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/*
* Copyright (C) 2009 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 COMPUTER, 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 COMPUTER, 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 <wtf/ArrayBuffer.h>
#include <algorithm>
#include <limits.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>
namespace WTF {
class WTF_EXPORT_PRIVATE_RTTI ArrayBufferView : public RefCounted<ArrayBufferView> {
public:
enum ViewType {
TypeInt8,
TypeUint8,
TypeUint8Clamped,
TypeInt16,
TypeUint16,
TypeInt32,
TypeUint32,
TypeFloat32,
TypeFloat64,
TypeDataView
};
virtual ViewType getType() const = 0;
PassRefPtr<ArrayBuffer> buffer() const
{
return m_buffer;
}
void* baseAddress() const
{
return m_baseAddress;
}
unsigned byteOffset() const
{
return m_byteOffset;
}
virtual unsigned byteLength() const = 0;
WTF_EXPORT_PRIVATE_NO_RTTI virtual ~ArrayBufferView();
protected:
WTF_EXPORT_PRIVATE_NO_RTTI 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);
// Helper to verify that a given sub-range of an ArrayBuffer is
// within range.
template <typename T>
static bool verifySubRange(PassRefPtr<ArrayBuffer> buffer,
unsigned byteOffset,
unsigned numElements)
{
if (!buffer)
return false;
if (sizeof(T) > 1 && byteOffset % sizeof(T))
return false;
if (byteOffset > buffer->byteLength())
return false;
unsigned remainingElements = (buffer->byteLength() - byteOffset) / sizeof(T);
if (numElements > remainingElements)
return false;
return true;
}
// 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);
}
WTF_EXPORT_PRIVATE_NO_RTTI virtual void neuter();
// This is the address of the ArrayBuffer's storage, plus the byte offset.
void* m_baseAddress;
unsigned m_byteOffset;
private:
friend class ArrayBuffer;
RefPtr<ArrayBuffer> m_buffer;
ArrayBufferView* m_prevView;
ArrayBufferView* m_nextView;
};
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 WTF
using WTF::ArrayBufferView;
#endif // ArrayBufferView_h