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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // require cr.js
      6 // require cr/event_target.js
      7 // require cr/util.js
      8 
      9 cr.define('chrome.sync', function() {
     10   'use strict';
     11 
     12   /**
     13    * A simple timer to measure elapsed time.
     14    * @constructor
     15    */
     16   function Timer() {
     17     /**
     18      * The time that this Timer was created.
     19      * @type {number}
     20      * @private
     21      * @const
     22      */
     23     this.start_ = Date.now();
     24   }
     25 
     26   /**
     27    * @return {number} The elapsed seconds since this Timer was created.
     28    */
     29   Timer.prototype.getElapsedSeconds = function() {
     30     return (Date.now() - this.start_) / 1000;
     31   };
     32 
     33   /** @return {!Timer} An object which measures elapsed time. */
     34   var makeTimer = function() {
     35     return new Timer;
     36   };
     37 
     38   /**
     39    * @param {string} name The name of the event type.
     40    * @param {!Object} details A collection of event-specific details.
     41    */
     42   var dispatchEvent = function(name, details) {
     43     var e = new Event(name);
     44     e.details = details;
     45     chrome.sync.events.dispatchEvent(e);
     46   };
     47 
     48   /**
     49    * Registers to receive a stream of events through
     50    * chrome.sync.dispatchEvent().
     51    */
     52   var registerForEvents = function() {
     53     chrome.send('registerForEvents');
     54   };
     55 
     56   /**
     57    * Registers to receive a stream of status counter update events
     58    * chrome.sync.dispatchEvent().
     59    */
     60   var registerForPerTypeCounters = function() {
     61     chrome.send('registerForPerTypeCounters');
     62   }
     63 
     64   /**
     65    * Asks the browser to refresh our snapshot of sync state.  Should result
     66    * in an onAboutInfoUpdated event being emitted.
     67    */
     68   var requestUpdatedAboutInfo = function() {
     69     chrome.send('requestUpdatedAboutInfo');
     70   };
     71 
     72   /**
     73    * Asks the browser to send us the list of registered types.  Should result
     74    * in an onReceivedListOfTypes event being emitted.
     75    */
     76   var requestListOfTypes = function() {
     77     chrome.send('requestListOfTypes');
     78   };
     79 
     80   /**
     81    * Counter to uniquely identify requests while they're in progress.
     82    * Used in the implementation of GetAllNodes.
     83    */
     84   var requestId = 0;
     85 
     86   /**
     87    * A map from counter values to asynchronous request callbacks.
     88    * Used in the implementation of GetAllNodes.
     89    * @type {{number: !Function}}
     90    */
     91   var requestCallbacks = {};
     92 
     93   /**
     94    * Asks the browser to send us a copy of all existing sync nodes.
     95    * Will eventually invoke the given callback with the results.
     96    *
     97    * @param {function(!Object)} callback The function to call with the response.
     98    */
     99   var getAllNodes = function(callback) {
    100     requestId++;
    101     requestCallbacks[requestId] = callback;
    102     chrome.send('getAllNodes', [requestId]);
    103   };
    104 
    105   /**
    106    * Called from C++ with the response to a getAllNodes request.
    107    * @param {number} id The requestId passed in with the request.
    108    * @param {Object} response The response to the request.
    109    */
    110   var getAllNodesCallback = function(id, response) {
    111     requestCallbacks[id](response);
    112     requestCallbacks[id] = undefined;
    113   };
    114 
    115   return {
    116     makeTimer: makeTimer,
    117     dispatchEvent: dispatchEvent,
    118     events: new cr.EventTarget(),
    119     getAllNodes: getAllNodes,
    120     getAllNodesCallback: getAllNodesCallback,
    121     registerForEvents: registerForEvents,
    122     registerForPerTypeCounters: registerForPerTypeCounters,
    123     requestUpdatedAboutInfo: requestUpdatedAboutInfo,
    124     requestListOfTypes: requestListOfTypes,
    125   };
    126 });
    127