/* -*- 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"
#include "mozilla/dom/DOMString.h"
namespace mozilla {
class ShadowParts;
}
struct MiscContainer final {
using ValueType = nsAttrValue::ValueType;
ValueType mType;
// mStringBits points to either nsAtom* or mozilla::StringBuffer* 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;
mozilla::DeclarationBlock* mCSSDeclaration;
nsIURI* mURL;
const mozilla::AttrAtomArray* mAtomArray;
const mozilla::ShadowParts* mShadowParts;
const mozilla::SVGAnimatedIntegerPair* mSVGAnimatedIntegerPair;
const mozilla::SVGAnimatedLength* mSVGLength;
const mozilla::SVGAnimatedNumberPair* mSVGAnimatedNumberPair;
const mozilla::SVGAnimatedOrient* mSVGAnimatedOrient;
const mozilla::SVGAnimatedPreserveAspectRatio*
mSVGAnimatedPreserveAspectRatio;
const mozilla::SVGAnimatedViewBox* mSVGAnimatedViewBox;
const mozilla::SVGLengthList* mSVGLengthList;
const mozilla::SVGNumberList* mSVGNumberList;
const mozilla::SVGPathData* mSVGPathData;
const mozilla::SVGPointList* mSVGPointList;
const mozilla::SVGStringList* mSVGStringList;
const mozilla::SVGTransformList* mSVGTransformList;
};
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* GetStringOrAtomPtr(
bool& aIsString)
const {
uintptr_t bits = mStringBits;
aIsString =
nsAttrValue::ValueBaseType(mStringBits & NS_ATTRVALUE_BASETYPE_MASK) ==
nsAttrValue::eStringBase;
return reinterpret_cast<
void*>(bits & NS_ATTRVALUE_POINTERVALUE_MASK);
}
nsAtom* GetStoredAtom()
const {
bool isString =
false;
void* ptr = GetStringOrAtomPtr(isString);
return isString ? nullptr :
static_cast<nsAtom*>(ptr);
}
mozilla::StringBuffer* GetStoredStringBuffer()
const {
bool isString =
false;
void* ptr = GetStringOrAtomPtr(isString);
return isString ?
static_cast<mozilla::StringBuffer*>(ptr) : nullptr;
}
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::eAtomArray ||
mType == nsAttrValue::eCSSDeclaration ||
mType == nsAttrValue::eShadowParts;
}
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 double nsAttrValue::GetPercentValue()
const {
MOZ_ASSERT(Type() == ePercent,
"wrong type");
if (BaseType() == eIntegerBase) {
return GetIntInternal() / 100.0f;
}
return GetMiscContainer()->mDoubleValue / 100.0f;
}
inline const mozilla::AttrAtomArray* 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::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: {
if (
auto* str =
static_cast<mozilla::StringBuffer*>(GetPtr())) {
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());
}
}
}
inline const mozilla::ShadowParts& nsAttrValue::GetShadowPartsValue()
const {
MOZ_ASSERT(Type() == eShadowParts);
return *GetMiscContainer()->mValue.mShadowParts;
}
#endif
