lzma.cpp

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/*
* Lzma Compressor
* (C) 2001 Peter J Jones
*     2001-2007,2014 Jack Lloyd
*     2006 Matt Johnston
*     2012 Vojtech Kral
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/lzma.h>
 
#include <botan/exceptn.h>
#include <botan/internal/compress_utils.h>
#include <lzma.h>
 
namespace Botan {
 
namespace {
 
class LZMA_Stream : public Zlib_Style_Stream<lzma_stream, uint8_t> {
   public:
      LZMA_Stream() {
         m_allocator.opaque = alloc();
         m_allocator.alloc = Compression_Alloc_Info::malloc<size_t>;
         m_allocator.free = Compression_Alloc_Info::free;
         streamp()->allocator = &m_allocator;
      }
 
      ~LZMA_Stream() override { ::lzma_end(streamp()); }
 
      LZMA_Stream(const LZMA_Stream& other) = delete;
      LZMA_Stream(LZMA_Stream&& other) = delete;
      LZMA_Stream& operator=(const LZMA_Stream& other) = delete;
      LZMA_Stream& operator=(LZMA_Stream&& other) = delete;
 
      bool run(uint32_t flags) override {
         lzma_ret rc = ::lzma_code(streamp(), static_cast<lzma_action>(flags));
 
         if(rc != LZMA_OK && rc != LZMA_STREAM_END) {
            throw Compression_Error("lzma_code", ErrorType::LzmaError, rc);
         }
 
         return (rc == LZMA_STREAM_END);
      }
 
      uint32_t run_flag() const override { return LZMA_RUN; }
 
      uint32_t flush_flag() const override { return LZMA_FULL_FLUSH; }
 
      uint32_t finish_flag() const override { return LZMA_FINISH; }
 
   private:
      ::lzma_allocator m_allocator;
};
 
class LZMA_Compression_Stream final : public LZMA_Stream {
   public:
      explicit LZMA_Compression_Stream(size_t level) {
         if(level == 0) {
            level = 6;  // default
         } else if(level > 9) {
            level = 9;  // clamp to maximum allowed value
         }
 
         lzma_ret rc = ::lzma_easy_encoder(streamp(), static_cast<uint32_t>(level), LZMA_CHECK_CRC64);
 
         if(rc != LZMA_OK) {
            throw Compression_Error("lzam_easy_encoder", ErrorType::LzmaError, rc);
         }
      }
};
 
class LZMA_Decompression_Stream final : public LZMA_Stream {
   public:
      LZMA_Decompression_Stream() {
         lzma_ret rc = ::lzma_stream_decoder(streamp(), UINT64_MAX, LZMA_TELL_UNSUPPORTED_CHECK);
 
         if(rc != LZMA_OK) {
            throw Compression_Error("lzma_stream_decoder", ErrorType::LzmaError, rc);
         }
      }
};
 
}  // namespace
 
std::unique_ptr<Compression_Stream> LZMA_Compression::make_stream(size_t level) const {
   return std::make_unique<LZMA_Compression_Stream>(level);
}
 
std::unique_ptr<Compression_Stream> LZMA_Decompression::make_stream() const {
   return std::make_unique<LZMA_Decompression_Stream>();
}
 
}  // namespace Botan