Gather word-start Information to Aid in Scoring.

chrome/browser/history/url_index_private_data.h

Index: chrome/browser/history/url_index_private_data.h
===================================================================
--- chrome/browser/history/url_index_private_data.h	(revision 125621)
+++ chrome/browser/history/url_index_private_data.h	(working copy)
@@ -23,6 +23,9 @@
 
 class HistoryDatabase;
 
+// Current version of the cache file.
+static const int kCurrentCacheFileVersion = 1;
+
 // A structure describing the InMemoryURLIndex's internal data and providing for
 // restoring, rebuilding and updating that internal data.
 class URLIndexPrivateData {
@@ -177,8 +180,9 @@
   // was actually updated.
   bool DeleteURL(const GURL& url);
 
-  // Parses and indexes the words in the URL and page title of |row|.
-  void AddRowWordsToIndex(const URLRow& row);
+  // Parses and indexes the words in the URL and page title of |row| and
+  // calculate the word starts in each, saving the starts in |word_starts|.
+  void AddRowWordsToIndex(const URLRow& row, RowWordStarts* word_starts);
 
   // Removes |row| and all associated words and characters from the index.
   void RemoveRowFromIndex(const URLRow& row);
@@ -222,7 +226,8 @@
   static ScoredHistoryMatch ScoredMatchForURL(
       const URLRow& row,
       const string16& lower_string,
-      const String16Vector& terms_vector);
+      const String16Vector& terms_vector,
+      const RowWordStarts& word_starts);
 
   // Calculates a component score based on position, ordering and total
   // substring match size using metrics recorded in |matches|. |max_length|
@@ -233,6 +238,10 @@
   // Determines if |gurl| has a whitelisted scheme and returns true if so.
   bool URLSchemeIsWhitelisted(const GURL& gurl) const;
 
+  // Sets the version of the cache file that will be saved when calling
+  // SavePrivateData(). For unit testing only.
+  void set_saved_cache_version(int version) { saved_cache_version_ = version; }
+
   // Encode a data structure into the protobuf |cache|.
   void SavePrivateData(imui::InMemoryURLIndexCacheItem* cache) const;
   void SaveWordList(imui::InMemoryURLIndexCacheItem* cache) const;
@@ -240,6 +249,7 @@
   void SaveCharWordMap(imui::InMemoryURLIndexCacheItem* cache) const;
   void SaveWordIDHistoryMap(imui::InMemoryURLIndexCacheItem* cache) const;
   void SaveHistoryInfoMap(imui::InMemoryURLIndexCacheItem* cache) const;
+  void SaveWordStartsMap(imui::InMemoryURLIndexCacheItem* cache) const;
 
   // Decode a data structure from the protobuf |cache|. Return false if there
   // is any kind of failure.
@@ -249,6 +259,7 @@
   bool RestoreCharWordMap(const imui::InMemoryURLIndexCacheItem& cache);
   bool RestoreWordIDHistoryMap(const imui::InMemoryURLIndexCacheItem& cache);
   bool RestoreHistoryInfoMap(const imui::InMemoryURLIndexCacheItem& cache);
+  bool RestoreWordStartsMap(const imui::InMemoryURLIndexCacheItem& cache);
 
   // Cache of search terms.
   SearchTermCacheMap search_term_cache_;
@@ -261,6 +272,11 @@
 
   // 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_;
+
   // 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.
@@ -297,8 +313,17 @@
   // index inclusion and relevance scoring.
   HistoryInfoMap history_info_map_;
 
+  // A one-to-one mapping from HistoryID to the word starts detected in each
+  // item's URL and page title.
+  WordStartsMap word_starts_map_;
+
   // End of data members that are cached ---------------------------------------
 
+  // For unit testing only. Specifies the version of the cache file to be saved.
+  // Used only for testing upgrading of an older version of the cache upon
+  // restore.
+  int saved_cache_version_;
+
   // 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.