dom/base/nsPropertyTable.cpp

   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 #include "nsPropertyTable.h"
  24
  25 #include "mozilla/MemoryReporting.h"
  26
  27 #include "pldhash.h"
  28 #include "nsError.h"
  29 #include "nsIAtom.h"
  30
  31 struct PropertyListMapEntry : public PLDHashEntryHdr {
  32   const void  *key;
  33   void        *value;
  34 };
  35
  36 //----------------------------------------------------------------------
  37
  38 class nsPropertyTable::PropertyList {
  39 public:
  40   PropertyList(nsIAtom*           aName,
  41                NSPropertyDtorFunc aDtorFunc,
  42                void*              aDtorData,
  43                bool               aTransfer);
  44   ~PropertyList();
  45
  46   // Removes the property associated with the given object, and destroys
  47   // the property value
  48   bool DeletePropertyFor(nsPropertyOwner aObject);
  49
  50   // Destroy all remaining properties (without removing them)
  51   void Destroy();
  52
  53   bool Equals(nsIAtom *aPropertyName)
  54   {
  55     return mName == aPropertyName;
  56   }
  57
  58   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
  59
  60   nsCOMPtr<nsIAtom>  mName;           // property name
  61   PLDHashTable       mObjectValueMap; // map of object/value pairs
  62   NSPropertyDtorFunc mDtorFunc;       // property specific value dtor function
  63   void*              mDtorData;       // pointer to pass to dtor
  64   bool               mTransfer;       // whether to transfer in
  65                                       // TransferOrDeleteAllPropertiesFor
  66
  67   PropertyList*      mNext;
  68 };
  69
  70 void
  71 nsPropertyTable::DeleteAllProperties()
  72 {
  73   while (mPropertyList) {
  74     PropertyList* tmp = mPropertyList;
  75
  76     mPropertyList = mPropertyList->mNext;
  77     tmp->Destroy();
  78     delete tmp;
  79   }
  80 }
  81
  82 void
  83 nsPropertyTable::DeleteAllPropertiesFor(nsPropertyOwner aObject)
  84 {
  85   for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
  86     prop->DeletePropertyFor(aObject);
  87   }
  88 }
  89
  90 nsresult
  91 nsPropertyTable::TransferOrDeleteAllPropertiesFor(nsPropertyOwner aObject,
  92                                                   nsPropertyTable *aOtherTable)
  93 {
  94   nsresult rv = NS_OK;
  95   for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
  96     if (prop->mTransfer) {
  97       PropertyListMapEntry *entry = static_cast<PropertyListMapEntry*>
  98                                                (PL_DHashTableLookup(&prop->mObjectValueMap, aObject));
  99       if (PL_DHASH_ENTRY_IS_BUSY(entry)) {
 100         rv = aOtherTable->SetProperty(aObject, prop->mName,
 101                                       entry->value, prop->mDtorFunc,
 102                                       prop->mDtorData, prop->mTransfer);
 103         if (NS_FAILED(rv)) {
 104           DeleteAllPropertiesFor(aObject);
 105           aOtherTable->DeleteAllPropertiesFor(aObject);
 106
 107           break;
 108         }
 109
 110         PL_DHashTableRawRemove(&prop->mObjectValueMap, entry);
 111       }
 112     }
 113     else {
 114       prop->DeletePropertyFor(aObject);
 115     }
 116   }
 117
 118   return rv;
 119 }
 120
 121 void
 122 nsPropertyTable::Enumerate(nsPropertyOwner aObject,
 123                            NSPropertyFunc aCallback, void *aData)
 124 {
 125   PropertyList* prop;
 126   for (prop = mPropertyList; prop; prop = prop->mNext) {
 127     PropertyListMapEntry *entry = static_cast<PropertyListMapEntry*>
 128       (PL_DHashTableLookup(&prop->mObjectValueMap, aObject));
 129     if (PL_DHASH_ENTRY_IS_BUSY(entry)) {
 130       aCallback(const_cast<void*>(aObject.get()), prop->mName, entry->value,
 131                  aData);
 132     }
 133   }
 134 }
 135
 136 struct PropertyEnumeratorData
 137 {
 138   nsIAtom* mName;
 139   NSPropertyFunc mCallBack;
 140   void* mData;
 141 };
 142
 143 static PLDHashOperator
 144 PropertyEnumerator(PLDHashTable* aTable, PLDHashEntryHdr* aHdr,
 145                    uint32_t aNumber, void* aArg)
 146 {
 147   PropertyListMapEntry* entry = static_cast<PropertyListMapEntry*>(aHdr);
 148   PropertyEnumeratorData* data = static_cast<PropertyEnumeratorData*>(aArg);
 149   data->mCallBack(const_cast<void*>(entry->key), data->mName, entry->value,
 150                   data->mData);
 151   return PL_DHASH_NEXT;
 152 }
 153
 154 void
 155 nsPropertyTable::EnumerateAll(NSPropertyFunc aCallBack, void* aData)
 156 {
 157   for (PropertyList* prop = mPropertyList; prop; prop = prop->mNext) {
 158     PropertyEnumeratorData data = { prop->mName, aCallBack, aData };
 159     PL_DHashTableEnumerate(&prop->mObjectValueMap, PropertyEnumerator, &data);
 160   }
 161 }
 162
 163 void*
 164 nsPropertyTable::GetPropertyInternal(nsPropertyOwner aObject,
 165                                      nsIAtom    *aPropertyName,
 166                                      bool        aRemove,
 167                                      nsresult   *aResult)
 168 {
 169   NS_PRECONDITION(aPropertyName && aObject, "unexpected null param");
 170   nsresult rv = NS_PROPTABLE_PROP_NOT_THERE;
 171   void *propValue = nullptr;
 172
 173   PropertyList* propertyList = GetPropertyListFor(aPropertyName);
 174   if (propertyList) {
 175     PropertyListMapEntry *entry = static_cast<PropertyListMapEntry*>
 176                                              (PL_DHashTableLookup(&propertyList->mObjectValueMap, aObject));
 177     if (PL_DHASH_ENTRY_IS_BUSY(entry)) {
 178       propValue = entry->value;
 179       if (aRemove) {
 180         // don't call propertyList->mDtorFunc.  That's the caller's job now.
 181         PL_DHashTableRawRemove(&propertyList->mObjectValueMap, entry);
 182       }
 183       rv = NS_OK;
 184     }
 185   }
 186
 187   if (aResult)
 188     *aResult = rv;
 189
 190   return propValue;
 191 }
 192
 193 nsresult
 194 nsPropertyTable::SetPropertyInternal(nsPropertyOwner     aObject,
 195                                      nsIAtom            *aPropertyName,
 196                                      void               *aPropertyValue,
 197                                      NSPropertyDtorFunc  aPropDtorFunc,
 198                                      void               *aPropDtorData,
 199                                      bool                aTransfer,
 200                                      void              **aOldValue)
 201 {
 202   NS_PRECONDITION(aPropertyName && aObject, "unexpected null param");
 203
 204   PropertyList* propertyList = GetPropertyListFor(aPropertyName);
 205
 206   if (propertyList) {
 207     // Make sure the dtor function and data and the transfer flag match
 208     if (aPropDtorFunc != propertyList->mDtorFunc ||
 209         aPropDtorData != propertyList->mDtorData ||
 210         aTransfer != propertyList->mTransfer) {
 211       NS_WARNING("Destructor/data mismatch while setting property");
 212       return NS_ERROR_INVALID_ARG;
 213     }
 214
 215   } else {
 216     propertyList = new PropertyList(aPropertyName, aPropDtorFunc,
 217                                     aPropDtorData, aTransfer);
 218     if (!propertyList || !propertyList->mObjectValueMap.ops) {
 219       delete propertyList;
 220       return NS_ERROR_OUT_OF_MEMORY;
 221     }
 222
 223     propertyList->mNext = mPropertyList;
 224     mPropertyList = propertyList;
 225   }
 226
 227   // The current property value (if there is one) is replaced and the current
 228   // value is destroyed
 229   nsresult result = NS_OK;
 230   PropertyListMapEntry *entry = static_cast<PropertyListMapEntry*>
 231                                            (PL_DHashTableAdd(&propertyList->mObjectValueMap, aObject));
 232   if (!entry)
 233     return NS_ERROR_OUT_OF_MEMORY;
 234   // A nullptr entry->key is the sign that the entry has just been allocated
 235   // for us.  If it's non-nullptr then we have an existing entry.
 236   if (entry->key) {
 237     if (aOldValue)
 238       *aOldValue = entry->value;
 239     else if (propertyList->mDtorFunc)
 240       propertyList->mDtorFunc(const_cast<void*>(entry->key), aPropertyName,
 241                               entry->value, propertyList->mDtorData);
 242     result = NS_PROPTABLE_PROP_OVERWRITTEN;
 243   }
 244   else if (aOldValue) {
 245     *aOldValue = nullptr;
 246   }
 247   entry->key = aObject;
 248   entry->value = aPropertyValue;
 249
 250   return result;
 251 }
 252
 253 nsresult
 254 nsPropertyTable::DeleteProperty(nsPropertyOwner aObject,
 255                                 nsIAtom    *aPropertyName)
 256 {
 257   NS_PRECONDITION(aPropertyName && aObject, "unexpected null param");
 258
 259   PropertyList* propertyList = GetPropertyListFor(aPropertyName);
 260   if (propertyList) {
 261     if (propertyList->DeletePropertyFor(aObject))
 262       return NS_OK;
 263   }
 264
 265   return NS_PROPTABLE_PROP_NOT_THERE;
 266 }
 267
 268 nsPropertyTable::PropertyList*
 269 nsPropertyTable::GetPropertyListFor(nsIAtom* aPropertyName) const
 270 {
 271   PropertyList* result;
 272
 273   for (result = mPropertyList; result; result = result->mNext) {
 274     if (result->Equals(aPropertyName)) {
 275       break;
 276     }
 277   }
 278
 279   return result;
 280 }
 281
 282 //----------------------------------------------------------------------
 283
 284 nsPropertyTable::PropertyList::PropertyList(nsIAtom            *aName,
 285                                             NSPropertyDtorFunc  aDtorFunc,
 286                                             void               *aDtorData,
 287                                             bool                aTransfer)
 288   : mName(aName),
 289     mDtorFunc(aDtorFunc),
 290     mDtorData(aDtorData),
 291     mTransfer(aTransfer),
 292     mNext(nullptr)
 293 {
 294   PL_DHashTableInit(&mObjectValueMap, PL_DHashGetStubOps(), this,
 295                     sizeof(PropertyListMapEntry));
 296 }
 297
 298 nsPropertyTable::PropertyList::~PropertyList()
 299 {
 300   PL_DHashTableFinish(&mObjectValueMap);
 301 }
 302
 303
 304 static PLDHashOperator
 305 DestroyPropertyEnumerator(PLDHashTable *table, PLDHashEntryHdr *hdr,
 306                           uint32_t number, void *arg)
 307 {
 308   nsPropertyTable::PropertyList *propList =
 309       static_cast<nsPropertyTable::PropertyList*>(table->data);
 310   PropertyListMapEntry* entry = static_cast<PropertyListMapEntry*>(hdr);
 311
 312   propList->mDtorFunc(const_cast<void*>(entry->key), propList->mName,
 313                       entry->value, propList->mDtorData);
 314   return PL_DHASH_NEXT;
 315 }
 316
 317 void
 318 nsPropertyTable::PropertyList::Destroy()
 319 {
 320   // Enumerate any remaining object/value pairs and destroy the value object
 321   if (mDtorFunc)
 322     PL_DHashTableEnumerate(&mObjectValueMap, DestroyPropertyEnumerator,
 323                            nullptr);
 324 }
 325
 326 bool
 327 nsPropertyTable::PropertyList::DeletePropertyFor(nsPropertyOwner aObject)
 328 {
 329   PropertyListMapEntry *entry = static_cast<PropertyListMapEntry*>
 330                                            (PL_DHashTableLookup(&mObjectValueMap, aObject));
 331   if (!PL_DHASH_ENTRY_IS_BUSY(entry))
 332     return false;
 333
 334   void* value = entry->value;
 335   PL_DHashTableRawRemove(&mObjectValueMap, entry);
 336
 337   if (mDtorFunc)
 338     mDtorFunc(const_cast<void*>(aObject.get()), mName, value, mDtorData);
 339
 340   return true;
 341 }
 342
 343 size_t
 344 nsPropertyTable::PropertyList::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
 345 {
 346   size_t n = aMallocSizeOf(this);
 347   n += PL_DHashTableSizeOfExcludingThis(&mObjectValueMap, nullptr, aMallocSizeOf);
 348   return n;
 349 }
 350
 351 size_t
 352 nsPropertyTable::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 353 {
 354   size_t n = 0;
 355
 356   for (PropertyList *prop = mPropertyList; prop; prop = prop->mNext) {
 357     n += prop->SizeOfIncludingThis(aMallocSizeOf);
 358   }
 359
 360   return n;
 361 }
 362
 363 size_t
 364 nsPropertyTable::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 365 {
 366   return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
 367 }
 368
 369 /* static */
 370 void
 371 nsPropertyTable::SupportsDtorFunc(void *aObject, nsIAtom *aPropertyName,
 372                                   void *aPropertyValue, void *aData)
 373 {
 374   nsISupports *propertyValue = static_cast<nsISupports*>(aPropertyValue);
 375   NS_IF_RELEASE(propertyValue);
 376 }