Files.app; Serializes event handler calls for particular URLs.

chrome/browser/resources/file_manager/background/js/drive_sync_handler.js

 // Copyright 2014 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.
 
 'use strict';
 
 /**
  * Handler of the background page for the drive sync events.
  * @param {ProgressCenter} progressCenter Progress center to submit the
  *     progressing items.
  * @constructor
  */
 function DriveSyncHandler(progressCenter) {
   /**
    * Progress center to submit the progressng item.
    * @type {ProgressCenter}
    * @private
    */
   this.progressCenter_ = progressCenter;
 
   /**
    * Counter for progress ID.
    * @type {number}
    * @private
    */
   this.idCounter_ = 0;
 
   /**
-   * Progressing file names.
-   * @type {Object.<string, ProgressCenterItem>} Map a file URL and a progress
-   *     center item.
+   * Map of file urls and progress center items.
+   * @type {Object.<string, ProgressCenterItem>}
    * @private
    */
   this.items_ = {};
 
+  /**
+   * Async queue.
+   * @type {AsyncUtil.Queue}
+   * @private
+   */
+  this.queue_ = new AsyncUtil.Queue();
+
   // Register events.
   chrome.fileBrowserPrivate.onFileTransfersUpdated.addListener(
       this.onFileTransfersUpdated_.bind(this));
   chrome.fileBrowserPrivate.onDriveSyncError.addListener(
       this.onDriveSyncError_.bind(this));
 }
 
 /**
  * Completed event name.
  * @type {string}
@@ skipping 49 matching lines @@
     }
   }
 };
 
 /**
  * Updates the item involved with the given status.
  * @param {FileTransferStatus} status Transfer status.
  * @private
  */
 DriveSyncHandler.prototype.updateItem_ = function(status) {
-  webkitResolveLocalFileSystemURL(status.fileUrl, function(entry) {
+  var entry;
+  this.queue_.run(function(callback) {

[mtomasz, 2014/01/30 05:11:13]

nit: We need to resolve the entry only when creating. Can we reorganize the code
to avoid resolving when it is not needed? If it makes the code more complex, I'm
fine with the current solution.

[hirono, 2014/01/30 06:36:13]

Done.

+    webkitResolveLocalFileSystemURL(status.fileUrl, function(inEntry) {
+      entry = inEntry;
+      callback();
+    }, function(error) {
+      console.warn('Resolving URL ' + status.fileUrl + 'is failed: ', error);
+      callback();
+    });
+  });
+  this.queue_.run(function(callback) {
+    if (!entry) {
+      callback();
+      return;
+    }
     var item;
     if (!this.items_[status.fileUrl]) {
       item = new ProgressCenterItem();
-      item.id = DriveSyncHandler.PROGRESS_ITEM_ID_PREFIX + (this.idCounter_++);
+      item.id =
+          DriveSyncHandler.PROGRESS_ITEM_ID_PREFIX + (this.idCounter_++);
       item.type = ProgressItemType.SYNC;
       item.quiet = true;
       item.message = strf('SYNC_FILE_NAME', entry.name);
       item.cancelCallback = this.requestCancel_.bind(this, entry);
       this.items_[status.fileUrl] = item;
     } else {
       item = this.items_[status.fileUrl];
     }
     item.progressValue = status.processed || 0;
     item.progressMax = status.total || 1;
     this.progressCenter_.updateItem(item);
-  }.bind(this), function() {
-    console.error('Cannot resolve the URL: ' + status.fileUrl);
-  });
+    callback();
+  }.bind(this));
 };
 
 /**
  * Removes the item involved with the given status.
  * @param {FileTransferStatus} status Transfer status.
  * @private
  */
 DriveSyncHandler.prototype.removeItem_ = function(status) {
-  var item = this.items_[status.fileUrl];
-  delete this.items_[status.fileUrl];
-  if (item) {
+  this.queue_.run(function(callback) {
+    var item = this.items_[status.fileUrl];
+    if (!item) {
+      callback();
+      return;
+    }
     item.state = status.transferState === 'completed' ?
         ProgressItemState.COMPLETED : ProgressItemState.CANCELED;
     this.progressCenter_.updateItem(item);
-  }
+    delete this.items_[status.fileUrl];
+    callback();
+  }.bind(this));
 };
 
 /**
  * Requests to cancel for the given files' drive sync.
  * @param {Entry} entry Entry to be canceled.
  * @private
  */
 DriveSyncHandler.prototype.requestCancel_ = function(entry) {
   chrome.fileBrowserPrivate.cancelFileTransfers([entry.toURL()], function() {});
 };
@@ skipping 19 matching lines @@
       case 'service_unavailable':
         item.message = str('SYNC_SERVICE_UNAVAILABLE_ERROR');
         break;
       case 'misc':
         item.message = strf('SYNC_MISC_ERROR', entry.name);
         break;
     }
     this.progressCenter_.updateItem(item);
   }.bind(this));
 };