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.

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
/* -*- 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/. */

/*
 * A unique per-element set of attributes that is used as an
 * nsIStyleRule; used to implement presentational attributes.
 */

#include "nsMappedAttributes.h"
#include "nsHTMLStyleSheet.h"
#include "nsRuleData.h"
#include "nsRuleWalker.h"
#include "mozilla/GenericSpecifiedValues.h"
#include "mozilla/HashFunctions.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/ServoDeclarationBlock.h"
#include "mozilla/ServoSpecifiedValues.h"

using namespace mozilla;

bool
nsMappedAttributes::sShuttingDown = false;
nsTArray<void*>*
nsMappedAttributes::sCachedMappedAttributeAllocations = nullptr;

void
nsMappedAttributes::Shutdown()
{
  sShuttingDown = true;
  if (sCachedMappedAttributeAllocations) {
    for (uint32_t i = 0; i < sCachedMappedAttributeAllocations->Length(); ++i) {
      void* cachedValue = (*sCachedMappedAttributeAllocations)[i];
      ::operator delete(cachedValue);
    }
  }

  delete sCachedMappedAttributeAllocations;
  sCachedMappedAttributeAllocations = nullptr;
}

nsMappedAttributes::nsMappedAttributes(nsHTMLStyleSheet* aSheet,
                                       nsMapRuleToAttributesFunc aMapRuleFunc)
  : mAttrCount(0),
    mSheet(aSheet),
    mRuleMapper(aMapRuleFunc),
    mServoStyle(nullptr)
{
  MOZ_ASSERT(mRefCnt == 0); // Ensure caching works as expected.
}

nsMappedAttributes::nsMappedAttributes(const nsMappedAttributes& aCopy)
  : mAttrCount(aCopy.mAttrCount),
    mSheet(aCopy.mSheet),
    mRuleMapper(aCopy.mRuleMapper),
    // This is only called by ::Clone, which is used to create independent
    // nsMappedAttributes objects which should not share a ServoDeclarationBlock
    mServoStyle(nullptr)
{
  NS_ASSERTION(mBufferSize >= aCopy.mAttrCount, "can't fit attributes");
  MOZ_ASSERT(mRefCnt == 0); // Ensure caching works as expected.

  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    new (&Attrs()[i]) InternalAttr(aCopy.Attrs()[i]);
  }
}

nsMappedAttributes::~nsMappedAttributes()
{
  if (mSheet) {
    mSheet->DropMappedAttributes(this);
  }

  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    Attrs()[i].~InternalAttr();
  }
}


nsMappedAttributes*
nsMappedAttributes::Clone(bool aWillAddAttr)
{
  uint32_t extra = aWillAddAttr ? 1 : 0;

  // This will call the overridden operator new
  return new (mAttrCount + extra) nsMappedAttributes(*this);
}

void* nsMappedAttributes::operator new(size_t aSize, uint32_t aAttrCount) CPP_THROW_NEW
{

  size_t size = aSize + aAttrCount * sizeof(InternalAttr);

  // aSize will include the mAttrs buffer so subtract that.
  // We don't want to under-allocate, however, so do not subtract
  // if we have zero attributes. The zero attribute case only happens
  // for <body>'s mapped attributes
  if (aAttrCount != 0) {
    size -= sizeof(void*[1]);
  }

  if (sCachedMappedAttributeAllocations) {
    void* cached =
      sCachedMappedAttributeAllocations->SafeElementAt(aAttrCount);
    if (cached) {
      (*sCachedMappedAttributeAllocations)[aAttrCount] = nullptr;
      return cached;
    }
  }

  void* newAttrs = ::operator new(size);

#ifdef DEBUG
  static_cast<nsMappedAttributes*>(newAttrs)->mBufferSize = aAttrCount;
#endif
  return newAttrs;
}

void
nsMappedAttributes::LastRelease()
{
  if (!sShuttingDown) {
    if (!sCachedMappedAttributeAllocations) {
      sCachedMappedAttributeAllocations = new nsTArray<void*>();
    }

    // Ensure the cache array is at least mAttrCount + 1 long and
    // that each item is either null or pointing to a cached item.
    // The size of the array is capped because mapped attributes are defined
    // statically in element implementations.
    sCachedMappedAttributeAllocations->SetCapacity(mAttrCount + 1);
    for (uint32_t i = sCachedMappedAttributeAllocations->Length();
         i < (uint32_t(mAttrCount) + 1); ++i) {
      sCachedMappedAttributeAllocations->AppendElement(nullptr);
    }

    if (!(*sCachedMappedAttributeAllocations)[mAttrCount]) {
      void* memoryToCache = this;
      this->~nsMappedAttributes();
      (*sCachedMappedAttributeAllocations)[mAttrCount] = memoryToCache;
      return;
    }
  }

  delete this;
}

NS_IMPL_ADDREF(nsMappedAttributes)
NS_IMPL_RELEASE_WITH_DESTROY(nsMappedAttributes, LastRelease())

NS_IMPL_QUERY_INTERFACE(nsMappedAttributes,
                        nsIStyleRule)

void
nsMappedAttributes::SetAndSwapAttr(nsAtom* aAttrName, nsAttrValue& aValue,
                                   bool* aValueWasSet)
{
  NS_PRECONDITION(aAttrName, "null name");
  *aValueWasSet = false;
  uint32_t i;
  for (i = 0; i < mAttrCount && !Attrs()[i].mName.IsSmaller(aAttrName); ++i) {
    if (Attrs()[i].mName.Equals(aAttrName)) {
      Attrs()[i].mValue.SwapValueWith(aValue);
      *aValueWasSet = true;
      return;
    }
  }

  NS_ASSERTION(mBufferSize >= mAttrCount + 1, "can't fit attributes");

  if (mAttrCount != i) {
    memmove(&Attrs()[i + 1], &Attrs()[i], (mAttrCount - i) * sizeof(InternalAttr));
  }

  new (&Attrs()[i].mName) nsAttrName(aAttrName);
  new (&Attrs()[i].mValue) nsAttrValue();
  Attrs()[i].mValue.SwapValueWith(aValue);
  ++mAttrCount;
}

const nsAttrValue*
nsMappedAttributes::GetAttr(nsAtom* aAttrName) const
{
  NS_PRECONDITION(aAttrName, "null name");

  for (uint32_t i = 0; i < mAttrCount; ++i) {
    if (Attrs()[i].mName.Equals(aAttrName)) {
      return &Attrs()[i].mValue;
    }
  }

  return nullptr;
}

const nsAttrValue*
nsMappedAttributes::GetAttr(const nsAString& aAttrName) const
{
  for (uint32_t i = 0; i < mAttrCount; ++i) {
    if (Attrs()[i].mName.Atom()->Equals(aAttrName)) {
      return &Attrs()[i].mValue;
    }
  }

  return nullptr;
}

bool
nsMappedAttributes::Equals(const nsMappedAttributes* aOther) const
{
  if (this == aOther) {
    return true;
  }

  if (mRuleMapper != aOther->mRuleMapper || mAttrCount != aOther->mAttrCount) {
    return false;
  }

  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    if (!Attrs()[i].mName.Equals(aOther->Attrs()[i].mName) ||
        !Attrs()[i].mValue.Equals(aOther->Attrs()[i].mValue)) {
      return false;
    }
  }

  return true;
}

PLDHashNumber
nsMappedAttributes::HashValue() const
{
  PLDHashNumber hash = HashGeneric(mRuleMapper);

  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    hash = AddToHash(hash,
                     Attrs()[i].mName.HashValue(),
                     Attrs()[i].mValue.HashValue());
  }

  return hash;
}

void
nsMappedAttributes::SetStyleSheet(nsHTMLStyleSheet* aSheet)
{
  if (mSheet) {
    mSheet->DropMappedAttributes(this);
  }
  mSheet = aSheet;  // not ref counted
}

/* virtual */ void
nsMappedAttributes::MapRuleInfoInto(nsRuleData* aRuleData)
{
  if (mRuleMapper) {
    (*mRuleMapper)(this, aRuleData);
  }
}

/* virtual */ bool
nsMappedAttributes::MightMapInheritedStyleData()
{
  // Just assume that we do, rather than adding checks to all of the different
  // kinds of attribute mapping functions we have.
  return true;
}

/* virtual */ bool
nsMappedAttributes::GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty,
                                                  nsCSSValue* aValue)
{
  MOZ_ASSERT(false, "GetDiscretelyAnimatedCSSValue is not implemented yet");
  return false;
}

#ifdef DEBUG
/* virtual */ void
nsMappedAttributes::List(FILE* out, int32_t aIndent) const
{
  nsAutoCString str;
  nsAutoString tmp;
  uint32_t i;

  for (i = 0; i < mAttrCount; ++i) {
    int32_t indent;
    for (indent = aIndent; indent > 0; --indent) {
      str.AppendLiteral("  ");
    }

    Attrs()[i].mName.GetQualifiedName(tmp);
    LossyAppendUTF16toASCII(tmp, str);

    Attrs()[i].mValue.ToString(tmp);
    LossyAppendUTF16toASCII(tmp, str);
    str.Append('\n');
    fprintf_stderr(out, "%s", str.get());
  }
}
#endif

void
nsMappedAttributes::RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue)
{
  Attrs()[aPos].mValue.SwapValueWith(aValue);
  Attrs()[aPos].~InternalAttr();
  memmove(&Attrs()[aPos], &Attrs()[aPos + 1],
          (mAttrCount - aPos - 1) * sizeof(InternalAttr));
  mAttrCount--;
}

const nsAttrName*
nsMappedAttributes::GetExistingAttrNameFromQName(const nsAString& aName) const
{
  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    if (Attrs()[i].mName.IsAtom()) {
      if (Attrs()[i].mName.Atom()->Equals(aName)) {
        return &Attrs()[i].mName;
      }
    }
    else {
      if (Attrs()[i].mName.NodeInfo()->QualifiedNameEquals(aName)) {
        return &Attrs()[i].mName;
      }
    }
  }

  return nullptr;
}

int32_t
nsMappedAttributes::IndexOfAttr(nsAtom* aLocalName) const
{
  uint32_t i;
  for (i = 0; i < mAttrCount; ++i) {
    if (Attrs()[i].mName.Equals(aLocalName)) {
      return i;
    }
  }

  return -1;
}

size_t
nsMappedAttributes::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
  NS_ASSERTION(mAttrCount == mBufferSize,
               "mBufferSize and mAttrCount are expected to be the same.");

  size_t n = aMallocSizeOf(this);
  for (uint16_t i = 0; i < mAttrCount; ++i) {
    n += Attrs()[i].mValue.SizeOfExcludingThis(aMallocSizeOf);
  }
  return n;
}

void
nsMappedAttributes::LazilyResolveServoDeclaration(nsPresContext* aContext)
{

  MOZ_ASSERT(!mServoStyle,
             "LazilyResolveServoDeclaration should not be called if mServoStyle is already set");
  if (mRuleMapper) {
    mServoStyle = Servo_DeclarationBlock_CreateEmpty().Consume();
    ServoSpecifiedValues servo = ServoSpecifiedValues(aContext, mServoStyle.get());
    (*mRuleMapper)(this, &servo);
  }
}