1  ///////////////////////////////////////////////////////////////////////////////
       2  //
       3  /// \file       block_encoder.h
       4  /// \brief      Encodes .xz Blocks
       5  //
       6  //  Author:     Lasse Collin
       7  //
       8  //  This file has been put into the public domain.
       9  //  You can do whatever you want with this file.
      10  //
      11  ///////////////////////////////////////////////////////////////////////////////
      12  
      13  #ifndef LZMA_BLOCK_ENCODER_H
      14  #define LZMA_BLOCK_ENCODER_H
      15  
      16  #include "common.h"
      17  
      18  
      19  /// \brief      Biggest Compressed Size value that the Block encoder supports
      20  ///
      21  /// The maximum size of a single Block is limited by the maximum size of
      22  /// a Stream, which in theory is 2^63 - 3 bytes (i.e. LZMA_VLI_MAX - 3).
      23  /// While the size is really big and no one should hit it in practice, we
      24  /// take it into account in some places anyway to catch some errors e.g. if
      25  /// application passes insanely big value to some function.
      26  ///
      27  /// We could take into account the headers etc. to determine the exact
      28  /// maximum size of the Compressed Data field, but the complexity would give
      29  /// us nothing useful. Instead, limit the size of Compressed Data so that
      30  /// even with biggest possible Block Header and Check fields the total
      31  /// encoded size of the Block stays as a valid VLI. This doesn't guarantee
      32  /// that the size of the Stream doesn't grow too big, but that problem is
      33  /// taken care outside the Block handling code.
      34  ///
      35  /// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of
      36  /// the Compressed Data field, it will still stay in the proper limit.
      37  ///
      38  /// This constant is in this file because it is needed in both
      39  /// block_encoder.c and block_buffer_encoder.c.
      40  #define COMPRESSED_SIZE_MAX ((LZMA_VLI_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \
      41  		- LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3))
      42  
      43  
      44  extern lzma_ret lzma_block_encoder_init(lzma_next_coder *next,
      45  		const lzma_allocator *allocator, lzma_block *block);
      46  
      47  #endif