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/*
* Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
* Copyright (C) Research In Motion Limited 2009-2010. 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 SharedBuffer_h
#define SharedBuffer_h
#include "platform/PlatformExport.h"
#include "third_party/skia/include/core/SkData.h"
#include "wtf/ArrayBuffer.h"
#include "wtf/Forward.h"
#include "wtf/OwnPtr.h"
#include "wtf/RefCounted.h"
#include "wtf/Vector.h"
#include "wtf/text/WTFString.h"
namespace WebCore {
class PurgeableBuffer;
class PLATFORM_EXPORT SharedBuffer : public RefCounted<SharedBuffer> {
public:
static PassRefPtr<SharedBuffer> create() { return adoptRef(new SharedBuffer); }
static PassRefPtr<SharedBuffer> create(size_t size) { return adoptRef(new SharedBuffer(size)); }
static PassRefPtr<SharedBuffer> create(const char* c, int i) { return adoptRef(new SharedBuffer(c, i)); }
static PassRefPtr<SharedBuffer> create(const unsigned char* c, int i) { return adoptRef(new SharedBuffer(c, i)); }
static PassRefPtr<SharedBuffer> adoptVector(Vector<char>& vector);
// The buffer must be in non-purgeable state before adopted to a SharedBuffer.
// It will stay that way until released.
static PassRefPtr<SharedBuffer> adoptPurgeableBuffer(PassOwnPtr<PurgeableBuffer>);
~SharedBuffer();
// Calling this function will force internal segmented buffers
// to be merged into a flat buffer. Use getSomeData() whenever possible
// for better performance.
const char* data() const;
void moveTo(Vector<char>&);
unsigned size() const;
bool isEmpty() const { return !size(); }
void append(SharedBuffer*);
void append(const char*, unsigned);
void append(const Vector<char>&);
void clear();
PassRefPtr<SharedBuffer> copy() const;
bool hasPurgeableBuffer() const { return m_purgeableBuffer.get(); }
// Ensure this buffer has no other clients before calling this.
PassOwnPtr<PurgeableBuffer> releasePurgeableBuffer();
// Return the number of consecutive bytes after "position". "data"
// points to the first byte.
// Return 0 when no more data left.
// When extracting all data with getSomeData(), the caller should
// repeat calling it until it returns 0.
// Usage:
// const char* segment;
// unsigned pos = 0;
// while (unsigned length = sharedBuffer->getSomeData(segment, pos)) {
// // Use the data. for example: decoder->decode(segment, length);
// pos += length;
// }
unsigned getSomeData(const char*& data, unsigned position = 0) const;
void createPurgeableBuffer() const;
// Creates an ArrayBuffer and copies this SharedBuffer's contents to that
// ArrayBuffer without merging segmented buffers into a flat buffer.
PassRefPtr<ArrayBuffer> getAsArrayBuffer() const;
// Creates an SkData and copies this SharedBuffer's contents to that
// SkData without merging segmented buffers into a flat buffer.
PassRefPtr<SkData> getAsSkData() const;
private:
SharedBuffer();
explicit SharedBuffer(size_t);
SharedBuffer(const char*, int);
SharedBuffer(const unsigned char*, int);
// Calling this function will force internal segmented buffers
// to be merged into a flat buffer. Use getSomeData() whenever possible
// for better performance.
// As well, be aware that this method does *not* return any purgeable
// memory, which can be a source of bugs.
const Vector<char>& buffer() const;
unsigned m_size;
mutable Vector<char> m_buffer;
mutable Vector<char*> m_segments;
mutable OwnPtr<PurgeableBuffer> m_purgeableBuffer;
};
} // namespace WebCore
#endif // SharedBuffer_h
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