docshell/shistory/src/nsSHistory.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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  16  * The Original Code is the Mozilla browser.
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  20  * Portions created by the Initial Developer are Copyright (C) 1999
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  23  * Contributor(s):
  24  *   Radha Kulkarni <radha@netscape.com>
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  39
  40 #ifndef nsSHistory_h
  41 #define nsSHistory_h
  42
  43 // Helper Classes
  44 #include "nsCOMPtr.h"
  45
  46 //Interfaces Needed
  47 #include "nsISHistory.h"
  48 #include "nsISHistoryInternal.h"
  49 #include "nsISHTransaction.h"
  50 #include "nsIWebNavigation.h"
  51 #include "nsIWeakReference.h"
  52 #include "nsISimpleEnumerator.h"
  53 #include "nsISHistoryListener.h"
  54 #include "nsIHistoryEntry.h"
  55 #include "nsIObserver.h"
  56 #include "nsIPrefBranch2.h"
  57
  58 // Needed to maintain global list of all SHistory objects
  59 #include "prclist.h"
  60
  61 class nsIDocShell;
  62 class nsSHEnumerator;
  63 class nsSHistoryObserver;
  64 class nsSHistory: public PRCList,
  65                   public nsISHistory_2_0_BRANCH,
  66                   public nsISHistoryInternal,
  67                   public nsIWebNavigation
  68 {
  69 public:
  70   nsSHistory();
  71
  72   NS_DECL_ISUPPORTS
  73   NS_DECL_NSISHISTORY
  74   NS_DECL_NSISHISTORYINTERNAL
  75   NS_DECL_NSIWEBNAVIGATION
  76   NS_DECL_NSISHISTORY_2_0_BRANCH
  77
  78   // One time initialization method called upon docshell module construction
  79   static nsresult Startup();
  80   static void UpdatePrefs(nsIPrefBranch *aPrefBranch);
  81
  82   // Max number of total cached content viewers.  If the pref
  83   // browser.sessionhistory.max_total_viewers is negative, then
  84   // this value is calculated based on the total amount of memory.
  85   // Otherwise, it comes straight from the pref.
  86   static PRUint32 GetMaxTotalViewers() { return sHistoryMaxTotalViewers; }
  87
  88 protected:
  89   virtual ~nsSHistory();
  90   friend class nsSHEnumerator;
  91   friend class nsSHistoryObserver;
  92
  93    // Could become part of nsIWebNavigation
  94    NS_IMETHOD GetEntryAtIndex(PRInt32 aIndex, PRBool aModifyIndex, nsISHEntry** aResult);
  95    NS_IMETHOD GetTransactionAtIndex(PRInt32 aIndex, nsISHTransaction ** aResult);
  96    nsresult CompareFrames(nsISHEntry * prevEntry, nsISHEntry * nextEntry, nsIDocShell * rootDocShell, long aLoadType, PRBool * aIsFrameFound);
  97    nsresult InitiateLoad(nsISHEntry * aFrameEntry, nsIDocShell * aFrameDS, long aLoadType);
  98
  99    NS_IMETHOD LoadEntry(PRInt32 aIndex, long aLoadType, PRUint32 histCmd);
 100
 101 #ifdef DEBUG
 102    nsresult PrintHistory();
 103 #endif
 104
 105   // Evict the viewers at indices between aStartIndex and aEndIndex,
 106   // including aStartIndex but not aEndIndex.
 107   void EvictContentViewersInRange(PRInt32 aStartIndex, PRInt32 aEndIndex);
 108   void EvictWindowContentViewers(PRInt32 aFromIndex, PRInt32 aToIndex);
 109   static void EvictGlobalContentViewer();
 110   static void EvictAllContentViewersGlobally();
 111
 112   // Calculates a max number of total
 113   // content viewers to cache, based on amount of total memory
 114   static PRUint32 CalcMaxTotalViewers();
 115
 116   void RemoveDynEntries(PRInt32 aOldIndex, PRInt32 aNewIndex);
 117
 118   nsresult LoadNextPossibleEntry(PRInt32 aNewIndex, long aLoadType, PRUint32 aHistCmd);
 119 protected:
 120   // aIndex is the index of the transaction which may be removed.
 121   // If aKeepNext is PR_TRUE, aIndex is compared to aIndex + 1,
 122   // otherwise comparison is done to aIndex - 1.
 123   PRBool RemoveDuplicate(PRInt32 aIndex, PRBool aKeepNext);
 124
 125   nsCOMPtr<nsISHTransaction> mListRoot;
 126   PRInt32 mIndex;
 127   PRInt32 mLength;
 128   PRInt32 mRequestedIndex;
 129   // Session History listener
 130   nsWeakPtr mListener;
 131   // Weak reference. Do not refcount this.
 132   nsIDocShell *  mRootDocShell;
 133
 134   // Max viewers allowed total, across all SHistory objects
 135   static PRInt32  sHistoryMaxTotalViewers;
 136 };
 137 //*****************************************************************************
 138 //***    nsSHEnumerator: Object Management
 139 //*****************************************************************************
 140 class nsSHEnumerator : public nsISimpleEnumerator
 141 {
 142 public:
 143
 144   NS_DECL_ISUPPORTS
 145   NS_DECL_NSISIMPLEENUMERATOR
 146
 147   nsSHEnumerator(nsSHistory *  aHistory);
 148
 149 protected:
 150   friend class nsSHistory;
 151   virtual ~nsSHEnumerator();
 152 private:
 153   PRInt32     mIndex;
 154   nsSHistory *  mSHistory;
 155 };
 156
 157 #endif   /* nsSHistory */