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/*
* Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
* Copyright (C) 2013 Google 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/OwnPtr.h"
#include "wtf/PassOwnPtr.h"
#include "platform/PlatformExport.h"
namespace blink {
class WebDiscardableMemory;
}
namespace WebCore {
class PLATFORM_EXPORT PurgeableBuffer {
WTF_MAKE_NONCOPYABLE(PurgeableBuffer);
public:
static PassOwnPtr<PurgeableBuffer> create(const char* data, size_t);
~PurgeableBuffer();
// Call lock and check the return value before accessing the data.
const char* data() const;
size_t size() const { return m_size; }
bool isPurgeable() const { return m_state != Locked; }
bool wasPurged() const;
bool lock();
void unlock();
private:
enum State {
Locked,
Unlocked,
Purged
};
PurgeableBuffer(PassOwnPtr<blink::WebDiscardableMemory>, const char* data, size_t);
OwnPtr<blink::WebDiscardableMemory> m_memory;
size_t m_size;
State m_state;
};
}
#endif
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