docshell/shistory/src/nsSHistory.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsSHistory_h
   8 #define nsSHistory_h
   9
  10 // Helper Classes
  11 #include "nsCOMPtr.h"
  12
  13 //Interfaces Needed
  14 #include "nsISHistory.h"
  15 #include "nsISHistoryInternal.h"
  16 #include "nsIWebNavigation.h"
  17 #include "nsISimpleEnumerator.h"
  18 #include "nsTObserverArray.h"
  19 #include "nsWeakPtr.h"
  20
  21 // Needed to maintain global list of all SHistory objects
  22 #include "prclist.h"
  23
  24 class nsIDocShell;
  25 class nsSHEnumerator;
  26 class nsSHistoryObserver;
  27 class nsISHEntry;
  28 class nsISHTransaction;
  29
  30 class nsSHistory: public PRCList,
  31                   public nsISHistory,
  32                   public nsISHistoryInternal,
  33                   public nsIWebNavigation
  34 {
  35 public:
  36   nsSHistory();
  37
  38   NS_DECL_ISUPPORTS
  39   NS_DECL_NSISHISTORY
  40   NS_DECL_NSISHISTORYINTERNAL
  41   NS_DECL_NSIWEBNAVIGATION
  42
  43   // One time initialization method called upon docshell module construction
  44   static nsresult Startup();
  45   static void Shutdown();
  46   static void UpdatePrefs();
  47
  48   // Max number of total cached content viewers.  If the pref
  49   // browser.sessionhistory.max_total_viewers is negative, then
  50   // this value is calculated based on the total amount of memory.
  51   // Otherwise, it comes straight from the pref.
  52   static uint32_t GetMaxTotalViewers() { return sHistoryMaxTotalViewers; }
  53
  54 protected:
  55   virtual ~nsSHistory();
  56   friend class nsSHEnumerator;
  57   friend class nsSHistoryObserver;
  58
  59    // Could become part of nsIWebNavigation
  60    NS_IMETHOD GetTransactionAtIndex(int32_t aIndex, nsISHTransaction ** aResult);
  61    nsresult CompareFrames(nsISHEntry * prevEntry, nsISHEntry * nextEntry, nsIDocShell * rootDocShell, long aLoadType, bool * aIsFrameFound);
  62    nsresult InitiateLoad(nsISHEntry * aFrameEntry, nsIDocShell * aFrameDS, long aLoadType);
  63
  64    NS_IMETHOD LoadEntry(int32_t aIndex, long aLoadType, uint32_t histCmd);
  65
  66 #ifdef DEBUG
  67    nsresult PrintHistory();
  68 #endif
  69
  70   // Evict content viewers in this window which don't lie in the "safe" range
  71   // around aIndex.
  72   void EvictOutOfRangeWindowContentViewers(int32_t aIndex);
  73   static void GloballyEvictContentViewers();
  74   static void GloballyEvictAllContentViewers();
  75
  76   // Calculates a max number of total
  77   // content viewers to cache, based on amount of total memory
  78   static uint32_t CalcMaxTotalViewers();
  79
  80   void RemoveDynEntries(int32_t aOldIndex, int32_t aNewIndex);
  81
  82   nsresult LoadNextPossibleEntry(int32_t aNewIndex, long aLoadType, uint32_t aHistCmd);
  83 protected:
  84   // aIndex is the index of the transaction which may be removed.
  85   // If aKeepNext is true, aIndex is compared to aIndex + 1,
  86   // otherwise comparison is done to aIndex - 1.
  87   bool RemoveDuplicate(int32_t aIndex, bool aKeepNext);
  88
  89   nsCOMPtr<nsISHTransaction> mListRoot;
  90   int32_t mIndex;
  91   int32_t mLength;
  92   int32_t mRequestedIndex;
  93   // Session History listeners
  94   nsAutoTObserverArray<nsWeakPtr, 2> mListeners;
  95   // Weak reference. Do not refcount this.
  96   nsIDocShell *  mRootDocShell;
  97
  98   // Max viewers allowed total, across all SHistory objects
  99   static int32_t  sHistoryMaxTotalViewers;
 100 };
 101 //*****************************************************************************
 102 //***    nsSHEnumerator: Object Management
 103 //*****************************************************************************
 104 class nsSHEnumerator : public nsISimpleEnumerator
 105 {
 106 public:
 107
 108   NS_DECL_ISUPPORTS
 109   NS_DECL_NSISIMPLEENUMERATOR
 110
 111   nsSHEnumerator(nsSHistory *  aHistory);
 112
 113 protected:
 114   friend class nsSHistory;
 115   virtual ~nsSHEnumerator();
 116 private:
 117   int32_t     mIndex;
 118   nsSHistory *  mSHistory;
 119 };
 120
 121 #endif   /* nsSHistory */