xpcom/components/nsCategoryManager.h

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  37
  38
  39 #ifndef NSCATEGORYMANAGER_H
  40 #define NSCATEGORYMANAGER_H
  41
  42 #include "prio.h"
  43 #include "prlock.h"
  44 #include "plarena.h"
  45 #include "nsClassHashtable.h"
  46 #include "nsICategoryManager.h"
  47
  48 #define NS_CATEGORYMANAGER_CLASSNAME     "Category Manager"
  49
  50 /* 16d222a6-1dd2-11b2-b693-f38b02c021b2 */
  51 #define NS_CATEGORYMANAGER_CID \
  52 { 0x16d222a6, 0x1dd2, 0x11b2, \
  53   {0xb6, 0x93, 0xf3, 0x8b, 0x02, 0xc0, 0x21, 0xb2} }
  54
  55 /**
  56  * a "leaf-node", managed by the nsCategoryNode hashtable.
  57  *
  58  * we need to keep a "persistent value" (which will be written to the registry)
  59  * and a non-persistent value (for the current runtime): these are usually
  60  * the same, except when aPersist==PR_FALSE. The strings are permanently arena-
  61  * allocated, and will never go away.
  62  */
  63 class CategoryLeaf : public nsDepCharHashKey
  64 {
  65 public:
  66   CategoryLeaf(const char* aKey)
  67     : nsDepCharHashKey(aKey),
  68       pValue(nsnull),
  69       nonpValue(nsnull) { }
  70   const char* pValue;
  71   const char* nonpValue;
  72 };
  73
  74
  75 /**
  76  * CategoryNode keeps a hashtable of its entries.
  77  * the CategoryNode itself is permanently allocated in
  78  * the arena.
  79  */
  80 class CategoryNode
  81 {
  82 public:
  83   NS_METHOD GetLeaf(const char* aEntryName,
  84                     char** _retval);
  85
  86   NS_METHOD AddLeaf(const char* aEntryName,
  87                     const char* aValue,
  88                     PRBool aPersist,
  89                     PRBool aReplace,
  90                     char** _retval,
  91                     PLArenaPool* aArena);
  92
  93   NS_METHOD DeleteLeaf(const char* aEntryName,
  94                        PRBool aDontPersist);
  95
  96   void Clear() {
  97     PR_Lock(mLock);
  98     mTable.Clear();
  99     PR_Unlock(mLock);
 100   }
 101
 102   PRUint32 Count() {
 103     PR_Lock(mLock);
 104     PRUint32 tCount = mTable.Count();
 105     PR_Unlock(mLock);
 106     return tCount;
 107   }
 108
 109   NS_METHOD Enumerate(nsISimpleEnumerator** _retval);
 110
 111   PRBool WritePersistentEntries(PRFileDesc* fd, const char* aCategoryName);
 112
 113   // CategoryNode is arena-allocated, with the strings
 114   static CategoryNode* Create(PLArenaPool* aArena);
 115   ~CategoryNode();
 116   void operator delete(void*) { }
 117
 118 private:
 119   CategoryNode() { }
 120   void* operator new(size_t aSize, PLArenaPool* aArena);
 121
 122   nsTHashtable<CategoryLeaf> mTable;
 123   PRLock* mLock;
 124 };
 125
 126
 127 /**
 128  * The main implementation of nsICategoryManager.
 129  *
 130  * This implementation is thread-safe.
 131  */
 132 class nsCategoryManager
 133   : public nsICategoryManager
 134 {
 135 public:
 136   NS_DECL_ISUPPORTS
 137   NS_DECL_NSICATEGORYMANAGER
 138
 139   /**
 140    * Write the categories to the XPCOM persistent registry.
 141    * This is to be used by nsComponentManagerImpl (and NO ONE ELSE).
 142    */
 143   NS_METHOD WriteCategoryManagerToRegistry(PRFileDesc* fd);
 144
 145   /**
 146    * Suppress or unsuppress notifications of category changes to the
 147    * observer service. This is to be used by nsComponentManagerImpl
 148    * on startup while reading the stored category list.
 149    */
 150   NS_METHOD SuppressNotifications(PRBool aSuppress);
 151
 152   nsCategoryManager()
 153     : mSuppressNotifications(PR_FALSE) { }
 154 private:
 155   friend class nsCategoryManagerFactory;
 156   static nsCategoryManager* Create();
 157
 158   ~nsCategoryManager();
 159
 160   CategoryNode* get_category(const char* aName);
 161   void NotifyObservers(const char* aTopic,
 162                        const char* aCategoryName,
 163                        const char* aEntryName);
 164
 165   PLArenaPool mArena;
 166   nsClassHashtable<nsDepCharHashKey, CategoryNode> mTable;
 167   PRLock* mLock;
 168   PRBool mSuppressNotifications;
 169 };
 170
 171 #endif