Omnibox: Rebuild HQP Cache if it's old

chrome/browser/history/url_index_private_data.h

 // 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.
 
 #ifndef CHROME_BROWSER_HISTORY_URL_INDEX_PRIVATE_DATA_H_
 #define CHROME_BROWSER_HISTORY_URL_INDEX_PRIVATE_DATA_H_
 
 #include <set>
 #include <string>
 
@@ skipping 16 matching lines @@
 
 namespace history {
 
 namespace imui = in_memory_url_index;
 
 class HistoryDatabase;
 class InMemoryURLIndex;
 class RefCountedBool;
 
 // Current version of the cache file.
-static const int kCurrentCacheFileVersion = 2;
+static const int kCurrentCacheFileVersion = 3;
 
 // A structure private to InMemoryURLIndex describing its internal data and
 // providing for restoring, rebuilding and updating that internal data. As
 // this class is for exclusive use by the InMemoryURLIndex class there should
 // be no calls from any other class.
 //
 // All public member functions are called on the main thread unless otherwise
 // annotated.
 class URLIndexPrivateData
     : public base::RefCountedThreadSafe<URLIndexPrivateData> {
@@ skipping 98 matching lines @@
  private:
   friend class base::RefCountedThreadSafe<URLIndexPrivateData>;
   ~URLIndexPrivateData();
 
   friend class AddHistoryMatch;
   friend class ::HistoryQuickProviderTest;
   friend class InMemoryURLIndexTest;
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, CacheSaveRestore);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, HugeResultSet);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, ReadVisitsFromHistory);
+  FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, RebuildFromHistoryIfCacheOld);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, Scoring);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, TitleSearch);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, TypedCharacterCaching);
   FRIEND_TEST_ALL_PREFIXES(InMemoryURLIndexTest, WhitelistedURLs);
   FRIEND_TEST_ALL_PREFIXES(LimitedInMemoryURLIndexTest, Initialization);
 
   // Support caching of term results so that we can optimize searches which
   // build upon a previous search. Each entry in this map represents one
   // search term from the most recent search. For example, if the user had
   // typed "google blog trans" and then typed an additional 'l' (at the end,
@@ skipping 162 matching lines @@
   // Allows canceling pending requests to update recent visits information.
   CancelableRequestConsumer recent_visits_consumer_;
 
   // Start of data members that are cached -------------------------------------
 
   // The version of the cache file most recently used to restore this instance
   // of the private data. If the private data was rebuilt from the history
   // database this will be 0.
   int restored_cache_version_;
 
+  // The last time the data was rebuilt from the history database.  If this
+  // instance was built from history right now, this time will be about Now().

[Peter Kasting, 2013/06/07 00:39:55]

This last sentence seems unnecessary.

[Mark P, 2013/06/07 00:50:27]

Okay.  Dropped.

+  base::Time last_time_rebuilt_from_history_;
+
   // A list of all of indexed words. The index of a word in this list is the
   // ID of the word in the word_map_. It reduces the memory overhead by
   // replacing a potentially long and repeated string with a simple index.
   String16Vector word_list_;
 
   // A list of available words slots in |word_list_|. An available word slot
   // is the index of a unused word in word_list_ vector, also referred to as
   // a WordID. As URL visits are added or modified new words may be added to
   // the index, in which case any available words are used, if any, and then
   // words are added to the end of the word_list_. When URL visits are
@@ skipping 37 matching lines @@
   // Used for unit testing only. Records the number of candidate history items
   // at three stages in the index searching process.
   size_t pre_filter_item_count_;    // After word index is queried.
   size_t post_filter_item_count_;   // After trimming large result set.
   size_t post_scoring_item_count_;  // After performing final filter/scoring.
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_URL_INDEX_PRIVATE_DATA_H_