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/*
* Copyright (C) 2009, 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ArrayBufferView_h
#define ArrayBufferView_h
#include "ArrayBuffer.h"
#include "TypedArrayType.h"
#include <algorithm>
#include <limits.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>
namespace JSC {
class JSArrayBufferView;
class JSGlobalObject;
class ExecState;
class ArrayBufferView : public RefCounted<ArrayBufferView> {
public:
virtual TypedArrayType getType() const = 0;
bool isNeutered() const
{
return !m_buffer || m_buffer->isNeutered();
}
PassRefPtr<ArrayBuffer> buffer() const
{
if (isNeutered())
return 0;
return m_buffer;
}
void* baseAddress() const
{
if (isNeutered())
return 0;
return m_baseAddress;
}
unsigned byteOffset() const
{
if (isNeutered())
return 0;
return m_byteOffset;
}
virtual unsigned byteLength() const = 0;
JS_EXPORT_PRIVATE void setNeuterable(bool flag);
bool isNeuterable() const { return m_isNeuterable; }
JS_EXPORT_PRIVATE virtual ~ArrayBufferView();
// Helper to verify byte offset is size aligned.
static bool verifyByteOffsetAlignment(unsigned byteOffset, size_t size)
{
return !(byteOffset & (size - 1));
}
// Helper to verify that a given sub-range of an ArrayBuffer is
// within range.
static bool verifySubRangeLength(PassRefPtr<ArrayBuffer> buffer, unsigned byteOffset, unsigned numElements, size_t size)
{
unsigned byteLength = buffer->byteLength();
if (byteOffset > byteLength)
return false;
unsigned remainingElements = (byteLength - byteOffset) / size;
if (numElements > remainingElements)
return false;
return true;
}
virtual JSArrayBufferView* wrap(ExecState*, JSGlobalObject*) = 0;
protected:
JS_EXPORT_PRIVATE ArrayBufferView(PassRefPtr<ArrayBuffer>, unsigned byteOffset);
inline bool setImpl(ArrayBufferView*, unsigned byteOffset);
inline bool setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset);
inline bool zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength);
static inline void calculateOffsetAndLength(
int start, int end, unsigned arraySize,
unsigned* offset, unsigned* length);
// Input offset is in number of elements from this array's view;
// output offset is in number of bytes from the underlying buffer's view.
template <typename T>
static void clampOffsetAndNumElements(
PassRefPtr<ArrayBuffer> buffer,
unsigned arrayByteOffset,
unsigned *offset,
unsigned *numElements)
{
unsigned maxOffset = (UINT_MAX - arrayByteOffset) / sizeof(T);
if (*offset > maxOffset) {
*offset = buffer->byteLength();
*numElements = 0;
return;
}
*offset = arrayByteOffset + *offset * sizeof(T);
*offset = std::min(buffer->byteLength(), *offset);
unsigned remainingElements = (buffer->byteLength() - *offset) / sizeof(T);
*numElements = std::min(remainingElements, *numElements);
}
// This is the address of the ArrayBuffer's storage, plus the byte offset.
void* m_baseAddress;
unsigned m_byteOffset : 31;
bool m_isNeuterable : 1;
private:
friend class ArrayBuffer;
RefPtr<ArrayBuffer> m_buffer;
};
bool ArrayBufferView::setImpl(ArrayBufferView* array, unsigned byteOffset)
{
if (byteOffset > byteLength()
|| byteOffset + array->byteLength() > byteLength()
|| byteOffset + array->byteLength() < byteOffset) {
// Out of range offset or overflow
return false;
}
char* base = static_cast<char*>(baseAddress());
memmove(base + byteOffset, array->baseAddress(), array->byteLength());
return true;
}
bool ArrayBufferView::setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset)
{
if (byteOffset > byteLength()
|| byteOffset + dataByteLength > byteLength()
|| byteOffset + dataByteLength < byteOffset) {
// Out of range offset or overflow
return false;
}
char* base = static_cast<char*>(baseAddress());
memmove(base + byteOffset, data, dataByteLength);
return true;
}
bool ArrayBufferView::zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength)
{
if (byteOffset > byteLength()
|| byteOffset + rangeByteLength > byteLength()
|| byteOffset + rangeByteLength < byteOffset) {
// Out of range offset or overflow
return false;
}
char* base = static_cast<char*>(baseAddress());
memset(base + byteOffset, 0, rangeByteLength);
return true;
}
void ArrayBufferView::calculateOffsetAndLength(
int start, int end, unsigned arraySize, unsigned* offset, unsigned* length)
{
if (start < 0)
start += arraySize;
if (start < 0)
start = 0;
if (end < 0)
end += arraySize;
if (end < 0)
end = 0;
if (static_cast<unsigned>(end) > arraySize)
end = arraySize;
if (end < start)
end = start;
*offset = static_cast<unsigned>(start);
*length = static_cast<unsigned>(end - start);
}
} // namespace JSC
using JSC::ArrayBufferView;
#endif // ArrayBufferView_h
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