Tiny optimization in auto completion of Drive files.

chrome/browser/chromeos/drive/search_metadata.cc

 // Copyright (c) 2013 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.
 
 #include "chrome/browser/chromeos/drive/search_metadata.h"
 
 #include <algorithm>
 #include <queue>
 
 #include "base/bind.h"
@@ skipping 110 matching lines @@
     ResourceMetadata* resource_metadata,
     FileCache* cache,
     const std::string& query,
     int options,
     size_t at_most_num_matches,
     ScopedPriorityQueue<MetadataSearchResult,
                         MetadataSearchResultComparator>* result_candidates,
     const ResourceEntry& entry) {
   DCHECK_GE(at_most_num_matches, result_candidates->size());
 
+  // If the candidate set is already full, and this |entry| is old, do nothing.
+  // We perform this check first in order to avoid the costly find-and-highlight
+  // or FilePath lookup as much as possible.
+  if (result_candidates->size() == at_most_num_matches &&
+      !CompareByTimestamp(entry, result_candidates->top()->entry))
+    return;
+
   // Add |entry| to the result if the entry is eligible for the given
   // |options| and matches the query. The base name of the entry must
   // contain |query| to match the query.
   std::string highlighted;
   if (!IsEligibleEntry(entry, cache, options) ||
       !FindAndHighlight(entry.base_name(), query, &highlighted))
     return;
 
   base::FilePath path = resource_metadata->GetFilePath(entry.resource_id());
   if (path.empty())
     return;
 
   // Make space for |entry| when appropriate.
-  if (result_candidates->size() == at_most_num_matches &&
-      CompareByTimestamp(entry, result_candidates->top()->entry))
+  if (result_candidates->size() == at_most_num_matches)
     result_candidates->pop();
-
-  // Add |entry| to the result when appropriate.
-  if (result_candidates->size() < at_most_num_matches)
-    result_candidates->push(new MetadataSearchResult(path, entry, highlighted));
+  result_candidates->push(new MetadataSearchResult(path, entry, highlighted));
 }
 
 // Implements SearchMetadata().
 scoped_ptr<MetadataSearchResultVector> SearchMetadataOnBlockingPool(
     ResourceMetadata* resource_metadata,
     FileCache* cache,
     const std::string& query,
     int options,
     int at_most_num_matches) {
   ScopedPriorityQueue<MetadataSearchResult,
@@ skipping 70 matching lines @@
   highlighted_text->append(net::EscapeForHTML(UTF16ToUTF8(pre)));
   highlighted_text->append("<b>");
   highlighted_text->append(net::EscapeForHTML(UTF16ToUTF8(match)));
   highlighted_text->append("</b>");
   highlighted_text->append(net::EscapeForHTML(UTF16ToUTF8(post)));
   return true;
 }
 
 }  // namespace internal
 }  // namespace drive