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/*
* Copyright (C) 2008 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 PurgeableBuffer_h
#define PurgeableBuffer_h
#include <wtf/Noncopyable.h>
#include <wtf/Vector.h>
namespace WebCore {
class PurgeableBuffer : Noncopyable {
public:
static PurgeableBuffer* create(const char* data, size_t);
static PurgeableBuffer* create(const Vector<char>& v) { return create(v.data(), v.size()); }
~PurgeableBuffer();
// Call makePurgeable(false) and check the return value before accessing the data.
const char* data() const;
size_t size() const { return m_size; }
enum PurgePriority { PurgeLast, PurgeMiddle, PurgeFirst, PurgeDefault = PurgeMiddle };
PurgePriority purgePriority() const { return m_purgePriority; }
void setPurgePriority(PurgePriority);
bool isPurgeable() const { return m_state != NonVolatile; }
bool wasPurged() const;
bool makePurgeable(bool purgeable);
private:
PurgeableBuffer(char* data, size_t);
char* m_data;
size_t m_size;
PurgePriority m_purgePriority;
enum State { NonVolatile, Volatile, Purged };
mutable State m_state;
};
#if !PLATFORM(DARWIN) || defined(BUILDING_ON_TIGER) || PLATFORM(QT)
inline PurgeableBuffer* PurgeableBuffer::create(const char*, size_t) { return 0; }
inline PurgeableBuffer::~PurgeableBuffer() { }
inline const char* PurgeableBuffer::data() const { return 0; }
inline void PurgeableBuffer::setPurgePriority(PurgePriority) { }
inline bool PurgeableBuffer::wasPurged() const { return false; }
inline bool PurgeableBuffer::makePurgeable(bool) { return false; }
#endif
}
#endif
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