The Tor Browser: layout/style/nsCSSDataBlock.cpp@7e26c7da4463 (annotated)

layout/style/nsCSSDataBlock.cpp@7e26c7da4463 (annotated)

layout/style/nsCSSDataBlock.cpp

Wed, 31 Dec 2014 06:55:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:50 +0100
changeset 2: 7e26c7da4463
permissions: -rw-r--r--

Added tag UPSTREAM_283F7C6 for changeset ca08bd8f51b2

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* 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/. */
 /*
  * compact representation of the property-value pairs within a CSS
  * declaration, and the code for expanding and compacting it
  */
 #include "nsCSSDataBlock.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/css/Declaration.h"
 #include "mozilla/css/ImageLoader.h"
 #include "nsRuleData.h"
 #include "nsStyleSet.h"
 #include "nsStyleContext.h"
 #include "nsIDocument.h"
 using namespace mozilla;
 /**
  * Does a fast move of aSource to aDest.  The previous value in
  * aDest is cleanly destroyed, and aSource is cleared.  Returns
  * true if, before the copy, the value at aSource compared unequal
  * to the value at aDest; false otherwise.
  */
 static bool
 MoveValue(nsCSSValue* aSource, nsCSSValue* aDest)
 {
     bool changed = (*aSource != *aDest);
     aDest->~nsCSSValue();
     memcpy(aDest, aSource, sizeof(nsCSSValue));
     new (aSource) nsCSSValue();
     return changed;
 }
 static bool
 ShouldIgnoreColors(nsRuleData *aRuleData)
 {
     return aRuleData->mLevel != nsStyleSet::eAgentSheet &&
            aRuleData->mLevel != nsStyleSet::eUserSheet &&
            !aRuleData->mPresContext->UseDocumentColors();
 }
 /**
  * Tries to call |nsCSSValue::StartImageLoad()| on an image source.
  * Image sources are specified by |url()| or |-moz-image-rect()| function.
  */
 static void
 TryToStartImageLoadOnValue(const nsCSSValue& aValue, nsIDocument* aDocument,
                            nsCSSValueTokenStream* aTokenStream)
 {
   MOZ_ASSERT(aDocument);
   if (aValue.GetUnit() == eCSSUnit_URL) {
     aValue.StartImageLoad(aDocument);
     if (aTokenStream) {
       aTokenStream->mImageValues.PutEntry(aValue.GetImageStructValue());
     }
   }
   else if (aValue.GetUnit() == eCSSUnit_Image) {
     // If we already have a request, see if this document needs to clone it.
     imgIRequest* request = aValue.GetImageValue(nullptr);
     if (request) {
       mozilla::css::ImageValue* imageValue = aValue.GetImageStructValue();
       aDocument->StyleImageLoader()->MaybeRegisterCSSImage(imageValue);
       if (aTokenStream) {
         aTokenStream->mImageValues.PutEntry(imageValue);
       }
     }
   }
   else if (aValue.EqualsFunction(eCSSKeyword__moz_image_rect)) {
     nsCSSValue::Array* arguments = aValue.GetArrayValue();
     NS_ABORT_IF_FALSE(arguments->Count() == 6, "unexpected num of arguments");
     const nsCSSValue& image = arguments->Item(1);
     TryToStartImageLoadOnValue(image, aDocument, aTokenStream);
   }
 }
 static void
 TryToStartImageLoad(const nsCSSValue& aValue, nsIDocument* aDocument,
                     nsCSSProperty aProperty,
                     nsCSSValueTokenStream* aTokenStream)
 {
   if (aValue.GetUnit() == eCSSUnit_List) {
     for (const nsCSSValueList* l = aValue.GetListValue(); l; l = l->mNext) {
       TryToStartImageLoad(l->mValue, aDocument, aProperty, aTokenStream);
     }
   } else if (nsCSSProps::PropHasFlags(aProperty,
                                       CSS_PROPERTY_IMAGE_IS_IN_ARRAY_0)) {
     if (aValue.GetUnit() == eCSSUnit_Array) {
       TryToStartImageLoadOnValue(aValue.GetArrayValue()->Item(0), aDocument,
                                  aTokenStream);
     }
   } else {
     TryToStartImageLoadOnValue(aValue, aDocument, aTokenStream);
   }
 }
 static inline bool
 ShouldStartImageLoads(nsRuleData *aRuleData, nsCSSProperty aProperty)
 {
   // Don't initiate image loads for if-visited styles.  This is
   // important because:
   //  (1) it's a waste of CPU and bandwidth
   //  (2) in some cases we'd start the image load on a style change
   //      where we wouldn't have started the load initially, which makes
   //      which links are visited detectable to Web pages (see bug
   //      557287)
   return !aRuleData->mStyleContext->IsStyleIfVisited() &&
          nsCSSProps::PropHasFlags(aProperty, CSS_PROPERTY_START_IMAGE_LOADS);
 }
 static void
 MapSinglePropertyInto(nsCSSProperty aProp,
                       const nsCSSValue* aValue,
                       nsCSSValue* aTarget,
                       nsRuleData* aRuleData)
 {
     NS_ABORT_IF_FALSE(aValue->GetUnit() != eCSSUnit_Null, "oops");
     // Although aTarget is the nsCSSValue we are going to write into,
     // we also look at its value before writing into it.  This is done
     // when aTarget is a token stream value, which is the case when we
     // have just re-parsed a property that had a variable reference (in
     // nsCSSParser::ParsePropertyWithVariableReferences).  TryToStartImageLoad
     // then records any resulting ImageValue objects on the
     // nsCSSValueTokenStream object we found on aTarget.  See the comment
     // above nsCSSValueTokenStream::mImageValues for why.
     NS_ABORT_IF_FALSE(aTarget->GetUnit() == eCSSUnit_TokenStream ||
                       aTarget->GetUnit() == eCSSUnit_Null,
                       "aTarget must only be a token stream (when re-parsing "
                       "properties with variable references) or null");
     nsCSSValueTokenStream* tokenStream =
         aTarget->GetUnit() == eCSSUnit_TokenStream ?
             aTarget->GetTokenStreamValue() :
             nullptr;
     if (ShouldStartImageLoads(aRuleData, aProp)) {
         nsIDocument* doc = aRuleData->mPresContext->Document();
         TryToStartImageLoad(*aValue, doc, aProp, tokenStream);
     }
     *aTarget = *aValue;
     if (nsCSSProps::PropHasFlags(aProp,
             CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED) &&
         ShouldIgnoreColors(aRuleData))
     {
         if (aProp == eCSSProperty_background_color) {
             // Force non-'transparent' background
             // colors to the user's default.
             if (aTarget->IsNonTransparentColor()) {
                 aTarget->SetColorValue(aRuleData->mPresContext->
                                        DefaultBackgroundColor());
             }
         } else {
             // Ignore 'color', 'border-*-color', etc.
             *aTarget = nsCSSValue();
         }
     }
 }
 void
 nsCSSCompressedDataBlock::MapRuleInfoInto(nsRuleData *aRuleData) const
 {
     // If we have no data for these structs, then return immediately.
     // This optimization should make us return most of the time, so we
     // have to worry much less (although still some) about the speed of
     // the rest of the function.
     if (!(aRuleData->mSIDs & mStyleBits))
         return;
     for (uint32_t i = 0; i < mNumProps; i++) {
         nsCSSProperty iProp = PropertyAtIndex(i);
         if (nsCachedStyleData::GetBitForSID(nsCSSProps::kSIDTable[iProp]) &
             aRuleData->mSIDs) {
             nsCSSValue* target = aRuleData->ValueFor(iProp);
             if (target->GetUnit() == eCSSUnit_Null) {
                 const nsCSSValue *val = ValueAtIndex(i);
                 MapSinglePropertyInto(iProp, val, target, aRuleData);
             }
         }
     }
 }
 const nsCSSValue*
 nsCSSCompressedDataBlock::ValueFor(nsCSSProperty aProperty) const
 {
     NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty),
                       "Don't call for shorthands");
     // If we have no data for this struct, then return immediately.
     // This optimization should make us return most of the time, so we
     // have to worry much less (although still some) about the speed of
     // the rest of the function.
     if (!(nsCachedStyleData::GetBitForSID(nsCSSProps::kSIDTable[aProperty]) &
           mStyleBits))
         return nullptr;
     for (uint32_t i = 0; i < mNumProps; i++) {
         if (PropertyAtIndex(i) == aProperty) {
             return ValueAtIndex(i);
         }
     }
     return nullptr;
 }
 bool
 nsCSSCompressedDataBlock::TryReplaceValue(nsCSSProperty aProperty,
                                           nsCSSExpandedDataBlock& aFromBlock,
                                           bool *aChanged)
 {
     nsCSSValue* newValue = aFromBlock.PropertyAt(aProperty);
     NS_ABORT_IF_FALSE(newValue && newValue->GetUnit() != eCSSUnit_Null,
                       "cannot replace with empty value");
     const nsCSSValue* oldValue = ValueFor(aProperty);
     if (!oldValue) {
         *aChanged = false;
         return false;
     }
     *aChanged = MoveValue(newValue, const_cast<nsCSSValue*>(oldValue));
     aFromBlock.ClearPropertyBit(aProperty);
     return true;
 }
 nsCSSCompressedDataBlock*
 nsCSSCompressedDataBlock::Clone() const
 {
     nsAutoPtr<nsCSSCompressedDataBlock>
         result(new(mNumProps) nsCSSCompressedDataBlock(mNumProps));
     result->mStyleBits = mStyleBits;
     for (uint32_t i = 0; i < mNumProps; i++) {
         result->SetPropertyAtIndex(i, PropertyAtIndex(i));
         result->CopyValueToIndex(i, ValueAtIndex(i));
     }
     return result.forget();
 }
 nsCSSCompressedDataBlock::~nsCSSCompressedDataBlock()
 {
     for (uint32_t i = 0; i < mNumProps; i++) {
 #ifdef DEBUG
         (void)PropertyAtIndex(i);   // this checks the property is in range
 #endif
         const nsCSSValue* val = ValueAtIndex(i);
         NS_ABORT_IF_FALSE(val->GetUnit() != eCSSUnit_Null, "oops");
         val->~nsCSSValue();
     }
 }
 /* static */ nsCSSCompressedDataBlock*
 nsCSSCompressedDataBlock::CreateEmptyBlock()
 {
     nsCSSCompressedDataBlock *result = new(0) nsCSSCompressedDataBlock(0);
     return result;
 }
 size_t
 nsCSSCompressedDataBlock::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
     size_t n = aMallocSizeOf(this);
     for (uint32_t i = 0; i < mNumProps; i++) {
         n += ValueAtIndex(i)->SizeOfExcludingThis(aMallocSizeOf);
     }
     return n;
 }
 bool
 nsCSSCompressedDataBlock::HasDefaultBorderImageSlice() const
 {
   const nsCSSValueList *slice =
     ValueFor(eCSSProperty_border_image_slice)->GetListValue();
   return !slice->mNext &&
          slice->mValue.GetRectValue().AllSidesEqualTo(
            nsCSSValue(1.0f, eCSSUnit_Percent));
 }
 bool
 nsCSSCompressedDataBlock::HasDefaultBorderImageWidth() const
 {
   const nsCSSRect &width =
     ValueFor(eCSSProperty_border_image_width)->GetRectValue();
   return width.AllSidesEqualTo(nsCSSValue(1.0f, eCSSUnit_Number));
 }
 bool
 nsCSSCompressedDataBlock::HasDefaultBorderImageOutset() const
 {
   const nsCSSRect &outset =
     ValueFor(eCSSProperty_border_image_outset)->GetRectValue();
   return outset.AllSidesEqualTo(nsCSSValue(0.0f, eCSSUnit_Number));
 }
 bool
 nsCSSCompressedDataBlock::HasDefaultBorderImageRepeat() const
 {
   const nsCSSValuePair &repeat =
     ValueFor(eCSSProperty_border_image_repeat)->GetPairValue();
   return repeat.BothValuesEqualTo(
     nsCSSValue(NS_STYLE_BORDER_IMAGE_REPEAT_STRETCH, eCSSUnit_Enumerated));
 }
 /*****************************************************************************/
 nsCSSExpandedDataBlock::nsCSSExpandedDataBlock()
 {
     AssertInitialState();
 }
 nsCSSExpandedDataBlock::~nsCSSExpandedDataBlock()
 {
     AssertInitialState();
 }
 void
 nsCSSExpandedDataBlock::DoExpand(nsCSSCompressedDataBlock *aBlock,
                                  bool aImportant)
 {
     /*
      * Save needless copying and allocation by copying the memory
      * corresponding to the stored data in the compressed block.
      */
     for (uint32_t i = 0; i < aBlock->mNumProps; i++) {
         nsCSSProperty iProp = aBlock->PropertyAtIndex(i);
         NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(iProp), "out of range");
         NS_ABORT_IF_FALSE(!HasPropertyBit(iProp),
                           "compressed block has property multiple times");
         SetPropertyBit(iProp);
         if (aImportant)
             SetImportantBit(iProp);
         const nsCSSValue* val = aBlock->ValueAtIndex(i);
         nsCSSValue* dest = PropertyAt(iProp);
         NS_ABORT_IF_FALSE(val->GetUnit() != eCSSUnit_Null, "oops");
         NS_ABORT_IF_FALSE(dest->GetUnit() == eCSSUnit_Null,
                           "expanding into non-empty block");
 #ifdef NS_BUILD_REFCNT_LOGGING
         dest->~nsCSSValue();
 #endif
         memcpy(dest, val, sizeof(nsCSSValue));
     }
     // Set the number of properties to zero so that we don't destroy the
     // remnants of what we just copied.
     aBlock->SetNumPropsToZero();
     delete aBlock;
 }
 void
 nsCSSExpandedDataBlock::Expand(nsCSSCompressedDataBlock *aNormalBlock,
                                nsCSSCompressedDataBlock *aImportantBlock)
 {
     NS_ABORT_IF_FALSE(aNormalBlock, "unexpected null block");
     AssertInitialState();
     DoExpand(aNormalBlock, false);
     if (aImportantBlock) {
         DoExpand(aImportantBlock, true);
     }
 }
 void
 nsCSSExpandedDataBlock::ComputeNumProps(uint32_t* aNumPropsNormal,
                                         uint32_t* aNumPropsImportant)
 {
     *aNumPropsNormal = *aNumPropsImportant = 0;
     for (size_t iHigh = 0; iHigh < nsCSSPropertySet::kChunkCount; ++iHigh) {
         if (!mPropertiesSet.HasPropertyInChunk(iHigh))
             continue;
         for (size_t iLow = 0; iLow < nsCSSPropertySet::kBitsInChunk; ++iLow) {
             if (!mPropertiesSet.HasPropertyAt(iHigh, iLow))
                 continue;
 #ifdef DEBUG
             nsCSSProperty iProp = nsCSSPropertySet::CSSPropertyAt(iHigh, iLow);
 #endif
             NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(iProp), "out of range");
             NS_ABORT_IF_FALSE(PropertyAt(iProp)->GetUnit() != eCSSUnit_Null,
                               "null value while computing size");
             if (mPropertiesImportant.HasPropertyAt(iHigh, iLow))
                 (*aNumPropsImportant)++;
             else
                 (*aNumPropsNormal)++;
         }
     }
 }
 void
 nsCSSExpandedDataBlock::Compress(nsCSSCompressedDataBlock **aNormalBlock,
                                  nsCSSCompressedDataBlock **aImportantBlock)
 {
     nsAutoPtr<nsCSSCompressedDataBlock> result_normal, result_important;
     uint32_t i_normal = 0, i_important = 0;
     uint32_t numPropsNormal, numPropsImportant;
     ComputeNumProps(&numPropsNormal, &numPropsImportant);
     result_normal =
         new(numPropsNormal) nsCSSCompressedDataBlock(numPropsNormal);
     if (numPropsImportant != 0) {
         result_important =
             new(numPropsImportant) nsCSSCompressedDataBlock(numPropsImportant);
     } else {
         result_important = nullptr;
     }
     /*
      * Save needless copying and allocation by copying the memory
      * corresponding to the stored data in the expanded block, and then
      * clearing the data in the expanded block.
      */
     for (size_t iHigh = 0; iHigh < nsCSSPropertySet::kChunkCount; ++iHigh) {
         if (!mPropertiesSet.HasPropertyInChunk(iHigh))
             continue;
         for (size_t iLow = 0; iLow < nsCSSPropertySet::kBitsInChunk; ++iLow) {
             if (!mPropertiesSet.HasPropertyAt(iHigh, iLow))
                 continue;
             nsCSSProperty iProp = nsCSSPropertySet::CSSPropertyAt(iHigh, iLow);
             NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(iProp), "out of range");
             bool important =
                 mPropertiesImportant.HasPropertyAt(iHigh, iLow);
             nsCSSCompressedDataBlock *result =
                 important ? result_important : result_normal;
             uint32_t* ip = important ? &i_important : &i_normal;
             nsCSSValue* val = PropertyAt(iProp);
             NS_ABORT_IF_FALSE(val->GetUnit() != eCSSUnit_Null,
                               "Null value while compressing");
             result->SetPropertyAtIndex(*ip, iProp);
             result->RawCopyValueToIndex(*ip, val);
             new (val) nsCSSValue();
             (*ip)++;
             result->mStyleBits |=
                 nsCachedStyleData::GetBitForSID(nsCSSProps::kSIDTable[iProp]);
         }
     }
     NS_ABORT_IF_FALSE(numPropsNormal == i_normal, "bad numProps");
     if (result_important) {
         NS_ABORT_IF_FALSE(numPropsImportant == i_important, "bad numProps");
     }
     ClearSets();
     AssertInitialState();
     *aNormalBlock = result_normal.forget();
     *aImportantBlock = result_important.forget();
 }
 void
 nsCSSExpandedDataBlock::AddLonghandProperty(nsCSSProperty aProperty,
                                             const nsCSSValue& aValue)
 {
     NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty),
                       "property out of range");
     nsCSSValue& storage = *static_cast<nsCSSValue*>(PropertyAt(aProperty));
     storage = aValue;
     SetPropertyBit(aProperty);
 }
 void
 nsCSSExpandedDataBlock::Clear()
 {
     for (size_t iHigh = 0; iHigh < nsCSSPropertySet::kChunkCount; ++iHigh) {
         if (!mPropertiesSet.HasPropertyInChunk(iHigh))
             continue;
         for (size_t iLow = 0; iLow < nsCSSPropertySet::kBitsInChunk; ++iLow) {
             if (!mPropertiesSet.HasPropertyAt(iHigh, iLow))
                 continue;
             nsCSSProperty iProp = nsCSSPropertySet::CSSPropertyAt(iHigh, iLow);
             ClearLonghandProperty(iProp);
         }
     }
     AssertInitialState();
 }
 void
 nsCSSExpandedDataBlock::ClearProperty(nsCSSProperty aPropID)
 {
   if (nsCSSProps::IsShorthand(aPropID)) {
     CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(p, aPropID) {
       ClearLonghandProperty(*p);
     }
   } else {
     ClearLonghandProperty(aPropID);
   }
 }
 void
 nsCSSExpandedDataBlock::ClearLonghandProperty(nsCSSProperty aPropID)
 {
     NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aPropID), "out of range");
     ClearPropertyBit(aPropID);
     ClearImportantBit(aPropID);
     PropertyAt(aPropID)->Reset();
 }
 bool
 nsCSSExpandedDataBlock::TransferFromBlock(nsCSSExpandedDataBlock& aFromBlock,
                                           nsCSSProperty aPropID,
                                           bool aIsImportant,
                                           bool aOverrideImportant,
                                           bool aMustCallValueAppended,
                                           css::Declaration* aDeclaration)
 {
     if (!nsCSSProps::IsShorthand(aPropID)) {
         return DoTransferFromBlock(aFromBlock, aPropID,
                                    aIsImportant, aOverrideImportant,
                                    aMustCallValueAppended, aDeclaration);
     }
     bool changed = false;
     CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(p, aPropID) {
         changed |= DoTransferFromBlock(aFromBlock, *p,
                                        aIsImportant, aOverrideImportant,
                                        aMustCallValueAppended, aDeclaration);
     }
     return changed;
 }
 bool
 nsCSSExpandedDataBlock::DoTransferFromBlock(nsCSSExpandedDataBlock& aFromBlock,
                                             nsCSSProperty aPropID,
                                             bool aIsImportant,
                                             bool aOverrideImportant,
                                             bool aMustCallValueAppended,
                                             css::Declaration* aDeclaration)
 {
   bool changed = false;
   NS_ABORT_IF_FALSE(aFromBlock.HasPropertyBit(aPropID), "oops");
   if (aIsImportant) {
     if (!HasImportantBit(aPropID))
       changed = true;
     SetImportantBit(aPropID);
   } else {
     if (HasImportantBit(aPropID)) {
       // When parsing a declaration block, an !important declaration
       // is not overwritten by an ordinary declaration of the same
       // property later in the block.  However, CSSOM manipulations
       // come through here too, and in that case we do want to
       // overwrite the property.
       if (!aOverrideImportant) {
         aFromBlock.ClearLonghandProperty(aPropID);
         return false;
       }
       changed = true;
       ClearImportantBit(aPropID);
     }
   }
   if (aMustCallValueAppended || !HasPropertyBit(aPropID)) {
     aDeclaration->ValueAppended(aPropID);
   }
   SetPropertyBit(aPropID);
   aFromBlock.ClearPropertyBit(aPropID);
   /*
    * Save needless copying and allocation by calling the destructor in
    * the destination, copying memory directly, and then using placement
    * new.
    */
   changed |= MoveValue(aFromBlock.PropertyAt(aPropID), PropertyAt(aPropID));
   return changed;
 }
 void
 nsCSSExpandedDataBlock::MapRuleInfoInto(nsCSSProperty aPropID,
                                         nsRuleData* aRuleData) const
 {
   MOZ_ASSERT(!nsCSSProps::IsShorthand(aPropID));
   const nsCSSValue* src = PropertyAt(aPropID);
   MOZ_ASSERT(src->GetUnit() != eCSSUnit_Null);
   nsCSSValue* dest = aRuleData->ValueFor(aPropID);
   MOZ_ASSERT(dest->GetUnit() == eCSSUnit_TokenStream &&
              dest->GetTokenStreamValue()->mPropertyID == aPropID);
   MapSinglePropertyInto(aPropID, src, dest, aRuleData);
 }
 #ifdef DEBUG
 void
 nsCSSExpandedDataBlock::DoAssertInitialState()
 {
     mPropertiesSet.AssertIsEmpty("not initial state");
     mPropertiesImportant.AssertIsEmpty("not initial state");
     for (uint32_t i = 0; i < eCSSProperty_COUNT_no_shorthands; ++i) {
         nsCSSProperty prop = nsCSSProperty(i);
         NS_ABORT_IF_FALSE(PropertyAt(prop)->GetUnit() == eCSSUnit_Null,
                           "not initial state");
     }
 }
 #endif

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layout/style/nsCSSDataBlock.cpp@7e26c7da4463 (annotated)

layout/style/nsCSSDataBlock.cpp