebInspector.Object}
+ * @implements {InspectorBackendClass.Channel}
+ */
+WebInspector.MainChannel = function()
+{
+    WebInspector.Object.call(this);
+    InspectorFrontendHost.events.addEventListener(InspectorFrontendHostAPI.Events.DispatchMessage, this._dispatchMessage, this);
+    InspectorFrontendHost.events.addEventListener(InspectorFrontendHostAPI.Events.DispatchMessageChunk, this._dispatchMessageChunk, this);
+    InspectorFrontendHost.events.addEventListener(InspectorFrontendHostAPI.Events.EvaluateForTestInFrontend, this._evaluateForTestInFrontend, this);
+}
+
+WebInspector.MainChannel.prototype = {
+    /**
+     * @override
+     * @param {string} message
+     */
+    sendMessage: function(message)
+    {
+        InspectorFrontendHost.sendMessageToBackend(message);
+    },
+
+    /**
+     * @param {!WebInspector.Event} event
+     */
+    _dispatchMessage: function(event)
+    {
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.MessageReceived, event.data);
+    },
+
+    /**
+     * @param {!WebInspector.Event} event
+     */
+    _dispatchMessageChunk: function(event)
+    {
+        var messageChunk = /** @type {string} */ (event.data["messageChunk"]);
+        var messageSize = /** @type {number} */ (event.data["messageSize"]);
+        if (messageSize) {
+            this._messageBuffer = "";
+            this._messageSize = messageSize;
+        }
+        this._messageBuffer += messageChunk;
+        if (this._messageBuffer.length === this._messageSize) {
+            this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.MessageReceived, this._messageBuffer);
+            this._messageBuffer = "";
+            this._messageSize = 0;
+        }
+    },
+
+    /**
+     * @param {!WebInspector.Event} event
+     */
+    _evaluateForTestInFrontend: function(event)
+    {
+        if (!InspectorFrontendHost.isUnderTest())
+            return;
+
+        var callId = /** @type {number} */ (event.data["callId"]);
+        var script = /** @type {number} */ (event.data["script"]);
+
+        /**
+         * @suppressGlobalPropertiesCheck
+         */
+        function invokeMethod()
+        {
+            try {
+                script = script + "//# sourceURL=evaluateInWebInspector" + callId + ".js";
+                window.eval(script);
+            } catch (e) {
+                console.error(e.stack);
+            }
+        }
+
+        InspectorBackendClass.mainConnectionForTesting.deprecatedRunAfterPendingDispatches(invokeMethod);
+    },
+
+    /**
+     * @override
+     * @param {function()} callback
+     */
+    reconnect: function(callback)
+    {
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.ChannelClosed, "reconnecting");
+        InspectorFrontendHost.reattach(callback);
+    },
+
+    __proto__: WebInspector.Object.prototype
+}
+
+/**
+ * @constructor
+ * @extends {WebInspector.Object}
+ * @implements {InspectorBackendClass.Channel}
+ * @param {string} url
+ * @param {function()} onChannelReady
+ */
+WebInspector.WebSocketChannel = function(url, onChannelReady)
+{
+    WebInspector.Object.call(this);
+    this._url = url;
+    this._connect(onChannelReady);
+}
+
+/**
+ * @param {string} url
+ * @return {!Promise<!InspectorBackendClass.Channel>}
+ */
+WebInspector.WebSocketChannel.Create = function(url)
+{
+    var fulfill;
+    var result = new Promise(resolve => fulfill = resolve);
+    var channel = new WebInspector.WebSocketChannel(url, () => fulfill(channel));
+    return result;
+}
+
+WebInspector.WebSocketChannel.prototype = {
+    /**
+     * @param {function()} onChannelReady
+     */
+    _connect: function(onChannelReady)
+    {
+        this._socket = new WebSocket(this._url);
+        this._socket.onmessage = this._onMessage.bind(this);
+        this._socket.onerror = this._onError.bind(this);
+        this._socket.onopen = onChannelReady.bind(null);
+        this._socket.onclose = this._onClosed.bind(this);
+    },
+
+    /**
+     * @param {!MessageEvent} message
+     */
+    _onMessage: function(message)
+    {
+        var data = /** @type {string} */ (message.data);
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.MessageReceived, data);
+    },
+
+    /**
+     * @param {!Event} error
+     */
+    _onError: function(error)
+    {
+        console.error(error);
+    },
+
+    _onClosed: function()
+    {
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.ChannelClosed, "websocket closed");
+    },
+
+    /**
+     * @override
+     * @param {string} message
+     */
+    sendMessage: function(message)
+    {
+        this._socket.send(message);
+    },
+
+    /**
+     * @override
+     * @param {function()} callback
+     */
+    reconnect: function(callback)
+    {
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.ChannelClosed, "reconnecting");
+        this._socket.onclose = null;
+        this._socket.close();
+        this._connect(callback);
+    },
+
+    __proto__: WebInspector.Object.prototype
+}
+
+/**
+ * @constructor
+ * @extends {WebInspector.Object}
+ * @implements {InspectorBackendClass.Channel}
+ */
+WebInspector.StubChannel = function()
+{
+    WebInspector.Object.call(this);
+}
+
+WebInspector.StubChannel.prototype = {
+    /**
+     * @override
+     * @param {string} message
+     */
+    sendMessage: function(message)
+    {
+        setTimeout(this._respondWithError.bind(this, message), 0);
+    },
+
+    /**
+     * @override
+     * @param {function()} callback
+     */
+    reconnect: function(callback)
+    {
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.ChannelClosed, "reconnecting");
+        setTimeout(callback, 0);
+    },
+
+    /**
+     * @param {string} message
+     */
+    _respondWithError: function(message)
+    {
+        var messageObject = JSON.parse(message);
+        var error = { message: "This is a stub connection, can't dispatch message.", code:  InspectorBackendClass.DevToolsStubErrorCode, data: messageObject };
+        this.dispatchEventToListeners(InspectorBackendClass.Channel.Events.MessageReceived, { id: messageObject.id, error: error });
+    },
+
+    __proto__: WebInspector.Object.prototype
+}