google-closure-library/closure/goog/labs/net/webchannel/wire.js

Google's common JavaScript library

/**
 * @license
 * Copyright The Closure Library Authors.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @fileoverview Interface and shared data structures for implementing
 * different wire protocol versions.
 */
goog.provide('goog.labs.net.webChannel.Wire');
goog.provide('goog.labs.net.webChannel.Wire.QueuedMap');



goog.require('goog.collections.maps');



/**
 * The interface class.
 * @interface
 */
goog.labs.net.webChannel.Wire = class {
  constructor() {}
};


/**
 * The latest protocol version that this class supports. We request this version
 * from the server when opening the connection. Should match
 * LATEST_CHANNEL_VERSION on the server code.
 * @type {number}
 */
goog.labs.net.webChannel.Wire.LATEST_CHANNEL_VERSION = 8;


/**
 * The JSON field key for the raw data wrapper object.
 * @type {string}
 */
goog.labs.net.webChannel.Wire.RAW_DATA_KEY = '__data__';



/**
 * Simple container class for a (mapId, map) pair.
 */
goog.labs.net.webChannel.Wire.QueuedMap = class {
  /**
   * @param {number} mapId The id for this map.
   * @param {!Object|!goog.collections.maps.MapLike} map The map itself.
   * @param {!Object=} opt_context The context associated with the map.
   */
  constructor(mapId, map, opt_context) {
    'use strict';
    /**
     * The id for this map.
     * @type {number}
     */
    this.mapId = mapId;

    /**
     * The map itself.
     * @type {!Object|!goog.collections.maps.MapLike}
     */
    this.map = map;

    /**
     * The context for the map.
     * @type {Object}
     */
    this.context = opt_context || null;
  }

  /**
   * @return {number|undefined} the size of the raw JSON message or
   * undefined if the message is not encoded as a raw JSON message
   */
  getRawDataSize() {
    'use strict';
    if (goog.labs.net.webChannel.Wire.RAW_DATA_KEY in this.map) {
      const data = this.map[goog.labs.net.webChannel.Wire.RAW_DATA_KEY];
      if (typeof data === 'string') {
        return data.length;
      }
    }

    return undefined;
  }
};