Index: headless/lib/browser/devtools_api/devtools_connection.js |
diff --git a/headless/lib/browser/devtools_api/devtools_connection.js b/headless/lib/browser/devtools_api/devtools_connection.js |
new file mode 100644 |
index 0000000000000000000000000000000000000000..82993e012ad80e3e300cd8fe772233e026ae535a |
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+++ b/headless/lib/browser/devtools_api/devtools_connection.js |
@@ -0,0 +1,157 @@ |
+// Copyright 2017 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. |
+ |
+/** |
+ * @fileoverview Contains a class which marshals DevTools protocol messages over |
+ * a provided low level message transport. This transport might be a headless |
+ * TabSocket, or a WebSocket or a mock for testing. |
+ */ |
+ |
+'use strict'; |
+ |
+goog.module('chromium.DevTools.Connection'); |
+ |
+/** |
+ * Handles sending and receiving DevTools JSON protocol messages over the |
+ * provided low level message transport. |
+ */ |
+class Connection { |
+ /** |
+ * @param {!Object} transport The API providing transport for devtools |
+ * commands. |
+ */ |
+ constructor(transport) { |
+ /** @private {!Object} */ |
+ this.transport_ = transport; |
+ |
+ /** @private {number} */ |
+ this.commandId_ = 1; |
+ |
+ /** |
+ * An object containing pending DevTools protocol commands keyed by id. |
+ * |
+ * @private {!Map<number, !Connection.CallbackFunction>} |
+ */ |
+ this.pendingCommands_ = new Map(); |
+ |
+ /** @private {number} */ |
+ this.nextListenerId_ = 1; |
+ |
+ /** |
+ * An object containing DevTools protocol events we are listening for keyed |
+ * by name. |
+ * |
+ * @private {!Map<string, !Map<number, !Connection.CallbackFunction>>} |
+ */ |
+ this.eventListeners_ = new Map(); |
+ |
+ /** |
+ * Used for removing event listeners by id. |
+ * |
+ * @private {!Map<number, string>} |
+ */ |
+ this.eventListenerIdToEventName_ = new Map(); |
+ |
+ this.transport_.onmessage = this.onMessage_.bind(this); |
+ } |
+ |
+ /** |
+ * Listens for DevTools protocol events of the specified name and issues the |
+ * callback upon reception. |
+ * |
+ * @param {string} eventName Name of the DevTools protocol event to listen |
+ * for. |
+ * @param {!Connection.CallbackFunction} listener The callback issued when we |
+ * receive a DevTools protocol event corresponding to the given name. |
+ * @return {number} The id of this event listener. |
+ */ |
+ addEventListener(eventName, listener) { |
+ if (!this.eventListeners_.has(eventName)) { |
+ this.eventListeners_.set(eventName, new Map()); |
+ } |
+ let id = this.nextListenerId_++; |
+ this.eventListeners_.get(eventName).set(id, listener); |
+ this.eventListenerIdToEventName_.set(id, eventName); |
+ return id; |
+ } |
+ |
+ |
+ /** |
+ * Removes an event listener previously added by |
+ * <code>addEventListener</code>. |
+ * |
+ * @param {number} id The id of the event listener to remove. |
+ * @return {boolean} Whether the event listener was actually removed. |
+ */ |
+ removeEventListener(id) { |
+ if (!this.eventListenerIdToEventName_.has(id)) return false; |
+ let eventName = this.eventListenerIdToEventName_.get(id); |
+ this.eventListenerIdToEventName_.delete(id); |
+ // This shouldn't happen, but lets check anyway. |
+ if (!this.eventListeners_.has(eventName)) return false; |
+ return this.eventListeners_.get(eventName).delete(id); |
+ } |
+ |
+ |
+ /** |
+ * Issues a DevTools protocol command and returns a promise for the results. |
+ * |
+ * @param {string} method The name of the DevTools protocol command method. |
+ * @param {!Object=} params An object containing the command parameters if |
+ * any. |
+ * @return {!Promise<!Object>} A promise for the results object. |
+ */ |
+ sendDevToolsMessage(method, params = {}) { |
+ let id = this.commandId_; |
+ // We increment by two because these bindings are intended to be used in |
+ // conjunction with HeadlessDevToolsClient::RawProtocolListener and using |
+ // odd numbers for js generated IDs lets the implementation of = |
+ // OnProtocolMessage easily distinguish between C++ and JS generated |
+ // commands and route the response accordingly. |
+ this.commandId_ += 2; |
+ // Note the names are in quotes to prevent closure compiler name mangling. |
+ this.transport_.send( |
+ JSON.stringify({'method': method, 'id': id, 'params': params})); |
+ return new Promise((resolve, reject) => { |
+ this.pendingCommands_.set(id, resolve); |
+ }); |
+ } |
+ |
+ |
+ /** |
+ * @param {string} jsonMessage An object containing a DevTools protocol |
+ * message. |
+ * @private |
+ */ |
+ onMessage_(jsonMessage) { |
+ const message = JSON.parse(jsonMessage); |
+ if (message.hasOwnProperty('id')) { |
+ if (!this.pendingCommands_.has(message.id)) |
+ throw new Error('Unrecognized id:' + jsonMessage); |
+ if (message.hasOwnProperty('error')) |
+ throw new Error('DevTools protocol error: ' + message.error); |
+ this.pendingCommands_.get(message.id)(message.result); |
+ this.pendingCommands_.delete(message.id); |
+ } else { |
+ if (!message.hasOwnProperty('method') || |
+ !message.hasOwnProperty('params')) { |
+ throw new Error('Bad message:' + jsonMessage); |
+ } |
+ const method = message['method']; |
+ const params = message['params']; |
+ if (this.eventListeners_.has(method)) { |
+ this.eventListeners_.get(method).forEach(function(listener) { |
+ listener(params); |
+ }); |
+ } |
+ } |
+ } |
+} |
+ |
+/** |
+ * @typedef {function(Object): undefined|function(string): undefined} |
+ */ |
+Connection.CallbackFunction; |
+ |
+exports = Connection; |