1  ///////////////////////////////////////////////////////////////////////////////
       2  //
       3  /// \file       index.h
       4  /// \brief      Handling of Index
       5  /// \note       This header file does not include common.h or lzma.h because
       6  ///             this file is needed by both liblzma internally and by the
       7  ///             tests. Including common.h will include and define many things
       8  ///             the tests do not need and prevents issues with header file
       9  ///             include order. This way, if lzma.h or common.h are not
      10  ///             included before this file it will break on every OS instead
      11  ///             of causing more subtle errors.
      12  //
      13  //  Author:     Lasse Collin
      14  //
      15  //  This file has been put into the public domain.
      16  //  You can do whatever you want with this file.
      17  //
      18  ///////////////////////////////////////////////////////////////////////////////
      19  
      20  #ifndef LZMA_INDEX_H
      21  #define LZMA_INDEX_H
      22  
      23  
      24  /// Minimum Unpadded Size
      25  #define UNPADDED_SIZE_MIN LZMA_VLI_C(5)
      26  
      27  /// Maximum Unpadded Size
      28  #define UNPADDED_SIZE_MAX (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
      29  
      30  /// Index Indicator based on xz specification
      31  #define INDEX_INDICATOR 0
      32  
      33  
      34  /// Get the size of the Index Padding field. This is needed by Index encoder
      35  /// and decoder, but applications should have no use for this.
      36  extern uint32_t lzma_index_padding_size(const lzma_index *i);
      37  
      38  
      39  /// Set for how many Records to allocate memory the next time
      40  /// lzma_index_append() needs to allocate space for a new Record.
      41  /// This is used only by the Index decoder.
      42  extern void lzma_index_prealloc(lzma_index *i, lzma_vli records);
      43  
      44  
      45  /// Round the variable-length integer to the next multiple of four.
      46  static inline lzma_vli
      47  vli_ceil4(lzma_vli vli)
      48  {
      49  	assert(vli <= UNPADDED_SIZE_MAX);
      50  	return (vli + 3) & ~LZMA_VLI_C(3);
      51  }
      52  
      53  
      54  /// Calculate the size of the Index field excluding Index Padding
      55  static inline lzma_vli
      56  index_size_unpadded(lzma_vli count, lzma_vli index_list_size)
      57  {
      58  	// Index Indicator + Number of Records + List of Records + CRC32
      59  	return 1 + lzma_vli_size(count) + index_list_size + 4;
      60  }
      61  
      62  
      63  /// Calculate the size of the Index field including Index Padding
      64  static inline lzma_vli
      65  index_size(lzma_vli count, lzma_vli index_list_size)
      66  {
      67  	return vli_ceil4(index_size_unpadded(count, index_list_size));
      68  }
      69  
      70  
      71  /// Calculate the total size of the Stream
      72  static inline lzma_vli
      73  index_stream_size(lzma_vli blocks_size,
      74  		lzma_vli count, lzma_vli index_list_size)
      75  {
      76  	return LZMA_STREAM_HEADER_SIZE + blocks_size
      77  			+ index_size(count, index_list_size)
      78  			+ LZMA_STREAM_HEADER_SIZE;
      79  }
      80  
      81  #endif