JSArrayBufferView.h [plain text]
#pragma once
#include "AuxiliaryBarrier.h"
#include "JSObject.h"
#include <wtf/TaggedArrayStoragePtr.h>
namespace JSC {
class LLIntOffsetsExtractor;
enum TypedArrayMode : uint32_t {
FastTypedArray,
OversizeTypedArray,
WastefulTypedArray,
DataViewMode
};
inline bool hasArrayBuffer(TypedArrayMode mode)
{
return mode >= WastefulTypedArray;
}
class JSArrayBufferView : public JSNonFinalObject {
public:
using Base = JSNonFinalObject;
template<typename, SubspaceAccess>
static void subspaceFor(VM&)
{
RELEASE_ASSERT_NOT_REACHED();
}
static constexpr unsigned fastSizeLimit = 1000;
using VectorPtr = CagedBarrierPtr<Gigacage::Primitive, void, tagCagedPtr>;
static void* nullVectorPtr()
{
VectorPtr null { };
return null.rawBits();
}
static size_t sizeOf(uint32_t length, uint32_t elementSize)
{
return (static_cast<size_t>(length) * elementSize + sizeof(EncodedJSValue) - 1)
& ~(sizeof(EncodedJSValue) - 1);
}
static size_t allocationSize(Checked<size_t> inlineCapacity)
{
ASSERT_UNUSED(inlineCapacity, !inlineCapacity);
return sizeof(JSArrayBufferView);
}
protected:
class ConstructionContext {
WTF_MAKE_NONCOPYABLE(ConstructionContext);
public:
enum InitializationMode { ZeroFill, DontInitialize };
JS_EXPORT_PRIVATE ConstructionContext(VM&, Structure*, uint32_t length, uint32_t elementSize, InitializationMode = ZeroFill);
ConstructionContext(Structure*, uint32_t length, void* vector);
JS_EXPORT_PRIVATE ConstructionContext(
VM&, Structure*, RefPtr<ArrayBuffer>&&,
unsigned byteOffset, unsigned length);
enum DataViewTag { DataView };
ConstructionContext(
Structure*, RefPtr<ArrayBuffer>&&,
unsigned byteOffset, unsigned length, DataViewTag);
bool operator!() const { return !m_structure; }
Structure* structure() const { return m_structure; }
void* vector() const { return m_vector.getMayBeNull(m_length); }
uint32_t length() const { return m_length; }
TypedArrayMode mode() const { return m_mode; }
Butterfly* butterfly() const { return m_butterfly; }
private:
Structure* m_structure;
using VectorType = CagedPtr<Gigacage::Primitive, void, tagCagedPtr>;
VectorType m_vector;
uint32_t m_length;
TypedArrayMode m_mode;
Butterfly* m_butterfly;
};
JS_EXPORT_PRIVATE JSArrayBufferView(VM&, ConstructionContext&);
JS_EXPORT_PRIVATE void finishCreation(VM&);
static bool put(JSCell*, JSGlobalObject*, PropertyName, JSValue, PutPropertySlot&);
static void visitChildren(JSCell*, SlotVisitor&);
public:
TypedArrayMode mode() const { return m_mode; }
bool hasArrayBuffer() const { return JSC::hasArrayBuffer(mode()); }
bool isShared();
JS_EXPORT_PRIVATE ArrayBuffer* unsharedBuffer();
inline ArrayBuffer* possiblySharedBuffer();
JSArrayBuffer* unsharedJSBuffer(JSGlobalObject* globalObject);
JSArrayBuffer* possiblySharedJSBuffer(JSGlobalObject* globalObject);
RefPtr<ArrayBufferView> unsharedImpl();
JS_EXPORT_PRIVATE RefPtr<ArrayBufferView> possiblySharedImpl();
bool isNeutered() { return hasArrayBuffer() && !hasVector(); }
void neuter();
bool hasVector() const { return !!m_vector; }
void* vector() const { return m_vector.getMayBeNull(length()); }
inline unsigned byteOffset();
inline Optional<unsigned> byteOffsetConcurrently();
unsigned length() const { return m_length; }
DECLARE_EXPORT_INFO;
static ptrdiff_t offsetOfVector() { return OBJECT_OFFSETOF(JSArrayBufferView, m_vector); }
static ptrdiff_t offsetOfLength() { return OBJECT_OFFSETOF(JSArrayBufferView, m_length); }
static ptrdiff_t offsetOfMode() { return OBJECT_OFFSETOF(JSArrayBufferView, m_mode); }
static RefPtr<ArrayBufferView> toWrapped(VM&, JSValue);
private:
enum Requester { Mutator, ConcurrentThread };
template<Requester, typename ResultType> ResultType byteOffsetImpl();
template<Requester> ArrayBuffer* possiblySharedBufferImpl();
JS_EXPORT_PRIVATE ArrayBuffer* slowDownAndWasteMemory();
static void finalize(JSCell*);
protected:
friend class LLIntOffsetsExtractor;
ArrayBuffer* existingBufferInButterfly();
VectorPtr m_vector;
uint32_t m_length;
TypedArrayMode m_mode;
};
}
namespace WTF {
JS_EXPORT_PRIVATE void printInternal(PrintStream&, JSC::TypedArrayMode);
}