content/base/src/nsPropertyTable.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim:cindent:ts=2:et:sw=2:
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * This Original Code has been modified by IBM Corporation. Modifications made by IBM
   9  * described herein are Copyright (c) International Business Machines Corporation, 2000.
  10  * Modifications to Mozilla code or documentation identified per MPL Section 3.3
  11  *
  12  * Date             Modified by     Description of modification
  13  * 04/20/2000       IBM Corp.      OS/2 VisualAge build.
  14  */
  15
  16 /**
  17  * nsPropertyTable allows a set of arbitrary key/value pairs to be stored
  18  * for any number of nodes, in a global hashtable rather than on the nodes
  19  * themselves.  Nodes can be any type of object; the hashtable keys are
  20  * nsIAtom pointers, and the values are void pointers.
  21  */
  22
  23 #ifndef nsPropertyTable_h_
  24 #define nsPropertyTable_h_
  25
  26 #include "mozilla/MemoryReporting.h"
  27 #include "nscore.h"
  28
  29 class nsIAtom;
  30
  31 typedef void
  32 (*NSPropertyFunc)(void           *aObject,
  33                   nsIAtom        *aPropertyName,
  34                   void           *aPropertyValue,
  35                   void           *aData);
  36
  37 /**
  38  * Callback type for property destructors.  |aObject| is the object
  39  * the property is being removed for, |aPropertyName| is the property
  40  * being removed, |aPropertyValue| is the value of the property, and |aData|
  41  * is the opaque destructor data that was passed to SetProperty().
  42  **/
  43 typedef NSPropertyFunc NSPropertyDtorFunc;
  44 class nsINode;
  45 class nsIFrame;
  46
  47 class nsPropertyOwner
  48 {
  49 public:
  50   nsPropertyOwner(const nsPropertyOwner& aOther) : mObject(aOther.mObject) {}
  51
  52   // These are the types of objects that can own properties. No object should
  53   // inherit more then one of these classes.
  54   // To add support for more types just add to this list.
  55   nsPropertyOwner(const nsINode* aObject) : mObject(aObject) {}
  56   nsPropertyOwner(const nsIFrame* aObject) : mObject(aObject) {}
  57
  58   operator const void*() { return mObject; }
  59   const void* get() { return mObject; }
  60
  61 private:
  62   const void* mObject;
  63 };
  64
  65 class nsPropertyTable
  66 {
  67  public:
  68   /**
  69    * Get the value of the property |aPropertyName| for node |aObject|.
  70    * |aResult|, if supplied, is filled in with a return status code.
  71    **/
  72   void* GetProperty(nsPropertyOwner aObject,
  73                     nsIAtom    *aPropertyName,
  74                     nsresult   *aResult = nullptr)
  75   {
  76     return GetPropertyInternal(aObject, aPropertyName, false, aResult);
  77   }
  78
  79   /**
  80    * Set the value of the property |aPropertyName| to
  81    * |aPropertyValue| for node |aObject|.  |aDtor| is a destructor for the
  82    * property value to be called if the property is removed.  It can be null
  83    * if no destructor is required.  |aDtorData| is an optional pointer to an
  84    * opaque context to be passed to the property destructor.  Note that the
  85    * destructor is global for each property name regardless of node; it is an
  86    * error to set a given property with a different destructor than was used
  87    * before (this will return NS_ERROR_INVALID_ARG). If aOldValue is non-null
  88    * it will contain the old value after the function returns (the destructor
  89    * for the old value will not be run in that case). If |aTransfer| is true
  90    * the property will be transfered to the new table when the property table
  91    * for |aObject| changes (currently the tables for nodes are owned by their
  92    * ownerDocument, so if the ownerDocument for a node changes, its property
  93    * table changes too). If |aTransfer| is false the property will just be
  94    * deleted instead.
  95    */
  96   NS_HIDDEN_(nsresult) SetProperty(nsPropertyOwner     aObject,
  97                                    nsIAtom            *aPropertyName,
  98                                    void               *aPropertyValue,
  99                                    NSPropertyDtorFunc  aDtor,
 100                                    void               *aDtorData,
 101                                    bool                aTransfer = false,
 102                                    void              **aOldValue = nullptr)
 103   {
 104     return SetPropertyInternal(aObject, aPropertyName, aPropertyValue,
 105                                aDtor, aDtorData, aTransfer, aOldValue);
 106   }
 107
 108   /**
 109    * Delete the property |aPropertyName| in the global category for object
 110    * |aObject|. The property's destructor function will be called.
 111    */
 112   NS_HIDDEN_(nsresult) DeleteProperty(nsPropertyOwner aObject,
 113                                       nsIAtom    *aPropertyName);
 114
 115   /**
 116    * Unset the property |aPropertyName| in the global category for object
 117    * |aObject|, but do not call the property's destructor function.  The
 118    * property value is returned.
 119    */
 120   void* UnsetProperty(nsPropertyOwner aObject,
 121                       nsIAtom    *aPropertyName,
 122                       nsresult   *aStatus = nullptr)
 123   {
 124     return GetPropertyInternal(aObject, aPropertyName, true, aStatus);
 125   }
 126
 127   /**
 128    * Deletes all of the properties for object |aObject|, calling the
 129    * destructor function for each property.
 130    */
 131   NS_HIDDEN_(void) DeleteAllPropertiesFor(nsPropertyOwner aObject);
 132
 133   /**
 134    * Transfers all properties for object |aObject| that were set with the
 135    * |aTransfer| argument as true to |aTable|. Deletes the other properties
 136    * for object |aObject|, calling the destructor function for each property.
 137    * If transfering a property fails, this deletes all the properties for
 138    * object |aObject|.
 139    */
 140   NS_HIDDEN_(nsresult)
 141     TransferOrDeleteAllPropertiesFor(nsPropertyOwner aObject,
 142                                      nsPropertyTable *aOtherTable);
 143
 144   /**
 145    * Enumerate the properties for object |aObject|.
 146    * For every property |aCallback| will be called with as arguments |aObject|,
 147    * the property name, the property value and |aData|.
 148    */
 149   NS_HIDDEN_(void) Enumerate(nsPropertyOwner aObject,
 150                              NSPropertyFunc aCallback, void *aData);
 151
 152   /**
 153    * Enumerate all the properties.
 154    * For every property |aCallback| will be called with arguments the owner,
 155    * the property name, the property value and |aData|.
 156    */
 157   NS_HIDDEN_(void) EnumerateAll(NSPropertyFunc aCallback, void *aData);
 158
 159   /**
 160    * Deletes all of the properties for all objects in the property
 161    * table, calling the destructor function for each property.
 162    */
 163   NS_HIDDEN_(void) DeleteAllProperties();
 164
 165   nsPropertyTable() : mPropertyList(nullptr) {}
 166   ~nsPropertyTable() {
 167     DeleteAllProperties();
 168   }
 169
 170   /**
 171    * Function useable as destructor function for property data that is
 172    * XPCOM objects. The function will call NS_IF_RELASE on the value
 173    * to destroy it.
 174    */
 175   static void SupportsDtorFunc(void *aObject, nsIAtom *aPropertyName,
 176                                void *aPropertyValue, void *aData);
 177
 178   class PropertyList;
 179
 180   size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
 181
 182  private:
 183   NS_HIDDEN_(void) DestroyPropertyList();
 184   NS_HIDDEN_(PropertyList*) GetPropertyListFor(nsIAtom *aPropertyName) const;
 185   NS_HIDDEN_(void*) GetPropertyInternal(nsPropertyOwner aObject,
 186                                         nsIAtom    *aPropertyName,
 187                                         bool        aRemove,
 188                                         nsresult   *aStatus);
 189   NS_HIDDEN_(nsresult) SetPropertyInternal(nsPropertyOwner     aObject,
 190                                            nsIAtom            *aPropertyName,
 191                                            void               *aPropertyValue,
 192                                            NSPropertyDtorFunc  aDtor,
 193                                            void               *aDtorData,
 194                                            bool                aTransfer,
 195                                            void              **aOldValue);
 196
 197   PropertyList *mPropertyList;
 198 };
 199 #endif