Stop history search going on beyond the start of history....

chrome/browser/history/history_types.h

 // Copyright (c) 2006-2008 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_HISTORY_TYPES_H__
 #define CHROME_BROWSER_HISTORY_HISTORY_TYPES_H__
 
 #include <algorithm>
 #include <map>
 #include <set>
@@ skipping 359 matching lines @@
   // than we were allowed to return, this represents the first date considered
   // in the query (this will be before the first result if there was time
   // queried with no results).
   //
   // TODO(brettw): bug 1203054: This field is not currently set properly! Do
   // not use until the bug is fixed.
   base::Time first_time_searched() const { return first_time_searched_; }
   void set_first_time_searched(base::Time t) { first_time_searched_ = t; }
   // Note: If you need end_time_searched, it can be added.
 
+  void set_reached_beginning(bool reached) { reached_beginning_ = reached; }
+  bool reached_beginning() { return reached_beginning_; }
+
   size_t size() const { return results_.size(); }
 
   URLResult& operator[](size_t i) { return *results_[i]; }
   const URLResult& operator[](size_t i) const { return *results_[i]; }
 
   // Returns a pointer to the beginning of an array of all matching indices
   // for entries with the given URL. The array will be |*num_matches| long.
   // |num_matches| can be NULL if the caller is not interested in the number of
   // results (commonly it will only be interested in the first one and can test
   // the pointer for NULL).
@@ skipping 34 matching lines @@
   // Inserts an entry into the |url_to_results_| map saying that the given URL
   // is at the given index in the results_.
   void AddURLUsageAtIndex(const GURL& url, size_t index);
 
   // Adds |delta| to each index in url_to_results_ in the range [begin,end]
   // (this is inclusive). This is used when inserting or deleting.
   void AdjustResultMap(size_t begin, size_t end, ptrdiff_t delta);
 
   base::Time first_time_searched_;
 
+  // Whether the query reaches the beginning of the database.
+  bool reached_beginning_;
+
   // The ordered list of results. The pointers inside this are owned by this
   // QueryResults object.
   URLResultVector results_;
 
   // Maps URLs to entries in results_.
   URLToResultIndices url_to_results_;
 
   DISALLOW_EVIL_CONSTRUCTORS(QueryResults);
 };
 
@@ skipping 47 matching lines @@
   // The time of the visit.
   base::Time time;
 
   // The search term that was used.
   std::wstring term;
 };
 
 }  // history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_TYPES_H__