[Files.app] Cache urls of entries before sorting.

toURL() consumes about a half time of filelist draw. In sort, toURL is called by the compare function, which is called many times in sort.

The great solution is making toURL faster, but as for now, we cache urls and use it in sort, instead of calling toURL in each call.

BUG=367123
TEST=manually.
R=hirono@chromium.org

Review URL: https://codereview.chromium.org/270573004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269009 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 8 insertions, 1 deletions

diff --git a/ui/file_manager/file_manager/foreground/js/directory_contents.js b/ui/file_manager/file_manager/foreground/js/directory_contents.js
index 6223883..37125ba 100644
--- a/ui/file_manager/file_manager/foreground/js/directory_contents.js
+++ b/ui/file_manager/file_manager/foreground/js/directory_contents.js
@@ -638,6 +638,11 @@ DirectoryContents.prototype.onNewEntries_ = function(entries) {
   var entriesFiltered = [].filter.call(
       entries, this.context_.fileFilter.filter.bind(this.context_.fileFilter));
 
+  // Caching URL to reduce a number of calls of toURL in sort.
+  // This is a temporary solution. We need to fix a root cause of slow toURL.
+  // See crbug.com/370908 for detail.
+  entriesFiltered.forEach(function(entry) { entry.cachedUrl = entry.toURL(); });
+
   // Update the filelist without waiting the metadata.
   this.fileList_.push.apply(this.fileList_, entriesFiltered);
   cr.dispatchSimpleEvent(this, 'scan-updated');
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js b/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
index c572578..33082e8 100644
--- a/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
+++ b/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
@@ -325,7 +325,9 @@ MetadataCache.prototype.getOne = function(entry, type, callback) {
  * @return {Object} The metadata or null.
  */
 MetadataCache.prototype.getCached = function(entry, type) {
-  var entryURL = entry.toURL();
+  // Entry.cachedUrl may be set in DirectoryContents.onNewEntries_().
+  // See the comment there for detail.
+  var entryURL = entry.cachedUrl || entry.toURL();
   var cache = this.cache_[entryURL];
   return cache ? (cache.properties[type] || null) : null;
 };