DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (5b81998bb7ab)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsBaseHashtable_h__
#define nsBaseHashtable_h__

#include "nsTHashtable.h"
#include "prlock.h"
#include "nsDebug.h"

template<class KeyClass,class DataType,class UserDataType>
class nsBaseHashtable; // forward declaration

/**
 * the private nsTHashtable::EntryType class used by nsBaseHashtable
 * @see nsTHashtable for the specification of this class
 * @see nsBaseHashtable for template parameters
 */
template<class KeyClass,class DataType>
class nsBaseHashtableET : public KeyClass
{
public:
  DataType mData;
  friend class nsTHashtable< nsBaseHashtableET<KeyClass,DataType> >;

private:
  typedef typename KeyClass::KeyType KeyType;
  typedef typename KeyClass::KeyTypePointer KeyTypePointer;
  
  nsBaseHashtableET(KeyTypePointer aKey);
  nsBaseHashtableET(nsBaseHashtableET<KeyClass,DataType>& toCopy);
  ~nsBaseHashtableET();
};

/**
 * templated hashtable for simple data types
 * This class manages simple data types that do not need construction or
 * destruction.
 *
 * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
 *   for a complete specification.
 * @param DataType the datatype stored in the hashtable,
 *   for example, uint32_t or nsCOMPtr.  If UserDataType is not the same,
 *   DataType must implicitly cast to UserDataType
 * @param UserDataType the user sees, for example uint32_t or nsISupports*
 */
template<class KeyClass,class DataType,class UserDataType>
class nsBaseHashtable :
  protected nsTHashtable< nsBaseHashtableET<KeyClass,DataType> >
{
  typedef mozilla::fallible_t fallible_t;

public:
  typedef typename KeyClass::KeyType KeyType;
  typedef nsBaseHashtableET<KeyClass,DataType> EntryType;

  // default constructor+destructor are fine

  /**
   * Initialize the object.
   * @param initSize the initial number of buckets in the hashtable,
   *        default 16
   * locking on all class methods
   * @return    true if the object was initialized properly.
   */
  void Init(uint32_t initSize = PL_DHASH_MIN_SIZE)
  { nsTHashtable<EntryType>::Init(initSize); }

  bool Init(const fallible_t&) NS_WARN_UNUSED_RESULT
  { return Init(PL_DHASH_MIN_SIZE, fallible_t()); }

  bool Init(uint32_t initSize, const fallible_t&) NS_WARN_UNUSED_RESULT
  { return nsTHashtable<EntryType>::Init(initSize, fallible_t()); }



  /**
   * Check whether the table has been initialized.
   * This function is especially useful for static hashtables.
   * @return true if the table has been initialized.
   */
  bool IsInitialized() const { return !!this->mTable.entrySize; }

  /**
   * Return the number of entries in the table.
   * @return    number of entries
   */
  uint32_t Count() const
  { return nsTHashtable<EntryType>::Count(); }

  /**
   * retrieve the value for a key.
   * @param aKey the key to retreive
   * @param pData data associated with this key will be placed at this
   *   pointer.  If you only need to check if the key exists, pData
   *   may be null.
   * @return true if the key exists. If key does not exist, pData is not
   *   modified.
   */
  bool Get(KeyType aKey, UserDataType* pData) const
  {
    EntryType* ent = this->GetEntry(aKey);

    if (!ent)
      return false;

    if (pData)
      *pData = ent->mData;

    return true;
  }

  /**
   * For pointer types, get the value, returning nullptr if the entry is not
   * present in the table.
   *
   * @param aKey the key to retrieve
   * @return The found value, or nullptr if no entry was found with the given key.
   * @note If nullptr values are stored in the table, it is not possible to
   *       distinguish between a nullptr value and a missing entry.
   */
  UserDataType Get(KeyType aKey) const
  {
    EntryType* ent = this->GetEntry(aKey);
    if (!ent)
      return 0;

    return ent->mData;
  }

  /**
   * put a new value for the associated key
   * @param aKey the key to put
   * @param aData the new data
   * @return always true, unless memory allocation failed
   */
  void Put(KeyType aKey, const UserDataType& aData)
  {
    if (!Put(aKey, aData, fallible_t()))
      NS_RUNTIMEABORT("OOM");
  }

  bool Put(KeyType aKey, const UserDataType& aData, const fallible_t&) NS_WARN_UNUSED_RESULT
  {
    EntryType* ent = this->PutEntry(aKey);

    if (!ent)
      return false;

    ent->mData = aData;

    return true;
  }

  /**
   * remove the data for the associated key
   * @param aKey the key to remove from the hashtable
   */
  void Remove(KeyType aKey) { this->RemoveEntry(aKey); }

  /**
   * function type provided by the application for enumeration.
   * @param aKey the key being enumerated
   * @param aData data being enumerated
   * @parm userArg passed unchanged from Enumerate
   * @return either
   *   @link PLDHashOperator::PL_DHASH_NEXT PL_DHASH_NEXT @endlink or
   *   @link PLDHashOperator::PL_DHASH_STOP PL_DHASH_STOP @endlink
   */
  typedef PLDHashOperator
    (* EnumReadFunction)(KeyType      aKey,
                         UserDataType aData,
                         void*        userArg);

  /**
   * enumerate entries in the hashtable, without allowing changes
   * @param enumFunc enumeration callback
   * @param userArg passed unchanged to the EnumReadFunction
   */
  uint32_t EnumerateRead(EnumReadFunction enumFunc, void* userArg) const
  {
    NS_ASSERTION(this->mTable.entrySize,
                 "nsBaseHashtable was not initialized properly.");

    s_EnumReadArgs enumData = { enumFunc, userArg };
    return PL_DHashTableEnumerate(const_cast<PLDHashTable*>(&this->mTable),
                                  s_EnumReadStub,
                                  &enumData);
  }

  /**
   * function type provided by the application for enumeration.
   * @param aKey the key being enumerated
   * @param aData Reference to data being enumerated, may be altered. e.g. for
   *        nsInterfaceHashtable this is an nsCOMPtr reference...
   * @parm userArg passed unchanged from Enumerate
   * @return bitflag combination of
   *   @link PLDHashOperator::PL_DHASH_REMOVE @endlink,
   *   @link PLDHashOperator::PL_DHASH_NEXT PL_DHASH_NEXT @endlink, or
   *   @link PLDHashOperator::PL_DHASH_STOP PL_DHASH_STOP @endlink
   */
  typedef PLDHashOperator
    (* EnumFunction)(KeyType       aKey,
                     DataType&     aData,
                     void*         userArg);

  /**
   * enumerate entries in the hashtable, allowing changes. This
   * functions write-locks the hashtable.
   * @param enumFunc enumeration callback
   * @param userArg passed unchanged to the EnumFunction
   */
  uint32_t Enumerate(EnumFunction enumFunc, void* userArg)
  {
    NS_ASSERTION(this->mTable.entrySize,
                 "nsBaseHashtable was not initialized properly.");

    s_EnumArgs enumData = { enumFunc, userArg };
    return PL_DHashTableEnumerate(&this->mTable,
                                  s_EnumStub,
                                  &enumData);
  }

  /**
   * reset the hashtable, removing all entries
   */
  void Clear() { nsTHashtable<EntryType>::Clear(); }

  /**
   * client must provide a SizeOfEntryExcludingThisFun function for
   *   SizeOfExcludingThis.
   * @param     aKey the key being enumerated
   * @param     aData Reference to data being enumerated.
   * @param     mallocSizeOf the function used to measure heap-allocated blocks
   * @param     userArg passed unchanged from SizeOf{In,Ex}cludingThis
   * @return    summed size of the things pointed to by the entries
   */
  typedef size_t
    (* SizeOfEntryExcludingThisFun)(KeyType           aKey,
                                    const DataType    &aData,
                                    nsMallocSizeOfFun mallocSizeOf,
                                    void*             userArg);

  /**
   * Measure the size of the table's entry storage and the table itself.
   * If |sizeOfEntryExcludingThis| is non-nullptr, measure the size of things
   * pointed to by entries.
   *
   * @param    sizeOfEntryExcludingThis
   *           the <code>SizeOfEntryExcludingThisFun</code> function to call
   * @param    mallocSizeOf the function used to meeasure heap-allocated blocks
   * @param    userArg a point to pass to the
   *           <code>SizeOfEntryExcludingThisFun</code> function
   * @return   the summed size of the entries, the table, and the table's storage
   */
  size_t SizeOfIncludingThis(SizeOfEntryExcludingThisFun sizeOfEntryExcludingThis,
                             nsMallocSizeOfFun mallocSizeOf, void *userArg = nullptr)
  {
    return mallocSizeOf(this) + this->SizeOfExcludingThis(sizeOfEntryExcludingThis,
                                                          mallocSizeOf, userArg);
  }

  /**
   * Measure the size of the table's entry storage, and if
   * |sizeOfEntryExcludingThis| is non-nullptr, measure the size of things pointed
   * to by entries.
   * 
   * @param     sizeOfEntryExcludingThis the
   *            <code>SizeOfEntryExcludingThisFun</code> function to call
   * @param     mallocSizeOf the function used to measure heap-allocated blocks
   * @param     userArg a pointer to pass to the
   *            <code>SizeOfEntryExcludingThisFun</code> function
   * @return    the summed size of all the entries
   */
  size_t SizeOfExcludingThis(SizeOfEntryExcludingThisFun sizeOfEntryExcludingThis,
                             nsMallocSizeOfFun mallocSizeOf, void *userArg = nullptr) const
  {
    if (!IsInitialized()) {
      return 0;
    }
    if (sizeOfEntryExcludingThis) {
      s_SizeOfArgs args = { sizeOfEntryExcludingThis, userArg };
      return PL_DHashTableSizeOfExcludingThis(&this->mTable, s_SizeOfStub,
                                              mallocSizeOf, &args);
    }
    return PL_DHashTableSizeOfExcludingThis(&this->mTable, NULL, mallocSizeOf);
  }

protected:
  /**
   * used internally during EnumerateRead.  Allocated on the stack.
   * @param func the enumerator passed to EnumerateRead
   * @param userArg the userArg passed to EnumerateRead
   */
  struct s_EnumReadArgs
  {
    EnumReadFunction func;
    void* userArg;
  };

  static PLDHashOperator s_EnumReadStub(PLDHashTable    *table,
                                        PLDHashEntryHdr *hdr,
                                        uint32_t         number,
                                        void            *arg);

  struct s_EnumArgs
  {
    EnumFunction func;
    void* userArg;
  };

  static PLDHashOperator s_EnumStub(PLDHashTable      *table,
                                    PLDHashEntryHdr   *hdr,
                                    uint32_t           number,
                                    void              *arg);

  struct s_SizeOfArgs
  {
    SizeOfEntryExcludingThisFun func;
    void* userArg;
  };
  
  static size_t s_SizeOfStub(PLDHashEntryHdr *entry,
                             nsMallocSizeOfFun mallocSizeOf,
                             void *arg);
};

class nsCycleCollectionTraversalCallback;

struct MOZ_STACK_CLASS nsBaseHashtableCCTraversalData
{
  nsBaseHashtableCCTraversalData(nsCycleCollectionTraversalCallback& aCallback,
                                 const char* aName,
                                 uint32_t aFlags)
  : mCallback(aCallback),
    mName(aName),
    mFlags(aFlags)
  {
  }

  nsCycleCollectionTraversalCallback& mCallback;
  const char* mName;
  uint32_t mFlags;

};

template <typename K, typename T>
PLDHashOperator
ImplCycleCollectionTraverse_EnumFunc(K aKey,
                                     T aData,
                                     void* aUserData)
{
  nsBaseHashtableCCTraversalData* userData =
    static_cast<nsBaseHashtableCCTraversalData*>(aUserData);

  CycleCollectionNoteChild(userData->mCallback,
                           aData,
                           userData->mName,
                           userData->mFlags);
  return PL_DHASH_NEXT;
}

/**
 * This class is a thread-safe version of nsBaseHashtable. It only exposes
 * an infallible API.
 */
template<class KeyClass,class DataType,class UserDataType>
class nsBaseHashtableMT :
  protected nsBaseHashtable<KeyClass,DataType,UserDataType>
{
public:
  typedef typename
    nsBaseHashtable<KeyClass,DataType,UserDataType>::EntryType EntryType;
  typedef typename
    nsBaseHashtable<KeyClass,DataType,UserDataType>::KeyType KeyType;
  typedef typename
    nsBaseHashtable<KeyClass,DataType,UserDataType>::EnumFunction EnumFunction;
  typedef typename
    nsBaseHashtable<KeyClass,DataType,UserDataType>::EnumReadFunction EnumReadFunction;

  nsBaseHashtableMT() : mLock(nullptr) { }
  ~nsBaseHashtableMT();

  void Init(uint32_t initSize = PL_DHASH_MIN_SIZE);
  bool IsInitialized() const { return mLock != nullptr; }
  uint32_t Count() const;
  bool Get(KeyType aKey, UserDataType* pData) const;
  void Put(KeyType aKey, UserDataType aData);
  void Remove(KeyType aKey);

  uint32_t EnumerateRead(EnumReadFunction enumFunc, void* userArg) const;
  uint32_t Enumerate(EnumFunction enumFunc, void* userArg);
  void Clear();

protected:
  PRLock* mLock;
};
  

//
// nsBaseHashtableET definitions
//

template<class KeyClass,class DataType>
nsBaseHashtableET<KeyClass,DataType>::nsBaseHashtableET(KeyTypePointer aKey) :
  KeyClass(aKey)
{ }

template<class KeyClass,class DataType>
nsBaseHashtableET<KeyClass,DataType>::nsBaseHashtableET
  (nsBaseHashtableET<KeyClass,DataType>& toCopy) :
  KeyClass(toCopy),
  mData(toCopy.mData)
{ }

template<class KeyClass,class DataType>
nsBaseHashtableET<KeyClass,DataType>::~nsBaseHashtableET()
{ }


//
// nsBaseHashtable definitions
//

template<class KeyClass,class DataType,class UserDataType>
PLDHashOperator
nsBaseHashtable<KeyClass,DataType,UserDataType>::s_EnumReadStub
  (PLDHashTable *table, PLDHashEntryHdr *hdr, uint32_t number, void* arg)
{
  EntryType* ent = static_cast<EntryType*>(hdr);
  s_EnumReadArgs* eargs = (s_EnumReadArgs*) arg;

  PLDHashOperator res = (eargs->func)(ent->GetKey(), ent->mData, eargs->userArg);

  NS_ASSERTION( !(res & PL_DHASH_REMOVE ),
                "PL_DHASH_REMOVE return during const enumeration; ignoring.");

  if (res & PL_DHASH_STOP)
    return PL_DHASH_STOP;

  return PL_DHASH_NEXT;
}

template<class KeyClass,class DataType,class UserDataType>
PLDHashOperator
nsBaseHashtable<KeyClass,DataType,UserDataType>::s_EnumStub
  (PLDHashTable *table, PLDHashEntryHdr *hdr, uint32_t number, void* arg)
{
  EntryType* ent = static_cast<EntryType*>(hdr);
  s_EnumArgs* eargs = (s_EnumArgs*) arg;

  return (eargs->func)(ent->GetKey(), ent->mData, eargs->userArg);
}

template<class KeyClass,class DataType,class UserDataType>
size_t
nsBaseHashtable<KeyClass,DataType,UserDataType>::s_SizeOfStub
  (PLDHashEntryHdr *hdr, nsMallocSizeOfFun mallocSizeOf, void *arg)
{
  EntryType* ent = static_cast<EntryType*>(hdr);
  s_SizeOfArgs* eargs = static_cast<s_SizeOfArgs*>(arg);

  return (eargs->func)(ent->GetKey(), ent->mData, mallocSizeOf, eargs->userArg);
}

//
// nsBaseHashtableMT  definitions
//

template<class KeyClass,class DataType,class UserDataType>
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::~nsBaseHashtableMT()
{
  if (this->mLock)
    PR_DestroyLock(this->mLock);
}

template<class KeyClass,class DataType,class UserDataType>
void
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Init(uint32_t initSize)
{
  if (!nsTHashtable<EntryType>::IsInitialized())
    nsTHashtable<EntryType>::Init(initSize);

  this->mLock = PR_NewLock();
  if (!this->mLock)
    NS_RUNTIMEABORT("OOM");
}

template<class KeyClass,class DataType,class UserDataType>
uint32_t
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Count() const
{
  PR_Lock(this->mLock);
  uint32_t count = nsTHashtable<EntryType>::Count();
  PR_Unlock(this->mLock);

  return count;
}

template<class KeyClass,class DataType,class UserDataType>
bool
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Get(KeyType       aKey,
                                                           UserDataType* pData) const
{
  PR_Lock(this->mLock);
  bool res =
    nsBaseHashtable<KeyClass,DataType,UserDataType>::Get(aKey, pData);
  PR_Unlock(this->mLock);

  return res;
}

template<class KeyClass,class DataType,class UserDataType>
void
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Put(KeyType      aKey,
                                                           UserDataType aData)
{
  PR_Lock(this->mLock);
  nsBaseHashtable<KeyClass,DataType,UserDataType>::Put(aKey, aData);
  PR_Unlock(this->mLock);
}

template<class KeyClass,class DataType,class UserDataType>
void
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Remove(KeyType aKey)
{
  PR_Lock(this->mLock);
  nsBaseHashtable<KeyClass,DataType,UserDataType>::Remove(aKey);
  PR_Unlock(this->mLock);
}

template<class KeyClass,class DataType,class UserDataType>
uint32_t
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::EnumerateRead
  (EnumReadFunction fEnumCall, void* userArg) const
{
  PR_Lock(this->mLock);
  uint32_t count =
    nsBaseHashtable<KeyClass,DataType,UserDataType>::EnumerateRead(fEnumCall, userArg);
  PR_Unlock(this->mLock);

  return count;
}

template<class KeyClass,class DataType,class UserDataType>
uint32_t
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Enumerate
  (EnumFunction fEnumCall, void* userArg)
{
  PR_Lock(this->mLock);
  uint32_t count =
    nsBaseHashtable<KeyClass,DataType,UserDataType>::Enumerate(fEnumCall, userArg);
  PR_Unlock(this->mLock);

  return count;
}

template<class KeyClass,class DataType,class UserDataType>
void
nsBaseHashtableMT<KeyClass,DataType,UserDataType>::Clear()
{
  PR_Lock(this->mLock);
  nsBaseHashtable<KeyClass,DataType,UserDataType>::Clear();
  PR_Unlock(this->mLock);
}

#endif // nsBaseHashtable_h__