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.

Implementation

Mercurial (56e7b9127e89)

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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 nsCOMArray_h__
#define nsCOMArray_h__

#include "mozilla/Attributes.h"
#include "mozilla/ArrayIterator.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/ReverseIterator.h"

#include "nsCycleCollectionNoteChild.h"
#include "nsTArray.h"
#include "nsISupports.h"

// See below for the definition of nsCOMArray<T>

// a class that's nsISupports-specific, so that we can contain the
// work of this class in the XPCOM dll
class nsCOMArray_base
{
  friend class nsArrayBase;
protected:
  nsCOMArray_base() {}
  explicit nsCOMArray_base(int32_t aCount) : mArray(aCount) {}
  nsCOMArray_base(const nsCOMArray_base& aOther);
  ~nsCOMArray_base();

  int32_t IndexOf(nsISupports* aObject, uint32_t aStartIndex = 0) const;
  bool Contains(nsISupports* aObject) const
  {
    return IndexOf(aObject) != -1;
  }

  int32_t IndexOfObject(nsISupports* aObject) const;
  bool ContainsObject(nsISupports* aObject) const
  {
    return IndexOfObject(aObject) != -1;
  }

  typedef bool (*nsBaseArrayEnumFunc)(void* aElement, void* aData);

  // enumerate through the array with a callback.
  bool EnumerateForwards(nsBaseArrayEnumFunc aFunc, void* aData) const;

  bool EnumerateBackwards(nsBaseArrayEnumFunc aFunc, void* aData) const;

  typedef int (*nsBaseArrayComparatorFunc)(nsISupports* aElement1,
                                           nsISupports* aElement2,
                                           void* aData);

  struct nsCOMArrayComparatorContext
  {
    nsBaseArrayComparatorFunc mComparatorFunc;
    void* mData;
  };

  static int nsCOMArrayComparator(const void* aElement1, const void* aElement2,
                                  void* aData);
  void Sort(nsBaseArrayComparatorFunc aFunc, void* aData);

  bool InsertObjectAt(nsISupports* aObject, int32_t aIndex);
  void InsertElementAt(uint32_t aIndex, nsISupports* aElement);
  void InsertElementAt(uint32_t aIndex, already_AddRefed<nsISupports> aElement);
  bool InsertObjectsAt(const nsCOMArray_base& aObjects, int32_t aIndex);
  void InsertElementsAt(uint32_t aIndex, const nsCOMArray_base& aElements);
  void InsertElementsAt(uint32_t aIndex, nsISupports* const* aElements,
                        uint32_t aCount);
  void ReplaceObjectAt(nsISupports* aObject, int32_t aIndex);
  void ReplaceElementAt(uint32_t aIndex, nsISupports* aElement)
  {
    nsISupports* oldElement = mArray[aIndex];
    NS_IF_ADDREF(mArray[aIndex] = aElement);
    NS_IF_RELEASE(oldElement);
  }
  bool AppendObject(nsISupports* aObject)
  {
    return InsertObjectAt(aObject, Count());
  }
  void AppendElement(nsISupports* aElement)
  {
    InsertElementAt(Length(), aElement);
  }
  void AppendElement(already_AddRefed<nsISupports> aElement)
  {
    InsertElementAt(Length(), std::move(aElement));
  }

  bool AppendObjects(const nsCOMArray_base& aObjects)
  {
    return InsertObjectsAt(aObjects, Count());
  }
  void AppendElements(const nsCOMArray_base& aElements)
  {
    return InsertElementsAt(Length(), aElements);
  }
  void AppendElements(nsISupports* const* aElements, uint32_t aCount)
  {
    return InsertElementsAt(Length(), aElements, aCount);
  }
  bool RemoveObject(nsISupports* aObject);
  nsISupports** Elements() { return mArray.Elements(); }
  void SwapElements(nsCOMArray_base& aOther)
  {
    mArray.SwapElements(aOther.mArray);
  }

  void Adopt(nsISupports** aElements, uint32_t aCount);
  uint32_t Forget(nsISupports*** aElements);
public:
  // elements in the array (including null elements!)
  int32_t Count() const { return mArray.Length(); }
  // nsTArray-compatible version
  uint32_t Length() const { return mArray.Length(); }
  bool IsEmpty() const { return mArray.IsEmpty(); }

  // If the array grows, the newly created entries will all be null;
  // if the array shrinks, the excess entries will all be released.
  bool SetCount(int32_t aNewCount);
  // nsTArray-compatible version
  void TruncateLength(uint32_t aNewLength)
  {
    if (mArray.Length() > aNewLength) {
      RemoveElementsAt(aNewLength, mArray.Length() - aNewLength);
    }
  }

  // remove all elements in the array, and call NS_RELEASE on each one
  void Clear();

  nsISupports* ObjectAt(int32_t aIndex) const { return mArray[aIndex]; }
  // nsTArray-compatible version
  nsISupports* ElementAt(uint32_t aIndex) const { return mArray[aIndex]; }

  nsISupports* SafeObjectAt(int32_t aIndex) const
  {
    return mArray.SafeElementAt(aIndex, nullptr);
  }
  // nsTArray-compatible version
  nsISupports* SafeElementAt(uint32_t aIndex) const
  {
    return mArray.SafeElementAt(aIndex, nullptr);
  }

  nsISupports* operator[](int32_t aIndex) const { return mArray[aIndex]; }

  // remove an element at a specific position, shrinking the array
  // as necessary
  bool RemoveObjectAt(int32_t aIndex);
  // nsTArray-compatible version
  void RemoveElementAt(uint32_t aIndex);

  // remove a range of elements at a specific position, shrinking the array
  // as necessary
  bool RemoveObjectsAt(int32_t aIndex, int32_t aCount);
  // nsTArray-compatible version
  void RemoveElementsAt(uint32_t aIndex, uint32_t aCount);

  void SwapElementsAt(uint32_t aIndex1, uint32_t aIndex2)
  {
    nsISupports* tmp = mArray[aIndex1];
    mArray[aIndex1] = mArray[aIndex2];
    mArray[aIndex2] = tmp;
  }

  // Ensures there is enough space to store a total of aCapacity objects.
  // This method never deletes any objects.
  void SetCapacity(uint32_t aCapacity) { mArray.SetCapacity(aCapacity); }
  uint32_t Capacity() { return mArray.Capacity(); }

  // Measures the size of the array's element storage. If you want to measure
  // anything hanging off the array, you must iterate over the elements and
  // measure them individually; hence the "Shallow" prefix. Note that because
  // each element in an nsCOMArray<T> is actually a T* any such iteration
  // should use a SizeOfIncludingThis() function on each element rather than a
  // SizeOfExcludingThis() function, so that the memory taken by the T itself
  // is included as well as anything it points to.
  size_t ShallowSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
  {
    return mArray.ShallowSizeOfExcludingThis(aMallocSizeOf);
  }

private:

  // the actual storage
  nsTArray<nsISupports*> mArray;

  // don't implement these, defaults will muck with refcounts!
  nsCOMArray_base& operator=(const nsCOMArray_base& aOther) = delete;
};

inline void
ImplCycleCollectionUnlink(nsCOMArray_base& aField)
{
  aField.Clear();
}

inline void
ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
                            nsCOMArray_base& aField,
                            const char* aName,
                            uint32_t aFlags = 0)
{
  aFlags |= CycleCollectionEdgeNameArrayFlag;
  int32_t length = aField.Count();
  for (int32_t i = 0; i < length; ++i) {
    CycleCollectionNoteChild(aCallback, aField[i], aName, aFlags);
  }
}


// a non-XPCOM, refcounting array of XPCOM objects
// used as a member variable or stack variable - this object is NOT
// refcounted, but the objects that it holds are
//
// most of the read-only accessors like ObjectAt()/etc do NOT refcount
// on the way out. This means that you can do one of two things:
//
// * does an addref, but holds onto a reference
// nsCOMPtr<T> foo = array[i];
//
// * avoids the refcount, but foo might go stale if array[i] is ever
// * modified/removed. Be careful not to NS_RELEASE(foo)!
// T* foo = array[i];
//
// This array will accept null as an argument for any object, and will store
// null in the array. But that also means that methods like ObjectAt() may
// return null when referring to an existing, but null entry in the array.
template<class T>
class nsCOMArray : public nsCOMArray_base
{
public:
  typedef int32_t                                       index_type;
  typedef mozilla::ArrayIterator<T*, nsCOMArray>        iterator;
  typedef mozilla::ArrayIterator<const T*, nsCOMArray>  const_iterator;
  typedef mozilla::ReverseIterator<iterator>            reverse_iterator;
  typedef mozilla::ReverseIterator<const_iterator>      const_reverse_iterator;

  nsCOMArray() {}
  explicit nsCOMArray(int32_t aCount) : nsCOMArray_base(aCount) {}
  explicit nsCOMArray(const nsCOMArray<T>& aOther) : nsCOMArray_base(aOther) {}
  nsCOMArray(nsCOMArray<T>&& aOther) { SwapElements(aOther); }
  ~nsCOMArray() {}

  // We have a move assignment operator, but no copy assignment operator.
  nsCOMArray<T>& operator=(nsCOMArray<T> && aOther)
  {
    SwapElements(aOther);
    return *this;
  }

  // these do NOT refcount on the way out, for speed
  T* ObjectAt(int32_t aIndex) const
  {
    return static_cast<T*>(nsCOMArray_base::ObjectAt(aIndex));
  }
  // nsTArray-compatible version
  T* ElementAt(uint32_t aIndex) const
  {
    return static_cast<T*>(nsCOMArray_base::ElementAt(aIndex));
  }

  // these do NOT refcount on the way out, for speed
  T* SafeObjectAt(int32_t aIndex) const
  {
    return static_cast<T*>(nsCOMArray_base::SafeObjectAt(aIndex));
  }
  // nsTArray-compatible version
  T* SafeElementAt(uint32_t aIndex) const
  {
    return static_cast<T*>(nsCOMArray_base::SafeElementAt(aIndex));
  }

  // indexing operator for syntactic sugar
  T* operator[](int32_t aIndex) const { return ObjectAt(aIndex); }

  // index of the element in question.. does NOT refcount
  // note: this does not check COM object identity. Use
  // IndexOfObject() for that purpose
  int32_t IndexOf(T* aObject, uint32_t aStartIndex = 0) const
  {
    return nsCOMArray_base::IndexOf(aObject, aStartIndex);
  }
  bool Contains(T* aObject) const
  {
    return nsCOMArray_base::Contains(aObject);
  }

  // index of the element in question.. be careful!
  // this is much slower than IndexOf() because it uses
  // QueryInterface to determine actual COM identity of the object
  // if you need to do this frequently then consider enforcing
  // COM object identity before adding/comparing elements
  int32_t IndexOfObject(T* aObject) const
  {
    return nsCOMArray_base::IndexOfObject(aObject);
  }
  bool ContainsObject(nsISupports* aObject) const
  {
    return nsCOMArray_base::ContainsObject(aObject);
  }

  // inserts aObject at aIndex, shifting the objects at aIndex and
  // later to make space
  bool InsertObjectAt(T* aObject, int32_t aIndex)
  {
    return nsCOMArray_base::InsertObjectAt(aObject, aIndex);
  }
  // nsTArray-compatible version
  void InsertElementAt(uint32_t aIndex, T* aElement)
  {
    nsCOMArray_base::InsertElementAt(aIndex, aElement);
  }

  // inserts the objects from aObject at aIndex, shifting the
  // objects at aIndex and later to make space
  bool InsertObjectsAt(const nsCOMArray<T>& aObjects, int32_t aIndex)
  {
    return nsCOMArray_base::InsertObjectsAt(aObjects, aIndex);
  }
  // nsTArray-compatible version
  void InsertElementsAt(uint32_t aIndex, const nsCOMArray<T>& aElements)
  {
    nsCOMArray_base::InsertElementsAt(aIndex, aElements);
  }
  void InsertElementsAt(uint32_t aIndex, T* const* aElements, uint32_t aCount)
  {
    nsCOMArray_base::InsertElementsAt(
      aIndex, reinterpret_cast<nsISupports* const*>(aElements), aCount);
  }

  // replaces an existing element. Warning: if the array grows,
  // the newly created entries will all be null
  void ReplaceObjectAt(T* aObject, int32_t aIndex)
  {
    nsCOMArray_base::ReplaceObjectAt(aObject, aIndex);
  }
  // nsTArray-compatible version
  void ReplaceElementAt(uint32_t aIndex, T* aElement)
  {
    nsCOMArray_base::ReplaceElementAt(aIndex, aElement);
  }

  typedef int (*nsCOMArrayComparatorFunc)(T* aElement1, T* aElement2,
                                          void* aData);

  void Sort(nsCOMArrayComparatorFunc aFunc, void* aData)
  {
    nsCOMArray_base::Sort(nsBaseArrayComparatorFunc(aFunc), aData);
  }

  // append an object, growing the array as necessary
  bool AppendObject(T* aObject)
  {
    return nsCOMArray_base::AppendObject(aObject);
  }
  // nsTArray-compatible version
  void AppendElement(T* aElement)
  {
    nsCOMArray_base::AppendElement(aElement);
  }
  void AppendElement(already_AddRefed<T> aElement)
  {
    nsCOMArray_base::AppendElement(std::move(aElement));
  }

  // append objects, growing the array as necessary
  bool AppendObjects(const nsCOMArray<T>& aObjects)
  {
    return nsCOMArray_base::AppendObjects(aObjects);
  }
  // nsTArray-compatible version
  void AppendElements(const nsCOMArray<T>& aElements)
  {
    return nsCOMArray_base::AppendElements(aElements);
  }
  void AppendElements(T* const* aElements, uint32_t aCount)
  {
    InsertElementsAt(Length(), aElements, aCount);
  }

  // remove the first instance of the given object and shrink the
  // array as necessary
  // Warning: if you pass null here, it will remove the first null element
  bool RemoveObject(T* aObject)
  {
    return nsCOMArray_base::RemoveObject(aObject);
  }
  // nsTArray-compatible version
  bool RemoveElement(T* aElement)
  {
    return nsCOMArray_base::RemoveObject(aElement);
  }

  T** Elements()
  {
    return reinterpret_cast<T**>(nsCOMArray_base::Elements());
  }
  void SwapElements(nsCOMArray<T>& aOther)
  {
    nsCOMArray_base::SwapElements(aOther);
  }

  /**
   * Adopt parameters that resulted from an XPIDL outparam. The aElements
   * parameter will be freed as a result of the call.
   *
   * Example usage:
   * nsCOMArray<nsISomeInterface> array;
   * nsISomeInterface** elements;
   * uint32_t length;
   * ptr->GetSomeArray(&elements, &length);
   * array.Adopt(elements, length);
   */
  void Adopt(T** aElements, uint32_t aSize)
  {
    nsCOMArray_base::Adopt(reinterpret_cast<nsISupports**>(aElements), aSize);
  }

  /**
   * Export the contents of this array to an XPIDL outparam. The array will be
   * Clear()'d after this operation.
   *
   * Example usage:
   * nsCOMArray<nsISomeInterface> array;
   * *length = array.Forget(retval);
   */
  uint32_t Forget(T*** aElements)
  {
    return nsCOMArray_base::Forget(reinterpret_cast<nsISupports***>(aElements));
  }

  // Methods for range-based for loops.
  iterator begin() { return iterator(*this, 0); }
  const_iterator begin() const { return const_iterator(*this, 0); }
  const_iterator cbegin() const { return begin(); }
  iterator end() { return iterator(*this, Length()); }
  const_iterator end() const { return const_iterator(*this, Length()); }
  const_iterator cend() const { return end(); }

  // Methods for reverse iterating.
  reverse_iterator rbegin() { return reverse_iterator(end()); }
  const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); }
  const_reverse_iterator crbegin() const { return rbegin(); }
  reverse_iterator rend() { return reverse_iterator(begin()); }
  const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
  const_reverse_iterator crend() const { return rend(); }

private:

  // don't implement these!
  nsCOMArray<T>& operator=(const nsCOMArray<T>& aOther) = delete;
};

template<typename T>
inline void
ImplCycleCollectionUnlink(nsCOMArray<T>& aField)
{
  aField.Clear();
}

template<typename E>
inline void
ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
                            nsCOMArray<E>& aField,
                            const char* aName,
                            uint32_t aFlags = 0)
{
  aFlags |= CycleCollectionEdgeNameArrayFlag;
  int32_t length = aField.Count();
  for (int32_t i = 0; i < length; ++i) {
    CycleCollectionNoteChild(aCallback, aField[i], aName, aFlags);
  }
}

#endif