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/*
* Copyright (C) 2022 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,
* 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.
*/
#pragma once
#include "BufferSource.h"
#if PLATFORM(COCOA)
#include <compression.h>
#endif
#include <cstring>
#include "ExceptionOr.h"
#include "Formats.h"
#include "SharedBuffer.h"
#include <JavaScriptCore/ArrayBuffer.h>
#include <JavaScriptCore/Forward.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>
#include <zlib.h>
namespace WebCore {
class DecompressionStreamDecoder : public RefCounted<DecompressionStreamDecoder> {
public:
static Ref<DecompressionStreamDecoder> create(unsigned char format)
{
return adoptRef(*new DecompressionStreamDecoder(format));
}
ExceptionOr<RefPtr<Uint8Array>> decode(const BufferSource&&);
ExceptionOr<RefPtr<Uint8Array>> flush();
~DecompressionStreamDecoder()
{
if (m_initialized) {
if (m_usingAppleCompressionFramework) {
#if PLATFORM(COCOA)
compression_stream_destroy(&m_stream);
#endif
} else
deflateEnd(&m_zstream);
}
}
private:
bool didInflateFinish(int) const;
bool didInflateContainExtraBytes(int) const;
ExceptionOr<RefPtr<JSC::ArrayBuffer>> decompressZlib(const uint8_t* input, const size_t inputLength);
ExceptionOr<bool> initialize();
explicit DecompressionStreamDecoder(unsigned char format)
: m_format(static_cast<Formats::CompressionFormat>(format))
{
std::memset(&m_zstream, 0, sizeof(m_zstream));
}
// When given an encoded input, it is difficult to guess the output size.
// My approach here is starting from one page and growing at a linear rate of x2 until the input data
// has been fully processed. To ensure the user's memory is not completely consumed, I am setting a cap
// of 1GB per allocation. This strategy enables very fast memory allocation growth without needing to perform
// unnecessarily large allocations upfront.
const size_t startingAllocationSize = 16384; // 16KB
const size_t maxAllocationSize = 1073741824; // 1GB
bool m_initialized { false };
bool m_didFinish { false };
z_stream m_zstream;
bool m_usingAppleCompressionFramework { false };
inline ExceptionOr<RefPtr<JSC::ArrayBuffer>> decompress(const uint8_t* input, const size_t inputLength);
#if PLATFORM(COCOA)
compression_stream m_stream;
ExceptionOr<RefPtr<JSC::ArrayBuffer>> decompressAppleCompressionFramework(const uint8_t* input, const size_t inputLength);
ExceptionOr<bool> initializeAppleCompressionFramework();
#endif
Formats::CompressionFormat m_format;
};
} // namespace WebCore
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