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.

Header

Mercurial (b6d82b1a6b02)

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
/* -*- 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/. */

/*
 * Storage of the children and attributes of a DOM node; storage for
 * the two is unified to minimize footprint.
 */

#include "AttrArray.h"

#include "mozilla/CheckedInt.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"

#include "nsMappedAttributeElement.h"
#include "nsString.h"
#include "nsHTMLStyleSheet.h"
#include "nsMappedAttributes.h"
#include "nsUnicharUtils.h"
#include "nsContentUtils.h"  // nsAutoScriptBlocker

using mozilla::CheckedUint32;
using mozilla::dom::Document;

AttrArray::Impl::~Impl() {
  for (InternalAttr& attr : NonMappedAttrs()) {
    attr.~InternalAttr();
  }

  NS_IF_RELEASE(mMappedAttrs);
}

const nsAttrValue* AttrArray::GetAttr(const nsAtom* aLocalName,
                                      int32_t aNamespaceID) const {
  if (aNamespaceID == kNameSpaceID_None) {
    // This should be the common case so lets make an optimized loop
    for (const InternalAttr& attr : NonMappedAttrs()) {
      if (attr.mName.Equals(aLocalName)) {
        return &attr.mValue;
      }
    }

    if (mImpl && mImpl->mMappedAttrs) {
      return mImpl->mMappedAttrs->GetAttr(aLocalName);
    }
  } else {
    for (const InternalAttr& attr : NonMappedAttrs()) {
      if (attr.mName.Equals(aLocalName, aNamespaceID)) {
        return &attr.mValue;
      }
    }
  }

  return nullptr;
}

const nsAttrValue* AttrArray::GetAttr(const nsAString& aLocalName) const {
  for (const InternalAttr& attr : NonMappedAttrs()) {
    if (attr.mName.Equals(aLocalName)) {
      return &attr.mValue;
    }
  }

  if (mImpl && mImpl->mMappedAttrs) {
    return mImpl->mMappedAttrs->GetAttr(aLocalName);
  }

  return nullptr;
}

const nsAttrValue* AttrArray::GetAttr(const nsAString& aName,
                                      nsCaseTreatment aCaseSensitive) const {
  // Check whether someone is being silly and passing non-lowercase
  // attr names.
  if (aCaseSensitive == eIgnoreCase &&
      nsContentUtils::StringContainsASCIIUpper(aName)) {
    // Try again with a lowercased name, but make sure we can't reenter this
    // block by passing eCaseSensitive for aCaseSensitive.
    nsAutoString lowercase;
    nsContentUtils::ASCIIToLower(aName, lowercase);
    return GetAttr(lowercase, eCaseMatters);
  }

  for (const InternalAttr& attr : NonMappedAttrs()) {
    if (attr.mName.QualifiedNameEquals(aName)) {
      return &attr.mValue;
    }
  }

  if (mImpl && mImpl->mMappedAttrs) {
    return mImpl->mMappedAttrs->GetAttr(aName);
  }

  return nullptr;
}

const nsAttrValue* AttrArray::AttrAt(uint32_t aPos) const {
  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");

  uint32_t nonmapped = NonMappedAttrCount();
  if (aPos < nonmapped) {
    return &mImpl->NonMappedAttrs()[aPos].mValue;
  }

  return mImpl->mMappedAttrs->AttrAt(aPos - nonmapped);
}

template <typename Name>
inline nsresult AttrArray::AddNewAttribute(Name* aName, nsAttrValue& aValue) {
  MOZ_ASSERT(!mImpl || mImpl->mCapacity >= mImpl->mAttrCount);
  if (!mImpl || mImpl->mCapacity == mImpl->mAttrCount) {
    if (!GrowBy(1)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  }

  InternalAttr& attr = mImpl->mBuffer[mImpl->mAttrCount++];
  new (&attr.mName) nsAttrName(aName);
  new (&attr.mValue) nsAttrValue();
  attr.mValue.SwapValueWith(aValue);
  return NS_OK;
}

nsresult AttrArray::SetAndSwapAttr(nsAtom* aLocalName, nsAttrValue& aValue,
                                   bool* aHadValue) {
  *aHadValue = false;

  for (InternalAttr& attr : NonMappedAttrs()) {
    if (attr.mName.Equals(aLocalName)) {
      attr.mValue.SwapValueWith(aValue);
      *aHadValue = true;
      return NS_OK;
    }
  }

  return AddNewAttribute(aLocalName, aValue);
}

nsresult AttrArray::SetAndSwapAttr(mozilla::dom::NodeInfo* aName,
                                   nsAttrValue& aValue, bool* aHadValue) {
  int32_t namespaceID = aName->NamespaceID();
  nsAtom* localName = aName->NameAtom();
  if (namespaceID == kNameSpaceID_None) {
    return SetAndSwapAttr(localName, aValue, aHadValue);
  }

  *aHadValue = false;
  for (InternalAttr& attr : NonMappedAttrs()) {
    if (attr.mName.Equals(localName, namespaceID)) {
      attr.mName.SetTo(aName);
      attr.mValue.SwapValueWith(aValue);
      *aHadValue = true;
      return NS_OK;
    }
  }

  return AddNewAttribute(aName, aValue);
}

nsresult AttrArray::RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue) {
  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds");

  uint32_t nonmapped = NonMappedAttrCount();
  if (aPos < nonmapped) {
    mImpl->mBuffer[aPos].mValue.SwapValueWith(aValue);
    mImpl->mBuffer[aPos].~InternalAttr();

    memmove(mImpl->mBuffer + aPos, mImpl->mBuffer + aPos + 1,
            (mImpl->mAttrCount - aPos - 1) * sizeof(InternalAttr));

    --mImpl->mAttrCount;

    return NS_OK;
  }

  if (MappedAttrCount() == 1) {
    // We're removing the last mapped attribute.  Can't swap in this
    // case; have to copy.
    aValue.SetTo(*mImpl->mMappedAttrs->AttrAt(0));
    NS_RELEASE(mImpl->mMappedAttrs);

    return NS_OK;
  }

  RefPtr<nsMappedAttributes> mapped =
      GetModifiableMapped(nullptr, nullptr, false);

  mapped->RemoveAttrAt(aPos - nonmapped, aValue);

  return MakeMappedUnique(mapped);
}

mozilla::dom::BorrowedAttrInfo AttrArray::AttrInfoAt(uint32_t aPos) const {
  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");

  uint32_t nonmapped = NonMappedAttrCount();
  if (aPos < nonmapped) {
    InternalAttr& attr = mImpl->mBuffer[aPos];
    return BorrowedAttrInfo(&attr.mName, &attr.mValue);
  }

  return BorrowedAttrInfo(mImpl->mMappedAttrs->NameAt(aPos - nonmapped),
                          mImpl->mMappedAttrs->AttrAt(aPos - nonmapped));
}

const nsAttrName* AttrArray::AttrNameAt(uint32_t aPos) const {
  NS_ASSERTION(aPos < AttrCount(), "out-of-bounds access in AttrArray");

  uint32_t nonmapped = NonMappedAttrCount();
  if (aPos < nonmapped) {
    return &mImpl->mBuffer[aPos].mName;
  }

  return mImpl->mMappedAttrs->NameAt(aPos - nonmapped);
}

const nsAttrName* AttrArray::GetSafeAttrNameAt(uint32_t aPos) const {
  uint32_t nonmapped = NonMappedAttrCount();
  if (aPos < nonmapped) {
    return &mImpl->mBuffer[aPos].mName;
  }

  if (aPos >= AttrCount()) {
    return nullptr;
  }

  return mImpl->mMappedAttrs->NameAt(aPos - nonmapped);
}

const nsAttrName* AttrArray::GetExistingAttrNameFromQName(
    const nsAString& aName) const {
  for (const InternalAttr& attr : NonMappedAttrs()) {
    if (attr.mName.QualifiedNameEquals(aName)) {
      return &attr.mName;
    }
  }

  if (mImpl && mImpl->mMappedAttrs) {
    return mImpl->mMappedAttrs->GetExistingAttrNameFromQName(aName);
  }

  return nullptr;
}

int32_t AttrArray::IndexOfAttr(const nsAtom* aLocalName,
                               int32_t aNamespaceID) const {
  if (!mImpl) {
    return -1;
  }

  int32_t idx;
  if (mImpl->mMappedAttrs && aNamespaceID == kNameSpaceID_None) {
    idx = mImpl->mMappedAttrs->IndexOfAttr(aLocalName);
    if (idx >= 0) {
      return NonMappedAttrCount() + idx;
    }
  }

  uint32_t i = 0;
  if (aNamespaceID == kNameSpaceID_None) {
    // This should be the common case so lets make an optimized loop
    // Note that here we don't check for AttrSlotIsTaken() in the loop
    // condition for the sake of performance because comparing aLocalName
    // against null would fail in the loop body (since Equals() just compares
    // the raw pointer value of aLocalName to what AttrSlotIsTaken() would be
    // checking.
    for (const InternalAttr& attr : NonMappedAttrs()) {
      if (attr.mName.Equals(aLocalName)) {
        return i;
      }
      ++i;
    }
  } else {
    for (const InternalAttr& attr : NonMappedAttrs()) {
      if (attr.mName.Equals(aLocalName, aNamespaceID)) {
        return i;
      }
      ++i;
    }
  }

  return -1;
}

nsresult AttrArray::SetAndSwapMappedAttr(nsAtom* aLocalName,
                                         nsAttrValue& aValue,
                                         nsMappedAttributeElement* aContent,
                                         nsHTMLStyleSheet* aSheet,
                                         bool* aHadValue) {
  bool willAdd = true;
  if (mImpl && mImpl->mMappedAttrs) {
    willAdd = !mImpl->mMappedAttrs->GetAttr(aLocalName);
  }

  RefPtr<nsMappedAttributes> mapped =
      GetModifiableMapped(aContent, aSheet, willAdd);

  mapped->SetAndSwapAttr(aLocalName, aValue, aHadValue);

  return MakeMappedUnique(mapped);
}

nsresult AttrArray::DoSetMappedAttrStyleSheet(nsHTMLStyleSheet* aSheet) {
  MOZ_ASSERT(mImpl && mImpl->mMappedAttrs, "Should have mapped attrs here!");
  if (aSheet == mImpl->mMappedAttrs->GetStyleSheet()) {
    return NS_OK;
  }

  RefPtr<nsMappedAttributes> mapped =
      GetModifiableMapped(nullptr, nullptr, false);

  mapped->SetStyleSheet(aSheet);

  return MakeMappedUnique(mapped);
}

nsresult AttrArray::DoUpdateMappedAttrRuleMapper(
    nsMappedAttributeElement& aElement) {
  MOZ_ASSERT(mImpl && mImpl->mMappedAttrs, "Should have mapped attrs here!");

  // First two args don't matter if the assert holds.
  RefPtr<nsMappedAttributes> mapped =
      GetModifiableMapped(nullptr, nullptr, false);

  mapped->SetRuleMapper(aElement.GetAttributeMappingFunction());

  return MakeMappedUnique(mapped);
}

void AttrArray::Compact() {
  if (!mImpl) {
    return;
  }

  if (!mImpl->mAttrCount && !mImpl->mMappedAttrs) {
    mImpl.reset();
    return;
  }

  // Nothing to do.
  if (mImpl->mAttrCount == mImpl->mCapacity) {
    return;
  }

  Impl* impl = mImpl.release();
  impl = static_cast<Impl*>(
      realloc(impl, Impl::AllocationSizeForAttributes(impl->mAttrCount)));
  MOZ_ASSERT(impl, "failed to reallocate to a smaller buffer!");
  impl->mCapacity = impl->mAttrCount;
  mImpl.reset(impl);
}

uint32_t AttrArray::DoGetMappedAttrCount() const {
  MOZ_ASSERT(mImpl && mImpl->mMappedAttrs);
  return static_cast<uint32_t>(mImpl->mMappedAttrs->Count());
}

nsresult AttrArray::ForceMapped(nsMappedAttributeElement* aContent,
                                Document* aDocument) {
  nsHTMLStyleSheet* sheet = aDocument->GetAttributeStyleSheet();
  RefPtr<nsMappedAttributes> mapped =
      GetModifiableMapped(aContent, sheet, false, 0);
  return MakeMappedUnique(mapped);
}

void AttrArray::ClearMappedServoStyle() {
  if (mImpl && mImpl->mMappedAttrs) {
    mImpl->mMappedAttrs->ClearServoStyle();
  }
}

nsMappedAttributes* AttrArray::GetModifiableMapped(
    nsMappedAttributeElement* aContent, nsHTMLStyleSheet* aSheet,
    bool aWillAddAttr, int32_t aAttrCount) {
  if (mImpl && mImpl->mMappedAttrs) {
    return mImpl->mMappedAttrs->Clone(aWillAddAttr);
  }

  MOZ_ASSERT(aContent, "Trying to create modifiable without content");

  nsMapRuleToAttributesFunc mapRuleFunc =
      aContent->GetAttributeMappingFunction();
  return new (aAttrCount) nsMappedAttributes(aSheet, mapRuleFunc);
}

nsresult AttrArray::MakeMappedUnique(nsMappedAttributes* aAttributes) {
  NS_ASSERTION(aAttributes, "missing attributes");

  if (!mImpl && !GrowBy(1)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  if (!aAttributes->GetStyleSheet()) {
    // This doesn't currently happen, but it could if we do loading right

    RefPtr<nsMappedAttributes> mapped(aAttributes);
    mapped.swap(mImpl->mMappedAttrs);

    return NS_OK;
  }

  RefPtr<nsMappedAttributes> mapped =
      aAttributes->GetStyleSheet()->UniqueMappedAttributes(aAttributes);
  NS_ENSURE_TRUE(mapped, NS_ERROR_OUT_OF_MEMORY);

  if (mapped != aAttributes) {
    // Reset the stylesheet of aAttributes so that it doesn't spend time
    // trying to remove itself from the hash. There is no risk that aAttributes
    // is in the hash since it will always have come from GetModifiableMapped,
    // which never returns maps that are in the hash (such hashes are by
    // nature not modifiable).
    aAttributes->DropStyleSheetReference();
  }
  mapped.swap(mImpl->mMappedAttrs);

  return NS_OK;
}

const nsMappedAttributes* AttrArray::GetMapped() const {
  return mImpl ? mImpl->mMappedAttrs : nullptr;
}

nsresult AttrArray::EnsureCapacityToClone(const AttrArray& aOther) {
  MOZ_ASSERT(!mImpl,
             "AttrArray::EnsureCapacityToClone requires the array be empty "
             "when called");

  uint32_t attrCount = aOther.NonMappedAttrCount();
  if (!attrCount) {
    return NS_OK;
  }

  // No need to use a CheckedUint32 because we are cloning. We know that we
  // have already allocated an AttrArray of this size.
  mImpl.reset(
      static_cast<Impl*>(malloc(Impl::AllocationSizeForAttributes(attrCount))));
  NS_ENSURE_TRUE(mImpl, NS_ERROR_OUT_OF_MEMORY);

  mImpl->mMappedAttrs = nullptr;
  mImpl->mCapacity = attrCount;
  mImpl->mAttrCount = 0;

  return NS_OK;
}

bool AttrArray::GrowBy(uint32_t aGrowSize) {
  const uint32_t kLinearThreshold = 16;
  const uint32_t kLinearGrowSize = 4;

  CheckedUint32 capacity = mImpl ? mImpl->mCapacity : 0;
  CheckedUint32 minCapacity = capacity;
  minCapacity += aGrowSize;
  if (!minCapacity.isValid()) {
    return false;
  }

  if (capacity.value() <= kLinearThreshold) {
    do {
      capacity += kLinearGrowSize;
      if (!capacity.isValid()) {
        return false;
      }
    } while (capacity.value() < minCapacity.value());
  } else {
    uint32_t shift = mozilla::CeilingLog2(minCapacity.value());
    if (shift >= 32) {
      return false;
    }
    capacity = 1u << shift;
  }

  CheckedUint32 sizeInBytes = capacity.value();
  sizeInBytes *= sizeof(InternalAttr);
  if (!sizeInBytes.isValid()) {
    return false;
  }

  sizeInBytes += sizeof(Impl);
  if (!sizeInBytes.isValid()) {
    return false;
  }

  MOZ_ASSERT(sizeInBytes.value() ==
             Impl::AllocationSizeForAttributes(capacity.value()));

  const bool needToInitialize = !mImpl;
  Impl* newImpl =
      static_cast<Impl*>(realloc(mImpl.release(), sizeInBytes.value()));
  NS_ENSURE_TRUE(newImpl, false);

  mImpl.reset(newImpl);

  // Set initial counts if we didn't have a buffer before
  if (needToInitialize) {
    mImpl->mMappedAttrs = nullptr;
    mImpl->mAttrCount = 0;
  }

  mImpl->mCapacity = capacity.value();
  return true;
}

size_t AttrArray::SizeOfExcludingThis(
    mozilla::MallocSizeOf aMallocSizeOf) const {
  size_t n = 0;
  if (mImpl) {
    // Don't add the size taken by *mMappedAttrs because it's shared.

    n += aMallocSizeOf(mImpl.get());

    for (const InternalAttr& attr : NonMappedAttrs()) {
      n += attr.mValue.SizeOfExcludingThis(aMallocSizeOf);
    }
  }

  return n;
}