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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 "platform/PurgeableVector.h"
#include "third_party/skia/include/core/SkData.h"
#include "wtf/Forward.h"
#include "wtf/OwnPtr.h"
#include "wtf/RefCounted.h"
#include "wtf/text/WTFString.h"
namespace blink {
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> createPurgeable(const char* c, unsigned size) { return adoptRef(new SharedBuffer(c, size, PurgeableVector::Purgeable)); }
static PassRefPtr<SharedBuffer> adoptVector(Vector<char>&);
~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;
unsigned size() const;
bool isEmpty() const { return !size(); }
void append(PassRefPtr<SharedBuffer>);
void append(const char*, unsigned);
void append(const Vector<char>&);
void clear();
PassRefPtr<SharedBuffer> copy() const;
// 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;
// Returns the content data into "dest" as a flat buffer. "byteLength" must
// exactly match with size(). Returns true on success, otherwise the content
// of "dest" is not guaranteed.
bool getAsBytes(void* dest, unsigned byteLength) 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;
// See PurgeableVector::lock().
bool lock();
// WARNING: Calling unlock() on a SharedBuffer that wasn't created with the
// purgeability option does an extra memcpy(). Please use
// SharedBuffer::createPurgeable() if you intend to call unlock().
void unlock();
bool isLocked() const;
private:
SharedBuffer();
explicit SharedBuffer(size_t);
SharedBuffer(const char*, int);
SharedBuffer(const unsigned char*, int);
SharedBuffer(const char*, unsigned, PurgeableVector::PurgeableOption);
// See SharedBuffer::data().
void mergeSegmentsIntoBuffer() const;
unsigned m_size;
mutable PurgeableVector m_buffer;
mutable Vector<char*> m_segments;
};
} // namespace blink
#endif // SharedBuffer_h
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