gecko-dev/dom/base/nsAttrValueInlines.h

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/* -*- 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 nsAttrValueInlines_h__
#define nsAttrValueInlines_h__
#include <stdint.h>
#include "nsAttrValue.h"
#include "mozilla/Atomics.h"
#include "mozilla/Attributes.h"
#include "mozilla/ServoUtils.h"
struct MiscContainer;
struct MiscContainer final
{
typedef nsAttrValue::ValueType ValueType;
ValueType mType;
// mStringBits points to either nsAtom* or nsStringBuffer* and is used when
// mType isn't eCSSDeclaration.
// Note eStringBase and eAtomBase is used also to handle the type of
// mStringBits.
//
// Note that we use an atomic here so that we can use Compare-And-Swap
// to cache the serialization during the parallel servo traversal. This case
// (which happens when the main thread is blocked) is the only case where
// mStringBits is mutated off-main-thread. The Atomic needs to be
// ReleaseAcquire so that the pointer to the serialization does not become
// observable to other threads before the initialization of the pointed-to
// memory is also observable.
mozilla::Atomic<uintptr_t, mozilla::ReleaseAcquire> mStringBits;
union {
struct {
union {
int32_t mInteger;
nscolor mColor;
uint32_t mEnumValue;
int32_t mPercent;
mozilla::DeclarationBlock* mCSSDeclaration;
nsIURI* mURL;
mozilla::AtomArray* mAtomArray;
nsIntMargin* mIntMargin;
const nsSVGAngle* mSVGAngle;
const nsSVGIntegerPair* mSVGIntegerPair;
const nsSVGLength2* mSVGLength;
const mozilla::SVGLengthList* mSVGLengthList;
const mozilla::SVGNumberList* mSVGNumberList;
const nsSVGNumberPair* mSVGNumberPair;
const mozilla::SVGPathData* mSVGPathData;
const mozilla::SVGPointList* mSVGPointList;
const mozilla::SVGAnimatedPreserveAspectRatio* mSVGPreserveAspectRatio;
const mozilla::SVGStringList* mSVGStringList;
const mozilla::SVGTransformList* mSVGTransformList;
const nsSVGViewBox* mSVGViewBox;
};
uint32_t mRefCount : 31;
uint32_t mCached : 1;
} mValue;
double mDoubleValue;
};
MiscContainer()
: mType(nsAttrValue::eColor),
mStringBits(0)
{
MOZ_COUNT_CTOR(MiscContainer);
mValue.mColor = 0;
mValue.mRefCount = 0;
mValue.mCached = 0;
}
protected:
// Only nsAttrValue should be able to delete us.
friend class nsAttrValue;
~MiscContainer()
{
if (IsRefCounted()) {
MOZ_ASSERT(mValue.mRefCount == 0);
MOZ_ASSERT(!mValue.mCached);
}
MOZ_COUNT_DTOR(MiscContainer);
}
public:
bool GetString(nsAString& aString) const;
void SetStringBitsMainThread(uintptr_t aBits)
{
// mStringBits is atomic, but the callers of this function are
// single-threaded so they don't have to worry about it.
MOZ_ASSERT(!mozilla::IsInServoTraversal());
MOZ_ASSERT(NS_IsMainThread());
mStringBits = aBits;
}
inline bool IsRefCounted() const
{
// Nothing stops us from refcounting (and sharing) other types of
// MiscContainer (except eDoubleValue types) but there's no compelling
// reason to.
return mType == nsAttrValue::eCSSDeclaration;
}
inline int32_t AddRef() {
MOZ_ASSERT(IsRefCounted());
return ++mValue.mRefCount;
}
inline int32_t Release() {
MOZ_ASSERT(IsRefCounted());
return --mValue.mRefCount;
}
void Cache();
void Evict();
};
/**
* Implementation of inline methods
*/
inline int32_t
nsAttrValue::GetIntegerValue() const
{
MOZ_ASSERT(Type() == eInteger, "wrong type");
return (BaseType() == eIntegerBase)
? GetIntInternal()
: GetMiscContainer()->mValue.mInteger;
}
inline int16_t
nsAttrValue::GetEnumValue() const
{
MOZ_ASSERT(Type() == eEnum, "wrong type");
// We don't need to worry about sign extension here since we're
// returning an int16_t which will cut away the top bits.
return static_cast<int16_t>((
(BaseType() == eIntegerBase)
? static_cast<uint32_t>(GetIntInternal())
: GetMiscContainer()->mValue.mEnumValue)
>> NS_ATTRVALUE_ENUMTABLEINDEX_BITS);
}
inline float
nsAttrValue::GetPercentValue() const
{
MOZ_ASSERT(Type() == ePercent, "wrong type");
return ((BaseType() == eIntegerBase)
? GetIntInternal()
: GetMiscContainer()->mValue.mPercent)
/ 100.0f;
}
inline mozilla::AtomArray*
nsAttrValue::GetAtomArrayValue() const
{
MOZ_ASSERT(Type() == eAtomArray, "wrong type");
return GetMiscContainer()->mValue.mAtomArray;
}
inline mozilla::DeclarationBlock*
nsAttrValue::GetCSSDeclarationValue() const
{
MOZ_ASSERT(Type() == eCSSDeclaration, "wrong type");
return GetMiscContainer()->mValue.mCSSDeclaration;
}
inline nsIURI*
nsAttrValue::GetURLValue() const
{
MOZ_ASSERT(Type() == eURL, "wrong type");
return GetMiscContainer()->mValue.mURL;
}
inline double
nsAttrValue::GetDoubleValue() const
{
MOZ_ASSERT(Type() == eDoubleValue, "wrong type");
return GetMiscContainer()->mDoubleValue;
}
inline bool
nsAttrValue::GetIntMarginValue(nsIntMargin& aMargin) const
{
MOZ_ASSERT(Type() == eIntMarginValue, "wrong type");
nsIntMargin* m = GetMiscContainer()->mValue.mIntMargin;
if (!m)
return false;
aMargin = *m;
return true;
}
inline bool
nsAttrValue::IsSVGType(ValueType aType) const
{
return aType >= eSVGTypesBegin && aType <= eSVGTypesEnd;
}
inline bool
nsAttrValue::StoresOwnData() const
{
if (BaseType() != eOtherBase) {
return true;
}
ValueType t = Type();
return t != eCSSDeclaration && !IsSVGType(t);
}
inline void
nsAttrValue::SetPtrValueAndType(void* aValue, ValueBaseType aType)
{
NS_ASSERTION(!(NS_PTR_TO_INT32(aValue) & ~NS_ATTRVALUE_POINTERVALUE_MASK),
"pointer not properly aligned, this will crash");
mBits = reinterpret_cast<intptr_t>(aValue) | aType;
}
inline void
nsAttrValue::ResetIfSet()
{
if (mBits) {
Reset();
}
}
inline MiscContainer*
nsAttrValue::GetMiscContainer() const
{
NS_ASSERTION(BaseType() == eOtherBase, "wrong type");
return static_cast<MiscContainer*>(GetPtr());
}
inline int32_t
nsAttrValue::GetIntInternal() const
{
NS_ASSERTION(BaseType() == eIntegerBase,
"getting integer from non-integer");
// Make sure we get a signed value.
// Lets hope the optimizer optimizes this into a shift. Unfortunatly signed
// bitshift right is implementaion dependant.
return static_cast<int32_t>(mBits & ~NS_ATTRVALUE_INTEGERTYPE_MASK) /
NS_ATTRVALUE_INTEGERTYPE_MULTIPLIER;
}
inline nsAttrValue::ValueType
nsAttrValue::Type() const
{
switch (BaseType()) {
case eIntegerBase:
{
return static_cast<ValueType>(mBits & NS_ATTRVALUE_INTEGERTYPE_MASK);
}
case eOtherBase:
{
return GetMiscContainer()->mType;
}
default:
{
return static_cast<ValueType>(static_cast<uint16_t>(BaseType()));
}
}
}
inline nsAtom*
nsAttrValue::GetAtomValue() const
{
MOZ_ASSERT(Type() == eAtom, "wrong type");
return reinterpret_cast<nsAtom*>(GetPtr());
}
inline void
nsAttrValue::ToString(mozilla::dom::DOMString& aResult) const
{
switch (Type()) {
case eString:
{
nsStringBuffer* str = static_cast<nsStringBuffer*>(GetPtr());
if (str) {
aResult.SetKnownLiveStringBuffer(
str, str->StorageSize()/sizeof(char16_t) - 1);
}
// else aResult is already empty
return;
}
case eAtom:
{
nsAtom *atom = static_cast<nsAtom*>(GetPtr());
aResult.SetKnownLiveAtom(atom, mozilla::dom::DOMString::eNullNotExpected);
break;
}
default:
{
ToString(aResult.AsAString());
}
}
}
#endif