Tweaks for improving file manager performance

chrome/browser/resources/file_manager/js/file_manager.js

 // Copyright (c) 2012 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.
 
 // Setting the src of an img to an empty string can crash the browser, so we
 // use an empty 1x1 gif instead.
 const EMPTY_IMAGE_URI = 'data:image/gif;base64,'
         + 'R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw%3D%3D';
 
 /**
@@ skipping 464 matching lines @@
       };
     }
 
     // Optional list of file types.
     this.fileTypes_ = this.params_.typeList;
 
     this.showCheckboxes_ =
         (this.dialogType_ == FileManager.DialogType.FULL_PAGE ||
          this.dialogType_ == FileManager.DialogType.SELECT_OPEN_MULTI_FILE);
 
-    this.table_.list.startBatchUpdates();
+    this.table_.startBatchUpdates();
     this.grid_.startBatchUpdates();
 
     this.initFileList_();
     this.initDialogs_();
 
     this.copyManager_ = new FileCopyManager();
     this.copyManager_.addEventListener('copy-progress',
                                        this.onCopyProgress_.bind(this));
 
     window.addEventListener('popstate', this.onPopState_.bind(this));
@@ skipping 47 matching lines @@
       sortDirection =
           window.localStorage['sort-direction-' + this.dialogType_] ||
           sortDirection;
     }
     this.directoryModel_.fileList.sort(sortField, sortDirection);
 
     this.refocus();
 
     this.createMetadataProvider_();
 
-    this.table_.list.endBatchUpdates();
+    this.table_.endBatchUpdates();
     this.grid_.endBatchUpdates();
 
     metrics.recordInterval('Load.DOM');
     metrics.recordInterval('Load.Total');
   };
 
   /**
    * One-time initialization of commands.
    */
   FileManager.prototype.initCommands_ = function() {
@@ skipping 190 matching lines @@
 
     var self = this;
     this.rootsList_.itemConstructor = function(entry) {
       return self.renderRoot_(entry);
     };
 
     this.rootsList_.selectionModel = this.directoryModel_.rootsListSelection;
 
     // TODO(dgozman): add "Add a drive" item.
     this.rootsList_.dataModel = this.directoryModel_.rootsList;
-    this.directoryModel_.updateRoots();
+    this.directoryModel_.updateRoots(function() {
+      self.rootsList_.endBatchUpdates();
+    });
   };
 
   FileManager.prototype.initGData_ = function() {
     metrics.startInterval('Load.GData');
     // TODO(zelidrag): We should do this first time user selects this provider.
     chrome.fileBrowserPrivate.addMount('', 'gdata', {});
   };
 
   /**
    * Get the icon type for a given Entry.
@@ skipping 618 matching lines @@
 
   /**
    * Restores current directory and may be a selected item after page load (or
    * reload) or popping a state (after click on back/forward). If location.hash
    * is present it means that the user has navigated somewhere and that place
    * will be restored. defaultPath primarily is used with save/open dialogs.
    * Default path may also contain a file name. Freshly opened file manager
    * window has neither.
    */
   FileManager.prototype.setupCurrentDirectory_ = function() {
+    // Avoid a bunch of intermediate list redraws while the data model is
+    // cleared and updated.  Note that it may (or may not) be desirable to draw
+    // partial results as we get them, but today the DirectoryReader API
+    // generally returns all entries in one chunk so even without this batching
+    // we wouldn't have incremental updates.
+    this.table_.startBatchUpdates();
+    var onLoaded = this.table_.endBatchUpdates.bind(this.table_);
+
     if (location.hash) {
       // Location hash has the highest priority.
       var path = decodeURI(location.hash.substr(1));
 
       // In the FULL_PAGE mode if the path points to a file we should invoke
       // the default action after selecting it.
       if (this.dialogType_ == FileManager.DialogType.FULL_PAGE) {
         // To prevent the file list flickering for a moment before the action
         // is executed we hide it under a white div.
         var shade = this.document_.createElement('div');
         shade.className = 'overlay-pane';
         shade.style.backgroundColor = 'white';
         this.document_.body.appendChild(shade);
         function removeShade() { shade.parentNode.removeChild(shade) }
 
+        // Keep track of whether the path is identified as an existing leaf
+        // node.  Note that onResolve is guaranteed to be called (exactly once)
+        // before onLoadedActivateLeaf.
+        var foundLeaf = true;

[Rick Byers, 2012/03/02 00:19:46]

Here's where I handled the special 'onFileSelected' case with a combination of
the two callbacks.  

         function onResolve(baseName, leafName, exists) {
           if (!exists || leafName == '') {
             // Non-existent file or a directory. Remove the shade immediately.
             removeShade();
+            foundLeaf = false;
           }
         }
 
         // TODO(kaznacheev): refactor dispatchDefaultTask to accept an array
         // of urls instead of a selection. This will remove the need to wait
         // until the selection is done.
         var self = this;
-        function onFileSelected() {
-          self.dispatchDefaultTask_();
-          setTimeout(removeShade, 1000);
+        function onLoadedActivateLeaf() {
+          onLoaded();
+          if (foundLeaf) {
+            self.dispatchDefaultTask_();
+            setTimeout(removeShade, 1000);
+          }
         }
-        this.directoryModel_.setupPath(path, onResolve, onFileSelected);
+        this.directoryModel_.setupPath(path, onLoadedActivateLeaf, onResolve);
+
         return;
       }
 
-      this.directoryModel_.setupPath(path);
+      this.directoryModel_.setupPath(path, onLoaded);
       return;
     }
 
     if (this.params_.defaultPath) {
       var path = this.params_.defaultPath;
       if (this.dialogType_ == FileManager.DialogType.SELECT_SAVEAS_FILE) {
-        this.directoryModel_.setupPath(path, function(basePath, leafName) {
-          this.filenameInput_.value = leafName;
-          this.selectDefaultPathInFilenameInput_();
-        }.bind(this));
+        this.directoryModel_.setupPath(path, onLoaded,
+            function(basePath, leafName) {
+              this.filenameInput_.value = leafName;
+              this.selectDefaultPathInFilenameInput_();
+            }.bind(this));
         return;
       }
 
-      this.directoryModel_.setupPath(path);
+      this.directoryModel_.setupPath(path, onLoaded);
       return;
     }
 
-    this.directoryModel_.setupDefaultPath();
+    this.directoryModel_.setupDefaultPath(onLoaded);
   };
 
   /**
    * Tweak the UI to become a particular kind of dialog, as determined by the
    * dialog type parameter passed to the constructor.
    */
   FileManager.prototype.initDialogType_ = function() {
     var defaultTitle;
     var okLabel = str('OPEN_LABEL');
 
@@ skipping 928 matching lines @@
           });
           return;
         }
         // Current durectory just unmounted. Move to the 'Downloads'.
         changeDirectoryTo = '/' + DirectoryModel.DOWNLOADS_DIRECTORY;
       }
 
       // Even if something failed root list should be rescanned.
       // Failed mounts can "give" us new devices which might be formatted,
       // so we have to refresh root list then.
-      self.directoryModel_.updateRoots(changeDirectoryTo);
+      self.directoryModel_.updateRoots(function() {
+        if (changeDirectoryTo) {
+          self.directoryModel_.changeDirectory(changeDirectoryTo);
+        }
+      });
     });
   };
 
   /**
    * Event handler called when some internal task should be executed.
    */
   FileManager.prototype.onFileTaskExecute_ = function(id, details) {
     var urls = details.urls;
     if (id == 'play') {
       var position = 0;
@@ skipping 1522 matching lines @@
           });
       }, onError);
 
       function onError(err) {
         console.log('Error while checking free space: ' + err);
         setTimeout(doCheck, 1000 * 60);
       }
     }
   }
 })();