1// Copyright (c) 2010 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef CHROME_BROWSER_HISTORY_VISIT_TRACKER_H__ 6#define CHROME_BROWSER_HISTORY_VISIT_TRACKER_H__ 7 8#include <map> 9#include <vector> 10 11#include "base/basictypes.h" 12#include "components/history/core/browser/history_types.h" 13 14namespace history { 15 16// Tracks history transitions between pages. The history backend uses this to 17// link up page transitions to form a chain of page visits, and to set the 18// transition type properly. 19// 20// This class is not thread safe. 21class VisitTracker { 22 public: 23 VisitTracker(); 24 ~VisitTracker(); 25 26 // Notifications ------------------------------------------------------------- 27 28 void AddVisit(ContextID context_id, 29 int32 page_id, 30 const GURL& url, 31 VisitID visit_id); 32 33 // When a RenderProcessHost is destroyed, we want to clear out our saved 34 // transitions/visit IDs for it. 35 void ClearCachedDataForContextID(ContextID context_id); 36 37 // Querying ------------------------------------------------------------------ 38 39 // Returns the visit ID for the transition given information about the visit 40 // supplied by the renderer. We will return 0 if there is no appropriate 41 // referring visit. 42 VisitID GetLastVisit(ContextID context_id, int32 page_id, const GURL& url); 43 44 private: 45 struct Transition { 46 GURL url; // URL that the event happened to. 47 int32 page_id; // ID generated by the render process host. 48 VisitID visit_id; // Visit ID generated by history. 49 }; 50 typedef std::vector<Transition> TransitionList; 51 typedef std::map<ContextID, TransitionList*> ContextList; 52 53 // Expires oldish items in the given transition list. This keeps the list 54 // size small by removing items that are unlikely to be needed, which is 55 // important for GetReferrer which does brute-force searches of this list. 56 void CleanupTransitionList(TransitionList* transitions); 57 58 // Maps render view hosts to lists of recent transitions. 59 ContextList contexts_; 60 61 DISALLOW_COPY_AND_ASSIGN(VisitTracker); 62}; 63 64} // namespace history 65 66#endif // CHROME_BROWSER_HISTORY_VISIT_TRACKER_H__ 67