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// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef SRC_INCLUDE_PUFFIN_PUFFER_H_
#define SRC_INCLUDE_PUFFIN_PUFFER_H_
#include <memory>
#include <vector>
#include "puffin/common.h"
#include "puffin/stream.h"
namespace puffin {
class BitReaderInterface;
class PuffWriterInterface;
class HuffmanTable;
class PUFFIN_EXPORT Puffer {
public:
// In older versions of puffin, there is a bug in the client which incorrectly
// identifies the number of bits to cache when number of bits for the current
// distance plus the number of bits for end of block Huffman code is smaller
// than the maximum number of bits needed for distance. If this situations
// happens at the very end of the block, it incorrectly tries to cache more
// bits than we have and crashes as a result. If |exclude_bad_distance_caches|
// is true, we identify those problematic deflate buffers and exclude them
// from the list of available deflates. The default is false.
explicit Puffer(bool exclude_bad_distance_caches);
Puffer();
~Puffer();
// Creates a puffed buffer from a deflate buffer.
//
// If |deflates| is not null, it will be populated with the location of the
// subblocks in the input data. In addition, the uncompressed deflate blocks
// will be ignored and will not be added to the |deflates|. For this case to
// happen correctly, the |pw| should write into an empty/null buffer,
// otherwise the created puff stream, will not match the deflate stream. In
// addition, in this case, the function will return when it reaches a final
// deflate subblock.
bool PuffDeflate(BitReaderInterface* br,
PuffWriterInterface* pw,
std::vector<BitExtent>* deflates) const;
private:
std::unique_ptr<HuffmanTable> dyn_ht_;
std::unique_ptr<HuffmanTable> fix_ht_;
bool exclude_bad_distance_caches_;
DISALLOW_COPY_AND_ASSIGN(Puffer);
};
} // namespace puffin
#endif // SRC_INCLUDE_PUFFIN_PUFFER_H_
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