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/*
* Copyright (C) 2012 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 PropertyOffset_h
#define PropertyOffset_h
#include <wtf/Platform.h>
#include <wtf/StdLibExtras.h>
#include <wtf/UnusedParam.h>
namespace JSC {
#if USE(JSVALUE32_64)
#define INLINE_STORAGE_CAPACITY 7
#else
#define INLINE_STORAGE_CAPACITY 6
#endif
typedef int PropertyOffset;
static const PropertyOffset invalidOffset = -1;
static const PropertyOffset firstOutOfLineOffset = 100;
// Declare all of the functions because they tend to do forward calls.
inline void checkOffset(PropertyOffset);
inline void checkOffset(PropertyOffset, PropertyOffset inlineCapacity);
inline void validateOffset(PropertyOffset);
inline void validateOffset(PropertyOffset, PropertyOffset inlineCapacity);
inline bool isValidOffset(PropertyOffset);
inline bool isInlineOffset(PropertyOffset);
inline bool isOutOfLineOffset(PropertyOffset);
inline size_t offsetInInlineStorage(PropertyOffset);
inline size_t offsetInOutOfLineStorage(PropertyOffset);
inline size_t offsetInRespectiveStorage(PropertyOffset);
inline size_t numberOfOutOfLineSlotsForLastOffset(PropertyOffset);
inline size_t numberOfSlotsForLastOffset(PropertyOffset, PropertyOffset inlineCapacity);
inline void checkOffset(PropertyOffset offset)
{
UNUSED_PARAM(offset);
ASSERT(offset >= invalidOffset);
}
inline void checkOffset(PropertyOffset offset, PropertyOffset inlineCapacity)
{
UNUSED_PARAM(offset);
UNUSED_PARAM(inlineCapacity);
ASSERT(offset >= invalidOffset);
ASSERT(offset == invalidOffset
|| offset < inlineCapacity
|| isOutOfLineOffset(offset));
}
inline void validateOffset(PropertyOffset offset)
{
checkOffset(offset);
ASSERT(isValidOffset(offset));
}
inline void validateOffset(PropertyOffset offset, PropertyOffset inlineCapacity)
{
checkOffset(offset, inlineCapacity);
ASSERT(isValidOffset(offset));
}
inline bool isValidOffset(PropertyOffset offset)
{
checkOffset(offset);
return offset != invalidOffset;
}
inline bool isInlineOffset(PropertyOffset offset)
{
checkOffset(offset);
return offset < firstOutOfLineOffset;
}
inline bool isOutOfLineOffset(PropertyOffset offset)
{
checkOffset(offset);
return !isInlineOffset(offset);
}
inline size_t offsetInInlineStorage(PropertyOffset offset)
{
validateOffset(offset);
ASSERT(isInlineOffset(offset));
return offset;
}
inline size_t offsetInOutOfLineStorage(PropertyOffset offset)
{
validateOffset(offset);
ASSERT(isOutOfLineOffset(offset));
return -static_cast<ptrdiff_t>(offset - firstOutOfLineOffset) - 1;
}
inline size_t offsetInRespectiveStorage(PropertyOffset offset)
{
if (isInlineOffset(offset))
return offsetInInlineStorage(offset);
return offsetInOutOfLineStorage(offset);
}
inline size_t numberOfOutOfLineSlotsForLastOffset(PropertyOffset offset)
{
checkOffset(offset);
if (offset < firstOutOfLineOffset)
return 0;
return offset - firstOutOfLineOffset + 1;
}
inline size_t numberOfSlotsForLastOffset(PropertyOffset offset, PropertyOffset inlineCapacity)
{
checkOffset(offset, inlineCapacity);
if (offset < inlineCapacity)
return offset + 1;
return inlineCapacity + numberOfOutOfLineSlotsForLastOffset(offset);
}
inline PropertyOffset propertyOffsetFor(PropertyOffset propertyNumber, PropertyOffset inlineCapacity)
{
PropertyOffset offset = propertyNumber;
if (offset >= inlineCapacity) {
offset += firstOutOfLineOffset;
offset -= inlineCapacity;
}
return offset;
}
} // namespace JSC
#endif // PropertyOffset_h