| // Copyright 2013 The Closure Library Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS-IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| /** |
| * @fileoverview Codec functions of the v8 wire protocol. Eventually we'd want |
| * to support pluggable wire-format to improve wire efficiency and to enable |
| * binary encoding. Such support will require an interface class, which |
| * will be added later. |
| * |
| * @visibility {:internal} |
| */ |
| |
| |
| goog.provide('goog.labs.net.webChannel.WireV8'); |
| |
| goog.require('goog.asserts'); |
| goog.require('goog.json'); |
| goog.require('goog.json.NativeJsonProcessor'); |
| goog.require('goog.structs'); |
| |
| |
| |
| /** |
| * The v8 codec class. |
| * |
| * @constructor |
| * @struct |
| */ |
| goog.labs.net.webChannel.WireV8 = function() { |
| /** |
| * Parser for a response payload. The parser should return an array. |
| * @private {!goog.string.Parser} |
| */ |
| this.parser_ = new goog.json.NativeJsonProcessor(); |
| }; |
| |
| |
| goog.scope(function() { |
| var WireV8 = goog.labs.net.webChannel.WireV8; |
| var Wire = goog.labs.net.webChannel.Wire; |
| |
| |
| /** |
| * Encodes a standalone message into the wire format. |
| * |
| * May throw exception if the message object contains any invalid elements. |
| * |
| * @param {!Object|!goog.structs.Map} message The message data. |
| * V8 only support JS objects (or Map). |
| * @param {!Array<string>} buffer The text buffer to write the message to. |
| * @param {string=} opt_prefix The prefix for each field of the object. |
| */ |
| WireV8.prototype.encodeMessage = function(message, buffer, opt_prefix) { |
| var prefix = opt_prefix || ''; |
| try { |
| goog.structs.forEach(message, function(value, key) { |
| var encodedValue = value; |
| if (goog.isObject(value)) { |
| encodedValue = goog.json.serialize(value); |
| } // keep the fast-path for primitive types |
| buffer.push(prefix + key + '=' + encodeURIComponent(encodedValue)); |
| }); |
| } catch (ex) { |
| // We send a map here because lots of the retry logic relies on map IDs, |
| // so we have to send something (possibly redundant). |
| buffer.push(prefix + 'type' + '=' + encodeURIComponent('_badmap')); |
| throw ex; |
| } |
| }; |
| |
| |
| /** |
| * Encodes all the buffered messages of the forward channel. |
| * |
| * @param {!Array<Wire.QueuedMap>} messageQueue The message data. |
| * V8 only support JS objects. |
| * @param {number} count The number of messages to be encoded. |
| * @param {?function(!Object)} badMapHandler Callback for bad messages. |
| */ |
| WireV8.prototype.encodeMessageQueue = function(messageQueue, count, |
| badMapHandler) { |
| var sb = ['count=' + count]; |
| var offset; |
| if (count > 0) { |
| // To save a bit of bandwidth, specify the base mapId and the rest as |
| // offsets from it. |
| offset = messageQueue[0].mapId; |
| sb.push('ofs=' + offset); |
| } else { |
| offset = 0; |
| } |
| for (var i = 0; i < count; i++) { |
| var mapId = messageQueue[i].mapId; |
| var map = messageQueue[i].map; |
| mapId -= offset; |
| try { |
| this.encodeMessage(map, sb, 'req' + mapId + '_'); |
| } catch (ex) { |
| if (badMapHandler) { |
| badMapHandler(map); |
| } |
| } |
| } |
| return sb.join('&'); |
| }; |
| |
| |
| /** |
| * Decodes a standalone message received from the wire. May throw exception |
| * if text is ill-formatted. |
| * |
| * Must be valid JSON as it is insecure to use eval() to decode JS literals; |
| * and eval() is disallowed in Chrome apps too. |
| * |
| * Invalid JS literals include null array elements, quotas etc. |
| * |
| * @param {string} messageText The string content as received from the wire. |
| * @return {*} The decoded message object. |
| */ |
| WireV8.prototype.decodeMessage = function(messageText) { |
| var response = this.parser_.parse(messageText); |
| goog.asserts.assert(goog.isArray(response)); // throw exception |
| return response; |
| }; |
| }); // goog.scope |